Impact of Atrial Fibrillation Ablation on Left Ventricular Filling Pressure and Left Atrial Remodeling

PubMed Central

dos Santos, Simone Nascimento; Henz, Benhur Davi; Zanatta, André Rodrigues; Barreto, José Roberto; Loureiro, Kelly Bianca; Novakoski, Clarissa; dos Santos, Marcus Vinícius Nascimento; Giuseppin, Fabio F.; Oliveira, Edna Maria; Leite, Luiz Roberto

2014-01-01

Background Left ventricular (LV) diastolic dysfunction is associated with new-onset atrial fibrillation (AF), and the estimation of elevated LV filling pressures by E/e' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process. Objective To evaluate the impact of AF ablation on estimated LV filling pressure. Methods A total of 141 patients underwent radiofrequency (RF) ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind), and transmitral pulsed and mitral annulus tissue Doppler (e' and E/e') were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation. Results One hundred seventeen patients (82.9%) were free of AF during the follow-up (average, 18 ± 5 months). LAVind reduced in the successful group (30.2 mL/m2 ± 10.6 mL/m2 to 22.6 mL/m2 ± 1.1 mL/m2, p < 0.001) compared to the non-successful group (37.7 mL/m2 ± 14.3 mL/m2 to 37.5 mL/m2 ± 14.5 mL/m2, p = ns). Improvement of LV filling pressure assessed by a reduction in the E/e' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001) but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns). The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001). Conclusion Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure. PMID:25590928

Predictors of Long-term Success After Concomitant Surgical Ablation for Atrial Fibrillation.

PubMed

Pecha, Simon; Ghandili, Susanne; Hakmi, Samer; Willems, Stephan; Reichenspurner, Hermann; Wagner, Florian Mathias

2017-01-01

According to guidelines, atrial fibrillation (AF) ablation success should be measured by 24-hour Holter electrocardiogram (ECG). However, information on long-term success, especially obtained by 24-hour Holter ECG, is rare. We therefore analyzed rhythm course and long-term outcomes of our patients undergoing concomitant surgical AF ablation. Between January 2003 and April 2011, 486 patients underwent concomitant surgical AF ablation in our institution. Patients with 24-hour Holter ECG rhythm status available between 5 and 10 years postoperatively were included in this retrospective data analysis (n = 155). Ablation lesions were limited to either a pulmonary vein isolation (n = 31, 20%), a more complex left atrial lesion set (n = 89, 57%), or biatrial lesions (n = 35, 23%). Primary end point of the study was freedom from AF during long-term follow-up. Mean patient age was 68.1 ± 8.4 years; 57.4% were male. Mean follow-up time was 5.9 years. Surgical AF ablation provided freedom from AF rate of 56.6% during long-term follow-up, with significantly better results in patients with paroxysmal than in those with persistent AF (67.2% vs 51.8% P = 0.03). A stable rhythm course was observed during follow-up, without statistically significant differences between 12 months and latest follow-up (63.2% vs 56.6%; P = 0.25). In multivariate analysis, preoperative paroxysmal AF, duration of AF, and left atrial diameter were predictors of long-term ablation success. Surgical AF ablation provided freedom from AF rate of 56.6% during long-term follow-up. Statistically significant predictors of ablation success at latest follow-up were preoperative paroxysmal AF, duration of AF, and a preoperative smaller left atrial diameter. Copyright © 2017. Published by Elsevier Inc.

Prospective study of atrial fibrillation termination during ablation guided by automated detection of fractionated electrograms.

PubMed

Porter, Michael; Spear, William; Akar, Joseph G; Helms, Ray; Brysiewicz, Neil; Santucci, Peter; Wilber, David J

2008-06-01

Complex fractionated atrial electrograms (CFAE) may identify critical sites for perpetuation of atrial fibrillation (AF) and provide useful targets for ablation. Current assessment of CFAE is subjective; automated detection algorithms may improve reproducibility, but their utility in guiding ablation has not been tested. In 67 patients presenting for initial AF ablation (42 paroxysmal, 25 persistent), LA and CS mapping were performed during induced or spontaneous AF. CFAE were identified by an online automated computer algorithm and displayed on electroanatomical maps. A mean of 28 +/- 18 sites/patient were identified (20 +/- 13% of mapped sites), and were more frequent during persistent AF. CFAE occurred most commonly within the CS, on the atrial septum, and around the pulmonary veins. Ablation initially targeting CFAE terminated AF in 88% of paroxysmal AF, but only 20% of persistent AF (P < 0.001). Subsequently, additional ablation was performed in all patients (PV isolation for paroxysmal AF, PV isolation + mitral and roof lines for persistent AF). Minimum follow-up was 1 year. One-year freedom from recurrent atrial arrhythmias without antiarrhythmic drug therapy after a single procedure was 90% for paroxysmal AF, and 68% for persistent AF. Ablation guided by automated detection of CFAE proved feasible, and was associated with a high AF termination rate in paroxysmal, but not persistent AF. As an adjunct to conventional techniques, it was associated with excellent long-term single procedure outcomes in both groups. Criteria for identifying optimal CFAE sites for ablation, and selection of patients most likely to benefit, require additional study.

Thinking outside the Box: Rotor Modulation in the Treatment of Atrial Fibrillation.

PubMed

Sehra, Ruchir; Narayan, Sanjiv M; Hummel, John

2013-01-01

Ablation for atrial fibrillation (AF) is an important and exciting therapy whose results remain suboptimal. Although most clinical trials show that ablation eliminates AF more effectively than medications, it is disappointing that the continued single procedural success remains ≈50% despite the substantial advances that have taken place in imaging, catheter positioning and energy delivery. Focal impulse and rotor modulation (FIRM), on the other hand, offers the opportunity to precisely define and then ablate patient-specific sustaining mechanisms for AF, rather than trying to eliminate all possible AF triggers. For over a decade, electrophysiologists have described cases in which AF terminates after only limited ablation - usually that cannot be explained by 'random' meandering wavelets. Indeed, recent studies from several laboratories show that all forms of clinical AF are typically 'driven' by stable electrical rotors and focal sources, not by multiple meandering waves. FIRM mapping enables an operator to place a catheter at typically 1-3 predicted sites in the atria, and with <5-10 minutes of RF ablation, terminate AF and potentially render it non-inducible. Several independent laboratories have now shown that such FIRM ablation alone can terminate or substantially slow AF in >80% of patients with persistent and paroxysmal AF and increase the single procedure rate of AF elimination from 50% with PV isolation alone to >80%. Ongoing studies hint that FIRM only ablation, enabling ablation times in the range observed for typical atrial flutter, may also achieve these high success rates without subsequent trigger ablation. This review summarizes the current state-of-the-art on FIRM mapping and ablation.

Improvements In AF Ablation Outcome Will Be Based More On Technological Advancement Versus Mechanistic Understanding.

PubMed

Jiang Md, Chen-Yang; Jiang Ms, Ru-Hong

2014-01-01

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Catheter ablation has proven more effective than antiarrhythmic drugs in preventing clinical recurrence of AF, however long-term outcome remains unsatisfactory. Ablation strategies have evolved based on progress in mechanistic understanding, and technologies have advanced continuously. This article reviews current mechanistic concepts and technological advancements in AF treatment, and summarizes their impact on improvement of AF ablation outcome.

State-of-the-art and emerging technologies for atrial fibrillation ablation.

PubMed

Dewire, Jane; Calkins, Hugh

2010-03-01

Catheter ablation is an important treatment modality for patients with atrial fibrillation (AF). Although the superiority of catheter ablation over antiarrhythmic drug therapy has been demonstrated in middle-aged patients with paroxysmal AF, the role the procedure in other patient subgroups-particularly those with long-standing persistent AF-has not been well defined. Furthermore, although AF ablation can be performed with reasonable efficacy and safety by experienced operators, long-term success rates for single procedures are suboptimal. Fortunately, extensive ongoing research will improve our understanding of the mechanisms of AF, and considerable funds are being invested in developing new ablation technologies to improve patient outcomes. These technologies include ablation catheters designed to electrically isolate the pulmonary veins with improved safety, efficacy, and speed, catheters designed to deliver radiofrequency energy with improved precision, robotic systems to address the technological demands of the procedure, improved imaging and electrical mapping systems, and MRI-guided ablation strategies. The tools, technologies, and techniques that will ultimately stand the test of time and become the standard approach to AF ablation in the future remain unclear. However, technological advances are sure to result in the necessary improvements in the safety and efficacy of AF ablation procedures.

Persistent Atrial Fibrillation Ablation in Females: Insight from the MAGIC-AF Trial.

PubMed

Singh, Sheldon M; D'Avila, Andre; Aryana, Arash; Kim, Young-Hoon; Mangrum, J Michael; Michaud, Gregory F; Dukkipati, Srinivas R; Heist, E Kevin; Barrett, Conor D; Thorpe, Kevin E; Reddy, Vivek Y

2016-07-27

Atrial fibrillation (AF) ablation is less frequently performed in women when compared to men. There are conflicting data on the safety and efficacy of AF ablation in women. The objective of this study was to compare the clinical characteristics and outcomes in a contemporary cohort of men and women undergoing persistent AF ablation procedures. A total of 182 men and 53 women undergoing a first-ever persistent AF catheter ablation procedure in The Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF) trial were evaluated. Clinical and procedural characteristics were compared between each gender. The primary efficacy endpoint was the 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs. Women undergoing catheter ablation procedures were older than men (P < 0.001). The duration of AF and associated co-morbidities were similar between both genders. Single procedure drug-free atrial arrhythmia recurrence occurred in 53% of the cohort with no difference based on gender (men = 54%, women = 53%; P = 1.0). Procedural (P = 0.04), fluoroscopic (P = 0.02), and ablation times (P = 0.003) were shorter in women compared to men. Periprocedural complications and postablation improvement in quality of life were similar between men and women. Women undergoing a first-ever persistent AF ablation procedure were older but had similar clinical outcomes and complications when compared with men. © 2016 Wiley Periodicals, Inc.

Atrial Fibrillation Ablation and its Impact on Stroke.

PubMed

Graves, Kevin G; Jacobs, Victoria; May, Heidi T; Cutler, Michael J; Day, John D; Bunch, T Jared

2018-01-24

Atrial fibrillation (AF) is a commonly encountered arrhythmia, which is not yet fully understood. Catheter ablation has shown to be an effective strategy for rhythm management and several small or retrospective studies have shown that stroke rates are decreased in ablated AF patients compared to those medically managed. Several studies even show that ablation returns stroke risk to that of non-AF patients. Large scale, prospective trials will further illuminate this connection and provide mechanistic understanding of the role of the procedure versus the process of selection for the procedure and peri- and post-procedural therapy and management. Furthermore, modification of risk factors associated with AF show a significant increase in the sustained success of AF ablation and can also moderate the progression of AF.

The role of rotors in atrial fibrillation

PubMed Central

Swarup, Vijay; Narayan, Sanjiv M.

2015-01-01

Despite significant advances in our understanding of atrial fibrillation (AF) mechanisms in the last 15 years, ablation outcomes remain suboptimal. A potential reason is that many ablation techniques focus on anatomic, rather than patient-specific functional targets for ablation. Panoramic contact mapping, incorporating phase analysis, repolarization and conduction dynamics, and oscillations in AF rate, overcomes many prior difficulties with mapping AF. This approach provides evidence that the mechanisms sustaining human AF are deterministic, largely due to stable electrical rotors and focal sources in either atrium. Ablation of such sources (Focal Impulse and Rotor Modulation: FIRM ablation) has been shown to improve ablation outcome compared with conventional ablation alone; independent laboratories directly targeting stable rotors have shown similar results. Clinical trials examining the role of stand-alone FIRM ablation are in progress. Looking forward, translating insights from patient-specific mapping to evidence-based guidelines and clinical practice is the next challenge in improving patient outcomes in AF management. PMID:25713729

Designing Comparative Effectiveness Trials of Surgical Ablation for Atrial Fibrillation: Experience of the Cardiothoracic Surgical Trials Network

PubMed Central

Gillinov, A. Marc; Argenziano, Michael; Blackstone, Eugene H.; Iribarne, Alexander; DeRose, Joseph J.; Ailawadi, Gorav; Russo, Mark J.; Ascheim, Deborah D.; Parides, Michael K.; Rodriguez, Evelio; Bouchard, Denis; Taddei-Peters, Wendy C.; Geller, Nancy L.; Acker, Michael A.; Gelijns, Annetine C.

2013-01-01

Background Since the introduction of the cut-and-sew Cox-Maze procedure for atrial fibrillation (AF) there has been substantial innovation in techniques for ablation. Use of alternate energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of AF patients treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this as an effective clinical therapy. Methods and Results This paper describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Trials Network, of surgical ablation with left atrial appendage (LAA) closure versus LAA closure alone in patients with persistent and longstanding persistent AF undergoing mitral valve surgery. Nested within this trial, is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and full Maze lesion set. This paper addresses trial design challenges, including how to best characterize the target population, operationalize freedom from AF as a primary endpoint, account for the impact of anti-arrhythmic drugs, and measure and analyze secondary endpoints, such as post-operative AF load. Conclusions This paper concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area. PMID:21616507

The impact of B-type natriuretic peptide levels on the suppression of accompanying atrial fibrillation in Wolff-Parkinson-White syndrome patients after accessory pathway ablation.

PubMed

Kawabata, Mihoko; Goya, Masahiko; Takagi, Takamitsu; Yamashita, Shu; Iwai, Shinsuke; Suzuki, Masahito; Takamiya, Tomomasa; Nakamura, Tomofumi; Hayashi, Tatsuya; Yagishita, Atsuhiko; Sasaki, Takeshi; Takahashi, Yoshihide; Ono, Yuhichi; Hachiya, Hitoshi; Yamauchi, Yasuteru; Otomo, Kenichiro; Nitta, Junichi; Okishige, Kaoru; Nishizaki, Mitsuhiro; Iesaka, Yoshito; Isobe, Mitsuaki; Hirao, Kenzo

2016-12-01

Atrial fibrillation (AF) often coexists with Wolff-Parkinson-White (WPW) syndrome. We compared the efficacy of Kent bundle ablation alone and additional AF ablation on accompanying AF, and examined which patients would still have a risk of AF after successful Kent bundle ablation. This retrospective multicenter study included 96 patients (56±15 years, 72 male) with WPW syndrome and AF undergoing Kent bundle ablation. Some patients underwent simultaneous pulmonary vein isolation (PVI) for AF. The incidence of post-procedural AF was examined. Sixty-four patients underwent only Kent bundle ablation (Kent-only group) and 32 also underwent PVI (+PVI group). There was no significant difference in the basic patient characteristics between the groups. Additional PVI did not improve the freedom from residual AF compared to Kent bundle ablation alone (p=0.53). In the Kent-only group, AF episodes remained in 25.0% during the follow-up (709 days). A univariate analysis showed that age ≥60 years, left atrial dimension ≥38mm, B-type natriuretic peptide (BNP) ≥40pg/ml, and concomitant hypertension were predictive factors for residual AF. However, in the multivariate analysis, only BNP ≥40pg/ml remained as an independent predictive factor (HR=17.1 and CI: 2.3-128.2; p=0.006). Among patients with WPW syndrome and AF, Kent bundle ablation alone may have a sufficient clinical impact of preventing recurrence of AF in select patients. Screening the BNP level would help decide the strategy to manage those patients. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Mechanistic Comparison of "Nearly Missed" Versus "On-Target" Rotor Ablation.

PubMed

Yamazaki, Masatoshi; Avula, Uma Mahesh R; Berenfeld, Omer; Kalifa, Jérôme

2015-08-01

This study used advanced optical mapping techniques to examine atrial fibrillation (AF) dynamics before and after 2 distinct electrogram-based ablation strategies: complex fractionated atrial electrograms (CFAEs) and DFmax/rotor ablation. Among the electrogram analytical features proposed to unravel the atrial regions that perpetuate AF, CFAEs, highest dominant frequency sites (DFmax), and, more recently, phase analysis-enabled rotor mapping have received the largest attention. Still, the mechanisms by which these approaches modulate AF dynamics and lead to AF termination are unknown. In Langendorff-perfused sheep hearts, AF was maintained by the continuous perfusion of acetylcholine and high-resolution endocardial-epicardial optical videos were recorded from the left atrial free wall and the posterior left atrium. Then, DFmax/rotor regions (n = 7), or CFAE regions harboring the highest wavebreak density (HWD) (n = 5), were targeted with a 4F ablation catheter (5 to 15 W, 30 to 60 s/point). Thereafter, we examined the changes in AF dynamics and whether AF terminated. DFmax/rotor point ablation resulted in a significant decrease in DFmax values. In 2 animals AF terminated, whereas in the remaining 5 animals the post-ablation DFmax domain remained in the vicinity of its pre-ablation location. However, after HWD/CFAEs density ablation, DFmax values did not change, AF did not terminate, and post-ablation DFmax domains relocated from the left atrial free wall to the pulmonary vein-posterior left atrium region. In another group of hearts (n = 12), we observed that upon a progressive increase in acetylcholine concentration-mimicking the acute electrophysiological changes occurring after ablation-3-dimensional rotors drifted from one atrial region to another along large gradients of myocardial thickness. "On-target" DFmax/rotor ablation leads to the annihilation of the fibrillation-driving rotor. This translates into large decreases in AF frequency or AF termination. In contrast, "nearly missed" HWD/CFAEs ablation spares the fibrillation-driving rotor, and set the stage for rotor drift along large myocardial thickness gradients. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

[Catheter ablation of atrial fibrillation: Health Technology Assessment Report from the Italian Association of Arrhythmology and Cardiac Pacing (AIAC)].

PubMed

Themistoclakis, Sakis; Tritto, Massimo; Bertaglia, Emanuele; Berto, Patrizia; Bongiorni, Maria Grazia; Catanzariti, Domenico; De Fabrizio, Giuseppe; De Ponti, Roberto; Grimaldi, Massimo; Pandozi, Claudio; Tondo, Claudio; Gulizia, Michele

2011-11-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and significantly impact patients' quality of life, morbidity and mortality. The number of affected patients is expected to increase as well as the costs associated with AF management, mainly driven by hospitalizations. Over the last decade, catheter ablation techniques targeting pulmonary vein isolation have demonstrated to be effective in treating AF and preventing AF recurrence. This Health Technology Assessment report of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) aims to define the current role of catheter ablation of AF in terms of effectiveness, efficiency and appropriateness. On the basis of an extensive review of the available literature, this report provides (i) an overview of the epidemiology, clinical impact and socio-economic burden of AF; (ii) an evaluation of therapeutic options other than catheter ablation of AF; and (iii) a detailed presentation of clinical outcomes and cost-benefit ratio associated with catheter ablation. The costs of catheter ablation of AF in Italy were obtained using a bottom-up analysis of a resource utilization survey of 52 hospitals that were considered a representative sample, including 4 Centers that contributed with additional unit cost information in a separate questionnaire. An analysis of budget impact was also performed to evaluate the impact of ablation on the management costs of AF. Results of this analysis show that (1) catheter ablation is effective, safe and superior to antiarrhythmic drug therapy in maintaining sinus rhythm; (2) the cost of an ablation procedure in Italy typically ranges from €8868 to €9455, though current reimbursement remains insufficient, covering only about 60% of the costs; (3) the costs of follow-up are modest (about 8% of total costs); (4) assuming an adjustment of reimbursement to the real cost of an ablation procedure and a 5-10% increase in the annual rate of ablation procedures, after approximately 5-6 years this would result in significant incremental savings for the Italian Healthcare System. In conclusion, catheter ablation of AF is a cost-effective procedure that is inadequately reimbursed in Italy. Insufficient reimbursement may serve as disincentive to perform AF ablation, thereby limiting patient access to this treatment. Considering the healthcare system perspective, higher initial costs for ablation procedures in the short term may be offset by cost savings mainly associated with decreased hospitalizations over time.

Persistent Atrial Fibrillation Ablation using the Tip-Versatile Ablation Catheter.

PubMed

Davies, Edward J; Clayton, Ben; Lines, Ian; Haywood, Guy A

2016-07-01

The mechanisms by which persistent atrial fibrillation (PsAF) develops are incompletely understood. Consequently, the optimal strategy for the ablative management of PsAF remains debated. Current methods are often time consuming, complex and non-reproducible. We assessed the Tip-Versatile Ablation Catheter (T-VAC) technique, a rapidly delivered, empirical technique based on the box-set concept using duty-cycled linear catheter ablation technology. Forty-four procedures in 40 patients undergoing PsAF ablation with the novel technique were prospectively entered onto a database: 27 de novo. Primary endpoint was freedom from arrhythmia at over two-year follow-up. Secondary endpoints were time to first arrhythmia recurrence, freedom from atrial fibrillation (AF) on and off antiarrhythmic drugs (AAD), procedural and fluoroscopy duration and complication rate. At mean follow-up of 33 months, absolute freedom from arrhythmia recurrence was 45% in the de novo group. Overall, at 33 (IQR 24-63) months, 60% of de novo patients were in sustained normal sinus rhythm and a further 15% reported only occasional paroxysms of AF at long-term follow-up. Procedure time was 192±25 mins, total energy delivered 2239±883s and fluoroscopy time was 60±10mins. In selected patients with persistent AF, a long-term rate of 60% arrhythmia free survival off AAD can be achieved using this novel T-VAC technique. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Clinical Implications of Ablation of Drivers for Atrial Fibrillation: A Systematic Review and Meta-Analysis.

PubMed

Baykaner, Tina; Rogers, Albert J; Meckler, Gabriela L; Zaman, Junaid; Navara, Rachita; Rodrigo, Miguel; Alhusseini, Mahmood; Kowalewski, Christopher A B; Viswanathan, Mohan N; Narayan, Sanjiv M; Clopton, Paul; Wang, Paul J; Heidenreich, Paul A

2018-05-01

The outcomes from pulmonary vein isolation (PVI) for atrial fibrillation (AF) are suboptimal, but the benefits of additional lesion sets remain unproven. Recent studies propose ablation of AF drivers improves outcomes over PVI, yet with conflicting reports in the literature. We undertook a systematic literature review and meta-analysis to determine outcomes from ablation of AF drivers in addition to PVI or as a stand-alone procedure. Database search was done using the terms atrial fibrillation and ablation or catheter ablation and driver or rotor or focal impulse or FIRM (Focal Impulse and Rotor Modulation). We pooled data using random effects model and assessed heterogeneity with I 2 statistic. Seventeen studies met inclusion criteria, in a cohort size of 3294 patients. Adding AF driver ablation to PVI reported freedom from AF of 72.5% (confidence interval [CI], 62.1%-81.8%; P <0.01) and from all arrhythmias of 57.8% (CI, 47.5%-67.7%; P <0.01). AF driver ablation when added to PVI or as stand-alone procedure compared with controls produced an odds ratio of 3.1 (CI, 1.3-7.7; P =0.02) for freedom from AF and an odds ratio of 1.8 (CI, 1.2-2.7; P <0.01) for freedom from all arrhythmias in 4 controlled studies. AF termination rate was 40.5% (CI, 30.6%-50.9%) and predicted favorable outcome from ablation( P <0.05). In controlled studies, the addition of AF driver ablation to PVI supports the possible benefit of a combined approach of AF driver ablation and PVI in improving single-procedure freedom from all arrhythmias. However, most studies are uncontrolled and are limited by substantial heterogeneity in outcomes. Large multicenter randomized trials are needed to precisely define the benefits of adding driver ablation to PVI. © 2018 American Heart Association, Inc.

Family history of atrial fibrillation as a predictor of atrial substrate and arrhythmia recurrence in patients undergoing atrial fibrillation catheter ablation.

PubMed

Kapur, Sunil; Kumar, Saurabh; John, Roy M; Stevenson, William G; Tedrow, Usha B; Koplan, Bruce A; Epstein, Laurence M; MacRae, Calum A; Michaud, Gregory F

2018-06-01

A commonly held notion is that patients with a family history of atrial fibrillation (AF) have worse atrial substrate and higher rates of arrhythmia recurrence following ablation. We sought to examine differences in atrial substrate and catheter ablation outcomes in patients with a 1st degree family member with paroxysmal or persistent AF (PeAF) compared to those without. A total of 256 consecutive patients undergoing their 1st ablation for AF (123 paroxysmal, 133 persistent) with >1 year follow up were included. The presence of one 1st-degree family relative was defined as a 'positive family history'. Clinical characteristics, electroanatomic map findings, ablation characteristics and outcomes were compared in patients with and without a positive family history of AF. Patients with paroxysmal fibrillation with a positive family history (n = 57; 46%) had similar clinical characteristics and arrhythmia recurrence after catheter ablation as those without. Of those that recurred, patients with a positive family history were more likely to have progressed to PeAF (P = 0.05). Patients with PeAF with a positive family history (n = 75; 56%) had similar clinical characteristics, electroanatomic mapping findings and ablation characteristics, but worse long term arrhythmia free survival (P = 0.04). The presence of a 1st-degree family member with AF does not impact the clinical outcomes of catheter ablation for paroxysmal AF. However, a positive family history is associated with worse arrhythmia free survival in patients with PeAF. This finding is not explained by differences in clinical characteristics, atrial substrate assessed by voltage maps or ablation characteristics.

Pulmonary vein region ablation in experimental vagal atrial fibrillation: role of pulmonary veins versus autonomic ganglia.

PubMed

Lemola, Kristina; Chartier, Denis; Yeh, Yung-Hsin; Dubuc, Marc; Cartier, Raymond; Armour, Andrew; Ting, Michael; Sakabe, Masao; Shiroshita-Takeshita, Akiko; Comtois, Philippe; Nattel, Stanley

2008-01-29

Pulmonary vein (PV) -encircling radiofrequency ablation frequently is effective in vagal atrial fibrillation (AF), and there is evidence that PVs may be particularly prone to cholinergically induced arrhythmia mechanisms. However, PV ablation procedures also can affect intracardiac autonomic ganglia. The present study examined the relative role of PVs versus peri-PV autonomic ganglia in an experimental vagal AF model. Cholinergic AF was studied under carbachol infusion in coronary perfused canine left atrial PV preparations in vitro and with cervical vagal stimulation in vivo. Carbachol caused dose-dependent AF promotion in vitro, which was not affected by excision of all PVs. Sustained AF could be induced easily in all dogs during vagal nerve stimulation in vivo both before and after isolation of all PVs with encircling lesions created by a bipolar radiofrequency ablation clamp device. PV elimination had no effect on atrial effective refractory period or its responses to cholinergic stimulation. Autonomic ganglia were identified by bradycardic and/or tachycardic responses to high-frequency subthreshold local stimulation. Ablation of the autonomic ganglia overlying all PV ostia suppressed the effective refractory period-abbreviating and AF-promoting effects of cervical vagal stimulation, whereas ablation of only left- or right-sided PV ostial ganglia failed to suppress AF. Dominant-frequency analysis suggested that the success of ablation in suppressing vagal AF depended on the elimination of high-frequency driver regions. Intact PVs are not needed for maintenance of experimental cholinergic AF. Ablation of the autonomic ganglia at the base of the PVs suppresses vagal responses and may contribute to the effectiveness of PV-directed ablation procedures in vagal AF.

Panoramic Electrophysiological Mapping but not Electrogram Morphology Identifies Stable Sources for Human Atrial Fibrillation

PubMed Central

Narayan, Sanjiv M.; Shivkumar, Kalyanam; Krummen, David E.; Miller, John M.; Rappel, Wouter-Jan

2013-01-01

Background The foundation for successful arrhythmia ablation is the mapping of electric propagation to identify underlying mechanisms. In atrial fibrillation (AF), however, mapping is difficult so that ablation has often targeted electrogram features, with mixed results. We hypothesized that wide field-of-view (panoramic) mapping of both atria would identify causal mechanisms for AF and allow interpretation of local electrogram features, including complex fractionated atrial electrograms (CFAE). Methods and Results Contact mapping was performed using biatrial multipolar catheters in 36 AF subjects (29 persistent). Stable AF rotors (spiral waves) or focal sources were seen in 35 of 36 cases and targeted for ablation (focal impulse and rotor modulation) before pulmonary vein isolation. In 31 of 36 subjects (86.1%), AF acutely terminated (n=20; 16 to sinus rhythm) or organized (n=11; 19±8% slowing) with 2.5 minutes focal impulse and rotor modulation (interquartile range, 1.0–3.1) at one source, defined as the primary source. Subjects exhibited 2.1±1.0 concurrent AF sources of which the primary, by phase mapping, precessed in limited areas (persistent 2.5±1.7 versus paroxysmal 1.7±0.5 cm2; P=0.30). Notably, source regions showed mixed electrogram amplitudes and CFAE grades that did not differ from surrounding atrium (P=NS). AF sources were not consistently surrounded by CFAE (P=0.67). Conclusions Stable rotors and focal sources for human AF were revealed by contact panoramic mapping (focal impulse and rotor modulation mapping), but not by electrogram footprints. AF sources precessed within areas of ≈2 cm2, with diverse voltage characteristics poorly correlated with CFAE. Most CFAE sites lie remote from AF sources and are not suitable targets for catheter ablation of AF. PMID:23392583

Are left ventricular ejection fraction and left atrial diameter related to atrial fibrillation recurrence after catheter ablation?

PubMed Central

Jin, Xiao; Pan, Jianke; Wu, Huanlin; Xu, Danping

2018-01-01

Abstract Atrial fibrillation (AF), the most common form of arrhythmia, is associated with the prevalence of many common cardiovascular and cerebrovascular diseases. Catheter ablation is considered the first-line therapy for AF; however, AF recurrence is very common after catheter ablation. Studies have been performed to analyze the factors associated with AF recurrence, but none have reached a consistent conclusion on whether left ventricular ejection fraction (LVEF) and left atrial diameter (LA diameter) affect AF recurrence after catheter ablation. The databases PubMed, Embase, and the Cochrane Library were used to search for relevant studies up to September 2017. RevMan 5.3.5 software provided by the Cochrane Collaboration Network was used to conduct this meta-analysis. Thirteen studies involving 2825 patients were included in this meta-analysis. Overall, the results revealed that elevated LA diameter values were significantly associated with AF recurrence in patients after catheter ablation (MD = 2.19, 95% CI: 1.63–2.75, P < .001), while baseline LVEF levels were not significantly positively associated with AF recurrence in patients after catheter ablation (MD = −0.91, 95% CI: −1.18 to 1.67, P = .14). Overall, elevated LA diameter may be associated with AF recurrence after catheter ablation; however, there was no direct relationship between LVEF values and AF recurrence after catheter ablation when baseline LVEF values are normal or mildly decreased. Besides, because of publication bias, further studies should be performed to explore the mechanisms underlying AF recurrence. PMID:29768386

Treatment of Recurrent Nonparoxysmal Atrial Fibrillation Using Focal Impulse and Rotor Mapping (FIRM)-Guided Rotor Ablation: Early Recurrence and Long-Term Outcomes.

PubMed

Spitzer, Stefan Georg; Károlyi, László; Rämmler, Carola; Scharfe, Frank; Weinmann, Thomas; Zieschank, Mirko; Langbein, Anke

2017-01-01

A patient-tailored ablation approach focused on the elimination of both pulmonary vein triggers as well as substrate drivers may result in favorable outcomes in recurrent persistent AF patients. We evaluated the long-term outcomes of rotor ablation combined with conventional pulmonary vein isolation (PVI) in patients with recurrent nonparoxysmal AF. Fifty-eight consecutive patients underwent FIRM-guided rotor ablation followed by conventional PVI for the treatment of recurrent nonparoxysmal AF. A software algorithm was used to display rotational activity at rotor sites by creating propagation maps from unipolar electrograms recorded using a 64-electrode basket catheter. These rotor sites were targeted for ablation, followed by conventional PVI. All patients had nonparoxysmal AF (83% longstanding persistent) and a previously failed conventional ablation procedure. Stable rotors were identified in all patients (mean of 3.0 ± 1.6 per patient), with 55.2% having right atrial rotors and 96.6% left atrial rotors, respectively. Complications occurred in 5.2% of patients, none related to the FIRM procedure. The median follow-up was 12 months. At 6 and 12 months of follow-up, 73.2% and 76.9% of patients remained free from AF/AT, respectively. Excluding 2 patients who underwent a successful redo ablation procedure/electrical cardioversion, at 12 months of follow-up, 69.2% were free from any AF/AT and 73.1% were free from AF after a single FIRM-guided ablation procedure. A high degree of success was observed in this cohort of primarily longstanding persistent AF patients treated for recurrent AF with FIRM-guided rotor ablation. Prospective randomized controlled trials are needed. © 2016 Wiley Periodicals, Inc.

Ablation as targeted perturbation to rewire communication network of persistent atrial fibrillation

PubMed Central

Tao, Susumu; Way, Samuel F.; Garland, Joshua; Chrispin, Jonathan; Ciuffo, Luisa A.; Balouch, Muhammad A.; Nazarian, Saman; Spragg, David D.; Marine, Joseph E.; Berger, Ronald D.; Calkins, Hugh

2017-01-01

Persistent atrial fibrillation (AF) can be viewed as disintegrated patterns of information transmission by action potential across the communication network consisting of nodes linked by functional connectivity. To test the hypothesis that ablation of persistent AF is associated with improvement in both local and global connectivity within the communication networks, we analyzed multi-electrode basket catheter electrograms of 22 consecutive patients (63.5 ± 9.7 years, 78% male) during persistent AF before and after the focal impulse and rotor modulation-guided ablation. Eight patients (36%) developed recurrence within 6 months after ablation. We defined communication networks of AF by nodes (cardiac tissue adjacent to each electrode) and edges (mutual information between pairs of nodes). To evaluate patient-specific parameters of communication, thresholds of mutual information were applied to preserve 10% to 30% of the strongest edges. There was no significant difference in network parameters between both atria at baseline. Ablation effectively rewired the communication network of persistent AF to improve the overall connectivity. In addition, successful ablation improved local connectivity by increasing the average clustering coefficient, and also improved global connectivity by decreasing the characteristic path length. As a result, successful ablation improved the efficiency and robustness of the communication network by increasing the small-world index. These changes were not observed in patients with AF recurrence. Furthermore, a significant increase in the small-world index after ablation was associated with synchronization of the rhythm by acute AF termination. In conclusion, successful ablation rewires communication networks during persistent AF, making it more robust, efficient, and easier to synchronize. Quantitative analysis of communication networks provides not only a mechanistic insight that AF may be sustained by spatially localized sources and global connectivity, but also patient-specific metrics that could serve as a valid endpoint for therapeutic interventions. PMID:28678805

Impact of Voltage Mapping to Guide Whether to Perform Ablation of the Posterior Wall in Patients With Persistent Atrial Fibrillation.

PubMed

Cutler, Michael J; Johnson, Jeremy; Abozguia, Khalid; Rowan, Shane; Lewis, William; Costantini, Otto; Natale, Andrea; Ziv, Ohad

2016-01-01

Fibrosis as a substrate for atrial fibrillation (AF) has been shown in numerous preclinical models. Voltage mapping enables in vivo assessment of scar in the left atrium (LA), which can be targeted with catheter ablation. We hypothesized that using the presence or absence of low voltage to guide ablation beyond pulmonary vein antral isolation (PVAI) will improve atrial arrhythmia (AF/AT)-free survival in persistent AF. Single-center retrospective analysis of 2 AF ablation strategies: (1) standard ablation (SA) versus (2) voltage-guided ablation (VGA). PVAI was performed in both groups. With SA, additional lesions beyond PVAI were performed at the discretion of the operator. With VGA, additional lesions to isolate the LA posterior wall were performed if voltage mapping of this region in sinus rhythm showed scar (LA voltage < 0.5 mV). AF-/AT-free endpoint was defined as no sustained AF/AT seen off antiarrhythmic medications after a 2-month postablation blanking period. Seventy-six patients underwent SA and 65 underwent VGA. Patients were well matched for comorbidities, LVEF, and left atrial size. Posterior wall ablation was performed in 57% of patient with SA compared to 42% with VGA. VGA ablation increased 1-year AF-/AT-free survival in patients when compared to SA (80% vs. 57%; P = 0.005). In a multivariate analysis, VGA was the only independent predictor of AF-/AT-free survival (hazard ratio of 0.30; P = 0.002). The presence of LA posterior wall scar may be an important ablation target in persistent AF. A prospective randomized trial is needed to confirm these data. © 2015 Wiley Periodicals, Inc.

HATCH score in the prediction of new-onset atrial fibrillation after catheter ablation of typical atrial flutter.

PubMed

Chen, Ke; Bai, Rong; Deng, Wenning; Gao, Chuanyu; Zhang, Jing; Wang, Xianqing; Wang, Shunbao; Fu, Haixia; Zhao, Yonghui; Zhang, Jiaying; Dong, Jianzeng; Ma, Changsheng

2015-07-01

New-onset atrial fibrillation (AF) is not uncommon after ablation of typical atrial flutter (AFL); however, limited data are available for a risk prediction model for the future occurrence of AF in patients with typical AFL undergoing successful catheter ablation. This study aimed to determine whether the HATCH score (which is based on hypertension, age ≥75 years, transient ischemic attack or stroke, chronic obstructive pulmonary disease, and heart failure) is useful for risk prediction of subsequent AF after ablation of typical AFL. A total of 216 consecutive patients presenting with typical AFL and no history of AF who underwent successful catheter ablation were enrolled in the study. The clinical endpoint was occurrence of new-onset AF during follow-up after ablation. During a follow-up period of 29.1 ± 18.3 months, 85 patients (39%) experienced at least 1 episode of AF. Multivariate Cox regression analysis demonstrated that the HATCH score (hazard ratio 1.784; 95% confidence interval 1.352-2.324; P < .001) and left atrial diameter (hazard ratio 1.270; 95% confidence interval 1.115-1.426; P < .001) were independently associated with new-onset AF after typical AFL ablation. The area under the receiver operator characteristic curve based on the HATCH score for prediction of new-onset AF was 0.743. The HATCH score could be used to stratify the patients into 2 groups with different incidences of new-onset AF (69% vs 27%, P < .001) at a cutoff value of 2. The HATCH score is a useful predictor of new-onset AF after typical AFL ablation. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Limitations of dormant conduction as a predictor of atrial fibrillation recurrence and pulmonary vein reconnection after catheter ablation.

PubMed

Lin, Frank S; Ip, James E; Markowitz, Steven M; Liu, Christopher F; Thomas, George; Lerman, Bruce B; Cheung, Jim W

2015-05-01

Adenosine (ADO) can uncover dormant conduction following pulmonary vein (PV) isolation. We sought to identify the value of dormant conduction for predicting atrial fibrillation (AF) recurrence and chronic PV reconnection. One hundred fifty-two patients (80 male; age 60 ± 11 years) undergoing PV isolation for AF were studied. After PV isolation, sites of ADO-induced PV reconnection were recorded and targeted with additional ablation. In patients undergoing repeat ablation for recurrent AF, chronic PV reconnection was assessed. Forty-five (30%) patients had ADO-induced PV reconnection following PV isolation. Dormant conduction was successfully eliminated with additional ablation in 41 (91%) of these patients. After follow-up of 598 ± 270 days, 60 (39%) patients had recurrent AF. Dormant PV conduction was not a significant predictor of AF recurrence (hazard ratio 1.51; 95% confidence interval: 0.89-2.56; P = 0.12) although three of four (75%) patients with residual dormant conduction following initial ablation developed recurrent AF. Twenty-six patients with recurrent AF underwent repeat ablation with 52 of 99 (53%) PVs found to have chronic reconnection. Nine of 11 (82%) PVs with dormant conduction and 43 of 88 (49%) PVs without dormant conduction at initial procedure had chronic reconnection at repeat ablation. When additional ablation is performed to eliminate ADO-induced PV reconnection after PV isolation, dormant conduction is not a significant predictor of recurrent AF. Although PVs with dormant conduction at initial procedure may develop chronic reconnection, the majority of PVs that show conduction recovery at repeat ablation occur in nondormant PVs. © 2015 Wiley Periodicals, Inc.

Critical phase transitions during ablation of atrial fibrillation

NASA Astrophysics Data System (ADS)

Iravanian, Shahriar; Langberg, Jonathan J.

2017-09-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia with significant morbidity and mortality. Pharmacological agents are not very effective in the management of AF. Therefore, ablation procedures have become the mainstay of AF management. The irregular and seemingly chaotic atrial activity in AF is caused by one or more meandering spiral waves. Previously, we have shown the presence of sudden rhythm organization during ablation of persistent AF. We hypothesize that the observed transitions from a disorganized to an organized rhythm is a critical phase transition. Here, we explore this hypothesis by simulating ablation in an anatomically-correct 3D AF model. In 722 out of 2160 simulated ablation, at least one sudden transition from AF to an organized rhythm (flutter) was noted (33%). They were marked by a sudden decrease in the cycle length entropy and increase in the mean cycle length. At the same time, the number of reentrant wavelets decreased from 2.99 ± 0.06 in AF to 1.76 ± 0.05 during flutter, and the correlation length scale increased from 13.3 ± 1.0 mm to 196.5 ± 86.6 mm (both P < 0.0001). These findings are consistent with the hypothesis that transitions from AF to an anatomical flutter behave as phase transitions in complex non-equilibrium dynamical systems with flutter acting as an absorbing state. Clinically, the facilitation of phase transition should be considered a novel mechanism of ablation and may help to design effective ablation strategies.

Role of Rotors in the Ablative Therapy of Persistent Atrial Fibrillation

PubMed Central

Schricker, Amir A; Zaman, Junaid; Narayan, Sanjiv M

2015-01-01

Atrial fibrillation (AF) ablation is increasingly used to maintain sinus rhythm yet its results are sub-optimal, especially in patients with persistent AF or prior unsuccessful procedures. Attempts at improvement have often targeted substrates that sustain AF after it is triggered, yet those mechanisms are debated. Many studies now challenge the concept that AF is driven by self-sustaining disordered wavelets, showing instead that localised drivers (rotors) may drive disorder via a process known as fibrillatory conduction. Novel mapping using wide-area recordings, physiological filtering and phase analysis demonstrates rotors in human AF. Contact mapping with focal impulse and rotor modulation (FIRM) shows that localised ablation at sources can improve procedural success in many populations on long-term follow up and some newer approaches to rotor mapping are qualitatively similar. This review critically evaluates the data on rotor mapping and ablation, which advances our conceptual understanding of AF and holds the promise of substantially improving ablative outcomes in patients with persistent AF. PMID:26835100

Atrial Fibrillation and Pulmonary Venous Electrical Conduction Recovery After Full Surgical Resection and Anastomosis of the Pulmonary Veins: Insights From Follow-Up and Ablation Procedures in Lung Transplant Recipients.

PubMed

Hussein, Ayman A; Panchabhai, Tanmay S; Budev, Marie M; Tarakji, Khaldoun; Barakat, Amr F; Saliba, Walid; Lindsay, Bruce; Wazni, Oussama M

2017-06-01

The authors report their experience with atrial fibrillation (AF) rates and ablation findings in lung transplant recipients. Pulmonary venous (PV) conduction recovery accounts for most failed atrial fibrillation (AF) catheter ablation procedures. Lung transplantation involves full surgical resection and replacement of the recipient's PVs with donor's PVs, which may represent the ultimate PV ablation. They followed 755 consecutive lung transplant recipients categorized based on transplant status (unilateral vs. bilateral) and pre-transplant AF. In patients without pre-transplant AF (n = 704), late AF (beyond 6 months after transplant) occurred in 2.5% and 3.3% of unilateral or bilateral lung transplants, respectively. In patients with pre-transplant AF (n = 51), AF recurred in 19.4% and 25.0% of bilateral and unilateral transplants, respectively. In a subset of patients who underwent left atrial ablations after transplant for recurrent refractory AF (n = 8), PV conduction recovery across the surgical anastomoses lines was observed in 22 of 26 previously disconnected PVs. Conduction recovery was observed in ≥1 vein in all but 1 patient. Re-isolation of the veins with additional substrate modification/flutter ablations successfully restored and maintained sinus rhythm in 7 of 8 patients. In lung transplant recipients who undergo full surgical resection of the PVs, a prior history of AF was associated with late AF, regardless of whether patients underwent single or bilateral lung transplantation. PV conduction recovery still occurred and was observed in most patients who underwent left atrial ablation procedures for recurrent AF. Copyright © 2017. Published by Elsevier Inc.

Conventional versus 3-D Echocardiography to Predict Arrhythmia Recurrence After Atrial Fibrillation Ablation.

PubMed

Bossard, Matthias; Knecht, Sven; Aeschbacher, Stefanie; Buechel, Ronny R; Hochgruber, Thomas; Zimmermann, Andreas J; Kessel-Schaefer, Arnheid; Stephan, Frank-Peter; Völlmin, Gian; Pradella, Maurice; Sticherling, Christian; Osswald, Stefan; Kaufmann, Beat A; Conen, David; Kühne, Michael

2017-06-01

Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. We assessed the value of conventional and 3-D echocardiography to predict AF recurrence. Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3-D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3-D (LAVI) were 52 ± 12% and 42 ± 13 mL/m 2 , respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3-D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3-D LAVI showed an HR of 1.885 (95%CI 1.066-3.334; P for trend = 0.015) for the highest compared to the lowest quartile. Our results show the important role of LA volume for the long-term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3-D echocardiography in this context and may facilitate patient selection for AF ablation. © 2017 Wiley Periodicals, Inc.

Catheter ablation of atrial fibrillation using remote magnetic catheter navigation: a case-control study.

PubMed

Arya, Arash; Zaker-Shahrak, Ruzbeh; Sommer, Phillip; Bollmann, Andreas; Wetzel, Ulrike; Gaspar, Thomas; Richter, Sergio; Husser, Daniela; Piorkowski, Christopher; Hindricks, Gerhard

2011-01-01

To compare the acute and the 6 month outcome of catheter ablation of atrial fibrillation (AF) using irrigated tip magnetic catheter and remote magnetic cathter navigation (RMN) with manual catheter navigation (MCN) in patients with paroxysmal and persistent AF. In this retrospective analysis 356 patients (235 male, mean age: 57.9 ± 10.9 years) with AF (70.5%, paroxysmal) who underwent catheter ablation between August 2007 and May 2008 using either RMN (n = 70, 46 male, mean age: 57.9 ± 10.1 years, 50% paroxysmal) or MCN (n = 286, 189 male, mean age: 58.0 ± 13.9 years, 75.5% paroxysmal) were included. All patients completed an intensive follow-up strategy. Complete pulmonary vein isolation was achieved in 87.6 and 99.6% of patients in RMN and MCN groups, respectively (P < 0.05). The procedure, fluoroscopy, and radiofrequency application times were 223 ± 44 vs. 166 ± 52 min (P < 0.0001), 13.7 ± 7.8 vs. 34.5 ± 15.1 min (P < 0.0001), and 75.4 ± 20.9 vs. 53.2 ± 21.4 min (P < 0.0001) in RMN and MCN groups, respectively. Seven (10.0%) and 28 (9.8%) patients in RMN and MCN groups received antiarrhythmic medications during the follow-up (P = 0.96). All the patients completed the 6 month follow-up. Freedom from AF at 6 months was achieved in 57.8 and 66.4% of the patients in RMN and MCN groups, respectively (P = 0.196). In patients without previous AF catheter ablation procedure the freedom from AF at 6 months were 68.2 and 60.5% in the MCN and RMN groups, respectively (P = 0.36). Catheter ablation using irrigated tip magnetic catheter and RMN is an effective and safe method for catheter ablation of AF. Compared to manual catheter navigation, the procedure and radiofrequency application times were longer and fluoroscopy time was shorter in the RMN group compared with the MCN group.

Is AF Ablation Cost Effective?

PubMed Central

Martin-Doyle, William; Reynolds, Matthew R.

2010-01-01

The use of catheter ablation to treat AF is increasing rapidly, but there is presently an incomplete understanding of its cost-effectiveness. AF ablation procedures involve significant up-front expenditures, but multiple randomized trials have demonstrated that ablation is more effective than antiarrhythmic drugs at maintaining sinus rhythm in a second-line and possibly first-line rhythm control setting. Although truly long-term data are limited, ablation, as compared with antiarrrhythmic drugs, also appears associated with improved symptoms and quality of life and a reduction in downstream hospitalization and other health care resource utilization. Several groups have developed cost effectiveness models comparing AF ablation primarily to antiarrhythmic drugs and the model results suggest that ablation likely falls within the range generally accepted as cost-effective in developed nations. This paper will review available information on the cost-effectiveness of catheter ablation for the treatment of atrial fibrillation, and discuss continued areas of uncertainty where further research is required. PMID:20936083

Origin and ablation of the adenosine triphosphate induced atrial fibrillation after circumferential pulmonary vein isolation: effects on procedural success rate.

PubMed

Zhang, Jinlin; Tang, Cheng; Zhang, Yonghua; Su, X I

2014-04-01

Adenosine triphosphate (ATP) has been used to provoke dormant pulmonary vein (PV) conduction after circumferential PV isolation (CPVI). However, there have been no systematic studies examining the incidence and the mechanism of ATP-induced atrial fibrillation (AF) following CPVI in paroxysmal AF. In this study, we explore the mechanism of ATP-induced AF and assess the feasibility of eliminating this response by additional radiofrequency (RF) ablation. A total of 300 consecutive patients with paroxysmal AF underwent CPVI. After all PVs were isolated, intravenous ATP (40 mg) was administered during an intravenous isoproterenol (ISP) infusion (5 μg/min). AF was reproducibly induced by ATP in 39 patients. Non-PV foci were confirmed and located in 29 of these patients at the onset of AF, including 27 foci in the superior vena cava (SVC), 1 focus in the crista terminalis, and 1 focus near the antrum of the PV. In all these cases, ATP-induced AF was eliminated after the non-PV foci were successfully ablated. For the other 10 patients, the foci triggering AF could not be confirmed or located due to the transient effect of ATP, thus no further ablation was performed. After a mean follow-up period of 18.7 ± 6.4 (8-24) months, the success rate in the ATP-induced AF group was not significantly different compared with the conventional treatment group who did not exhibit ATP-induced AF (76.9% vs 67.3%; P = 0.25). But in the subgroup of which the ATP-induced AF could be eliminated by additional RF ablation, the success rate was significantly higher than the non-ATP inducible group (86.2% vs 67.3%; P = 0.04). A large proportion of the ATP-induced AF post CPVI were initiated by rapid firing in the SVC. Eliminating this response by additional ablation may have an influence on clinical results of paroxysmal AF ablation. © 2014 Wiley Periodicals, Inc.

Cost-Effectiveness of Radiofrequency Catheter Ablation Compared with Antiarrhythmic Drug Therapy for Paroxysmal Atrial Fibrillation

PubMed Central

Reynolds, Matthew R.; Zimetbaum, Peter; Josephson, Mark E.; Ellis, Ethan; Danilov, Tatyana; Cohen, David J.

2009-01-01

Background Radiofrequency catheter ablation (RFA) has emerged as an important treatment strategy for AF. The potential cost-effectiveness of RFA for AF, relative to antiarrhythmic drug (AAD) therapy, has not been fully explored from a U.S. perspective. Methods and Results We constructed a Markov disease simulation model for a hypothetical cohort of drug- refractory paroxysmal AF patients managed either with RFA ± AAD or AAD alone. Costs and quality-adjusted life years (QALYs) were projected over 5 years. Model inputs were drawn from published clinical trial and registry data, from new registry and trial data analysis, and from data prospectively collected from AF patients managed with RFA at our institution. We assumed no benefit form ablation on stroke, heart failure or death, but did estimate changes in quality-adjusted life expectancy using data from several AF cohorts. In the base case scenario, cumulative costs with the RFA and AAD strategies were $26,584 and $19,898, respectively. Over 5 years, quality adjusted life expectancy was 3.51 QALYs with RFA, versus 3.38 for the AAD group. The incremental cost-effectiveness ratio for RFA vs. AAD was thus $51,431/QALY. Model results were most sensitive to time horizon, the relative utility weights of successful ablation vs. unsuccessful drug therapy, and to the cost of an ablation procedure. Conclusions RFA ± AAD for symptomatic, drug-refractory paroxysmal AF appears to be reasonably cost-effective compared with AAD therapy alone from the perspective of the US health care system, based on improved quality of life and avoidance of future health care costs. PMID:19808491

Identification of active atrial fibrillation sources and their discrimination from passive rotors using electrographical flow mapping.

PubMed

Bellmann, Barbara; Lin, Tina; Ruppersberg, Peter; Zettwitz, Marit; Guttmann, Selma; Tscholl, Verena; Nagel, Patrick; Roser, Mattias; Landmesser, Ulf; Rillig, Andreas

2018-05-09

The optimal ablation approach for the treatment of persistent atrial fibrillation (AF) is still under debate; however, the identification and elimination of AF sources is thought to play a key role. Currently available technologies for the identification of AF sources are not able to differentiate between active rotors or focal impulse (FI) and passive circular turbulences as generated by the interaction of a wave front with a functional obstacle such as fibrotic tissue. This study introduces electrographic flow (EGF) mapping as a novel technology for the identification and characterization of AF sources in humans. Twenty-five patients with AF (persistent: n = 24, long-standing persistent: n = 1; mean age 70.0 ± 8.3 years, male: n = 17) were included in this prospective study. Focal impulse and Rotor-Mapping (FIRM) was performed in addition to pulmonary vein isolation using radiofrequency in conjunction with a 3D-mapping-system. One-minute epochs were exported from the EP-recording-system and re-analyzed using EGF mapping after the procedure. 44 potential AF sources (43 rotors and one FI) were identified with FIRM and 39 of these rotors were targeted for ablation. EGF mapping verified 40 of these patterns and identified 24/40 (60%) as active sources while 16/40 (40%) were classified as passive circular turbulences. Four rotors were not identified by EGF mapping. EGF is the first method to identify active AF sources during AF ablation procedures in humans and discriminate them from passive rotational phenomena, which occur if the excitation wavefront passes conduction bariers. EGF mapping may allow improved guidance of AF ablation procedures.

Atrial fibrillation patients with isolated pulmonary veins: Is sinus rhythm achievable?

PubMed

Szilágyi, Judit; Marcus, Gregory M; Badhwar, Nitish; Lee, Byron K; Lee, Randall J; Vedantham, Vasanth; Tseng, Zian H; Walters, Tomos; Scheinman, Melvin; Olgin, Jeffrey; Gerstenfeld, Edward P

2017-07-01

The cornerstone of atrial fibrillation (AF) ablation is isolation of the pulmonary veins (PVs). Patients with recurrent AF undergoing repeat ablation usually have PV reconnection (PVr). The ablation strategy and outcome of patients undergoing repeat ablation who have persistent isolation of all PVs (PVi) at the time of repeat ablation is unknown. We studied consecutive patients with recurrent AF undergoing repeat ablation and compared patients with PVi to those with PVr. One hundred fifty-two patients underwent repeat ablation, and of these, 25 patients (16.4%) had PVi. Patients with PVi underwent ablation targeting any isoproterenol induced AF triggers, atrial substrate, or inducible atrial tachycardias or flutters. Patients with PVi compared to PVr were more likely to have a history of persistent AF (64% vs. 26%; P < 0.0001), obesity (BMI 30.4 vs. 28.2; P = 0.05), and prior use of contact force sensing catheters (28% vs. 0.8%, P < 0.0001). After a mean follow-up of 19 ± 15 months, 56% of PVi patients remained in sinus rhythm compared to 76.3% of PVr patients (P = 0.036). In a multivariable model, PVi patients and those with cardiomyopathy had a higher risk of recurrent atrial tachyarrhythmias (HR = 3.6 95%, CI 1.6-8.3, P = 0.002 and HR = 6.2, 95% CI 2.3-16.3, P < 0.0001, respectively). In patients who have all PVs isolated at the time of the redo AF ablation, a strategy of targeting non-PV AF triggers and inducible flutters can still lead to AF freedom in more than half of patients. Patients with PVr, however, have a better long-term outcome. © 2017 Wiley Periodicals, Inc.

Identification and Characterization of Sites Where Persistent Atrial Fibrillation Is Terminated by Localized Ablation.

PubMed

Zaman, Junaid A B; Sauer, William H; Alhusseini, Mahmood I; Baykaner, Tina; Borne, Ryan T; Kowalewski, Christopher A B; Busch, Sonia; Zei, Paul C; Park, Shirley; Viswanathan, Mohan N; Wang, Paul J; Brachmann, Johannes; Krummen, David E; Miller, John M; Rappel, Wouter Jan; Narayan, Sanjiv M; Peters, Nicholas S

2018-01-01

The mechanisms by which persistent atrial fibrillation (AF) terminates via localized ablation are not well understood. To address the hypothesis that sites where localized ablation terminates persistent AF have characteristics identifiable with activation mapping during AF, we systematically examined activation patterns acquired only in cases of unequivocal termination by ablation. We recruited 57 patients with persistent AF undergoing ablation, in whom localized ablation terminated AF to sinus rhythm or organized tachycardia. For each site, we performed an offline analysis of unprocessed unipolar electrograms collected during AF from multipolar basket catheters using the maximum -dV/dt assignment to construct isochronal activation maps for multiple cycles. Additional computational modeling and phase analysis were used to study mechanisms of map variability. At all sites of AF termination, localized repetitive activation patterns were observed. Partial rotational circuits were observed in 26 of 57 (46%) cases, focal patterns in 19 of 57 (33%), and complete rotational activity in 12 of 57 (21%) cases. In computer simulations, incomplete segments of partial rotations coincided with areas of slow conduction characterized by complex, multicomponent electrograms, and variations in assigning activation times at such sites substantially altered mapped mechanisms. Local activation mapping at sites of termination of persistent AF showed repetitive patterns of rotational or focal activity. In computer simulations, complete rotational activation sequence was observed but was sensitive to assignment of activation timing particularly in segments of slow conduction. The observed phenomena of repetitive localized activation and the mechanism by which local ablation terminates putative AF drivers require further investigation. © 2018 American Heart Association, Inc.

Pulmonary Vein Isolation Alone Versus Additional Linear Ablation in Patients With Persistent Atrial Fibrillation Converted to Paroxysmal Type With Antiarrhythmic Drug Therapy: A Multicenter, Prospective, Randomized Study.

PubMed

Yu, Hee Tae; Shim, Jaemin; Park, Junbeom; Kim, In-Soo; Kim, Tae-Hoon; Uhm, Jae-Sun; Joung, Boyoung; Lee, Moon-Hyoung; Kim, Young-Hoon; Pak, Hui-Nam

2017-06-01

Atrial fibrillation (AF) type can vary depending on condition and timing, and some patients who initially present with persistent AF may be changed to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether circumferential pulmonary vein isolation (CPVI) alone is an effective rhythm control strategy in patients with persistent AF to paroxysmal AF. We enrolled 113 patients with persistent AF to paroxysmal AF (male 75%, 60.4±10.1 years old) who underwent catheter ablation for nonvalvular AF at 3 tertiary hospitals. The participants were randomly assigned to 2 groups: CPVI alone (n=59) or CPVI plus linear ablation (CPVI+Line; posterior box+anterior line, n=54). Compared with the CPVI+Line, CPVI alone required shorter procedure (187.2±58.0 versus 211.2±63.9 min; P =0.043) and ablation times (4922.1±1110.5 versus 6205.7±1425.2 s; P <0.001) without difference in procedure-related major complication (3% versus 2%; P =0.611). Antiarrhythmic drug utility rates after ablation were not different between the 2 groups (22% versus 30%; P =0.356). Overall, AF-free survival (log-rank; P =0.206) and AF and antiarrhythmic drug-free survival (log-rank; P =0.321) were not different between groups. CPVI alone is an effective rhythm control strategy with a shorter procedure time in persistent AF patients converted to paroxysmal AF compared with CPVI with linear ablation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02176616. © 2017 American Heart Association, Inc.

Use of Oral Steroid and its Effects on Atrial Fibrillation Recurrence and Inflammatory Cytokines Post Ablation - The Steroid AF Study.

PubMed

Iskandar, Sandia; Reddy, Madhu; Afzal, Muhammad R; Rajasingh, Johnson; Atoui, Moustapha; Lavu, Madhav; Atkins, Donita; Bommana, Sudha; Umbarger, Linda; Jaeger, Misty; Pimentel, Rhea; Dendi, Raghuveer; Emert, Martin; Turagam, Mohit; Di Biase, Luigi; Natale, Andrea; Lakkireddy, Dhanunjaya

2017-01-01

Use of corticosteroids before and after atrial fibrillation (AF) ablation can decrease acute inflammation and reduce AF recurrence. To assess the efficacy of oral prednisone in improving the outcomes of pulmonary vein isolation with radiofrequency ablation and its effect on inflammatory cytokine. A total of 60 patients with paroxysmal AF undergoing radiofrequency ablation were randomized (1:1) to receive either 3 doses of 60 mg daily of oral prednisone or a placebo. Inflammatory cytokine levels (TNF-α, IL-1, IL6, IL-8) were measured at baseline, prior to ablation, immediately after ablation, and 24 hours post ablation. Patients underwent 30 day event monitoring at 3 months, 6 months and 12 months post procedure. Immediate post ablation levels of inflammatory cytokines were lower in the steroid group when compared to the placebo group; IL-6: 9.0 ±7 vs 15.8 ±13 p=0.031; IL-8: 10.5 ±9 vs 15.3 ±8; p=0.047 respectively. Acute PV reconnection rates during the procedure (7/23% vs 10/36%; p = 0.39), and RF ablation time (51±13 vs 56±11 min, p = 0.11) trended to be lower in the placebo group than the steroid group. There was no difference in the incidence of early recurrence of AF during the blanking period and freedom from AF off AAD at 12 months between both groups (5/17% vs 8/27%; p = 0.347 and 21/70% vs 18/60%; p=0.417 in placebo and steroid groups respectively). Although oral corticosteroids have significant effect in lowering certain cytokines, it did not impact the clinical outcomes of AF ablation.

Long-term survival in patients undergoing cardiac resynchronization therapy: the importance of performing atrio-ventricular junction ablation in patients with permanent atrial fibrillation

PubMed Central

Gasparini, Maurizio; Auricchio, Angelo; Metra, Marco; Regoli, François; Fantoni, Cecilia; Lamp, Barbara; Curnis, Antonio; Vogt, Juergen; Klersy, Catherine

2008-01-01

Aims To investigate the effects of cardiac resynchronization therapy (CRT) on survival in heart failure (HF) patients with permanent atrial fibrillation (AF) and the role of atrio-ventricular junction (AVJ) ablation in these patients. Methods and results Data from 1285 consecutive patients implanted with CRT devices are presented: 1042 patients were in sinus rhythm (SR) and 243 (19%) in AF. Rate control in AF was achieved by either ablating the AVJ in 118 patients (AVJ-abl) or prescribing negative chronotropic drugs (AF-Drugs). Compared with SR, patients with AF were significantly older, more likely to be non-ischaemic, with higher ejection fraction, shorter QRS duration, and less often received ICD back-up. During a median follow-up of 34 months, 170/1042 patients in SR and 39/243 in AF died (mortality: 8.4 and 8.9 per 100 person-year, respectively). Adjusted hazard ratios were similar for all-cause and cardiac mortality [0.9 (0.57–1.42), P = 0.64 and 1.00 (0.60–1.66) P = 0.99, respectively]. Among AF patients, only 11/118 AVJ-abl patients died vs. 28/125 AF-Drugs patients (mortality: 4.3 and 15.2 per 100 person-year, respectively, P < 0.001). Adjusted hazard ratios of AVJ-abl vs. AF-Drugs was 0.26 [95% confidence interval (CI) 0.09–0.73, P = 0.010] for all-cause mortality, 0.31 (95% CI 0.10–0.99, P = 0.048) for cardiac mortality, and 0.15 (95% CI 0.03–0.70, P = 0.016) for HF mortality. Conclusion Patients with HF and AF treated with CRT have similar mortality compared with patients in SR. In AF, AVJ ablation in addition to CRT significantly improves overall survival compared with CRT alone, primarily by reducing HF death. PMID:18390869

Clinical impact of rotor ablation in atrial fibrillation: a systematic review.

PubMed

Parameswaran, Ramanathan; Voskoboinik, Aleksandr; Gorelik, Alexandra; Lee, Geoffrey; Kistler, Peter M; Sanders, Prashanthan; Kalman, Jonathan M

2018-01-11

Rotor mapping and ablation have gained favour over the recent years as an emerging ablation strategy targeting drivers of atrial fibrillation (AF). Their efficacy, however, has been a topic of great debate with variable outcomes across centres. The aim of this study was to systematically review the recent medical literature to determine the medium-term outcomes of rotor ablation in patients with paroxysmal atrial fibrillation (PAF) and persistent atrial fibrillation (PeAF). A systematic search of the contemporary scientific literature (PubMed and EMBASE) was performed in August 2017. Only studies assessing arrhythmia-free survival from rotor ablation of AF were included. We used the random-effects model to assess the primary outcome of pooled medium-term single-procedure AF-free survival for both PAF and PeAF. Success rates from multiple procedures and complication rates were also examined. We included 11 observational studies (4 PAF and 10 PeAF) with a total of 556 patients (166 PAF and 390 PeAF). Pooled single-procedure freedom from AF was 37.8% [95% confidence interval 5.6-86.3%] at a mean follow-up period of 13.8 ± 1.8 months for PAF and 59.2% (95% CI 41.4-74.9%) at a mean follow-up period of 12.9 ± 6 months for PeAF. There was a marked heterogeneity between studies (I2 = 93.8% for PAF and 88.3% for PeAF). The mean complication rate of rotor ablation among the reported studies was 3.4%. The wide variability in success rate between different centres performing rotor ablations suggests that the optimal ablation strategy, particularly targeting rotors, is unclear. Results from randomized studies are necessary before this technique can be considered as an established clinical tool. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.

Left Atrial Appendage Electrical Isolation and Concomitant Device Occlusion to Treat Persistent Atrial Fibrillation: A First-in-Human Safety, Feasibility, and Efficacy Study.

PubMed

Panikker, Sandeep; Jarman, Julian W E; Virmani, Renu; Kutys, Robert; Haldar, Shouvik; Lim, Eric; Butcher, Charles; Khan, Habib; Mantziari, Lilian; Nicol, Edward; Foran, John P; Markides, Vias; Wong, Tom

2016-07-01

Left atrial appendage (LAA) electric isolation is reported to improve persistent atrial fibrillation (AF) ablation outcomes. However, loss of LAA mechanical function may increase thromboembolic risk. Concomitant LAA electric isolation and occlusion as part of conventional AF ablation has never been tested in humans. We therefore evaluated the feasibility, safety, and efficacy of LAA electric isolation and occlusion in patients undergoing long-standing persistent AF ablation. Patients with long-standing persistent AF (age, 68±7 years; left atrium diameter, 46±3 mm; and AF duration, 25±15 months) underwent AF ablation, LAA electric isolation, and occlusion. Outcomes were compared with a balanced (1:2 ratio) control group who had AF ablation alone. Among 22 patients who underwent ablation, LAA electric isolation was possible in 20. Intraprocedural LAA reconnection occurred in 17 of 20 (85%) patients, predominantly at anterior and superior locations. All were reisolated. LAA occlusion was successful in all 20 patients. There were no major periprocedural complications. Imaging at 45 days and 9 months confirmed satisfactory device position and excluded pericardial effusion. One of twenty (5%) patients had a gap of ≥5 mm requiring anticoagulation. Nineteen of twenty (95%) patients stopped warfarin at 3 months. Without antiarrhythmic drugs, freedom from AF at 12 months after a single procedure was significantly higher in the study group (19/20, 95%) than in the control group (25/40, 63%), P=0.036. Freedom from atrial arrhythmias was demonstrated in 12 of 20 (60%) and 18 of 20 (90%) patients after 1 and ≤2 procedures (mean, 1.3), respectively. Persistent AF ablation, LAA electric isolation, and mechanical occlusion can be performed concomitantly. This technique may improve the success of persistent AF ablation while obviating the need for chronic anticoagulation. URL: https://clinicaltrials.gov. Unique identifier: NCT02028130. © 2016 American Heart Association, Inc.

Left atrial concomitant surgical ablation for treatment of atrial fibrillation in cardiac surgery: A meta-analysis of randomized controlled trials

PubMed Central

Wang, Chunguo; Ye, Minhua; Lin, Jiang; Jin, Jiang; Hu, Quanteng; Zhu, Chengchu; Chen, Baofu

2018-01-01

Introduction Surgical ablation is a generally established treatment for patients with atrial fibrillation undergoing concomitant cardiac surgery. Left atrial (LA) lesion set for ablation is a simplified procedure suggested to reduce the surgery time and morbidity after procedure. The present meta-analysis aims to explore the outcomes of left atrial lesion set versus no ablative treatment in patients with AF undergoing cardiac surgery. Methods A literature research was performed in six database from their inception to July 2017, identifying all relevant randomized controlled trials (RCTs) comparing left atrial lesion set versus no ablative treatment in AF patient undergoing cardiac surgery. Data were extracted and analyzed according to predefined clinical endpoints. Results Eleven relevant RCTs were included for analysis in the present study. The prevalence of sinus rhythm in ablation group was significantly higher at discharge, 6-month and 1-year follow-up period. The morbidity including 30 day mortality, late all-cause mortality, reoperation for bleeding, permanent pacemaker implantation and neurological events were of no significant difference between two groups. Conclusions The result of our meta-analysis demonstrates that left atrial lesion set is an effective and safe surgical ablation strategy for AF patients undergoing concomitant cardiac surgery. PMID:29360851

A Randomised Controlled Trial on the Effect of Nurse-Led Educational Intervention at the Time of Catheter Ablation for Atrial Fibrillation on Quality of Life, Symptom Severity and Rehospitalisation.

PubMed

Bowyer, John L; Tully, Phillip J; Ganesan, Anand N; Chahadi, Fahd K; Singleton, Cameron B; McGavigan, Andrew D

2017-01-01

Atrial Fibrillation (AF) is a common condition associated with impaired quality of life (QOL) and recurrent hospitalisation. Catheter ablation for AF is a well-established treatment for symptomatic patients despite medical therapy. We sought to examine the effect of point specific nurse-led education on QOL, AF symptomatology and readmission rate post AF ablation. Forty-one patients undergoing AF ablation were randomised to Nurse Intervention (NI) versus Control (C), n=22 vs. 19. Both groups were well matched with respect to age, sex and AF subtype. All patients completed SF36 and AF Symptom Checklist, Frequency and Severity Scale questionnaires at baseline and six months post ablation. The NI group underwent nurse education on admission, prior to discharge, and with telephone contact. Baseline SF-36 and AF Symptom Checklist, Frequency and Severity scores were similar. The NI group showed significant differences compared to Control with respect to higher QOL on the SF-36 score of Physical Functioning and Vitality at six months. There were significant improvements in seven components of the AF Symptom Checklist, Frequency and Severity at six months in the NI group with a trend in a further seven. There was no difference in AF related hospital readmissions at six months between C and NI groups (10.5% vs. 13.6%, p=ns). Nurse-led education at time of AF ablation is associated with improved QOL and reduced symptom frequency and severity compared to usual care. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Quantitative Analysis of Localized Sources Identified by Focal Impulse and Rotor Modulation Mapping in Atrial Fibrillation

PubMed Central

Benharash, Peyman; Buch, Eric; Frank, Paul; Share, Michael; Tung, Roderick; Shivkumar, Kalyanam; Mandapati, Ravi

2015-01-01

Background New approaches to ablation of atrial fibrillation (AF) include focal impulse and rotor modulation (FIRM) mapping, and initial results reported with this technique have been favorable. We sought to independently evaluate the approach by analyzing quantitative characteristics of atrial electrograms used to identify rotors and describe acute procedural outcomes of FIRM-guided ablation. Methods and Results All FIRM-guided ablation procedures (n=24; 50% paroxysmal) at University of California, Los Angeles Medical Center were included for analysis. During AF, unipolar atrial electrograms collected from a 64-pole basket catheter were used to construct phase maps and identify putative AF sources. These sites were targeted for ablation, in conjunction with pulmonary vein isolation in most patients (n=19; 79%). All patients had rotors identified (mean, 2.3±0.9 per patient; 72% in left atrium). Prespecified acute procedural end point was achieved in 12 of 24 (50%) patients: AF termination (n=1), organization (n=3), or >10% slowing of AF cycle length (n=8). Basket electrodes were within 1 cm of 54% of left atrial surface area, and a mean of 31 electrodes per patient showed interpretable atrial electrograms. Offline analysis revealed no differences between rotor and distant sites in dominant frequency or Shannon entropy. Electroanatomic mapping showed no rotational activation at FIRM-identified rotor sites in 23 of 24 patients (96%). Conclusions FIRM-identified rotor sites did not exhibit quantitative atrial electrogram characteristics expected from rotors and did not differ quantitatively from surrounding tissue. Catheter ablation at these sites, in conjunction with pulmonary vein isolation, resulted in AF termination or organization in a minority of patients (4/24; 17%). Further validation of this approach is necessary. PMID:25873718

Randomised clinical trial of cryoballoon versus irrigated radio frequency catheter ablation for atrial fibrillation-the effect of double short versus standard exposure cryoablation duration during pulmonary vein isolation (CIRCA-DOSE): methods and rationale.

PubMed

Andrade, Jason G; Deyell, Marc W; Badra, Mariano; Champagne, Jean; Dubuc, Marc; Leong-Sit, Peter; Macle, Laurent; Novak, Paul; Roux, Jean-Francois; Sapp, John; Tang, Anthony; Verma, Atul; Wells, George A; Khairy, Paul

2017-10-05

Pulmonary vein isolation (PVI) is an effective therapy for paroxysmal atrial fibrillation (AF), but it has limitations. The two most significant recent advances have centred on the integration of real-time quantitative assessment of catheter contact force into focal radio frequency (RF) ablation catheters and the development of dedicated ablation tools capable of achieving PVI with a single ablation lesion (Arctic Front cryoballoon, Medtronic, Minneapolis, MN, USA). Although each of these holds promise for improving the clinical success of catheter ablation of AF, there has not been a rigorous comparison of these advanced ablation technologies. Moreover, the optimal duration of cryoablation (freezing time) has not been determined. Patients undergoing an initial PVI procedure for paroxysmal AF will be recruited. Patients will be randomised 1:1:1 between contact-force irrigated RF ablation, short duration cryoballoon ablation (2 min applications) and standard duration cryoballoon ablation (4 min applications). The primary outcome is time to first documented AF recurrence on implantable loop recorder. With a sample size of 111 per group and a two-sided 0.025 significance level (to account for the two main comparisons), the study will have 80% power (using a log-rank test) to detect a difference of 20% between contact force RF catheter ablation and either of the two cryoballoon ablation groups. Factoring in a 4% loss to follow-up, 116 patients per group should be randomised and followed for a year (total study population of 348). The study was approved by the University of British Columbia Office of Research (Services) Ethics Clinical Research Ethics Board. Results of the study will be submitted for publication in a peer-reviewed journal. NCT01913522; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Mechanisms for the Termination of Atrial Fibrillation by Localized Ablation: Computational and Clinical Studies.

PubMed

Rappel, Wouter-Jan; Zaman, Junaid A B; Narayan, Sanjiv M

2015-12-01

Human atrial fibrillation (AF) can terminate after ablating localized regions, which supports the existence of localized rotors (spiral waves) or focal drivers. However, it is unclear why ablation near a spiral wave tip would terminate AF and not anchor reentry. We addressed this question by analyzing competing mechanisms for AF termination in numeric simulations, referenced to clinical observations. Spiral wave reentry was simulated in monodomain 2-dimensional myocyte sheets using clinically realistic rate-dependent values for repolarization and conduction. Heterogeneous models were created by introduction of parameterized variations in tissue excitability. Ablation lesions were applied as nonconducting circular regions. Models confirmed that localized ablation may anchor spiral wave reentry, producing organized tachycardias. Several mechanisms referenced to clinical observations explained termination of AF to sinus rhythm. First, lesions may create an excitable gap vulnerable to invasion by fibrillatory waves. Second, ablation of rotors in regions of low-excitability (from remodeling) produced re-entry in more excitable tissue allowing collision of wavefront and back. Conversely, ablation of rotors in high-excitability regions migrated spiral waves to less excitable tissue, where they detached to collide with nonconducting boundaries. Third, ablation may connect rotors to nonconducting anatomic orifices. Fourth, reentry through slow-conducting channels may terminate if ablation closes these channels. Limited ablation can terminate AF by several mechanisms. These data shed light on how clinical AF may be sustained in patients' atria, emphasizing heterogeneities in tissue excitability, slow-conducting channels, and obstacles that are increasingly detectable in patients and should be the focus of future translational studies. © 2015 American Heart Association, Inc.

Safe and rapid isolation of pulmonary veins using a novel circular ablation catheter and duty-cycled RF generator.

PubMed

Fredersdorf, Sabine; Weber, Stefan; Jilek, Clemens; Heinicke, Norbert; VON Bary, Christian; Jungbauer, Carsten; Riegger, Günter A; Hamer, Okka W; Jeron, Andreas

2009-10-01

Ablation of atrial fibrillation (AF) has been one of the most difficult and time-consuming electrophysiological procedures. Due to the rapidly increasing demand for ablation procedures, technical advances would be helpful to reduce complexity and procedure time in AF ablation. Therefore, we investigated the feasibility of a single-catheter technique for pulmonary vein (PV) isolation utilizing a decapolar catheter combined with a duty-cycled, unipolar-bipolar radiofrequency (RF) generator. AF mapping and ablation was performed in 21 consecutive patients (mean age 59 +/- 12 years, 9 males) with paroxysmal AF (n = 17) and persistent AF (n = 4). The ablation catheter was forwarded to the LA via single-transseptal puncture. All electrodes were energized in 2 to 5 applications per vein, followed by segmental RF applications, as needed, to achieve electrical isolation. To assess left atrial anatomy for purposes of catheter manipulation, and later evaluate the possibility of asymptomatic PV-stenosis, CT or MR imaging was performed both prior to ablation and at 6-month follow-up. Isolation could be achieved in 85/86 veins (99%). Procedure time for ablation was 81 +/- 13 minutes, and fluoroscopy time was 30 +/- 11 minutes. There were no procedural complications. Success rate at 6 months was 86% (18/21). MR or CT imaging excluded asymptomatic PV-stenosis. Mapping and ablation of PVs can be performed in a safe and efficient manner using a single-catheter technique, with short procedure times and minimal learning curve. Thus, this system may be of high interest not only for high volume but all centers performing AF ablation.

Expression of TGFbeta1 in pulmonary vein stenosis after radiofrequency ablation in chronic atrial fibrillation of dogs.

PubMed

Li, Shufeng; Li, Hongli; Mingyan, E; Yu, Bo

2009-02-01

The development of pulmonary vein stenosis has recently been described after radiofrequency ablation (RF) to treat atrial fibrillation (AF). The purpose of this study was to examine expression of TGFbeta1 in pulmonary vein stenosis after radiofrequency ablation in chronic atrial fibrillation of dogs. About 28 mongrel dogs were randomly assigned to the sham-operated group (n = 7), the AF group (n = 7), AF + RF group (n = 7), and RF group (n = 7). In AF or AF + RF groups, dogs underwent chronic pulmonary vein (PV) pacing to induce sustained AF. RF application was applied around the PVs until electrical activity was eliminated. Histological assessment of pulmonary veins was performed using hematoxylin and eosin staining; TGFbeta1 gene expression in pulmonary veins was examined by RT-PCR analysis; expression of TGFbeta1 protein in pulmonary veins was assessed by Western blot analysis. Rapid pacing from the left superior pulmonary vein (LSPV) induced sustained AF in AF group and AF + RF group. Pulmonary vein ablation terminated the chronic atrial fibrillation in dogs. Histological examination revealed necrotic tissues in various stages of collagen replacement, intimal thickening, and cartilaginous metaplasia with chondroblasts and chondroclasts. Compared with sham-operated and AF group, TGFbeta1 gene and protein expressions was increased in AF + RF or RF groups. It was concluded that TGFbeta1 might be associated with pulmonary vein stenosis after radiofrequency ablation in chronic atrial fibrillation of dogs.

Safety and Long-Term Outcomes of Catheter Ablation of Atrial Fibrillation Using Magnetic Navigation versus Manual Conventional Ablation: A Propensity-Score Analysis.

PubMed

Adragão, Pedro Pulido; Cavaco, Diogo; Ferreira, António Miguel; Costa, Francisco Moscoso; Parreira, Leonor; Carmo, Pedro; Morgado, Francisco Bello; Santos, Katya Reis; Santos, Pedro Galvão; Carvalho, Maria Salomé; Durazzo, Anai; Marques, Hugo; Gonçalves, Pedro Araújo; Raposo, Luís; Mendes, Miguel

2016-03-01

Whether or not the potential advantages of using a magnetic navigation system (MNS) translate into improved outcomes in patients undergoing atrial fibrillation (AF) ablation is a question that remains unanswered. In this observational registry study, we used propensity-score matching to compare the outcomes of patients with symptomatic drug-refractory AF who underwent catheter ablation using MNS with the outcomes of those who underwent catheter ablation using conventional manual navigation. Among 1,035 eligible patients, 287 patients in each group had similar propensity scores and were included in the analysis. The primary efficacy outcome was the rate of AF relapse after a 3-month blanking period. At a mean follow-up of 2.6 ± 1.5 years, AF ablation with MNS was associated with a similar risk of AF relapse as compared with manual navigation (18.4% per year and 22.3% per year, respectively; hazard ratio 0.81, 95% CI 0.63-1.05; P = 0.108). Major complications occurred in two patients (0.7%) using MNS, and in six patients (2.1%) undergoing manually navigated ablation (P = 0.286). Fluoroscopy times were 21 ± 10 minutes in the manual navigation group, and 12 ± 9 minutes in the MNS group (P < 0.001), whereas total procedure times were 152 ± 52 minutes and 213 ± 58 minutes, respectively (P < 0.001). In this propensity-score matched comparison, magnetic navigation and conventional manual AF ablations seem to have similar relapse rates and a similar risk of complications. AF ablations with magnetic navigation take longer to perform but expose patients to significantly shorter fluoroscopy times. © 2015 Wiley Periodicals, Inc.

Long-term influence of body mass index on cardiovascular events after atrial fibrillation ablation.

PubMed

Bunch, T Jared; May, Heidi T; Bair, Tami L; Crandall, Brian G; Cutler, Michael J; Jacobs, Victoria; Mallender, Charles; Muhlestein, Joseph B; Osborn, Jeffrey S; Weiss, J Peter; Day, John D

2016-09-01

Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Obesity is a dominant driver of AF recurrence after ablation. However, being both overweight and underweight drives long-term cardiac and general health risks. Long-term data are needed to understand the influence of body mass index (BMI) on outcomes after ablation in regard to arrhythmia recurrence and cardiovascular outcomes. All patients who underwent an index ablation with a BMI recorded and at least 3 years of follow-up were included (n = 1558). The group was separated and compared by index ablation BMI status (≤20, 21-25, 26-30, >30 kg/m(2)). Long-term outcomes included AF recurrence, stroke/TIA, heart failure (HF) hospitalization, and death. Patients with advancing BMI status were more likely to be male and have hypertension, a smoking history, diabetes, HF, and a prior cardioversion. Patients with a BMI ≤20 were more likely to have a moderate-high congestive heart failure, hypertension, age >75, diabetes, stroke (CHADS2) score. At 3 years, recurrence rates of AF increased significantly with increasing BMI status (p = 0.02); paradoxically, there was a trend for increased stroke risk with decreasing BMI (p = 0.06). Long-term death rates tended to increase inversely with BMI status, and HF rates were greatest in the highest and lowest BMI groups. Lower weight at AF ablation lowers arrhythmia recurrence risk. However, AF ablation patients who are normal or underweight remain at high risk of other cardiovascular outcomes including increased stroke risk with less AF burden.

Recent advances in rhythm control for atrial fibrillation

PubMed Central

Bond, Richard; Olshansky, Brian; Kirchhof, Paulus

2017-01-01

Atrial fibrillation (AF) remains a difficult management problem. The restoration and maintenance of sinus rhythm—rhythm control therapy—can markedly improve symptoms and haemodynamics for patients who have paroxysmal or persistent AF, but some patients fare well with rate control alone. Sinus rhythm can be achieved with anti-arrhythmic drugs or electrical cardioversion, but the maintenance of sinus rhythm without recurrence is more challenging. Catheter ablation of the AF triggers is more effective than anti-arrhythmic drugs at maintaining sinus rhythm. Whilst pulmonary vein isolation is an effective strategy, other ablation targets are being evaluated to improve sinus rhythm maintenance, especially in patients with chronic forms of AF. Previously extensive ablation strategies have been used for patients with persistent AF, but a recent trial has shown that pulmonary vein isolation without additional ablation lesions is associated with outcomes similar to those of more extensive ablation. This has led to an increase in catheter-based technology to achieve durable pulmonary vein isolation. Furthermore, a combination of anti-arrhythmic drugs and catheter ablation seems useful to improve the effectiveness of rhythm control therapy. Two large ongoing trials evaluate whether a modern rhythm control therapy can improve prognosis in patients with AF. PMID:29043080

Outcomes after cardioversion and atrial fibrillation ablation in patients treated with rivaroxaban and warfarin in the ROCKET AF trial.

PubMed

Piccini, Jonathan P; Stevens, Susanna R; Lokhnygina, Yuliya; Patel, Manesh R; Halperin, Jonathan L; Singer, Daniel E; Hankey, Graeme J; Hacke, Werner; Becker, Richard C; Nessel, Christopher C; Mahaffey, Kenneth W; Fox, Keith A A; Califf, Robert M; Breithardt, Günter

2013-05-14

This study sought to investigate the outcomes following cardioversion or catheter ablation in patients with atrial fibrillation (AF) treated with warfarin or rivaroxaban. There are limited data on outcomes following cardioversion or catheter ablation in AF patients treated with factor Xa inhibitors. We compared the incidence of electrical cardioversion (ECV), pharmacologic cardioversion (PCV), or AF ablation and subsequent outcomes in patients in a post hoc analysis of the ROCKET AF (Efficacy and Safety Study of Rivaroxaban With Warfarin for the Prevention of Stroke and Non-Central Nervous System Systemic Embolism in Patients With Non-Valvular Atrial Fibrillation) trial. Over a median follow-up of 2.1 years, 143 patients underwent ECV, 142 underwent PCV, and 79 underwent catheter ablation. The overall incidence of ECV, PCV, or AF ablation was 1.45 per 100 patient-years (n = 321; 1.44 [n = 161] in the warfarin arm, 1.46 [n = 160] in the rivaroxaban arm). The crude rates of stroke and death increased in the first 30 days after cardioversion or ablation. After adjustment for baseline differences, the long-term incidence of stroke or systemic embolism (hazard ratio [HR]: 1.38; 95% confidence interval [CI]: 0.61 to 3.11), cardiovascular death (HR: 1.57; 95% CI: 0.69 to 3.55), and death from all causes (HR: 1.75; 95% CI: 0.90 to 3.42) were not different before and after cardioversion or AF ablation. Hospitalization increased after cardioversion or AF ablation (HR: 2.01; 95% CI: 1.51 to 2.68), but there was no evidence of a differential effect by randomized treatment (p value for interaction = 0.58). The incidence of stroke or systemic embolism (1.88% vs. 1.86%) and death (1.88% vs. 3.73%) were similar in the rivaroxaban-treated and warfarin-treated groups. Despite an increase in hospitalization, there were no differences in long-term stroke rates or survival following cardioversion or AF ablation. Outcomes were similar in patients treated with rivaroxaban or warfarin. (An Efficacy and Safety Study of Rivaroxaban With Warfarin for the Prevention of Stroke and Non-Central Nervous System Systemic Embolism in Patients With Non-Valvular Atrial Fibrillation [ROCKET AF]; NCT00403767). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Is HATCH score a reliable predictor of atrial fibrillation after cavotricuspid isthmus ablation for typical atrial flutter?

PubMed

García-Seara, Javier; Gude Sampedro, Francisco; Martínez Sande, Jose L; Fernández López, Xesus Alberte; Rodríguez Mañero, Moisés; González Melchor, Laila; Alvarez Alvarez, Belén; Iglesias Alvarez, Diego; González Juanatey, José Ramón

2016-09-01

We determined the effectiveness of the HATCH score in patients with typical atrial flutter (AFl) undergoing cavotricuspid isthmus (CTI) ablation to predict long-term atrial fibrillation (AF). We conducted an observational retrospective single-center cohort study including all patients admitted to our hospital for a CTI ablation between 1998 and 2010. The patients were divided into four categories: 1) new-onset AF (no prior AF and AF during follow-up (FU)); 2) old AF (prior AF and no AF during FU); 3) prior and post AF (AF prior and post CTI ablation); and 4) no AF. Four hundred and eight patients were included. In patients without prior AF, the hazard ratio (HR) for new-onset AF during FU was 0.98 (CI 95%: 0.65-1.50; p = 0.95) and 1.00 (CI 95%: 0.57-1.77; p = 0.98) for HATCH ≥ 2 and HATCH ≥ 3, respectively. In patients with prior AF, the HR for AF was 1.41 (CI 95%: 0.87-2.28; p = 0.17) and 1.79 (CI 95%: 0.96-3.35; p = 0.06), for HATCH ≥ 2 and HATCH ≥ 3, respectively. Left atrial enlargement was positively correlated with the occurrence of AF during FU, especially in the subgroup without prior AF, which had a HR of 2.44 (CI 95%: 1.35-4.40; p = 0.003), a HR of 2.88 (CI 95%: 1.36-6.10; p = 0.006) and a HR of 3.68 (CI 95%: 1.71-7.94; p = 0.001), for slight, moderate and severely dilated left atrial dimension, respectively, compared with a normal value. HATCH score did not predict AF in patients with typical AFl who underwent CTI ablation. Basal left atrium dimension could help predict new-onset AF.

Safety and Efficacy of Uninterrupted Apixaban Therapy Versus Warfarin During Atrial Fibrillation Ablation.

PubMed

Shah, Ruchit R; Pillai, Ajay; Schafer, Pascha; Meggo, David; McElderry, Tom; Plumb, Vance; Yamada, Takumi; Kumar, Vineet; Doppalapudi, Harish; Gunter, Alicia; Pentecost, Emily; Maddox, William R

2017-08-01

Thromboembolic cerebrovascular accident remains a rare but potentially devastating complication of catheter-based atrial fibrillation (AF) ablation. Uninterrupted oral anticoagulant therapy with warfarin has become the standard of care when performing catheter-based AF ablation. Compared with warfarin, apixaban, a factor Xa inhibitor, has been shown to reduce the risk of stroke and major bleeding in nonvalvular AF. With an increase in apixaban use for stroke prophylaxis in patients with AF, there is an increased interest in the safety and efficacy of uninterrupted apixaban therapy during AF ablation. We compared the safety and efficacy of uninterrupted OA therapy with either warfarin or apixaban in all patients who underwent catheter-based AF ablation at the University of Alabama at Birmingham and at Augusta University Medical Center from January 7, 2013, to February 25, 2016. All patients underwent a transesophageal echocardiogram on the day of their ablation to assess for the presence of intracardiac thrombi. All complications were identified and classified as bleeding, thromboembolic events, or other. A total of 627 patients were analyzed as described earlier. There were 310 patients in the warfarin group and 317 patients in the apixaban group. There were 8 complications in the warfarin group and 5 complications in the apixaban group (p = 0.38). There were no thromboembolic complications in either group. In conclusion, the use of apixaban is as safe and effective as warfarin for uninterrupted OA therapy during catheter-based ablation of AF. Copyright © 2017 Elsevier Inc. All rights reserved.

Arrhythmia Termination Versus Elimination of Dormant Pulmonary Vein Conduction as a Procedural End Point of Catheter Ablation for Paroxysmal Atrial Fibrillation: A Prospective Randomized Trial.

PubMed

Theis, Cathrin; Konrad, Torsten; Mollnau, Hanke; Sonnenschein, Sebastian; Kämpfner, Denise; Potstawa, Maik; Ocete, Blanca Quesada; Bock, Karsten; Himmrich, Ewald; Münzel, Thomas; Rostock, Thomas

2015-10-01

Pulmonary vein isolation (PVI) is still associated with a substantial number of arrhythmia recurrences in paroxysmal atrial fibrillation (AF). This prospective, randomized study aimed to compare 2 different procedural strategies. A total of 152 patients undergoing de novo ablation for paroxysmal AF were randomized to 2 different treatment arms. The procedure in group A consisted of PVI exclusively. In this group, all isolated PVs were challenged with adenosine to reveal and ablate dormant conduction. In group B, PVI was performed with the patient either in spontaneous or in induced AF. If AF did not terminate with PVI, ablation was continued by targeting extra-PV AF sources with the desired procedural end point of termination to sinus rhythm. Primary study end point was freedom from arrhythmia during 1-year follow-up. In group A, adenosine provoked dormant conduction in 31 (41%) patients with a mean of 1.6±0.8 transiently recovered PVs per patient. Termination of AF during PVI was observed in 31 (65%) patients, whereas AF persisted afterward in 17 (35%) patients. AF termination occurred in 13 (76%) patients by AF source ablation. After 1-year follow-up, significantly more group B patients were free of arrhythmia recurrences (87 versus 68%; P=0.006). During redo ablation, the rate of PV reconduction did not differ between both groups (group A: 55% versus group B: 61%; P=0.25). Elimination of extra-PV AF sources after PVI is superior to sole PV isolation with the adjunct of abolishing potential dormant conduction. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02238392. © 2015 The Authors.

Termination of persistent atrial fibrillation during pulmonary vein isolation: insight from the MAGIC-AF trial.

PubMed

Singh, Sheldon M; d'Avila, Andre; Kim, Young-Hoon; Aryana, Arash; Mangrum, J Michael; Michaud, Gregory F; Dukkipati, Srinivas R; Barrett, Conor D; Heist, E Kevin; Parides, Michael K; Thorpe, Kevin E; Reddy, Vivek Y

2017-10-01

Controversy on the optimal ablation strategy for persistent atrial fibrillation (AF) exists with limited work evaluating a strategy of pulmonary vein isolation (PVI) alone when AF terminates during PVI. Thirty-five patients had AF termination during PVI in the Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF; ClinicalTrials.gov number: NCT01014741) study. The objective of the current study is to report the 1-year outcome after PVI alone in this unique patient group. The 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs was reported for the 35 patients in the MAGIC-AF study with persistent AF termination during or upon completion of PVI. Freedom from recurrent atrial arrhythmia was achieved in 60% of patients where AF terminated during PVI. Cavotricuspid isthmus flutter was common when AF terminated to a macro re-entrant flutter during PVI, and responsible for 92% of all flutter circuits with AF termination. Persistent AF termination during PVI may identify a subgroup of patients who experience a similar long-term clinical outcome with PVI ablation alone when compared with other more extensive persistent AF ablation strategies. Pulmonary vein isolation alone may be an appropriate tactic in this subgroup of persistent AF patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Impact of acute atrial fibrillation termination and prolongation of atrial fibrillation cycle length on the outcome of ablation of persistent atrial fibrillation: A substudy of the STAR AF II trial.

PubMed

Kochhäuser, Simon; Jiang, Chen-Yang; Betts, Timothy R; Chen, Jian; Deisenhofer, Isabel; Mantovan, Roberto; Macle, Laurent; Morillo, Carlos A; Haverkamp, Wilhelm; Weerasooriya, Rukshen; Albenque, Jean-Paul; Nardi, Stefano; Menardi, Endrj; Novak, Paul; Sanders, Prashanthan; Verma, Atul

2017-04-01

Controversy exists about the impact of acute atrial fibrillation (AF) termination and prolongation of atrial fibrillation cycle length (AFCL) during ablation on long-term procedural outcome. The purpose of this study was to analyze the influence of AF termination and AFCL prolongation on freedom from AF in patients from the STAR AF II (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial-Part II) trial. Acute changes in AFCL and AF termination were collected during the index procedure of the STAR AF II trial and compared to recurrence of AF at 18 months. Recurrence was assessed by ECG, Holter (3, 6, 9, 12, 18 months), and weekly transtelephonic ECG monitoring for 18 months. AF terminated in 8% of the pulmonary vein isolation (PVI) arm, 45% in the PVI+complex electrogram arm, and 22% of the PVI+linear ablation arm (P <.001), but freedom from AF did not differ among the 3 groups (P = .15). Freedom from AF was significantly higher in patients who presented to the laboratory in sinus rhythm (SR) compared to those without AF termination (63% vs 44%, P = .007). Patients with AF termination had an intermediate outcome (53%) that was not significantly different from those in SR (P = .84) or those who did not terminate (P = .08). AF termination was a univariable predictor of success (P = .007), but by multivariable analysis, presence of early SR was the strongest predictor of success (hazard ratio 0.67, P = .004). Prolongation of AFCL was not predictive of 18-month freedom from AF. Acute AF termination and prolongation in AFCL did not consistently predict 18-month freedom from AF. Presence of SR before or early during the ablation was the strongest predictor of better outcome. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Comparison of treatment outcomes between convergent procedure and catheter ablation for paroxysmal atrial fibrillation evaluated with implantable loop recorder monitoring.

PubMed

Jan, Matevž; Žižek, David; Geršak, Živa Miriam; Geršak, Borut

2018-05-03

While catheter ablation (CA) is an established treatment for symptomatic paroxysmal atrial fibrillation (AF), convergent epicardial and endocardial ablation procedure (CVP) has been primarily used to treat persistent AF. The aim of this single-center, prospective, randomized study was to compare treatment efficacy of CA and CVP in paroxysmal AF patients by monitoring AF, atrial tachycardia (AT), and atrial flutter (AFL) recurrence with Implantable Loop Recorder (ILR). Fifty patients (74% male) with history of paroxysmal AF were randomized between CA and CVP. Outcomes were determined by ILRs; every episode of AF/AT/AFL lasting 6 minutes or more was defined as a recurrence. AF burden (AFB) and required AF reinterventions (cardioversions and repeat ablations) were quantified after a 3-month blanking period. Total procedural (266 ± 44 vs. 242 ± 39 minutes) and ablation duration (52 ± 10 vs. 48 ± 12 minutes) was similar in both groups. Recurrence of AF/AT/AFL was more likely in the CA group compared to the CVP group (OR 3.78 (95% CI (1.17, 12.19), P  =  0.048)). During the follow-up period (mean 30.5 ± 6.9 months), higher AF burden and more reinterventions for recurrent AF were recorded in the CA group. There were more periprocedural complications in the CVP group (12.5%) compared to the CA group (0%). Treatment of paroxysmal AF with CVP showed less arrhythmia recurrence compared to CA. In addition, patients after CVP had fewer reinterventions and lower AF burden, but more periprocedural complications. © 2018 Wiley Periodicals, Inc.

Novel Percutaneous Epicardial Autonomic Modulation in the Canine for Atrial Fibrillation: Results of an Efficacy and Safety Study

PubMed Central

Madhavan, Malini; Venkatachalam, K. L.; Swale, Matthew J.; DeSimone, Christopher V.; Gard, Joseph J.; Johnson, Susan B.; Suddendorf, Scott H.; Mikell, Susan B.; Ladewig, Dorothy J.; Nosbush, Toni Grabinger; Danielsen, Andrew J.; Knudson, Mark; Asirvatham, Samuel J.

2016-01-01

Background Endocardial ablation of atrial ganglionated plexi (GP) has been described for treatment of atrial fibrillation (AF). Our objective in this study was to develop percutaneous epicardial GP ablation in a canine model using novel energy sources and catheters. Methods Phase 1: The efficacy of several modalities to ablate the GP was tested in an open chest canine model (n=10). Phase 2: Percutaneous epicardial ablation of GP was done in 6 dogs using the most efficacious modality identified in phase 1 using 2 novel catheters. Results Phase 1: DC in varying doses [blocking (7 -12μA), electroporation (300-500μA), ablation (3000- 7500μA)], radiofrequency ablation (25–50 W), ultrasound (1.5MHz), and alcohol (2-5ml) injection were successful at 0/8, 4/12, 5/7, 3/8, 1/5 and 5/7 GP sites. DC (500–5000μA) along with alcohol irrigation was tested in phase 2. Phase 2: Percutaneous epicardial ablation of the right atrium, oblique sinus, vein of Marshall, and transverse sinus GP was successful in 5/6 dogs. One dog died of ventricular fibrillation (VF) during DC ablation at 5000 μA. Programmed stimulation induced AF in 6 dogs pre-ablation and no atrial arrhythmia in 3, flutter in 1 and AF in 1 post-ablation. Heart rate, blood pressure, effective atrial refractory period and local atrial electrogram amplitude did not change significantly post-ablation. Microscopic examination showed elimination of GP, and minimal injury to atrial myocardium. Conclusion Percutaneous epicardial ablation of GP using direct current and novel catheters is safe and feasible and may be used as an adjunct to pulmonary vein isolation in the treatment of atrial fibrillation in order to minimize additional atrial myocardial ablation. PMID:26854009

Outcomes after cryoablation vs. radiofrequency in patients with paroxysmal atrial fibrillation: impact of pulmonary veins anatomy.

PubMed

Khoueiry, Z; Albenque, J-P; Providencia, R; Combes, S; Combes, N; Jourda, F; Sousa, P A; Cardin, C; Pasquie, J-L; Cung, T T; Massin, F; Marijon, E; Boveda, S

2016-09-01

Pulmonary vein isolation is the mainstay of treatment in catheter ablation of paroxysmal atrial fibrillation (AF). Cryoballoon ablation has been introduced more recently than radiofrequency ablation, the standard technique in most centres. Pulmonary veins frequently display anatomical variants, which may compromise the results of cryoballoon ablation. We aimed to evaluate the mid-term outcomes of cryoballoon ablation in an unselected population with paroxysmal AF from an anatomical viewpoint. Consecutive patients with paroxysmal AF who underwent a first procedure of cryoballoon ablation or radiofrequency were enrolled in this single-centre study. All patients underwent systematic standardized follow-up. Comparisons between radiofrequency and cryoballoon ablation (Arctic Front™ or Arctic Front Advance™) were performed regarding safety and efficacy endpoints, according to pulmonary vein (PV) anatomical variants. A total of 687 patients were enrolled (376 radiofrequency and 311 cryoballoon ablation). Baseline characteristics and distribution of PV anatomical variants were generally similar in the groups. After a mean follow-up of 14 ± 8 months, there was no difference in the incidence of relapse (17.0% cryoballoon ablation vs. 14.1% radiofrequency, P = 0.25). We observed no interaction of PV anatomical variants on mid-term procedural success. Our findings suggest that mid-term outcomes of cryoballoon ablation for paroxysmal AF ablation are similar to those of radiofrequency, regardless of PV anatomy. The presence of anatomical variants of PVs should not discourage the referral of patients with paroxysmal AF for cryoballoon ablation. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

The modified stepwise ablation guided by low-dose ibutilide in chronic atrial fibrillation trial (The MAGIC-AF Study).

PubMed

Singh, Sheldon M; d'Avila, Andre; Kim, Young-Hoon; Aryana, Arash; Mangrum, J Michael; Michaud, Gregory F; Dukkipati, Srinivas R; Barrett, Conor D; Heist, E Kevin; Parides, Michael K; Thorpe, Kevin E; Reddy, Vivek Y

2016-05-21

Complex fractionated atrial electrograms (CFAE) are targeted during persistent atrial fibrillation (AF) ablation. However, many CFAE sites are non-specific resulting in extensive ablation. Ibutilide has been shown to reduce left atrial surface area exhibiting CFAE. We hypothesized that ibutilide administration prior to CFAE ablation would identify sites critical for persistent AF maintenance allowing for improved procedural efficacy and long-term freedom from atrial arrhythmias. Two hundred patients undergoing a first-ever persistent AF catheter ablation procedure were randomly assigned to receive either 0.25 mg of intravenous ibutilide or saline placebo upon completion of pulmonary vein isolation. Complex fractionated atrial electrogram sites were then targeted with ablation. The primary efficacy endpoint was the 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs. Similar procedural characteristics (procedure, fluoroscopy, and ablation times) were observed with both strategies despite a greater reduction in left atrial surface area with CFAE sites (8 vs. 1%, P < 0.0001) and AF termination during CFAE ablation with ibutilide compared with placebo (75 vs. 57%, P = 0.007). The primary efficacy endpoint was achieved in 56% of patients receiving ibutilide and 49% receiving placebo (P = 0.35). No significant differences in peri-procedural complications were observed in both groups. Despite a reduction in CFAE area and greater AF termination during CFAE ablation, procedural characteristics and clinical outcomes were unchanged when CFAE ablation was guided by ibutilide administration. ClinicalTrials.gov number: NCT01014741. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Real-time dominant frequency mapping and ablation of dominant frequency sites in atrial fibrillation with left-to-right frequency gradients predicts long-term maintenance of sinus rhythm.

PubMed

Atienza, Felipe; Almendral, Jesús; Jalife, José; Zlochiver, Sharon; Ploutz-Snyder, Robert; Torrecilla, Esteban G; Arenal, Angel; Kalifa, Jérôme; Fernández-Avilés, Francisco; Berenfeld, Omer

2009-01-01

Spectral analysis identifies localized sites of high-frequency activity during atrial fibrillation (AF). This study sought to determine the effectiveness of using real-time dominant frequency (DF) mapping for radiofrequency ablation of maximal DF (DFmax) sites and elimination of left-to-right frequency gradients in the long-term maintenance of sinus rhythm (SR) in AF patients. DF mapping was performed in 50 patients during ongoing AF (32 paroxysmal, 18 persistent), acquiring a mean of 117 +/- 38 points. Ablation was performed targeting DFmax sites, followed by circumferential pulmonary vein isolation. Ablation significantly reduced DFs (Hz) in the LA (7.9 +/- 1.4 vs. 5.7 +/- 1.3, P <.001), coronary sinus (CS) (5.7 +/- 1.1 vs. 5.3 +/- 1.2, P = .006), and RA (6.3 +/- 1.4 vs. 5.4 +/- 1.3, P <.001) abolishing baseline left-to-right atrial DF gradient (1.7 +/- 1.7 vs. 0.2 +/- 0.9; P <.001). Only a significant reduction in DFs in all chambers with a loss of the left-to-right atrial gradient after ablation was associated with a higher probability of long-term SR maintenance in both paroxysmal and persistent AF patients. After a mean follow-up of 9.3 +/- 5.4 months, 88% of paroxysmal and 56% of persistent AF patients were free of AF (P = .02). Ablation of DFmax sites was associated with a higher probability of remaining both free of arrhythmias (78% vs. 20%; P = .001) and free of AF (88% vs. 30%; P <.001). Radiofrequency ablation leading to elimination of LA-to-RA frequency gradients predicts long-term SR maintenance in AF patients.

Remote magnetic navigation in atrial fibrillation.

PubMed

Szili-Torok, Tamas; Akca, Ferdi

2012-05-01

Atrial fibrillation (AF) is of profound public health importance and is largely a disease of aging and is responsible for increased morbidity- and mortality-related healthcare expenditures. Catheter ablation to isolate the pulmonary veins has become the therapy of choice for treatment of drug-refractory AF. Procedures can be very challenging and multiple difficulties must be overcome in order to achieve a successful outcome. The magnetic navigation system (MNS) has advantages in catheter maneuverability, stability and reproducibility. Due to the catheter design safety and efficacy of AF, ablation has increased. New developments are being made to allow fully remote ablation procedures in combination with the MNS. However, new technologies are still necessary to improve MNS ablation for AF.

Catheter Ablation of Atrial Fibrillation in Patients with Hardware in the Heart - Septal Closure Devices, Mechanical Valves and More.

PubMed

Bartoletti, Stefano; Santangeli, Pasquale; DI Biase, Luigi; Natale, Andrea

2013-01-01

Patients with mechanical "hardware" in the heart, such as those with mechanical cardiac valves or atrial septal closure devices, represent a population at high risk of developing AF. Catheter ablation of AF in these subjects might represent a challenge, due to the perceived higher risk of complications associated with the presence of intracardiac mechanical devices. Accordingly, such patients were excluded or poorly represented in major trials proving the benefit of catheter ablation for the rhythm-control of AF. However, recent evidence supports the concept that catheter ablation procedures might be equally effective in these patients, without a significant increase in the risk of procedural complications. This review will summarize the current state-of-the-art on catheter ablation of AF in patients with mechanical "hardware" in the heart.

Electrophysiological Rotor Ablation in In-Silico Modeling of Atrial Fibrillation: Comparisons with Dominant Frequency, Shannon Entropy, and Phase Singularity.

PubMed

Hwang, Minki; Song, Jun-Seop; Lee, Young-Seon; Li, Changyong; Shim, Eun Bo; Pak, Hui-Nam

2016-01-01

Although rotors have been considered among the drivers of atrial fibrillation (AF), the rotor definition is inconsistent. We evaluated the nature of rotors in 2D and 3D in- silico models of persistent AF (PeAF) by analyzing phase singularity (PS), dominant frequency (DF), Shannon entropy (ShEn), and complex fractionated atrial electrogram cycle length (CFAE-CL) and their ablation. Mother rotor was spatiotemporally defined as stationary reentries with a meandering tip remaining within half the wavelength and lasting longer than 5 s. We generated 2D- and 3D-maps of the PS, DF, ShEn, and CFAE-CL during AF. The spatial correlations and ablation outcomes targeting each parameter were analyzed. 1. In the 2D PeAF model, we observed a mother rotor that matched relatively well with DF (>9 Hz, 71.0%, p<0.001), ShEn (upper 2.5%, 33.2%, p<0.001), and CFAE-CL (lower 2.5%, 23.7%, p<0.001). 2. The 3D-PeAF model also showed mother rotors that had spatial correlations with DF (>5.5 Hz, 39.7%, p<0.001), ShEn (upper 8.5%, 15.1%, p <0.001), and CFAE (lower 8.5%, 8.0%, p = 0.002). 3. In both the 2D and 3D models, virtual ablation targeting the upper 5% of the DF terminated AF within 20 s, but not the ablations based on long-lasting PS, high ShEn area, or lower CFAE-CL area. Mother rotors were observed in both 2D and 3D human AF models. Rotor locations were well represented by DF, and their virtual ablation altered wave dynamics and terminated AF.

[Electrophysiological findings and ablation strategies in patients with atrial tachyarrhythmias after left atrial circumferential ablation in the treatment of atrial fibrillation].

PubMed

Chen, Ming-long; Yang, Bing; Xu, Dong-jie; Zou, Jian-gang; Shan, Qi-jun; Chen, Chun; Chen, Hong-wu; Li, Wen-qi; Cao, Ke-jiang

2007-02-01

To report the electrophysiological findings and the ablation strategies in patients with atrial tachyarrhythmias (ATAs) or atrial fibrillation (AF) recurrence after left atrial circumferential ablation (LACA) in the treatment of AF. 91 patients with AF had LACA procedure from April 2004 to May 2006, 19 of which accepted the second ablation procedure due to ATAs or AF recurrence. In all the 19 patients [17 male, 2 female, age 25 - 65 (53 +/- 12) years], 11 presented with paroxysmal AF before the first ablation procedure, 2 with persistent AF and 6 with permanent AF. Pulmonary vein potentials (PVP) were investigated in both sides in all the patients. Delayed PVP was identified inside the left circular line in 5 patients, in the right in 1 and both in 2 during sinus rhythm. "Gap" conduction was found and successfully closed guided by circular mapping catheter. In 3 cases, irregular left atrial tachycardia was caused by fibrillation rhythm inside the left ring via decremental "gap" conduction. Reisolation was done successfully again guided by 3-D mapping and made the left atrium in sinus rhythm but the fibrillation rhythm was still inside the left ring. Pulmonary vein tachycardia with 1:1 conduction to the left atrium presented in one case and reisolation stopped the tachycardia. No PVP was discovered in both sides in 4 patients but other tachycardias could be induced, including two right atrial scar related tachycardias, two supraventricular tachycardias mediated by concealed accessory pathway, one cavo-tricuspid isthmus dependent atrial flutter and one focal atrial tachycardia near the coronary sinus ostium. All the tachycardias in these 4 patients were successfully ablated with the help of routine and 3-D mapping techniques. In the rest 3, which were in AF rhythm, LACA was successfully done again. After a mean follow-up of 4 - 26 (11.5 +/- 8.5) months, 16 patients were symptom free without anti-arrhythmic drug therapy; 1 of them had frequent palpitation attack with Holter recording of atrial premature contractions; 2 of them with permanent AF became paroxysmal in one, and still in AF in the other. Reconduction between the left atrium and the pulmonary veins is the dominant factor for post-LACA ATAs and AF recurrence. Other forms of atrial tachycardias or supraventricular tachycardias may coexist with AF or sometimes trigger AF. LACA can not sufficiently modify AF substrate in some permanent AF patients.

Isolation of canine coronary sinus musculature from the atria by radiofrequency catheter ablation prevents induction of atrial fibrillation.

PubMed

Morita, Hiroshi; Zipes, Douglas P; Morita, Shiho T; Wu, Jiashin

2014-12-01

The junction between the coronary sinus (CS) musculature and both atria contributes to initiation of atrial tachyarrhythmias. The current study investigated the effects of CS isolation from the atria by radiofrequency catheter ablation on the induction and maintenance of atrial fibrillation (AF). Using an optical mapping system, we mapped action potentials at 256 surface sites in 17 isolated and arterially perfused canine atrial tissues containing the entire musculature of the CS, right atrial septum, posterior left atrium, left inferior pulmonary vein, and vein of Marshal. Rapid pacing from each site before and after addition of acetylcholine (0.5 μmol/L) was applied to induce AF. Epicardial radiofrequency catheter ablation at CS-atrial junctions isolated the CS from the atria. Rapid pacing induced sustained AF in all tissues after acetylcholine. Microreentry within the CS drove AF in 88% of preparations. Reentries associated with the vein of Marshall (29%), CS-atrial junctions (53%), right atrium (65%), and pulmonary vein (76%) (frequently with 2-4 simultaneous circuits) were additional drivers of AF. Radiofrequency catheter ablation eliminated AF in 13 tissues before acetylcholine (P<0.01) and in 5 tissues after acetylcholine. Radiofrequency catheter ablation also abbreviated the duration of AF in 12 tissues (P<0.01). CS and its musculature developed unstable reentry and AF, which were prevented by isolation of CS musculature from atrial tissue. The results suggest that CS can be a substrate of recurrent AF in patients after pulmonary vein isolation and that CS isolation might help prevent recurrent AF. © 2014 American Heart Association, Inc.

Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation Are Sufficient to Achieve Favorable Long-Term Outcomes Including Transformation to Paroxysmal Arrhythmias in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation.

PubMed

Liang, Jackson J; Elafros, Melissa A; Muser, Daniele; Pathak, Rajeev K; Santangeli, Pasquale; Zado, Erica S; Frankel, David S; Supple, Gregory E; Schaller, Robert D; Deo, Rajat; Garcia, Fermin C; Lin, David; Hutchinson, Mathew D; Riley, Michael P; Callans, David J; Marchlinski, Francis E; Dixit, Sanjay

2016-11-01

Transformation from persistent to paroxysmal atrial fibrillation (AF) after ablation suggests modification of the underlying substrate. We examined the nature of initial arrhythmia recurrence in patients with nonparoxysmal AF undergoing antral pulmonary vein isolation and nonpulmonary vein trigger ablation and correlated recurrence type with long-term ablation efficacy after the last procedure. Three hundred and seventeen consecutive patients with persistent (n=200) and long-standing persistent (n=117) AF undergoing first ablation were included. AF recurrence was defined as early (≤6 weeks) or late (>6 weeks after ablation) and paroxysmal (either spontaneous conversion or treated with cardioversion ≤7 days) or persistent (lasting >7 days). During median follow-up of 29.8 (interquartile range: 14.8-49.9) months, 221 patients had ≥1 recurrence. Initial recurrence was paroxysmal in 169 patients (76%) and persistent in 52 patients (24%). Patients experiencing paroxysmal (versus persistent) initial recurrence were more likely to achieve long-term freedom off antiarrhythmic drugs (hazard ratio, 2.2; 95% confidence interval, 1.5-3.2; P<0.0001), freedom on/off antiarrhythmic drugs (hazard ratio, 2.5; 95% confidence interval, 1.6-3.8; P<0.0001), and arrhythmia control (hazard ratio, 5.2; 95% confidence interval, 2.9-9.2; P<0.0001) after last ablation. In patients with persistent and long-standing persistent AF, limited ablation targeting pulmonary veins and documented nonpulmonary vein triggers improves the maintenance of sinus rhythm and reverses disease progression. Transformation to paroxysmal AF after initial ablation may be a step toward long-term freedom from recurrent arrhythmia. © 2016 American Heart Association, Inc.

Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter.

PubMed

Golden, Keith; Mounsey, John Paul; Chung, Eugene; Roomiani, Pahresah; Morse, Michael Andew; Patel, Ankit; Gehi, Anil

2012-05-01

Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open-irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed-irrigated RF catheters create equivalent lesions, but clinical outcomes are limited. A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed-irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan-Meier survival analysis and Cox proportional hazards models. Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow-up was 55.8 weeks. Overall event-free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow-up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1-4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1-6.9, P = 0.038). Our study represents the largest cohort of patients receiving AFA with closed-irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open-irrigation ablation catheters. Given the theoretical benefits of a closed-irrigation system, a large head-to-head comparison using this catheter is warranted. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Left Atrial Size and Left Ventricular End-Systolic Dimension Predict the Progression of Paroxysmal Atrial Fibrillation After Catheter Ablation.

PubMed

Liao, Ying-Chieh; Liao, Jo-Nan; Lo, Li-Wei; Lin, Yenn-Jiang; Chang, Shih-Lin; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Tuan, Ta-Chuan; Te, Abigail Louise D; Walia, Rohit; Yamada, Shinya; Lin, Chung-Hsing; Lin, Chin-Yu; Chang, Yao-Ting; Allamsetty, Suresh; Yu, Wen-Chung; Huang, Jing-Long; Wu, Tsu-Juey; Chen, Shih-Ann

2017-01-01

Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months' follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02-1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03-1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients. © 2016 Wiley Periodicals, Inc.

The Effect of Atrial Fibrillation Ablation Techniques on P Wave Duration and P Wave Dispersion.

PubMed

Furniss, Guy O; Panagopoulos, Dimitrios; Kanoun, Sadeek; Davies, Edward J; Tomlinson, David R; Haywood, Guy A

2018-02-14

A reduction in surface electrocardiogram (ECG) P wave duration and dispersion is associated with improved outcomes in atrial fibrillation ablation. We investigated the effects of different ablation strategies on P wave duration and dispersion, hypothesising that extensive left atrial (LA) ablation with left atrial posterior wall isolation would give a greater reduction in P wave duration than more limited ablation techniques. A retrospective analysis of ECGs from patients who have undergone atrial fibrillation (AF) ablation was performed and pre-procedural sinus rhythm ECGs were compared with the post procedure ECGs. Maximal P wave duration was measured in leads I or II, minimum P wave duration in any lead and values were calculated for P wave duration and dispersion. Left atrial dimensions and medications at the time of ECG were documented. Ablation strategies compared were; pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) and the persistent AF (PsAF) ablation strategies of pulmonary vein isolation plus additional linear lesions (Lines), left atrial posterior wall isolation via catheter (PWI) and left atrial posterior wall isolation via staged surgical and catheter ablation (Hybrid). Sixty-nine patients' ECGs were analysed: 19 PVI, 21 Lines, 14 PWI, 15 Hybrid. Little correlation was seen between pre-procedure left atrial size and P wave duration (r=0.24) but LA size and P wave duration was larger in PsAF patients. A significant difference was seen in P wave reduction driven by Hybrid AF ablation (p<0.005) and Lines (<0.02). There was no difference amongst P wave dispersion between groups but the largest reduction was seen in the Hybrid ablation group. P wave duration increased with duration of continuous atrial fibrillation. Hybrid AF ablation significantly reduced P wave duration and dispersion compared to other ablation strategies including posterior wall isolation via catheter despite this being the same lesion set. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Long-term outcomes of the current remote magnetic catheter navigation technique for ablation of atrial fibrillation.

PubMed

Yuan, Shiwen; Holmqvist, Fredrik; Kongstad, Ole; Jensen, Steen M; Wang, Lingwei; Ljungström, Erik; Hertervig, Eva; Borgquist, Rasmus

2017-12-01

Comparisons between remote magnetic (RMN) and manual catheter navigation for atrial fibrillation (AF) ablation have earlier been reported with controversial results. However, these reports were based on earlier generations of the RMN system. To evaluate the outcomes of the most current RMN system for AF ablation in a larger patient population with longer follow-up time, 112 patients with AF (78 paroxysmal, 34 persistent) who underwent AF ablation utilizing RMN (RMN group) were compared to 102 AF ablation patients (72 paroxysmal, 30 persistent) utilizing manual technique (Manual group). The RMN group was associated with significantly shorter fluoroscopy time (10.4 ± 6.4 vs. 16.3 ± 10.9 min, p < .001) but used more RF energy (64.1 ± 19.4KJ vs. 54.3 ± 24.1 KJ, p < .05), while total procedure time showed no significant difference (201 ± 35 vs. 196 ± 44 min, NS). After 39 ± 9/44 ± 10 months of follow-up, AF-free rates at 1year, 2 years and 3.5 years post ablation were 63%, 46% and 42% in the RMN group vs. 60%, 32% and 30% (survival analysis p < .05) in the Manual group, whereas clinically effective rates were 82%, 73% and 70% for the former vs. 70%, 56% and 49% for the latter (survival analysis p < .005). Differing from previous reports, our data from a larger patient population and longer follow-up time demonstrates that compared to manual technique, the most current RMN technique is associated with better procedural and clinical outcomes for AF ablation.

Comparisons of the underlying mechanisms of left atrial remodeling after repeat circumferential pulmonary vein isolation with or without additional left atrial linear ablation in patients with recurrent atrial fibrillation.

PubMed

Yang, Chia-Hung; Chou, Chung-Chuan; Hung, Kuo-Chun; Wen, Ming-Shien; Chang, Po-Cheng; Wo, Hung-Ta; Lee, Cheng-Hung; Lin, Fen-Chiung

2017-02-01

Radiofrequency catheter ablation (RFCA) is a potentially curative treatment for atrial fibrillation (AF), however, whether or not additional left atrial (LA) linear ablation for recurrent AF adversely affects LA remodeling is unknown. Thirty-eight patients experiencing AF recurrence after the 1st circumferential pulmonary vein isolation (CPVI) underwent a repeat RFCA, including 20 and 18 patients receiving a repeat CPVI (group I) or CPVI plus LA linear ablation (group II), respectively. 2-D echocardiography was performed during sinus rhythm within 24h, at 1-m and 6-m after RFCA. Longitudinal strains and strain rate were measured with speckle-tracking echocardiography. The standard deviation of contraction duration was defined as LA mechanical dispersion. One and two patients experienced AF recurrence after the 2nd RFCA in group I and II, respectively (P=NS). The 1st CPVI with AF recurrence did not reduce LA size significantly in two groups. After a repeat CPVI, LA diameter but not LA maximal and minimal volume was significantly reduced in group I; additional LA linear ablation significantly decreased LA diameter, maximal and minimal volume in group II. However, there was no significant difference in LA emptying function, global and segmental LA strain and strain rate among the baseline, 1-m and 6-m follow-up in two groups. RFCA did not significantly increase LA mechanical dispersion regardless of the AF ablation strategies. In patients with recurrent AF, a successful repeat CPVI with or without additional LA linear ablation reduced LA size without significant deleterious effects on LA function and mechanical dispersion. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Impact of a Novel Catheter Tracking System on Radiation Exposure during the Procedural Phases of Atrial Fibrillation and Flutter Ablation.

PubMed

Malliet, Nicolas; Andrade, Jason G; Khairy, Paul; Thanh, Hien Kiem Nguyen; Venier, Sandrine; Dubuc, Marc; Dyrda, Katia; Guerra, Peter; Mondésert, Blandine; Rivard, Léna; Tadros, Rafik; Talajic, Mario; Thibault, Bernard; Roy, Denis; Macle, Laurent

2015-07-01

Fluoroscopic guidance is used to position catheters during cardiac ablation. We evaluated the impact of a novel nonfluoroscopic sensor-guided electromagnetic navigation system (MG) on radiation exposure during catheter ablation of atrial fibrillation (AF) or atrial flutter (AFL). A total of 134 consecutive patients referred for ablation of AF (n = 44) or AFL (n = 90) ablation were prospectively enrolled. In one group the MG system was used for nonfluoroscopic catheter positioning, whereas in the conventional group standard fluoroscopy was utilized. Fluoroscopy times were assessed for each stage of procedure and total radiation exposure was quantified. Patient characteristics were similar between the groups. The procedural end point was achieved in all. Median (interquartile range [IQR]) fluoroscopy times were 12.5 minutes (7.6, 17.4) MG group versus 21.5 minutes (15.3, 23.0) conventional group (P < 0.0001) for AF ablation, and 0.8 minutes (0.4, 2.5) MG group versus 9.9 minutes (5.1, 22.5) conventional group (P < 0.0001) for AFL ablation. Median (IQR) total radiation exposure (μGy·m(2)) was 1,107 (906, 2,033) MG group versus 2,835 (1,688, 3,855) conventional group (P = 0.0001) for AF ablation, and 161 (65, 537) MG group versus 1,651 (796, 4,569) conventional group (P < 0.0001) for AFL ablation. No difference in total procedural time was seen. The use of a novel nonfluoroscopic catheter tracking system is associated with a significant reduction in radiation exposure during AF and AFL ablation (61% and 90% reduction, respectively). In the era of heightened awareness of the importance of radiation reduction, this system represents a safe and efficient tool to decrease radiation exposure during electrophysiological ablation procedures. ©2015 Wiley Periodicals, Inc.

Impact of obesity on atrial fibrillation ablation: Patient characteristics, long-term outcomes, and complications.

PubMed

Winkle, Roger A; Mead, R Hardwin; Engel, Gregory; Kong, Melissa H; Fleming, William; Salcedo, Jonathan; Patrawala, Rob A

2017-06-01

There is an association between obesity and atrial fibrillation (AF). The impact of obesity on AF ablation procedures is unclear. The purpose of this study was to evaluate the influence of body mass index (BMI) on patient characteristics, long-term ablation outcomes, and procedural complications. We evaluated 2715 patients undergoing 3742 AF ablation procedures. BMI was ≥30 kg/m 2 in 1058 (39%) and ≥40 kg/m 2 in 129 (4.8%). Patients were grouped by BMI ranges (<25, 25-<30, 30-<35, 35-<40, and ≥40 kg/m 2 ). As BMI increased from <25 to ≥40 kg/m 2 , age decreased from 65.3 ± 11.2 to 61.2 ± 9.2 years (P < .001), left atrial size increased from 3.91 ± 0.68 to 4.72 ± 0.62 cm (P < .005), and CHADS 2 scores increased from 1.24 ± 1.10 to 1.62 ± 1.09 (P < .001). As BMI increased, paroxysmal AF decreased from 48.0% to 16.3% (P < .0001) and there was an increase in dilated cardiomyopathy (from 7.6% to 12.4%; P < .0001), hypertension (from 41.0% to 72.9%; P < .0001), diabetes (from 4.3% to 23.3%; P < .0001), and sleep apnea (from 7.0% to 46.9%; P < .0001). For the entire cohort, for BMI ≥35 kg/m 2 the 5-year ablation freedom from AF decreased from 67%-72% to 57% (P = .036). For paroxysmal AF, when BMI was ≥40 kg/m 2 ablation success decreased from 79%-82% to 60% (P = .064), and for persistent AF, when BMI was ≥35 kg/m 2 ablation success decreased from 64%-70% to 52%-57% (P = .021). For long-standing AF, there was no impact of BMI on outcomes (P = .624). In multivariate analysis, BMI ≥35 kg/m 2 predicted worse outcomes (P = .036). Higher BMI did not impact major complication rates (P = .336). However, when BMI was ≥40 kg/m 2 , minor (from 2.1% to 4.4%; P = .035) and total (from 3.5% to 6.7%; P = .023) complications increased. In patients undergoing AF ablation, increasing BMI is associated with more patient comorbidities and more persistent and long-standing AF. BMI ≥35 kg/m 2 adversely impacts ablation outcomes, and BMI ≥40 kg/m 2 increases minor complications. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

History of hyperthyroidism and long-term outcome of catheter ablation of drug-refractory atrial fibrillation.

PubMed

Wongcharoen, Wanwarang; Lin, Yenn-Jiang; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chung, Fa-Po; Chong, Eric; Chao, Tze-Fan; Tuan, Ta-Chuan; Chang, Yao-Ting; Lin, Chin-Yu; Liao, Jo-Nan; Lin, Yi-Chun; Chen, Yun-Yu; Chen, Shih-Ann

2015-09-01

Hyperthyroidism is a known reversible cause of atrial fibrillation (AF). However, some patients remain in AF despite restoration of euthyroid status. The purpose of this study was to compare the electrophysiologic characteristics and long-term ablation outcome in AF patients with and without history of hyperthyroidism. The study enrolled 717 consecutive patients with AF who underwent first AF ablation, which involved pulmonary vein (PV) isolation in paroxysmal AF and additional substrate modification in nonparoxysmal AF patients. Eighty-four patients (12%) with hyperthyroidism history were compared to those without. Euthyroid status was achieved for ≥3 months before ablation in hyperthyroid patients. Patients with hyperthyroid history were associated with older age, more female gender, lower mean right atrial voltage, higher number of PV ectopic foci (1.3 ± 0.4 vs 1.0 ± 0.2, P < .01), and higher prevalence of non-PV foci (42% vs 23%, P < .01). Ectopic foci from ligament of Marshall were demonstrated more often in hyperthyroid patients (7.1% vs 1.6%, P < .01) in whom alcohol ablations were required. After propensity score matching for potential covariates, history of hyperthyroidism was an independent predictor of AF recurrence after single procedure (hazard ratio 2.07, 95% confidence interval 1.27-3.38). AF recurrence rates after multiple procedures were not different between patients with and those without hyperthyroid history. Patients with hyperthyroid history had a significantly higher number of PV ectopies and higher prevalence of non-PV ectopic foci compared to euthyroid patients, which resulted in a higher AF recurrence rate after a single procedure. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Assessment of Atrial Fibrillation and Vulnerability in Patients with Wolff-Parkinson-White Syndrome Using Two-Dimensional Speckle Tracking Echocardiography

PubMed Central

Li, Jing-Jie; Wei, Fang; Chen, Ju-Gang; Yu, Yan-Wei; Gu, Hong-Yue; Jiang, Rui; Wu, Xiu-Li; Sun, Qian

2014-01-01

Purpose The aim was to assess atrial fibrillation (AF) and vulnerability in Wolff-Parkinson-White (WPW) syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE). Methods All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. Results Results showed significant differences in both body mass index (BMI) and supraventricular tachycardia (SVT) duration between WPW patients and DAVNP patients (both P<0.05). Echocardiography revealed that the maximum left atrial volume (LAVmax) and the left ventricular mass index (LVMI) in diastole increased noticeably in patients with WPW compared to patients with DAVNP both before and after ablation (all P<0.05). Before ablation, there were obvious differences in the levels of SRs, SRe, and SRa from the 4-chamber view (LA) in the WPW patients group compared with patients in the DAVNP group (all P<0.05). In the AF group, there were significant differences in the levels of systolic strain rate (SRs), early diastolic strain rate (SRe), and late diastolic strain rate (SRa) from the 4-chamber view (LA) both before and after ablation (all P<0.05). In the non-AF group, there were decreased SRe levels from the 4-chamber view (LA/RA) pre-ablation compared to post-ablation (all P<0.05). Conclusion Our findings provide convincing evidence that WPW syndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period. PMID:25397668

Cost Analysis of Periprocedural Imaging in Patients Undergoing Catheter Ablation for Atrial Fibrillation

PubMed Central

Pokorney, Sean D.; Hammill, Bradley G.; Qualls, Laura G.; Steinberg, Benjamin A.; Curtis, Lesley H.; Piccini, Jonathan P.

2014-01-01

Cardiovascular imaging is an important part of procedural planning and safety for catheter ablation of atrial fibrillation (AF). However, the costs of imaging surrounding catheter ablation of AF have not been described. Medicare fee-for-service data were used to evaluate Medicare expenditures before, during, and after catheter ablation for AF from July 2007 to December 2009. Among 11,525 patients who underwent catheter ablation for AF, the mean overall expenditure on the day of the procedure was $14,455 (SD $7,441). The mean imaging expenditure in the periprocedural period, which included the 30 days before the catheter ablation and the day of the ablation itself, was $884 (SD $455). Periprocedural imaging expenditures varied by the imaging strategy used, ranging from a mean of $557 (SD $269) for patients with electroanatomic mapping only to $1,234 (SD $461) for patients with electroanatomic mapping, transesophageal echocardiogram, and computed tomography or magnetic resonance imaging. Mean patient-level imaging expenditures varied by provider (mean $872, SD $249). Periprocedural imaging expenditures also varied by patient risk, with mean expenditures of $862 (SD $444) for patients with a CHADS2 score of ≥2 compared with $907 (SD $466) for CHADS2 score <2 (p <0.001). In conclusion, peri-procedural imaging accounts for approximately 6% of mean Medicare expenditures for catheter ablation of AF. The expenditures for periprocedural imaging vary both at the patient and at the provider level and they are inversely related to stroke risk by CHADS2 score. PMID:24952929

Surgical RF ablation of atrial fibrillation in patients undergoing mitral valve repair for Barlow disease.

PubMed

Rostagno, Carlo; Droandi, G; Gelsomino, S; Carone, E; Gensini, G F; Stefàno, P L

2013-01-01

At present, limited experience exists on the treatment of atrial fibrillation (AF) in patients undergoing mitral valve repair (MVR) for Barlow disease. The aim of this investigation was to prospectively evaluate the radiofrequency ablation of AF in patients undergoing MVR for severe regurgitation due to Barlow disease. From January 1, 2007 to December 31, 2010, out of 85 consecutive patients with Barlow disease, 27 with AF underwent RF ablation associated with MVR. They were examined every 4 months in the first year after surgery and thereafter twice yearly. At follow-up, AF was observed in 4/25 (16.0%). NYHA (New York Heart Association) functional class improved significantly, with no patients in class III or IV (before surgery, 81.5% had been). Otherwise, among 58 patients in sinus rhythm, 6 (11%) developed AF during follow-up. No clinical or echocardiographic predictive factor was found in this subgroup. Results from our investigation suggest that radiofrequency ablation of AF in patients with Barlow disease undergoing MVR for severe regurgitation is effective and should be considered in every patient with Barlow disease and AF undergoing valve surgical repair. Copyright © 2013 S. Karger AG, Basel.

Long-term outcomes following high intensity focused ultrasound ablation for atrial fibrillation.

PubMed

Davies, Edward J; Bazerbashi, Samer; Asopa, Sanjay; Haywood, Guy; Dalrymple-Hay, Malcolm

2014-01-01

The aim of this study is to assess the safety and efficacy of the Epicor high intensity focused ultrasound (St. Jude, Inc.®, Minneapolis, MN, USA) system using seven-day ambulatory electrocardiogram (ECG) monitoring over a two-year follow-up period. One hundred and ten patients undergoing ablation were included from a single center between January 2006 and December 2009. Rhythm was assessed using seven-day ambulatory ECG or permanent pacemaker interrogation. Seventeen patients were lost to follow-up, seven through death. Results were reported according to atrial fibrillation (AF) class preoperatively: paroxysmal, persistent, and long-standing persistent (LSP). Forty-nine percent of patients remained in sinus rhythm at greater than two years. The percentage of patients in sinus rhythm according to preoperative AF class were 81% (paroxysmal AF), 56% (persistent AF), and 18% (long-standing AF). The class of AF prior to surgery, left atrium size, and body mass index determined the long-term outcome. There were no procedure-related complications. We conclude that high intensity focused ultrasound ablation for atrial fibrillation using the Epicor system is safe and effective for surgical patients with paroxysmal AF. The persistent and LSP AF results suggest that alternative ablation strategies should be considered for these patients. © 2013 Wiley Periodicals, Inc.

Apixaban versus Warfarin for the Prevention of Periprocedural Cerebral Thromboembolism in Atrial Fibrillation Ablation: Multicenter Prospective Randomized Study.

PubMed

Kuwahara, Taishi; Abe, Mitsunori; Yamaki, Masaru; Fujieda, Hiroyuki; Abe, Yumiko; Hashimoto, Katsushi; Ishiba, Misako; Sakai, Hirotsuka; Hishikari, Keiichi; Takigawa, Masateru; Okubo, Kenji; Takagi, Katsumasa; Tanaka, Yasuaki; Nakajima, Jun; Takahashi, Atsushi

2016-05-01

Stroke can be a life-threatening complication of atrial fibrillation (AF) catheter ablation. Uninterrupted warfarin treatment contributes to minimizing the risk of stroke complications. This was a prospective, open-label, randomized, multicenter study assessing the safety and efficacy of apixaban for the prevention of cerebral thromboembolism complicating AF catheter ablation. Two hundred patients with drug-resistant AF were equally assigned to take either apixaban (5 mg or 2.5 mg twice daily) or warfarin (target international normalized ratio, 2-3) for at least 1 month before AF ablation. Neither drug regimen was interrupted throughout the operative period. Diffusion-weighted magnetic resonance imaging was performed for all patients to detect silent cerebral infarction (SCI) after the ablation. Primary outcomes were defined as the occurrence of stroke, transient ischemic attack, SCI, or major bleeding that required intervention. The secondary outcome was minor bleeding. The groups did not statistically differ in patients' backgrounds or procedural parameters. During AF ablation, the apixaban group required administration of more heparin to maintain an activated clotting time > 300 seconds than the warfarin group (apixaban, 14,000 ± 4,000 units; warfarin, 9,000 ± 3,000 units). Three primary outcome events occurred in each group (apixaban, 2 SCI and 1 major bleed; warfarin, 3 SCI, P = 1.00), and 3 and 4 secondary outcome events occurred in the apixaban and warfarin groups (P = 0.70), respectively. Apixaban has similar safety and effectiveness to warfarin for the prevention of cerebral thromboembolism during the periprocedural period of AF ablation. © 2016 Wiley Periodicals, Inc.

Significant effects of atrioventricular node ablation and pacemaker implantation on left ventricular function and long-term survival in patients with atrial fibrillation and left ventricular dysfunction.

PubMed

Ozcan, Cevher; Jahangir, Arshad; Friedman, Paul A; Munger, Thomas M; Packer, Douglas L; Hodge, David O; Hayes, David L; Gersh, Bernard J; Hammill, Stephen C; Shen, Win-Kuang

2003-07-01

Control of ventricular rate by atrioventricular node ablation and pacemaker implantation in patients with drug-refractory atrial fibrillation (AF) is associated with improved left ventricular (LV) function. The objective of this study was to determine the effect of atrioventricular node ablation on long-term survival in patients with AF and LV dysfunction. Survival was determined by the Kaplan-Meier method for 56 study patients with LV ejection fraction (EF) < or =40% who underwent atrioventricular node ablation and pacemaker implantation and 56 age- and gender-matched control patients with AF and LVEF >40%, and age- and gender-matched control subjects from Minnesota. Groups were compared using the log-rank test. In study patients (age 69 +/- 10 years; 45 men), LVEF was 26% +/- 8% and 34% +/- 13% (p <0.001) before and after ablation, respectively. During follow-up (40 +/- 23 months), 23 patients died. Observed survival was worse than that of normal subjects (p <0.001) and control patients (p = 0.005). After ablation, LVEF nearly normalized (> or =45%) in 16 study patients (29%), in whom observed survival was comparable to that of normal subjects (p = 0.37). Coronary artery disease, hyperlipidemia, chronic renal failure, previous myocardial infarction, and coronary artery operation were independent predictors for mortality. Near normalization of LVEF occurred in 29% of study patients, suggesting that AF-induced EF reduction is reversible in many patients. Normal survival in patients with reversible LV dysfunction highlights potential survival benefits of rate control. Poor survival in patients with persistent LV dysfunction confirms the importance of optimal medical therapy.

Accuracy of Voltage Signal Measurement During Radiofrequency Delivery Through the SMARTTOUCH Catheter.

PubMed

Safavi-Naeini, Payam; Zafar-Awan, Dreema; Zhu, Hongjian; Zablah, Gerardo; Ganapathy, Anand V; Rasekh, Abdi; Saeed, Mohammad; Razavi, Joanna Esther Molina; Razavi, Mehdi

2017-01-01

Current methods for measuring voltage during radiofrequency (RF) ablation (RFA) necessitate turning off the ablation catheter. If voltage could be accurately read without signal attenuation during RFA, turning off the catheter would be unnecessary, allowing continuous ablation. We evaluated the accuracy of the Thermocool SMARTTOUCH catheter for measuring voltage while RF traverses the catheter. We studied 26 patients undergoing RFA for arrhythmias. A 7.5F SMARTTOUCH catheter was used for sensing voltage and performing RFA. Data were collected from the Carto-3 3-dimensional mapping system. Voltages were measured during ablation (RF-ON) and immediately before or after ablation (RF-OFF). In evaluating the accuracy of RF-ON measurements, we utilized the RF-OFF measure as the gold standard. We measured 465 voltage signals. The median values were 0.2900 and 0.3100 for RF-ON and RF-OFF, respectively. Wilcoxon signed rank testing showed no significant difference in these values (P = 0.608). The intraclass correlation coefficient (ICC) was 0.96, indicating that voltage measurements were similarly accurate during RF-OFF versus RF-ON. Five patients had baseline atrial fibrillation (AF), for whom 82 ablation points were measured; 383 additional ablation points were measured for the remaining patients. The voltages measured during RF-ON versus RF-OFF were similar in the presence of AF (P = 0.800) versus non-AF rhythm (P = 0.456) (ICC, 0.96 for both). Voltage signal measurement was similarly accurate during RF-ON versus RF-OFF independent of baseline rhythm. Physicians should consider not turning off the SMARTTOUCH ablation catheter when measuring voltage during RFA. © 2016 Wiley Periodicals, Inc.

Does a patent foramen ovale matter when using a remote-controlled magnetic system for pulmonary vein isolation?

PubMed

Gate-Martinet, Alexie; Da Costa, Antoine; Romeyer-Bouchard, Cécile; Bisch, Laurence; Levallois, Marie; Isaaz, Karl

2014-02-01

Pulmonary vein isolation (PVI) takes longer when using a patent foramen ovale (PFO) compared with a transseptal puncture in paroxysmal atrial fibrillation (AF) with manual catheter ablation. To our knowledge, no data exist concerning the impact of a PFO on AF ablation procedure variables when using a remote magnetic navigation (RMN) system. To assess the impact of a PFO when using an RMN system in patients requiring AF ablation. Between December 2011 and December 2012, catheter ablation was performed remotely using the CARTO(®) 3 system in 167 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35 W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation for all patients and including additional lesion lines (left atrial roof) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data. Mean age 58±10 years; 18% women; 107 (64%) patients with symptomatic paroxysmal AF; 60 (36%) with persistent AF; CHA2DS2-VASc score 1.2 ± 1. The PFO presence was evidenced in 49/167 (29.3%) patients during the procedure but in only 26/167 (16%) by transoesophageal echocardiography. Median procedure time 2.5 ± 1 hours; median total X-ray exposure time 14 ± 7 minutes; transseptal puncture and catheter positioning time 7.5 ± 5 minutes; left atrium electroanatomical reconstruction time 3 ± 2.3 minutes; catheter ablation time 3 ± 3 minutes. No procedure time or X-ray exposure differences were observed between patients with or without a PFO during magnetic navigation catheter ablation. X-ray exposure time was significantly reduced using a PFO compared with double transseptal puncture access. A PFO does not affect magnetic navigation during AF ablation; procedure times and X-ray exposure were similar. Septal catheter probing is mandatory to limit X-ray exposure and prevent potential complications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Pace-capture-guided ablation after contact-force-guided pulmonary vein isolation: results of the randomized controlled DRAGON trial.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Ohashi, Takuya; Uematsu, Masaaki

2017-11-17

Before the discovery of contact-force guidance, eliminating pacing capture along the pulmonary vein (PV) isolation line had been reported to improve PV isolation durability and rhythm outcomes. DRAGON (UMIN-CTR, UMIN000015332) aimed to elucidate the efficacy of pace-capture-guided ablation following contact-force-guided PV isolation ablation in paroxysmal atrial fibrillation (AF) patients. A total of 156 paroxysmal AF patients with AF-trigger ectopies from any of the four PVs induced by isoproterenol were randomly assigned to undergo pace-capture-guided ablation along a contact-force-guided isolation line around AF-trigger PVs (PC group, n = 76) or contact-force-guided PV isolation ablation alone (control group, n = 80). Follow-up of at least 1 year commenced with serial 24 h Holter and symptom-triggered ambulatory monitoring. There was no significant difference in acute PV reconnection rates during a 20 min waiting period after the last ablation or adenosine infusion testing between the PC and the control groups (per patient, 21% vs. 27%, P = 0.27; per AF-trigger PV, 5.9% vs. 7.3%, P = 0.70; and per non-AF-trigger PV, 7.1% vs. 7.4%, P = 0.92). Atrial tachyarrhythmia-free survival rates off antiarrhythmic drugs after the initial session were comparable at 19.3 ± 6.2 months between the two groups (82% vs. 80%, P = 0.80). Among 22 patients who required a second ablation procedure, there was no difference between the PC and the control groups in the PV reconnection rates at both previously AF-trigger (29% vs. 43%, P = 0.70) and non-AF-trigger PVs (18% vs. 19%, P = 0.88). Pace-capture-guided ablation performed after contact-force-guided PV isolation demonstrated no improvement in PV isolation durability or rhythm outcome. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Atrial fibrillation ablation using very short duration 50 W ablations and contact force sensing catheters.

PubMed

Winkle, Roger A; Moskovitz, Ryan; Hardwin Mead, R; Engel, Gregory; Kong, Melissa H; Fleming, William; Salcedo, Jonathan; Patrawala, Rob A; Tranter, John H; Shai, Isaac

2018-06-01

The optimal radiofrequency (RF) power and lesion duration using contact force (CF) sensing catheters for atrial fibrillation (AF) ablation are unknown. We evaluate 50 W RF power for very short durations using CF sensing catheters during AF ablation. We evaluated 51 patients with paroxysmal (n = 20) or persistent (n = 31) AF undergoing initial RF ablation. A total of 3961 50 W RF lesions were given (average 77.6 ± 19.1/patient) for an average duration of only 11.2 ± 3.7 s. As CF increased from < 10 to > 40 g, the RF application duration decreased from 13.7 ± 4.4 to 8.6 ± 2.5 s (p < 0.0005). Impedance drops occurred in all ablations, and for patients in sinus rhythm, there was loss of pacing capture during RF delivery suggesting lesion creation. Only 3% of the ablation lesions were at < 5 g and 1% at > 40 g of force. As CF increased, the force time integral (FTI) increased from 47 ± 24 to 376 ± 102 gs (p < 0.0005) and the lesion index (LSI) increased from 4.10 ± 0.51 to 7.63 ± 0.50 (p < 0.0005). Both procedure time (101 ± 19.7 min) and total RF energy time (895 ± 258 s) were very short. For paroxysmal AF, the single procedure freedom from AF was 86% at 1 and 2 years. For persistent AF, it was 83% at 1 year and 72% at 2 years. There were no complications. Short duration 50 W ablations using CF sensing catheters are safe and result in excellent long-term freedom from AF for both paroxysmal and persistent AF with short procedure times and small amounts of total RF energy delivery.

Biomarkers in Persistent AF and Heart Failure: Impact of Catheter Ablation Compared with Rate Control.

PubMed

Jones, David G; Haldar, Shouvik K; Donovan, Jacqueline; McDonagh, Theresa A; Sharma, Rakesh; Hussain, Wajid; Markides, Vias; Wong, Tom

2016-09-01

To investigate the effects of catheter ablation and rate control strategies on cardiac and inflammatory biomarkers in patients with heart failure and persistent atrial fibrillation (AF). Patients were recruited from the ARC-HF trial (catheter Ablation vs Rate Control for management of persistent AF in Heart Failure, NCT00878384), which compared ablation with rate control for persistent AF in heart failure. B-type natriuretic peptide (BNP), midregional proatrial natriuretic peptide (MR-proANP), apelin, and interleukin-6 (IL-6) were assayed at baseline, 3 months, 6 months, and 12 months. The primary end point, analyzed per-protocol, was changed from baseline at 12 months. Of 52 recruited patients, 24 ablation and 25 rate control subjects were followed to 12 months. After 1.2 ± 0.5 procedures, sinus rhythm was present in 22 (92%) ablation patients; under rate control, rate criteria were achieved in 23 (96%) of 24 patients remaining in AF. At 12 months, MR-proANP fell significantly in the ablation arm (-106.0 pmol/L, interquartile range [IQR] -228.2 to -60.6) compared with rate control (-28.7 pmol/L, IQR -69 to +9.5, P = 0.028). BNP showed a similar trend toward reduction (P = 0.051), with no significant difference in apelin (P = 0.13) or IL-6 (P = 0.68). Changes in MR-proANP and BNP correlated with peak VO2 and ejection fraction, and MR-proANP additionally with quality-of-life score. Catheter ablation, compared with rate control, in patients with heart failure and persistent AF was associated with significant reduction in MR-proANP, which correlated with physiological and symptomatic improvement. Ablation-based rhythm control may induce beneficial cardiac remodeling, unrelated to changes in inflammatory state. This may have prognostic implications, which require confirmation by event end point studies. © 2016 Wiley Periodicals, Inc.

Changes in Left Atrial Transport Function in Patients Who Maintained Sinus Rhythm After Successful Radiofrequency Catheter Ablation for Atrial Fibrillation: A 1-Year Follow-Up Multislice Computed Tomography Study.

PubMed

Kim, Jin-Seok; Im, Sung Il; Shin, Seung Yong; Kang, Jun Hyuk; Na, Jin Oh; Choi, Cheol Ung; Kim, Seong Hwan; Kim, Eung Ju; Rha, Seung-Woon; Park, Chang Gyu; Seo, Hong Seog; Oh, Dong Joo; Hwang, Chun; Kim, Young-Hoon; Yong, Hwan Seok; Lim, Hong Euy

2017-02-01

Functional remodeling of left atrium (LA) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has not been fully elucidated. This study aimed to determine the impact of RFCA on LA transport function in patients who maintained sinus rhythm (SR) after AF ablation. A total of 96 patients (paroxysmal AF [PAF] = 52) who maintained SR during 1 year after AF ablation were enrolled. Multislice computed tomography was performed to determine LA volume (LAV) and LA emptying fraction (LAEF) at pre-RFCA and 1-year post-RFCA. Creatine kinase-MB (CK-MB) and troponin-T levels were analyzed 1-day post-RFCA. At 1-year post-RFCA, mean LAV and LAEF decreased in overall patients. Based on LAEF change (ΔLAEF) cutoff of 5.0%, LAEF reduced in 41 patients (worsened group) and improved or showed no change in 55 patients (preserved group). Compared with preserved group, worsened group had a higher proportion of PAF, higher levels of CK-MB and troponin-T, and additional LA ablation. ΔLAEF was inversely correlated with CK-MB and troponin-T levels. Subgroup analysis showed that LAEF significantly decreased in PAF patients who underwent additional LA ablation. Multivariate analysis revealed that high baseline LAEF and additional LA ablation were independent predictors for worsened LAEF. Although SR was maintained for 1 year after AF ablation, LAEF as well as LAV decreased. The extent of LAEF deterioration was significantly associated with the amount of iatrogenic myocardial damage. Our data indicate that extensive atrial ablation may lead to LA functional deterioration, especially in patients with PAF. © 2016 Wiley Periodicals, Inc.

The role of adenosine challenge in catheter ablation for atrial fibrillation: A systematic review and meta-analysis.

PubMed

McLellan, Alex J A; Kumar, Saurabh; Smith, Catherine; Ling, Liang-Han; Prabhu, Sandeep; Kalman, Jonathan M; Kistler, Peter M

2017-06-01

Adenosine may unmask dormant PV conduction and facilitate consolidation of PV isolation. We performed a meta-analysis to determine the impact of adenosine administration on clinical outcomes in patients undergoing PVI. References and electronic databases reporting AF ablation and adenosine following PVI were searched through to 22nd November 2015. The impact of adenosine on freedom from AF was assessed in twenty publications after radiofrequency ablation (RFA), and in four publications after cryoablation to achieve PVI. Relative risks were calculated and combined in a meta-analysis using random effects modeling. In patients undergoing RFA with adenosine challenge, there was a significant reduction in freedom from AF in patients with versus without adenosine induced reconnection (RR 0.86; 95%CI 0.77-0.98; p=0.02) particularly if no further ablation was performed (RR 0.66; 95%CI 0.50-0.87; p<0.01). There was no difference when comparing outcomes in studies of routine adenosine challenge vs no adenosine (RR 1.07; 95%CI 0.93-1.22; p=0.36). There was a non-significant trend to an increase in freedom from AF in patients receiving routine adenosine challenge (RR 1.18 95%CI 0.99-1.42; p=0.07) in non-randomized studies using cryoablation. Adenosine induced PV reconnection following PVI is associated with a significant increase in AF recurrence, particularly if the reconnection sites are not targeted for ablation. The routine use of adenosine may be beneficial in AF ablation if given early post-PVI, at sufficient dose and reconnection is ablated. Copyright © 2017 Elsevier B.V. All rights reserved.

Apixaban for periprocedural anticoagulation during catheter ablation of atrial fibrillation: a systematic review and meta-analysis of 1691 patients.

PubMed

Blandino, Alessandro; Bianchi, Francesca; Biondi-Zoccai, Giuseppe; Grossi, Stefano; Conte, Maria Rosa; Rametta, Francesco; Gaita, Fiorenzo

2016-09-01

Apixaban, a direct factor Xa inhibitor recently approved for thromboembolic prophylaxis in patients with nonvalvular atrial fibrillation (AF), is increasingly used in patients undergoing catheter ablation of AF. However, large randomized studies supporting its use in the ablation context are still lacking. We undertook the present meta-analysis to assess the impact of apixaban in terms of thromboembolic and bleeding events in patients undergoing AF ablation as compared to warfarin. MEDLINE/PubMed, Cochrane Library, and references reporting AF ablation and apixaban were screened and studies included if matching inclusion and exclusion criteria. One randomized and five nonrandomized studies were included in the analysis. Patients enrolled were 1691 patients (668 on apixaban and 1023 on warfarin). There was no heterogeneity in all the outcome comparisons. No deaths were reported. We did not observe any difference between apixaban and warfarin with respect to thromboembolic events (OR = 1.10, 95 % CI 0.24-5.16), major bleedings (OR = 1.56, 95 % CI 0.59-4.13), cardiac tamponade (OR 1.69, 95 % CI 0.52-5.54), minor bleedings (OR 0.96, 95 % CI 0.58-1.59), and the composite endpoint of death, thromboembolic events, and bleedings (OR 1.03, 95 % CI 0.65-1.64). The rates of death, thromboembolic events, major bleedings including cardiac tamponade, and minor bleedings in patients on apixaban undergoing AF ablation are very low and similar to that seen in patients treated with uninterrupted warfarin. Although primary driven by nonrandomized studies, these results support apixaban as periprocedural anticoagulation during AF ablation procedures.

Strict sequential catheter ablation strategy targeting the pulmonary veins and superior vena cava for persistent atrial fibrillation.

PubMed

Yoshiga, Yasuhiro; Shimizu, Akihiko; Ueyama, Takeshi; Ono, Makoto; Fukuda, Masakazu; Fumimoto, Tomoko; Ishiguchi, Hironori; Omuro, Takuya; Kobayashi, Shigeki; Yano, Masafumi

2018-08-01

An effective catheter ablation strategy, beyond pulmonary vein isolation (PVI), for persistent atrial fibrillation (AF) is necessary. Pulmonary vein (PV)-reconduction also causes recurrent atrial tachyarrhythmias. The effect of the PVI and additional effect of a superior vena cava (SVC) isolation (SVCI) was strictly evaluated. Seventy consecutive patients with persistent AF who underwent a strict sequential ablation strategy targeting the PVs and SVC were included in this study. The initial ablation strategy was a circumferential PVI. A segmental SVCI was only applied as a repeat procedure when patients demonstrated no PV-reconduction. After the initial procedure, persistent AF was suppressed in 39 of 70 (55.7%) patients during a median follow-up of 32 months. After multiple procedures, persistent AF was suppressed in 46 (65.7%) and 52 (74.3%) patients after receiving the PVI alone and PVI plus SVCI strategies, respectively. In 6 of 15 (40.0%) patients with persistent AF resistant to PVI, persistent AF was suppressed. The persistent AF duration independently predicted persistent AF recurrences after multiple PVI alone procedures [HR: 1.012 (95% confidence interval: 1.006-1.018); p<0.001] and PVI plus SVCI strategies [HR: 1.018 (95% confidence interval: 1.011-1.025); p<0.001]. A receiver-operating-characteristic analysis for recurrent persistent AF indicated an optimal cut-off value of 20 and 32 months for the persistent AF duration using the PVI alone and PVI plus SVCI strategies, respectively. The outcomes of the PVI plus SVCI strategy were favorable for patients with shorter persistent AF durations. The initial SVCI had the additional effect of maintaining sinus rhythm in some patients with persistent AF resistant to PVI. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of paroxysmal atrial fibrillation (RAAFT-2): a randomized trial.

PubMed

Morillo, Carlos A; Verma, Atul; Connolly, Stuart J; Kuck, Karl H; Nair, Girish M; Champagne, Jean; Sterns, Laurence D; Beresh, Heather; Healey, Jeffrey S; Natale, Andrea

2014-02-19

Atrial fibrillation (AF) is the most common rhythm disorder seen in clinical practice. Antiarrhythmic drugs are effective for reduction of recurrence in patients with symptomatic paroxysmal AF. Radiofrequency ablation is an accepted therapy in patients for whom antiarrhythmic drugs have failed; however, its role as a first-line therapy needs further investigation. To compare radiofrequency ablation with antiarrhythmic drugs (standard therapy) in treating patients with paroxysmal AF as a first-line therapy. A randomized clinical trial involving 127 treatment-naive patients with paroxysmal AF were randomized at 16 centers in Europe and North America to received either antiarrhythmic therapy or ablation. The first patient was enrolled July 27, 2006; the last patient, January 29, 2010. The last follow-up was February 16, 2012. Sixty-one patients in the antiarrhythmic drug group and 66 in the radiofrequency ablation group were followed up for 24 months. The time to the first documented atrial tachyarrhythmia of more than 30 seconds (symptomatic or asymptomatic AF, atrial flutter, or atrial tachycardia), detected by either scheduled or unscheduled electrocardiogram, Holter, transtelephonic monitor, or rhythm strip, was the primary outcome. Secondary outcomes included symptomatic recurrences of atrial tachyarrhythmias and quality of life measures assessed by the EQ-5D tool. Forty-four patients (72.1%) in the antiarrhythmic group and in 36 patients (54.5%) in the ablation group experienced the primary efficacy outcome (hazard ratio [HR], 0.56 [95% CI, 0.35-0.90]; P = .02). For the secondary outcomes, 59% in the drug group and 47% in the ablation group experienced the first recurrence of symptomatic AF, atrial flutter, atrial tachycardia (HR, 0.56 [95% CI, 0.33-0.95]; P = .03). No deaths or strokes were reported in either group; 4 cases of cardiac tamponade were reported in the ablation group. In the standard treatment group, 26 patients (43%) underwent ablation after 1-year. Quality of life was moderately impaired at baseline in both groups and improved at the 1 year follow-up. However, improvement was not significantly different among groups. Among patients with paroxysmal AF without previous antiarrhythmic drug treatment, radiofrequency ablation compared with antiarrhythmic drugs resulted in a lower rate of recurrent atrial tachyarrhythmias at 2 years. However, recurrence was frequent in both groups. clinicaltrials.gov Identifier: NCT00392054.

Feasibility of zero or near zero fluoroscopy during catheter ablation procedures.

PubMed

Haegeli, Laurent M; Stutz, Linda; Mohsen, Mohammed; Wolber, Thomas; Brunckhorst, Corinna; On, Chol-Jun; Duru, Firat

2018-04-03

Awareness of risks associated with radiation exposure to patients and medical staff has significantly increased. It has been reported before that the use of advanced three-dimensional electro-anatomical mapping (EAM) system significantly reduces fluoroscopy time, however this study aimed for zero or near zero fluoroscopy ablation to assess its feasibility and safety in ablation of atrial fibrillation (AF) and other tachyarrhythmias in a "real world" experience of a single tertiary care center. This was a single-center study where ablation procedures were attempted without fluoroscopy in 34 consecutive patients with different tachyarrhythmias under the support of EAM system. When transseptal puncture (TSP) was needed, it was attempted under the guidance of intracardiac echocardiography (ICE). Among 34 patients consecutively enrolled in this study, 28 (82.4%) patients were referred for radiofrequency ablation (RFA) of AF, 3 (8.8%) patients for ablation of right ventricular outflow tract (RVOT) ventricular extrasystole (VES), 1 (2.9%) patient for ablation of atrioventricular nodal reentry tachycardia (AVNRT), 2 (5.9%) patients for typical atrial flutter ablation. In 21 (62%) patients the entire procedure was carried out without the use of fluoroscopy. Among 28 AF patients, 15 (54%) patients underwent ablation without the use of fluoroscopy and among these 15 patients, 10 (67%) patients required TSP under ICE guidance while 5 (33%) patients the catheters were introduced to left atrium through a patent foramen ovale. In 13 AF patients, fluoroscopy was only required for double TSP. The total procedure time of AF ablation was 130 ± 50 min. All patients referred for atrial flutter, AVNRT, and VES of the RVOT ablation did not require any fluoroscopy. This study demonstrates the feasibility of zero or near zero fluoroscopy procedure including TSP with the support of EAM and ICE guidance in a "real world" experience of a single tertiary care center. When fluoroscopy was required, it was limited to TSP hence keeping the radiation dose very low. .

Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics.

PubMed

Jadidi, Amir S; Lehrmann, Heiko; Keyl, Cornelius; Sorrel, Jérémie; Markstein, Viktor; Minners, Jan; Park, Chan-Il; Denis, Arnaud; Jaïs, Pierre; Hocini, Mélèze; Potocnik, Clemens; Allgeier, Juergen; Hochholzer, Willibald; Herrera-Sidloky, Claudia; Kim, Steve; Omri, Youssef El; Neumann, Franz-Josef; Weber, Reinhold; Haïssaguerre, Michel; Arentz, Thomas

2016-03-01

Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only. A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA < 0.5 mV in AF) associated with electric activity lasting > 70% of AF cycle length on a single electrode (fractionated activity) or multiple electrodes around the circumferential mapping catheter (rotational activity) or discrete rapid local activity (group I). The procedural end point was AF termination. Arrhythmia freedom was compared with a control group (66 patients) undergoing PVI only (group II). PVI alone was performed in 23 of 85 (27%) patients of group I with low amount (< 10% of left atrial surface area) of atrial low voltage. Selective atrial ablation in addition to PVI was performed in 62 patients with termination of AF in 45 (73%) after 11 ± 9 minutes radiofrequency delivery. AF-termination sites colocalized within LVA in 80% and at border zones in 20%. Single-procedural arrhythmia freedom at 13 months median follow-up was achieved in 59 of 85 (69%) patients in group I, which was significantly higher than the matched control group (31/66 [47%], P < 0.001). There was no significant difference in the success rate of patients in group I with a low amount of low voltage undergoing PVI only and patients requiring PVI+selective low-voltage ablation (P = 0.42). Ablation of sites with distinct activation characteristics within/at borderzones of LVA in addition to PVI is more effective than conventional PVI-only strategy for persistent AF. PVI only seems to be sufficient to treat patients with left atrial low voltage < 10%. © 2016 American Heart Association, Inc.

High intensity focused ultrasound ablation for atrial fibrillation: results from the National Spanish Registry.

PubMed

Reyes, Guillermo; Ruyra, Xavier; Valderrama, Francisco; Jimenez, Antonio; Duran, Dario; Perez, Enrique; Daroca, Tomas; Moya, Javier; Ramirez, Ulises; Aldamiz, Gonzalo

2016-10-01

A National Spanish Registry to compile all patients treated with high intensity focused ultrasound (HIFU) energy for atrial fibrillation (AF) was created to evaluate the safety and efficacy of AF surgical ablation. A national Spanish registry was created, and ten hospitals using HIFU to ablate AF joined it. A total of 412 patients undergoing cardiac surgery between 2006 and February 2013 were included. AF was divided between paroxysmal AF (33%) and persistent AF (67%) with a mean AF duration of 29.3±108.2 months. Mean left atrial diameter was 51.2±6.5 mm. Mean underlying heart disease were aortic valve disease (49.3%), ischemic disease (25.2%) and mitral disease (33.2%) Clinical follow-up of patients and a 6 months postoperative echocardiogram were performed in all patients. A pacemaker implantation was needed in 4.9% of patients with a perioperative stroke in 2.5%. Rhythm at discharge from hospital was sinus rhythm in 58%, AF in 35.9% and atrial flutter in 0.8% of patients. Sinus rhythm restoration at 6, 12, 24 and 36 months follow-up was achieved in 66.1%, 63.8%, 63.9% and 45.9% of patients respectively. Multivariate analysis showed paroxysmal AF and sinus rhythm restoration in the operating theatre as factors related to sinus rhythm long term restoration. The Spanish national registry showed an efficacy of AF ablation with the HIFU Epicor system of 66.1%, 63.8%, 63.9% and 45.9% at 6, 12, 24 and 36 months follow-up. There were no device-related complications.

Low Left Atrial Compliance Contributes to the Clinical Recurrence of Atrial Fibrillation after Catheter Ablation in Patients with Structurally and Functionally Normal Heart.

PubMed

Park, Junbeom; Yang, Pil-sung; Kim, Tae-Hoon; Uhm, Jae-Sun; Kim, Joung-Youn; Joung, Boyoung; Lee, Moon-Hyoung; Hwang, Chun; Pak, Hui-Nam

2015-01-01

Stiff left atrial (LA) syndrome was initially reported in post-cardiac surgery patients and known to be associated with low LA compliance. We investigated the physiological and clinical implications of LA compliance by estimating LA pulse pressure (LApp) among patients with atrial fibrillation (AF) and structurally and functionally normal heart. Among 1038 consecutive patients with LA pressure measurements before AF ablation, we included 334 patients with structurally and functionally normal heart (81.7% male, 54.1±10.6 years, 77.0% paroxysmal AF) after excluding those with hypertension, diabetes, and previous ablation or cardiac surgery. We measured LApp (peak-nadir LA pressure) at the beginning of the ablation procedure and compared the values with clinical parameters and the AF recurrence rate. AF patients with normal heart were younger and more frequently male and had paroxysmal AF, a lower body mass index, and a lower LApp compared to others (all p<0.05). Based on the median value, the low LA compliance group (LApp≥13 mmHg) had a smaller LA volume index and lower LA voltage (all p<0.05) compared to the high LA compliance group. During a mean follow-up of 16.7±11.8 months, low LA compliance was independently associated with two fold-higher risk of clinical AF recurrence (HR:2.202; 95%CI:1.077-4.503; p = 0.031). Low LA compliance, as determined by an elevated LApp, was associated with a smaller LA volume index and lower LA voltage and independently associated with higher clinical recurrence after catheter ablation in AF patients with structurally and functionally normal heart.

Current status of the surgical treatment of atrial fibrillation.

PubMed

Geha, Alexander S; Abdelhady, Khaled

2008-03-01

Atrial fibrillation (AF) affects several million patients worldwide and is associated with a number of heart conditions, particularly coronary artery disease, rheumatic heart disease, hypertension, and congestive heart failure. The treatment of AF and its complications is quite costly. Atrial fibrillation usually results from multiple macro-re-entrant circuits in the left atrium. Very frequently, particularly in association with mitral valve disease, these circuits arise from the area of the junction of the pulmonary venous endothelium and the left atrial endocardium. Pharmacological therapy is at best 50% effective. Therapeutic options for AF include antiarrhythmic drugs, cardioversion, atrioventricular (A-V) node block, pacemaker insertion, and ablative surgery. In 1987, Cox developed an effective surgical procedure to achieve ablation. Current ablative procedures include the classic cut-and-sew Maze operation or a modification of it, namely through catheter ablation, namely, cryoablation, radiofrequency ablation (dry or irrigated), and other forms of ablation (e.g., laser, microwave). These procedures will be described, along with the indications, advantages and disadvantages of each. Special emphasis on the alternative means to cutting and sewing to achieve appropriate effective atrial scars will be stressed, and our experience with these approaches in 50 patients with AF and associated cardiac lesions and their outcomes is presented.

Left atrial low-voltage areas predict atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Matsuda, Yasuhiro; Okuno, Shota; Ohashi, Takuya; Tsuji, Aki; Mano, Toshiaki

2018-04-15

Association between the presence of left atrial low-voltage areas and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been shown mainly in persistent AF patients. We sought to compare the AF recurrence rate in paroxysmal AF patients with and without left atrial low-voltage areas. This prospective observational study included 147 consecutive patients undergoing initial ablation for paroxysmal AF. Voltage mapping was performed after PVI during sinus rhythm, and low-voltage areas were defined as regions where bipolar peak-to-peak voltage was <0.50mV. Left atrial low-voltage areas after PVI were observed in 22 (15%) patients. Patients with low-voltage areas were significantly older (72±6 vs. 66±10, p<0.0001), more likely to be female (68% vs. 32%, p=0.002), and had higher CHA 2 DS 2 -VASc score (2.5±1.5 vs. 1.8±1.3, p=0.028). During a mean follow-up of 22 (18, 26) months, AF recurrence was observed in 24 (16%) and 16 (11%) patients after the single and multiple ablation procedures, respectively. AF recurrence rate after multiple ablations was higher in patients with low-voltage areas than without (36% vs. 6%, p<0.001). Low-voltage areas were independently associated with AF recurrence even after adjustment for the other related factors (Hazard ratio, 5.89; 95% confidence interval, 2.16 to 16.0, p=0.001). The presence of left atrial low-voltage areas after PVI predicts AF recurrence in patients with paroxysmal AF as well as in patients with persistent AF. Copyright © 2017 Elsevier B.V. All rights reserved.

Late outcomes after the Cox maze IV procedure for atrial fibrillation.

PubMed

Henn, Matthew C; Lancaster, Timothy S; Miller, Jacob R; Sinn, Laurie A; Schuessler, Richard B; Moon, Marc R; Melby, Spencer J; Maniar, Hersh S; Damiano, Ralph J

2015-11-01

The Cox maze IV procedure (CMPIV) has been established as the gold standard for surgical ablation; however, late outcomes using current consensus definitions of treatment failure have not been well described. To compare to reported outcomes of catheter-based ablation, we report our institutional outcomes of patients who underwent a left-sided or biatrial CMPIV at 5 years of follow-up. Between January 2002 and September 2014, data were collected prospectively on 576 patients with AF who underwent a CMPIV (n = 532) or left-sided CMPIV (n = 44). Perioperative variables and long-term freedom from AF, with and without AADs, were compared in multiple subgroups. Follow-up at any time point was 89%. At 5 years, overall freedom from AF was 93 of 119 (78%), and freedom from AF off AADs was 77 of 177 (66%). No differences were found in freedom from AF, with or without AADs, at 1, 2, 3, 4, and 5 years for patients with paroxysmal AF (n = 204) versus with persistent/longstanding persistent AF (n = 305), or for those who underwent standalone versus a concomitant CMP. Duration of preoperative AF and hospital length of stay were the best predictors of failure at 5 years. The outcomes of the CMPIV remain good at late follow-up. The type of preoperative AF or the addition of a concomitant procedure did not affect late success. The results of the CMPIV remain superior to those reported for catheter ablation and other forms of surgical AF ablation, especially for patients with persistent or longstanding AF. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Pulmonary vein activity does not predict the outcome of catheter ablation for persistent atrial fibrillation: A long-term multicenter prospective study.

PubMed

Prabhu, Sandeep; Kalla, Manish; Peck, Kah Y; Voskoboinik, Aleksandr; McLellan, Alex J A; Pathik, Bupesh; Nalliah, Chrishan J; Wong, Geoff R; Sugumar, Hariharan; Azzopardi, Sonia M; Lee, Geoffrey; Ling, Liang-Han; Kalman, Jonathan M; Kistler, Peter M

2018-03-02

Pulmonary vein (PV) isolation (PVI) remains the cornerstone of catheter ablation (CA) in persistent atrial fibrillation (AF) (PeAF), although less successful than for paroxysmal AF. Whether rapid or fibrillatory (PV AF) PV firing may identify patients with PeAF more likely to benefit from a PV-based ablation approach is unclear. The purpose of this study was to determine the relationship between the PV cycle length (PVCL) and the PV AF outcome after CA. Before ablation, the multipolar catheter was placed in each PV and the left atrial appendage (LAA) for 100 consecutive cycles. The presence of PV AF, the average PVCL of all 4 veins (PV 4VAverage ), the fastest vein average (PV FVAverage ), the fastest cycle length (PV Fast ) both individually and relative to the average LAA cycle length were calculated. The ablation strategy included PVI and posterior wall isolation with a minimum of 12 months follow-up. A total of 123 patients underwent CA (age 62 ± 9.1 years; CHA 2 DS 2 -VASC score 1.6 ± 1.1; left ventricular ejection fraction 48% ± 13%; left atrial area 31 ± 8.7 cm 2 ; AF duration 16 ± 17 months). PVI was achieved in 100% of patients. Multiprocedure success (MPS; freedom from AF/atrial tachycardia episodes lasting >30 seconds) was achieved in 76% of patients at 24 ± 8.1 months of follow-up after 1.2 ± 0.4 procedures. PV activity was not associated with MPS either absolutely (PV 4VAverage [MPS no vs yes: 178 ± 27 ms vs 177 ± 24 ms; P = .92], PV FVAverage [P = .69], or PV Fast [P = .82]) or as a ratio relative to the LAA cycle length (PV 4VAverage /LAA 1.05 ± 0.11 vs 1.06 ± 0.21; P = .87). The presence of PV AF (31% vs 47%; P = .13) did not predict MPS. The rapidity of PV firing or presence of fibrillation within the PV was not predictive of outcome of CA for PeAF. PV activity does not identify patients most likely to benefit from a PV-based ablation strategy. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Echocardiographic predictors of atrial fibrillation recurrence after catheter ablation: A literature review.

PubMed

Liżewska-Springer, Aleksandra; Dąbrowska-Kugacka, Alicja; Lewicka, Ewa; Drelich, Łukasz; Królak, Tomasz; Raczak, Grzegorz

2018-06-20

Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to determine AF recurrence after CA, however their predictive value is rather small. Identification of novel predictors of CA outcome is therefore of primary importance to reduce health costs and improve long-term results of this intervention. The recurrence of AF following CA is related to the severity of left ventricular (LV) dysfunction, extend of atrial dilatation and fibrosis. The aim of this paper was to present and discuss the latest studies on utility of echocardiographic parameters in terms of CA effectiveness in patients with paroxysmal and persistent AF. PubMed, Google Scholar, EBSCO databases were searched for studies reporting echocardiographic preprocedural predictors of AF recurrence after CA. LV systolic and diastolic function, as well as atrial size, strain and dyssynchrony were taken into consideration. Twenty one full-text articles were analyzed, including three meta-analyses. Several echocardiographic parameters have been reported to determine a risk of AF recurrence after CA. There are conventional methods that measure left atrial (LA) size and volume, LV ejection fraction, parameters assessing LV diastolic dysfunction, and methods using more innovative technologies based on speckle tracking echocardiography (STE) to determine LA synchrony and strain. Each of these parameters has its own predictive value. Regarding CA effectiveness, every patient has to be evaluated individually to estimate the risk of AF recurrence, optimally using a combination of several echocardiographic parameters.

Effect of interconnection between cervical vagus trunk, epicardial fat pad on sinus node function, and atrial fibrillation.

PubMed

Zhou, Qina; Zhang, Ling; Wang, Kun; Xu, Xiaoxia; Ji, Meng; Zhang, Feng; Wang, Hongli; Hou, Yuemei

2014-03-01

The epicardial fat pad (FP) integrates the autonomic innervation between the extrinsic and intrinsic cardiac autonomic nervous system and affects atrial electrophysiology and pathophysiology. Eighteen dogs were divided into two groups: sequential ablation of sinoatrial node FP (SAN-FP) and atrioventricular node FP (AVN-FP). Sinus rate (SR), atrial fibrillation (AF) inducibility, and effective refractory period (ERP) changes during electrical stimulation of the vagus trunk were detected before and after ablation. In the SAN-FP group, the SR slowing, increasing AF inducibility, and ERP shortening that induced by vagus trunk stimulation were significantly attenuated by isolated SAN-FP ablation, compared with the same group prior to ablation (all P < 0.05). Subsequent AVN-FP ablation following SAN-FP ablation almost cannot produce further attenuation during vagus trunk stimulation, compared with isolated SAN-FP ablation (P > 0.05). In the AVN-FP group, SR slowing, increasing AF inducibility, and ERP shortening that induced by vagus trunk stimulation were completely eliminated by isolated AVN-FP ablation, compared with the same group prior to ablation (all P < 0.05). Subsequent SAN-FP ablation following AVN-FP ablation produced no further attenuation, compared with isolated AVN-FP ablation (P > 0.05). A neural pathway from the cervical vagus trunk to the sinus node and atrium runs through the SAN-FP, but eventually converges at the AVN-FP and also suggested that the AVN-FP serves as an "integration center" for the SAN-FP to modulate sinus node function. The AVN-FP may play a more critical role in the initiation and maintenance of AF. ©2013 First Affilated Hospital of Xingiang Medical University Pacing and Clinical Electrophysiology ©2013 Wiley Periodicals, Inc.

How to perform posterior wall isolation in catheter ablation for atrial fibrillation.

PubMed

Sugumar, Hariharan; Thomas, Stuart P; Prabhu, Sandeep; Voskoboinik, Aleksandr; Kistler, Peter M

2018-02-01

Catheter ablation has become standard of care in patients with symptomatic atrial fibrillation (AF). Although there have been significant advances in our understanding and technology, a substantial proportion of patients have ongoing AF requiring repeat procedures. Pulmonary vein isolation (PVI) is the cornerstone of AF ablation; however, it is less effective in patients with persistent as opposed to paroxysmal atrial fibrillation. Left atrial posterior wall isolation (PWI) is commonly performed as an adjunct to PVI in patients with persistent AF with nonrandomized studies showing improved outcomes. Anatomical considerations and detailed outline of the various approaches and techniques to performing PWI are detailed, and advantages and pitfalls to assist the clinical electrophysiologist successfully and safely complete PWI are described. © 2017 Wiley Periodicals, Inc.

Decrease in B-Type Natriuretic Peptide Levels and Successful Catheter Ablation for Atrial Fibrillation in Patients with Heart Failure.

PubMed

Yanagisawa, Satoshi; Inden, Yasuya; Kato, Hiroyuki; Fujii, Aya; Mizutani, Yoshiaki; Ito, Tadahiro; Kamikubo, Yosuke; Kanzaki, Yasunori; Hirai, Makoto; Murohara, Toyoaki

2016-03-01

Little is known about the association between B-type natriuretic peptide (BNP) levels and catheter ablation of atrial fibrillation (AF) in patients with heart failure. This study aimed to examine the impact of elimination of AF by catheter ablation on BNP levels in patients with left ventricular systolic dysfunction. Fifty-four AF patients with left ventricular ejection fraction (LVEF) ≤ 50%, who underwent radiofrequency catheter ablation therapy of AF, were included. BNP sampling was performed at baseline, 3 days, and 1 month after ablation. After a follow-up period of 6 months, the BNP levels decreased significantly in the nonrecurrence group (n = 35; median 126.3 [interquartile 57.2-206.5] pg/mL, 63.5 [23.9-180.2] pg/mL, and 45.9 [21.9-160.3] pg/mL, P < 0.001, respectively), but not in the recurrence group (n = 19; 144.7 [87.1-217.3] pg/mL, 88.8 [12.9-213.2] pg/mL, and 118.5 [51.6-298.2] pg/mL, P = 0.368, respectively). The patients in the nonrecurrence group had a higher percentage relative reduction in BNP levels from baseline to 1 month after ablation than those in the recurrence group (56.5 [-9.0-77.4]% vs -2.4 [-47.1-60.9]%, P = 0.027). Additionally, a relative reduction in BNP levels significantly correlated with an increase in LVEF after ablation (r = 0.486, P < 0.001). Plasma BNP levels decreased significantly with successful catheter ablation of AF in patients with impaired LVEF. The decrease in BNP levels might be associated with early recovery of cardiac function and subsequent maintenance of sinus rhythm at follow-up. ©2015 Wiley Periodicals, Inc.

Efficacy of Antiarrhythmic Drugs Short-Term Use After Catheter Ablation for Atrial Fibrillation (EAST-AF) trial.

PubMed

Kaitani, Kazuaki; Inoue, Koichi; Kobori, Atsushi; Nakazawa, Yuko; Ozawa, Tomoya; Kurotobi, Toshiya; Morishima, Itsuro; Miura, Fumiharu; Watanabe, Tetsuya; Masuda, Masaharu; Naito, Masaki; Fujimoto, Hajime; Nishida, Taku; Furukawa, Yoshio; Shirayama, Takeshi; Tanaka, Mariko; Okajima, Katsunori; Yao, Takenori; Egami, Yasuyuki; Satomi, Kazuhiro; Noda, Takashi; Miyamoto, Koji; Haruna, Tetsuya; Kawaji, Tetsuma; Yoshizawa, Takashi; Toyota, Toshiaki; Yahata, Mitsuhiko; Nakai, Kentaro; Sugiyama, Hiroaki; Higashi, Yukei; Ito, Makoto; Horie, Minoru; Kusano, Kengo F; Shimizu, Wataru; Kamakura, Shiro; Morimoto, Takeshi; Kimura, Takeshi; Shizuta, Satoshi

2016-02-14

Substantial portion of early arrhythmia recurrence after catheter ablation for atrial fibrillation (AF) is considered to be due to irritability in left atrium (LA) from the ablation procedure. We sought to evaluate whether 90-day use of antiarrhythmic drug (AAD) following AF ablation could reduce the incidence of early arrhythmia recurrence and thereby promote reverse remodelling of LA, leading to improved long-term clinical outcomes. A total of 2038 patients who had undergone radiofrequency catheter ablation for paroxysmal, persistent, or long-lasting AF were randomly assigned to either 90-day use of Vaughan Williams class I or III AAD (1016 patients) or control (1022 patients) group. The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of class I or III AAD at 1 year, following the treatment period of 90 days post ablation. Patients assigned to AAD were associated with significantly higher event-free rate from recurrent atrial tachyarrhythmias when compared with the control group during the treatment period of 90 days [59.0 and 52.1%, respectively; adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.73-0.96; P = 0.01]. However, there was no significant difference in the 1-year event-free rates from the primary endpoint between the groups (69.5 and 67.8%, respectively; adjusted HR 0.93; 95% CI 0.79-1.09; P = 0.38). Short-term use of AAD for 90 days following AF ablation reduced the incidence of recurrent atrial tachyarrhythmias during the treatment period, but it did not lead to improved clinical outcomes at the later phase. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Catheter-Based Renal Sympathetic Denervation Significantly Inhibits Atrial Fibrillation Induced by Electrical Stimulation of the Left Stellate Ganglion and Rapid Atrial Pacing

PubMed Central

Po, Sunny S.; Wang, Huan; Zhang, Ling; Zhang, Feng; Wang, Kun; Zhou, Qina

2013-01-01

Background Sympathetic activity involves the pathogenesis of atrial fibrillation (AF). Renal sympathetic denervation (RSD) decreases sympathetic renal afferent nerve activity, leading to decreased central sympathetic drive. The aim of this study was to identify the effects of RSD on AF inducibility induced by hyper-sympathetic activity in a canine model. Methods To establish a hyper-sympathetic tone canine model of AF, sixteen dogs were subjected to stimulation of left stellate ganglion (LSG) and rapid atrial pacing (RAP) for 3 hours. Then animals in the RSD group (n = 8) underwent radiofrequency ablation of the renal sympathetic nerve. The control group (n = 8) underwent the same procedure except for ablation. AF inducibility, effective refractory period (ERP), ERP dispersion, heart rate variability and plasma norepinephrine levels were measured at baseline, after stimulation and after ablation. Results LSG stimulation combined RAP significantly induced higher AF induction rate, shorter ERP, larger ERP dispersion at all sites examined and higher plasma norepinephrine levels (P<0.05 in all values), compared to baseline. The increased AF induction rate, shortened ERP, increased ERP dispersion and elevated plasma norepinephrine levels can be almost reversed by RSD, compared to the control group (P<0.05). LSG stimulation combined RAP markedly shortened RR-interval and standard deviation of all RR-intervals (SDNN), Low-frequency (LF), high-frequency (HF) and LF/HF ratio (P<0.05). These changes can be reversed by RSD, compared to the control group (P<0.05). Conclusions RSD significantly reduced AF inducibility and reversed the atrial electrophysiological changes induced by hyper-sympathetic activity. PMID:24223140

Radiofrequency Catheter Ablation Improves the Quality of Life Measured with a Short Form-36 Questionnaire in Atrial Fibrillation Patients: A Systematic Review and Meta-Analysis

PubMed Central

Choi, Jong-Il; Kim, Young-Hoon

2016-01-01

Background The main purpose of performing radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) patients is to improve the quality of life (QoL) and alleviate AF-related symptoms. We aimed to determine the qualitative and quantitative effects of RFCA on the QoL in AF patients. Methods We performed a systemic review and meta-analysis using a random effects model. We searched for the studies that reported the physical component summary score (PCS) and mental component summary score (MCS) of the short form-36, a validated system to assess and quantify the QoL, before and after RFCA in AF patients. PCS and MCS are T-scores with a mean of 50 and standard deviation of 10. Results Of the 470 studies identified through systematic search, we included 13 studies for pre-RFCA vs. the post-RFCA analysis and 5 studies for treatment success vs. AF recurrence analyses. In the pre-RFCA vs. post-RFCA analysis, RFCA was associated with a significant increase in both the PCS (weighted mean difference [WMD] = 6.33 [4.81–7.84]; p < 0.001) and MCS (WMD = 7.80 [6.15–9.44]; p < 0.001). The ΔPCS (post-RFCA PCS–pre-RFCA PCS) and ΔMCS values were used for the treatment success vs. AF recurrence analysis. Patients with successful ablation had a higher ΔPCS (WMD = 7.46 [4.44–10.49]; p < 0.001) and ΔMCS (WMD = 7.59 [4.94–10.24]; p < 0.001). Conclusions RFCA is associated with a significant increase in the PCS and MCS in AF patients. Patients without AF recurrence after RFCA had a better improvement in the PCS and MCS than patients who had AF recurrence. PMID:27681507

Targeting Stable Rotors to Treat Atrial Fibrillation.

PubMed

Narayan, Sanjiv M; Krummen, David E

2012-09-01

Therapy for atrial fibrillation (AF) remains suboptimal, in large part because its mechanisms are unclear. While pulmonary vein ectopy may trigger AF, it remains uncertain how AF, once triggered, is actually sustained. Recent discoveries show that human AF is maintained by a small number of rotors or focal sources. AF sources are widely distributed in patient-specific locations, often remote from pulmonary veins and in the right atrium and stable for prolonged periods of time. In a multicentre experience, brief targeted ablation at sources (focal impulse and rotor modulation [FIRM]) terminated AF predominantly to sinus rhythm prior to pulmonary vein isolation and eliminated AF on rigorous followup. This review summarises the evidence for stable rotors and focal sources of human AF and their clinical role as ablation targets to eliminate paroxysmal, persistent and long-standing persistent AF.

Atrial ectopy predicts late recurrence of atrial fibrillation after pulmonary vein isolation.

PubMed

Gang, Uffe J O; Nalliah, Chrishan J; Lim, Toon Wei; Thiagalingam, Aravinda; Kovoor, Pramesh; Ross, David L; Thomas, Stuart P

2015-06-01

Late recurrence of atrial fibrillation (AF) after radiofrequency ablation remains significant. Asymptomatic recurrence poses a difficult clinical problem as it is associated with an equally increased risk of stroke and death compared with symptomatic AF events. Meta-analyses reveal that no single preablation patient characteristic efficiently predicts these AF recurrences. This study aimed to evaluate the prognostic value of premature atrial complex (PAC) occurrence with regard to the risk of late AF recurrence after radiofrequency ablation. The study cohort consisted of 124 patients with 7-day Holter recordings at 6 months post radiofrequency ablation for AF. No patients had AF recurrence before this time. Patients were followed-up every 6 months. Holter-detected PACs were defined as any supraventricular complexes occurring >30% earlier than expected. During a median follow-up of 4.2 years (first quartile to third quartile [Q1-Q3]=1.6-4.5), 32 patients (26%) had late recurrences of AF at a median of 462 days (Q1-Q3=319-1026) post radiofrequency ablation. The number of PACs per 24 hours was 248 (Q1-Q3=62-1026) in patients with and 77 (Q1-Q3=24-448) in patients without recurrence of AF (P=0.02). Multivariate analysis of the risk of late AF recurrence found ≥142 PACs per 24 hours to have a hazard ratio 2.84 (confidence interval, 1.26-6.43), P=0.01. This study showed that occurrence of ≥142 PACs per day at 6 months after PVI was independently associated with a significantly increased risk of late AF recurrence. These results could have important clinical implications for the design of post-PVI follow-up. URL: http://www.anzctr.org.au. Unique identifier: ACRTN12606000467538. © 2015 American Heart Association, Inc.

The New 2016 European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines: Enough Guidance? Enough Evidence?

PubMed

Castellá, Manuel

2018-04-01

For the first time, the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery have joined forces to develop consensus guidelines for the management of atrial fibrillation (AF). One of the main issues is the integrated care of patients with AF, with emphasis on multidisciplinary teams of general physicians, cardiologists, stroke specialists and surgeons, together with the patient's involvement for better management of AF. These guidelines also help in the detection of risk factors and concomitant cardiovascular diseases, stroke prevention therapies, including anticoagulation and antiplatelet therapies after acute coronary episodes, major haemorrhages or strokes. In the field of ablation, surgery plays an important role as concomitant with other surgical procedures, and it should be considered in symptomatic patients with the highest level of evidence. Asymptomatic patients with mitral insufficiency should also be considered for combined mitral and AF surgery if they have new-onset AF. In patients with stand-alone AF, recommendations for minimally invasive ablation have an increased level of recommendation and should be considered as the same level as catheter ablation in patients with persistent or long-standing persistent AF or with paroxysmal AF who fail catheter ablation. Surgical occlusion or exclusion of the left atrial appendage may be considered for stroke prevention in patients with AF about to have surgery. Nevertheless, not enough is known to avoid long-term anticoagulation in patients at risk of stroke even if the left atrial appendage has been excluded. These Guidelines provide a full spectrum of recommendations on the management of patients with AF including prevention, treatment and complications based on the latest published evidence.

Catheter ablation of atrial fibrillation in patients with concomitant sinus bradycardia-Insights from the German Ablation Registry.

PubMed

Zylla, Maura M; Brachmann, Johannes; Lewalter, Thorsten; Hoffmann, Ellen; Kuck, Karl-Heinz; Andresen, Dietrich; Willems, Stephan; Hochadel, Matthias; Senges, Jochen; Katus, Hugo A; Thomas, Dierk

2016-01-01

This investigation addresses procedural characteristics of catheter ablation in patients with atrial fibrillation (AF) and sinus bradycardia. From the prospective, multi-center German Ablation Registry 1073 patients with sinus rhythm at the time of AF ablation were divided into two groups according to heart rate at start of procedure (A, <60 beats per minute (bpm), n=197; B, 60-99bpm, n=876). Acute procedural success was high (≥98%) and similar between groups. Procedure duration and energy application time were increased in group A (180min vs. 155min and 2561s vs. 1879s, respectively). Major complications were more frequent in group A (2.2% vs. 0.5%), and a greater proportion of these patients was discharged under antiarrhythmic medication (64% vs. 52%). Catheter ablation of AF with concomitant sinus bradycardia is associated with high procedural efficacy, longer procedure- and energy application durations, and a slightly elevated complication rate. Copyright © 2016 Elsevier Inc. All rights reserved.

Atrial fibrillation ablation: "perpetual motion" of open irrigated tip catheters at 50 W is safe and improves outcomes.

PubMed

Winkle, Roger A; Mead, R Hardwin; Engel, Gregory; Patrawala, Rob A

2011-05-01

Point-by-point use of open irrigated tip catheters (OITCs) at 50 W increases atrial fibrillation (AF) ablation cure rates but also increases complications. We determined if constantly moving the OITC (perpetual motion) when using 50 W increases ablation cure rates without increasing complications. We evaluated procedural data, complications, and individual procedure cure rates (IPCRs) for AF ablation using closed tip catheters (CTC) versus OITC at 40, 45, and 50 W in 1,122 ablations. We used "perpetual motion" to move the OITC at 50 W every 3-10 seconds. The OITC showed higher IPCR than CTC at 45 W (P = 0.012) and 50 W (P < 0.0005). For the OITC, IPCR increased from 44.6% to 60.7% as power increased from 40 to 50 W (P = 0.008). The OITC appeared superior to the CTC for all types of AF. For paroxysmal AF, increasing OITC power from 40 to 50 W provided no increase in IPCR (70.6% vs 71.2%, P = 0.827). For persistent AF, increasing power from 40 to 50 W increased IPCR from 34.5% to 59.5% (P = 0.001). Complications were similar for the CTC and the OITC at any power. The OITC at 50 W had shorter procedure, left atrial, and fluoroscopy times (P < 0.0005). Increasing OITC power from 40 to 50 W increases IPCR with no increase in complications as long as the 50 W setting is done using "perpetual motion." The OITC 50 W power setting results in shorter procedure and fluoroscopy times and should be considered for AF ablations. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

Multifractal analysis for grading complex fractionated electrograms in atrial fibrillation.

PubMed

Orozco-Duque, A; Novak, D; Kremen, V; Bustamante, J

2015-11-01

Complex fractionated atrial electrograms provide an important tool for identifying arrhythmogenic substrates that can be used to guide catheter ablation for atrial fibrillation (AF). However, fractionation is a phenomenon that remains unclear. This paper aims to evaluate the multifractal properties of electrograms in AF in order to propose a method based on multifractal analysis able to discriminate between different levels of fractionation. We introduce a new method, the h-fluctuation index (hFI), where h is the generalised Hurst exponent, to extract information from the shape of the multifractal spectrum. Two multifractal frameworks are evaluated: multifractal detrended fluctuation analysis and wavelet transform modulus maxima. hFI is exemplified through its application in synthetic signals, and it is evaluated in a database of electrograms labeled on the basis of four degrees of fractionation. We compare the performance of hFI with other indexes, and find that hFI outperforms them. The results of the study provide evidence that multifractal analysis is useful for studying fractionation phenomena in AF electrograms, and indicate that hFI can be proposed as a tool for grade fractionation associated with the detection of target sites for ablation in AF.

Left atrial ejection force predicts the outcome after catheter ablation for paroxysmal atrial fibrillation.

PubMed

Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru

2018-02-01

Left atrium (LA) systolic dysfunction is observed in the early stages of atrial fibrillation (AF) prior to LA anatomical change. We investigated whether LA systolic dysfunction predicts recurrent AF after catheter ablation (CA) in patients with paroxysmal AF. We studied 106 patients who underwent CA for paroxysmal AF. LA systolic function was assessed with the LA emptying volume = Maximum LA volume (LAV max ) - Minimum LA volume (LAV min ), LA emptying fraction = [(LAV max - LAV min )/LAV max ] × 100, and LA ejection force calculated with Manning's method [LA ejection force = (0.5 × ρ × mitral valve area × A 2 )], where ρ is the blood density and A is the late-diastolic mitral inflow velocity. Recurrent AF was detected in 35/106 (33%) during 14.6 ± 9.1 months. Univariate analysis revealed reduced LA ejection force, decreased LA emptying fraction, larger LA diameter, and elevated brain natriuretic peptide as significant variables. On multivariate analysis, reduced LA ejection force and larger LA diameter were independently associated with recurrent AF. Moreover, patients with reduced LA ejection force and larger LA diameter had a higher risk of recurrent AF than preserved LA ejection force (log-rank P = 0.0004). Reduced LA ejection force and larger LA diameter were associated with poor outcome after CA for paroxysmal AF, and could be a new index to predict recurrent AF. © 2017 Wiley Periodicals, Inc.

Initial experience of a novel mapping system combined with remote magnetic navigation in the catheter ablation of atrial fibrillation.

PubMed

Lin, Changjian; Pehrson, Steen; Jacobsen, Peter Karl; Chen, Xu

2017-12-01

There have been advancements of sophisticated mapping systems used for ablation procedures over the last decade. Utilization of these novel mapping systems in combination with remote magnetic navigation (RMN) needs to be established. We investigated the new EnSite Precision mapping system (St. Jude Medical, Inc., St. Paul, MN, USA), which collects magnetic data for checking navigation field stability and is built on an open platform, allowing physicians to choose diagnostic and ablation catheters. We address its compatibility with RMN. To assess the clinical utility of a novel 3D mapping system (EnSite Precision mapping system) combined with RMN (Niobe ES, Stereotaxis, Inc., St. Louis, MO, USA) for atrial fibrillation (AF) ablation. In this prospective nonrandomized study, two groups of patients were treated in our center for drug refractory AF. Patients were consecutively enrolled in each group. Group A (n = 35, 14 persistent AF [PsAF]) was treated using the novel 3D mapping system combined with RMN. Group B (n = 38, 16 PsAF) was treated using Carto ® 3 (Biosense Webster, Inc., Diamond Bar, CA, USA) combined with RMN. In Group A, the left atrium (LA) was mapped with a circular magnetic catheter manually and was then replaced by a RMN ablation catheter. At the end of the procedures in Group A, the circular catheter was used for confirming field stability. In Group B, an ablation catheter was controlled by RMN to perform both LA mapping and ablation. All patients underwent pulmonary vein antrum isolation. Additional complex fractionated atrial electrograms (CFAEs) ablation was performed for PsAF. Procedural, ablation, and fluoroscopy times were recorded and complications were assessed. Electrophysiological end points were achieved in all patients. Using the novel mapping system, LA mapping time was fast (308 ± 60 seconds) with detailed anatomy points (178,831 ± 70,897) collected and magnetic points throughout LA. At the end of the procedures in Group A, the LA model was confirmed to be stable and its location was within the distance threshold (1 mm). Procedure time (117.9 ± 29.6 minutes vs. 119.2 ± 29.7 minutes, P = 0.89), fluoroscopy time (6.1 ± 2.4 minutes vs. 4.8 ± 2.2 minutes, P = 0.07), and ablation time (28.0 ± 12.9 minutes vs. 27.9 ± 15.8 minutes, P = 0.98) were similar in Group A versus Group B, respectively. No complications occurred in either group. LA mapped by the novel system is stable and reliable. Combined with RMN, it could be effectively used for AF ablation without impacting overall procedural times. © 2017 Wiley Periodicals, Inc.

Association of Left Atrial Function Index With Late Atrial Fibrillation Recurrence after Catheter Ablation.

PubMed

Sardana, Mayank; Ogunsua, Adedotun A; Spring, Matthew; Shaikh, Amir; Asamoah, Owusu; Stokken, Glenn; Browning, Clifford; Ennis, Cynthia; Donahue, J Kevin; Rosenthal, Lawrence S; Floyd, Kevin C; Aurigemma, Gerard P; Parikh, Nisha I; McManus, David D

2016-12-01

Although catheter ablation (CA) for atrial fibrillation (AF) is commonly used to improve symptoms, AF recurrence is common and new tools are needed to better inform patient selection for CA. Left atrial function index (LAFI), an echocardiographic measure of atrial mechanical function, has shown promise as a noninvasive predictor of AF. We hypothesized that LAFI would relate to AF recurrence after CA. All AF patients undergoing index CA were enrolled in a prospective institutional AF Treatment Registry between 2011 and 2014. LAFI was measured post hoc from pre-ablation clinical echocardiographic images in 168 participants. Participants were mostly male (33% female), middle-aged (60 ± 10 years), obese and had paroxysmal AF (64%). Mean LAFI was 25.9 ± 17.6. Over 12 months of follow-up, 78 participants (46%) experienced a late AF recurrence. In logistic regression analyses adjusting for factors known to be associated with AF, lower LAFI remained associated with AF recurrence after CA [OR 0.04 (0.01-0.67), P = 0.02]. LAFI discriminated AF recurrence after CA slightly better than CHADS2 (C-statistic 0.60 LAFI, 0.57 CHADS2). For participants with persistent AF, LAFI performed significantly better than CHADS2 score (C statistic = 0.79 LAFI, 0.56 CHADS2, P = 0.02). LAFI, an echocardiographic measure of atrial function, is associated with AF recurrence after CA and has improved ability to discriminate AF recurrence as compared to the CHADS-2 score, especially among persistent AF patients. Since LAFI can be calculated using standard 2D echocardiographic images, it may be a helpful tool for predicting AF recurrence. © 2016 Wiley Periodicals, Inc.

Arrhythmia-free survival and pulmonary vein reconnection patterns after second-generation cryoballoon and contact-force radiofrequency pulmonary vein isolation.

PubMed

Buist, Thomas J; Adiyaman, Ahmet; Smit, Jaap Jan J; Ramdat Misier, Anand R; Elvan, Arif

2018-06-01

The aim of this study was to compare second-generation cryoballoon and contact-force radiofrequency point-by-point pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients with regard to pulmonary vein reconnection and arrhythmia-free survival. Altogether, 269 consecutive patients with drug-refractory AF undergoing PVI were included and randomly allocated to second-generation cryoballoon or contact-force point-by-point radiofrequency ablation. Median follow-up duration was 389 days (interquartile range 219-599). Mean age was 59 years (71% male); 136 patients underwent cryoballoon and 133 patients underwent radiofrequency ablation. Acute electrical PVI was 100% for both techniques. Procedure duration was significantly shorter in cryoballoon vs radiofrequency (166.5 vs 184.13 min P = 0.016). Complication rates were similar (6.0 vs 6.7%, P = 1.00). Single procedure freedom of atrial arrhythmias was significantly higher in cryoballoon as compared to radiofrequency (75.2 vs 57.4%, P = 0.013). In multivariate analysis, persistent AF, AF duration, and cryoballoon ablation were associated with freedom of atrial tachyarrhythmias. The number of repeat ablation procedures was significantly lower in the cryoballoon compared to radiofrequency (15.0 vs 24.3%, P = 0.045). At repeat ablation, pulmonary vein reconnection rate was significantly lower after cryoballoon as compared to radiofrequency ablation (36.8 vs 58.1%, P = 0.003). Improved arrhythmia-free survival and more durable pulmonary vein isolation is seen after PVI using second-generation cryoballoon as compared to contact-force radiofrequency, in patients with drug-refractory paroxysmal AF. Complication rates for both ablation techniques are low.

Longterm effects of cardiac mediastinal nerve cryoablation on neural inducibility of atrial fibrillation in canines.

PubMed

Leiria, Tiago Luiz Luz; Glavinovic, Tamara; Armour, J Andrew; Cardinal, René; de Lima, Gustavo Glotz; Kus, Teresa

2011-04-26

In canines, excessive activation of select mediastinal nerve inputs to the intrinsic cardiac nervous system induces atrial fibrillation (AF). Since ablation of neural elements is proposed as an adjunct to circumferential pulmonary vein ablation for AF, we investigated the short and long-term effects of mediastinal nerve ablation on AF inducibility. Under general anesthesia, in 11 dogs several mediastinal nerve sites were identified on the superior vena cava that, when stimulated electrically during the atrial refractory period, reproducibly initiated AF. Cryoablation of one nerve site was then performed and inducibility retested early (1-2 months post Cryo; n=7) or late (4 months post Cryo; n=4). Four additional dogs that underwent a sham procedure were retested 1 to 2 months post-surgery. Stimulation induced AF at 91% of nerve sites tested in control versus 21% nerve sites early and 54% late post-ablation (both P<0.05). Fewer stimuli were required to induce AF in controls versus the Early Cryo group; this capacity returned to normal values in the Late Cryo group. AF episodes were longer in control versus the Early or Late Cryo groups. Heart rate responses to vagal or stellate ganglion stimulation, as well as to local nicotine infusion into the right coronary artery, were similar in all groups. In conclusion, focal damage to intrinsic cardiac neuronal inputs causes short-term stunning of neuronal inducibility of AF without major loss of overall adrenergic or cholinergic efferent neuronal control. That recovery of AF inducibility occurs rapidly post-surgery indicates the plasticity of intrathoracic neuronal elements to focal injury. Copyright © 2011 Elsevier B.V. All rights reserved.

Implantable defibrillators configured for hybrid therapy of persistent and permanent atrial fibrillation: initial clinical experience with a novel lead system.

PubMed

Rao, Hygriv B; Saksena, Sanjeev

2005-08-01

Hybrid therapy strategies have combined antiarrhythmic drugs (AAD) with pacemakers, atrio-ventricular defibrillators (AV ICD) or atrial ablation individually. The feasibility combining AAD with dual site RA pacing (DAP) in an AV ICD has not been examined. We used an AV ICD with a novel lead configuration permitting DAP, antitachycardia pacing (ATP) or atrial shocks (ADF) in patients (pts) with refractory persistent or permanent AF. Hybrid therapy included linear RA ablation and/or focal ablation. Continuous DAP and automatic ATP with patient or physician activated ADF. 24 pts, mean age 66 +/- 10 yrs, with cardiac disease (22 pts), underwent insertion of an AVICD with dual RA leads. 20 patients had concomitant ablative procedures (RA only = 19, RA + LA = 1) and all pts continued previously ineffective AAD. During a follow-up of 2-36 months (mean 17 +/- 8 mos), rhythm control was restored in all pts & maintained long-term in 19 (83%) pts. 8 pts used AF termination therapies successfully. Device datalogs showed no episodes of AF in 6 pts, asymptomatic brief arrhythmias in 4 pts, infrequent paroxysmal AF in 9 pts & persistent AF recurred in 5 pts. AV ICD detection algorithms reliably detected AF or AT in the DAP mode in all pts. Intermittent brief P wave double counting occurred during AT in selected pts. No pt received inappropriate ADF therapy. 1. DAP can be safely incorporated in an AVICD devices for use in an hybrid therapy strategy for AF pts. 2. These devices can be effective for both AF prevention & termination. 3. Long term rhythm control can be achieved and documented by device datalogs in persistent and permanent AF.

A cost-utility analysis for catheter ablation of atrial fibrillation in combination with warfarin and dabigatran based on the CHADS2 score in Japan.

PubMed

Kimura, Takehiro; Igarashi, Ataru; Ikeda, Shunya; Nakajima, Kazuaki; Kashimura, Shin; Kunitomi, Akira; Katsumata, Yoshinori; Nishiyama, Takahiko; Nishiyama, Nobuhiro; Fukumoto, Kotaro; Tanimoto, Yoko; Aizawa, Yoshiyasu; Fukuda, Keiichi; Takatsuki, Seiji

2017-01-01

We aimed to clarify the cost-effectiveness of an expensive combination therapy for atrial fibrillation (AF) using both catheter ablation and dabigatran compared with warfarin at each CHADS 2 score for patients in Japan. A Markov model was constructed to analyze costs and quality-adjusted life years associated with AF therapeutic options with a time horizon of 10 years. The target population was 60-year-old patients with paroxysmal AF. The indication for anticoagulation was determined according to the Japanese guideline. Anticoagulation-related data were derived from the RE-LY study and the AF recurrence rate was set at 2.7% per month during the first 12 months and at 0.40% per month afterwards. Stroke risk was determined according to AF recurrence, anticoagulation, and CHADS 2 score. The risks for stroke recurrence and stroke death were also considered. Costs were calculated from the healthcare payer's perspective, and only direct medical costs were included. Warfarin was the most preferred option for patients with a CHADS 2 score of 0 from a health economics aspect. Ablation under warfarin was preferred for a CHADS 2 score of 1-3, while ablation under dabigatran was preferred for a CHADS 2 score ≥4. The quality of life score for AF had the largest impact on the incremental cost-effectiveness ratios in the analysis between the anticoagulation arm and the anticoagulation+ablation arm for a CHADS 2 score of 2. Within the range of the Japanese willingness-to-pay threshold (¥5,000,000), the ablation+warfarin arm became the best option with its probability of 81.7% for a CHADS 2 score of 2; the dabigatran+ablation arm was the most preferred option with its probability of 56.1% for a CHADS 2 score of 4. Ablation under dabigatran therapy is an expensive therapeutic option, but it might benefit patients with a low quality of life and a high CHADS 2 score. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Simulation of Spiral Waves and Point Sources in Atrial Fibrillation with Application to Rotor Localization

PubMed Central

Ganesan, Prasanth; Shillieto, Kristina E.; Ghoraani, Behnaz

2018-01-01

Cardiac simulations play an important role in studies involving understanding and investigating the mechanisms of cardiac arrhythmias. Today, studies of arrhythmogenesis and maintenance are largely being performed by creating simulations of a particular arrhythmia with high accuracy comparable to the results of clinical experiments. Atrial fibrillation (AF), the most common arrhythmia in the United States and many other parts of the world, is one of the major field where simulation and modeling is largely used. AF simulations not only assist in understanding its mechanisms but also help to develop, evaluate and improve the computer algorithms used in electrophysiology (EP) systems for ablation therapies. In this paper, we begin with a brief overeview of some common techniques used in simulations to simulate two major AF mechanisms – spiral waves (or rotors) and point (or focal) sources. We particularly focus on 2D simulations using Nygren et al.’s mathematical model of human atrial cell. Then, we elucidate an application of the developed AF simulation to an algorithm designed for localizing AF rotors for improving current AF ablation therapies. Our simulation methods and results, along with the other discussions presented in this paper is aimed to provide engineers and professionals with a working-knowledge of application-specific simulations of spirals and foci. PMID:29629398

The burden of proof: The current state of atrial fibrillation prevention and treatment trials

PubMed Central

Zakeri, Rosita; Van Wagoner, David R.; Calkins, Hugh; Wong, Tom; Ross, Heather M.; Heist, E. Kevin; Meyer, Timothy E.; Kowey, Peter R.; Mentz, Robert J.; Cleland, John G.; Pitt, Bertram; Zannad, Faiez; Linde, Cecilia

2017-01-01

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3–5, 2015. PMID:28161513

Trends in U.S. Hospitalizations Rates and Rhythm Control Therapies Following Publication of the AFFIRM and RACE Trials

PubMed Central

Martin-Doyle, William; Essebag, Vidal; Zimetbaum, Peter; Reynolds, Matthew R.

2010-01-01

Introduction The impact of trials comparing rate vs. rhythm control for AF on subsequent use of rhythm control therapies and hospitalizations at a national level has not been described. Methods and Results We queried the Healthcare Cost & Utilization Project on the frequency of hospital admissions and performance of specific rhythm control procedures from 1998–2006. We analyzed trends in hospitalization for AF as principal diagnosis before and after the publication of key rate vs. rhythm trials in 2002. We also reviewed the use of electrical cardioversion and catheter ablation as principal procedures during hospital admissions for any cause and for AF as principal diagnosis. We additionally appraised the overall outpatient utilization of antiarrhythmic drugs during this same time frame using IMS Health’s National Prescription Audit.™ Admissions for AF as a principal diagnosis increased at 5%/year from 1998–2002. Following publication of the AFFIRM and RACE trials in 2002, admissions declined by 2%/year from 2002–2004, before rising again from 2004–06. In-hospital electrical cardioversion followed a similar pattern. National prescription volumes for antiarrhythmic drugs grew at <1%/yr from 2002–06, with a marked decline in the use of Class I-A agents, while catheter ablations during admissions for AF as the principal diagnosis increased at 30%/year. Conclusion The use of rhythm control therapies in the U.S. declined significantly in the first few years after publication of AFFIRM and RACE. This trend reversed by 2005, at which time rapid growth in the use of catheter ablation for AF was observed. PMID:21087329

The influence of residual apixaban on bleeding complications during and after catheter ablation of atrial fibrillation.

PubMed

Mukai, Yutaro; Wada, Kyoichi; Miyamoto, Koji; Nakagita, Kazuki; Fujimoto, Mai; Hosomi, Kouichi; Kuwahara, Takeshi; Takada, Mitsutaka; Kusano, Kengo; Oita, Akira

2017-10-01

The periprocedural protocol for atrial fibrillation (AF) ablation commonly includes anticoagulation therapy. Apixaban, a direct oral anticoagulant, is currently approved for clinical use; however, little is known about the effects of residual apixaban concentration on bleeding complications during/after AF ablation. Therefore, we measured residual apixaban concentration by using mass spectrometry and examined the anticoagulant's residual effects on bleeding complications. Fifty-eight patients (Mean age of 64.7±12.5 years; 31 males, 27 females) were enrolled and administered apixaban twice daily. We analyzed trough apixaban concentration, activated clotting time (ACT), heparin dose, and bleeding complications during/after AF ablation. Apixaban concentrations were directly measured using mass spectrometry. Bleeding complications were observed in 19 patients (delayed hemostasis at the puncture site, 16; hematuria, 3; hemosputum, 1). No patient required blood transfusion. The mean trough apixaban concentration was significantly lower in patients with bleeding complications than without (152.4±73.1 vs. 206.8±98.8 ng/mL respectively, P =0.037), while the heparin dose to achieve ACT>300 s was significantly higher in patients with bleeding complications (9368.4±2929.0 vs. 7987.2±2135.2 U/body respectively, P =0.046). Interestingly, a negative correlation was found between the trough apixaban concentration and the heparin dose to achieve ACT>300 s ( P =0.033, R=-0.281). Low residual plasma apixaban is associated with a higher incidence of bleeding complications during/after AF ablation, potentially because of a greater heparin requirement during AF ablation.

Atrial fibrillation surgery in nonrheumatic mitral valve disease.

PubMed

Gillinov, Marc

2007-12-01

Atrial fibrillation (AF) is present in 30-50% of patients presenting for mitral valve surgery. If left untreated, AF in these patients is associated with increased morbidity and, possibly, increased mortality. Therefore, concomitant management of the arrhythmia is indicated in most mitral valve patients with preexisting AF. The cut-and-sew Cox-Maze III procedure is extremely effective, eliminating AF in 80-95%; however, it has been supplanted by newer operations that rely upon alternate energy sources to create lines of conduction block. Early and midterm results are good with a variety of technologies. Choice of lesion set remains a matter of debate, but success of ablation appears to be enhanced by a biatrial lesion set and exceeds 90% in some series. Targeted areas for improvement in combined mitral valve surgery and AF ablation include acceptance of uniform standards for reporting results, development of improved technology for ablation and intraoperative assessment, and creation of instrumentation that facilitates minimally invasive approaches.

Surgical treatment of atrial fibrillation.

PubMed

Pagé, Pierre; Skanes, Allan C

2005-09-01

Surgery aims to eliminate atrial fibrillation (AF) through direct modification of the arrhythmogenic substratum. The Maze procedure, developed two decades ago, has proven to be clearly effective in restoring sinus rhythm in AF patients with or without associated organic cardiac disorders. Indications for surgery may be tailored to the clinical situation involved. In patients with continuous AF associated with structural heart disease (eg, valvular, congenital or coronary artery disease), the performance of a concomitant AF ablation procedure proven to add minimal morbidity to the operation may be highly beneficial to patient outcome. It is likely, although not entirely proven, that the restoration and maintenance of sinus rhythm after mitral valve surgery promotes survival by preventing tachycardia-induced cardiomyopathy and stroke. Novel strategies for AF surgery involve the use of alternate energy sources to create the lines of block in the atria and the simplification of the lesion pattern compared with the earlier Cox-Maze procedure. Published clinical data support the contention that left atrial ablation techniques performed concomitantly with valvular and/or coronary artery bypass surgery are likely to result in a 70% to 90% cure rate of AF in patients with preoperatively documented AF. Despite the lack of evidence for long-term outcome benefit, intraoperative pulmonary vein ablation, feasible with minimal morbidity, clearly appears to be an improvement over simply ignoring AF in patients undergoing cardiac surgery. Left atrial appendectomy appears warranted in patients with chronic persistent AF.

Cigarette smoking causes a worse long-term outcome in persistent atrial fibrillation following catheter ablation.

PubMed

Cheng, Wen-Han; Lo, Li-Wei; Lin, Yenn-Jiang; Chang, Shih-Lin; Hu, Yu-Feng; Hung, Yuan; Chung, Fa-Po; Chang, Ting-Yung; Huang, Ting-Chung; Yamada, Shinya; Salim, Simon; Te, Abigail Louise D; Liao, Jo-Nan; Tuan, Ta-Chuan; Chao, Tze-Fan; Tsai, Tseng-Ying; Liu, Shin-Huei; Chen, Shih-Ann

2018-02-09

Cigarette smoking contributes to the development of atrial fibrosis via nicotine. The impact of smoking on ablation results in persistent atrial fibrillation (AF) is unknown. We aimed to investigate the triggers and long-term outcome between smokers and nonsmokers in the patients with persistent AF after catheter ablation. This study included 201 (177 males, 53 ± 10 years old) patients who received index catheter ablation, including pulmonary vein isolation (PVI) and complex fractionated atrial electrograms (CFAEs) ablation for persistent AF, retrospectively. Electrophysiological characteristics at the index procedure and long-term outcome were investigated to determine the differences between smokers and nonsmokers. Baseline characteristics were similar between two groups. Pulmonary vein (PV) triggers were found in all patients in the two groups. There was a higher incidence of nonpulmonary vein (NPV) triggers in smokers than in nonsmokers (61% vs. 31%, P < 0.05). There were no differences of the long-term ablation outcomes between smokers and nonsmokers in Kaplan-Meier analysis. Smokers with PV plus right atrial NPV (RA-NPV) triggers had a higher incidence of recurrence (log-rank P < 0.05) than those without RA-NPV triggers, but not in nonsmokers, after a mean follow-up of 31 ± 25 months. Smoking increases the incidence of NPV triggers in patients with persistent AF. Smokers who have RA-NPV triggers during index procedure do have a worse outcome after catheter ablation, indicating the harmful effects of nicotine to right atrium. © 2018 Wiley Periodicals, Inc.

The efficacy of intraoperative atrial radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery-the Surgical Atrial Fibrillation Suppression (SAFS) Study.

PubMed

Veasey, Rick A; Segal, Oliver R; Large, Janet K; Lewis, Michael E; Trivedi, Uday H; Cohen, Andrew S; Hyde, Jonathan A J; Sulke, A Neil

2011-10-01

Studies assessing radiofrequency ablation (RFA) for atrial fibrillation (AF) performed at the time of concomitant cardiac surgery have reported high success rates. The efficacy of this treatment has primarily been determined by a single electrocardiogram (ECG) or 24-h Holter monitor at follow-up. We sought to assess the true efficacy of this procedure using prolonged cardiac rhythm monitoring. One hundred patients with paroxysmal (n = 47) and persistent AF (n = 53) requiring cardiac surgery were enrolled. Patients were clinically reviewed 6 weeks post-operatively and were monitored with 7-day Holter with full disclosure, 6 months post-surgery. A cohort of 50 patients also underwent 7 day Holter monitoring preoperatively. AF recurrence was defined as >30 s of AF. At 6 months, 75% of patients were in sinus rhythm according to a single ECG. However, only 62% of patients were free from AF on 7-day Holter; all AF episodes in these patients were asymptomatic. The procedure resulted in a significant decrease in AF burden from 56.2% at baseline to 27.5% at 6 months follow-up, (p < 0.001). Predictors of AF recurrence were (1) pre-operative AF duration; (2) persistent compared with paroxysmal AF; (3) increasing left atrial diameter and (4) requirement for mitral valve surgery. Surgical RFA for the treatment of AF, during concomitant cardiac surgery, is a successful procedure and significantly reduces AF burden. However, 13% of patients have asymptomatic AF episodes only identified with continuous monitoring. This has important implications for post-operative anti-arrhythmic and anticoagulant management and for the definition of surgical AF ablation success.

Increase in pulmonary arterial pressure after atrial fibrillation ablation: incidence and associated findings.

PubMed

Witt, Chance M; Fenstad, Eric R; Cha, Yong-Mei; Kane, Garvan C; Kushwaha, Sudhir S; Hodge, David O; Asirvatham, Samuel J; Oh, Jae K; Packer, Douglas L; Powell, Brian D

2014-06-01

The stiff left atrial (LA) syndrome is defined as pulmonary hypertension (PH) secondary to reduced LA compliance and has recently been shown to be one cause of PH after atrial fibrillation (AF) ablation. We aimed to determine the incidence of an increase in pulmonary arterial (PA) pressure post-ablation and examine the clinical and echocardiographic associations. Patients who underwent AF ablation between 1999 and 2011 were included if they had both an echocardiogram pre-ablation and 3 months post-ablation. Patients were then separated into two groups with the increased PA pressure group defined as patients with >10 mmHg increase in right ventricular systolic pressure (RVSP) post-ablation and a post-ablation RVSP >35 mmHg. Of the 499 patients meeting the study criteria, 41 (8.2%) had an increase in RVSP >10 mmHg and RVSP >35 mmHg post-ablation. On echocardiogram, the two groups had similar E/A and E/e' ratios pre-ablation. However, post-ablation, the increased PA pressure group had higher E/A (2.12 vs. 1.49, p < 0.01) and E/e' (14.7 vs. 11.2, p < 0.01) ratios. LA expansion index values were lower in the increased PA pressure group pre-ablation (51 vs. 92%, p < 0.01), but not significantly different post-ablation (82 vs. 88%, p = 0.44). Around 8% of patients develop an increase in estimated PA pressure after AF ablation. Echocardiographic parameters suggest that patients who develop increased PA pressure are developing (or unmasking) left ventricular diastolic dysfunction.

Radiofrequency catheter ablation of atrial fibrillation: Electrical modification suggesting transmurality is faster achieved with remote magnetic catheter in comparison with contact force use.

PubMed

Bun, Sok-Sithikun; Ayari, Anis; Latcu, Decebal Gabriel; Errahmouni, Abdelkarim; Saoudi, Nadir

2017-07-01

Remote magnetic navigation (RMN) and contact force (CF) sensing catheters are available technologies for radiofrequency (RF) catheter ablation of atrial fibrillation (AF). Our purpose was to compare time to electrogram (EGM) modification suggesting transmural lesions between RMN and CF-guided AF ablation. A total of 1,008 RF applications were analyzed in 21 patients undergoing RMN (n = 11) or CF-guided ablation (n = 10) for paroxysmal AF. All procedures were performed in sinus rhythm during general anesthesia. Time to EGM modification was measured until transmurality criteria were fulfilled: (1) complete disappearance of R if initial QR morphology; (2) diminution > 75% of R if initial QRS morphology; (3) complete disappearance of R' of initial RSR' morphology. Impedance drop as well as force time integral (FTI) were also assessed for each application. Mean CF at the beginning of each RF application in the CF group was 11 ± 2 g and mean FTI per application was 488 ± 163 gs. Time to EGM modification was significantly shorter in the RMN group (4.52 ± 0.1 seconds vs. 5.6 ± 0.09 seconds; P < 0.00001). There was no significant difference between other procedural parameters. Remote magnetic AF ablation is associated with faster EGM modification suggesting transmurality than optimized CF and FTI-guided catheter ablation. © 2017 Wiley Periodicals, Inc.

Remotely controlled steerable sheath improves result and procedural parameters of atrial fibrillation ablation with magnetic navigation

PubMed Central

Errahmouni, Abdelkarim; Latcu, Decebal Gabriel; Bun, Sok-Sithikun; Rijo, Nicolas; Dugourd, Céline; Saoudi, Nadir

2015-01-01

Aims The magnetic navigation (MN) system may be coupled with a new advancement system that fully controls both the catheter and a robotic deflectable sheath (RSh) or with a fixed-curve sheath and a catheter-only advancement system (CAS). We aimed to compare these approaches for atrial fibrillation (AF) ablation. Methods and results Atrial fibrillation ablation patients (45, 23 paroxysmal and 22 persistent) performed with MN–RSh (RSh group) were compared with a control group (37, 18 paroxysmal and19 persistent) performed with MN–CAS (CAS group). Setup duration was measured from the procedure's start to operator transfer to control room. Ablation step duration was defined as the time from the beginning of the first radiofrequency (RF) pulse to the end of the last one and was separately acquired for the left and the right pulmonary vein (PV) pairs. Clinical characteristics, left atrial size, and AF-type distribution were similar between the groups. Setup duration as well as mapping times was also similar. Ablation step duration for the left PVs was similar, but was shorter for the right PVs in RSh group (46 ± 9 vs. 63 ± 12 min, P < 0.0001). Radiofrequency delivery time (34 ± 9 vs. 40 ± 11 min, P = 0.007) and procedure duration (227 ± 36 vs. 254 ± 62 min, P = 0.01) were shorter in RSh group. No complication occurred in RSh group. During follow-up, there were five recurrences (11%) in RSh group and 11 (29%) in CAS group (P = 0.027). Conclusion The use of the RSh for AF ablation with MN is safe and improves outcome. Right PV isolation is faster, RF delivery time and procedure time are reduced. PMID:25662989

Contact-force guided single-catheter approach for pulmonary vein isolation: Feasibility, outcomes, and cost-effectiveness.

PubMed

Pambrun, Thomas; Combes, Stéphane; Sousa, Pedro; Bloa, Mathieu Le; El Bouazzaoui, Rim; Grand-Larrieu, Delphine; Thompson, Nathaniel; Martin, Ruairidh; Combes, Nicolas; Boveda, Serge; Haïssaguerre, Michel; Albenque, Jean-Paul

2017-03-01

For conventional ablation of paroxysmal atrial fibrillation (AF), an ablation catheter in conjunction with a circular mapping catheter (CMC) is typically used for pulmonary vein isolation (PVI). The purpose of this study was to evaluate an approach for PVI with a single contact-force (CF) ablation catheter in terms of procedural reliability, outcomes, and cost-effectiveness. One hundred consecutive patients with paroxysmal AF were included in the study. Fifty patients (study group) underwent a CF-guided single-catheter approach, whereby PVI was demonstrated when sequential pacing at 9 equidistant points within the lesion set (carina included) failed to capture the left atrium. For confirmation, PVI was verified with a CMC. In comparison, 50 patients (control group) underwent a conventional PVI ablation guided by a CMC. Procedure time (101 ± 17 minutes vs 107 ± 15 minutes, P = .11), ablation time (24.2 ± 7.1 minutes vs 22.6 ± 8.8 minutes, P = .37), fluoroscopy time (5.6 ± 2.2 minutes vs 8.3 ± 3.4 minutes, P = .09), and applied CF (17.8 ± 2.6 g vs 18 ± 2.8 g, P = .72) did not reach statistical difference between the study and control groups. CF-guided single-catheter ablation achieved successful PVI in 98% of the study group and a 31% reduction in cost. At 1-year follow-up, sinus rhythm maintenance rate was similar in both groups (86% vs 84%, P = .78). In paroxysmal AF, a CF-guided single-catheter technique is an effective method for PVI, yielding substantial cost savings and clinical results similar to a conventional approach. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrogram Morphology Recurrence Patterns during Atrial Fibrillation

PubMed Central

Ng, Jason; Gordon, David; Passman, Rod S.; Knight, Bradley P.; Arora, Rishi; Goldberger, Jeffrey J.

2014-01-01

Background Traditional mapping of atrial fibrillation (AF) is limited by changing electrogram morphologies and variable cycle lengths. Objective We tested the hypothesis that morphology recurrence plot analysis would identify sites of stable and repeatable electrogram morphology patterns. Methods AF electrograms recorded from left atrial (LA) and right atrial (RA) sites in 19 patients (10 male, 59±10 years old) prior to AF ablation were analyzed. Morphology recurrence plots for each electrogram recording were created by cross-correlation of each automatically detected activation with every other activation in the recording. A recurrence percentage, the percentage of the most common morphology, and the mean cycle length of activations with the most common morphology (CLR) were computed. Results The morphology recurrence plots commonly showed checkerboard patterns of alternating high and low cross correlation values indicating periodic recurrences in morphologies. The mean recurrence percentage for all sites and all patients was 38±25%. The highest recurrence percentage per patient averaged 83±17%. The highest recurrence percentage was located in the RA in 5 patients and in the LA in 14 patients. Patients with sites of shortest CLR in the LA and RA had ablation failure rates of 25% and 100%, respectively (HR=4.95; p=0.05). Conclusions A new technique to characterize electrogram morphology recurrence demonstrated that there is a distribution of sites with high and low repeatability of electrogram morphologies. Sites with rapid activation of highly repetitive morphology patterns may be critical to sustaining AF. Further testing of this approach to map and ablate AF sources is warranted. PMID:25101485

Direct His bundle pacing post AVN ablation.

PubMed

Lakshmanadoss, Umashankar; Aggarwal, Ashim; Huang, David T; Daubert, James P; Shah, Abrar

2009-08-01

Atrioventricular nodal (AVN) ablation with concomitant pacemaker implantation is one of the strategies that reduce symptoms in patients with atrial fibrillation (AF). However, the long-term adverse effects of right ventricular (RV) apical pacing have led to the search for alternating sites of pacing. Biventricular pacing produces a significant improvement in functional capacity over RV pacing in patients undergoing AVN ablation. Another alternative site for pacing is direct His bundle to reduce the adverse outcome of RV pacing. Here, we present a case of direct His bundle pacing using steerable lead delivery system in a patient with symptomatic paroxysmal AF with concurrent AVN ablation.

Catheter ablation of atrial fibrillation in patients with heart failure and preserved ejection fraction.

PubMed

Black-Maier, Eric; Ren, Xinru; Steinberg, Benjamin A; Green, Cynthia L; Barnett, Adam S; Rosa, Normita Sta; Al-Khatib, Sana M; Atwater, Brett D; Daubert, James P; Frazier-Mills, Camille; Grant, Augustus O; Hegland, Donald D; Jackson, Kevin P; Jackson, Larry R; Koontz, Jason I; Lewis, Robert K; Sun, Albert Y; Thomas, Kevin L; Bahnson, Tristam D; Piccini, Jonathan P

2018-05-01

Few studies have examined outcomes of catheter ablation for atrial fibrillation (AF) in patients with heart failure (HF) with preserved ejection fraction (HFpEF). The purpose of this study was to compare outcomes of AF ablation in patients with HFpEF vs HF with reduced ejection fraction (HFrEF). We performed a retrospective study of 230 patients with HF who underwent AF ablation, including 97 (42.2%) with HFrEF and 133 (57.8%) with HFpEF. Outcomes included adverse events, symptoms (Mayo AF Symptom Inventory [MAFSI]), New York Heart Association (NYHA) functional class, and freedom from recurrent atrial arrhythmia at 12 months. Overall, 150 of 230 patients had nonparoxysmal AF (62.8% HFpEF vs 63.0% HFrEF). Patients with HFpEF had a smaller mean left atrial diameter (4.4 ± 0.8 cm vs 4.7 ± 0.7 cm; P = .013) and were less likely to be taking a beta-blocker at baseline (72.9% vs 85.6%; P = .022). Median (Q1, Q3) procedure times (233 minutes [192, 290] vs 233.5 minutes [193.0, 297.5]; P = .780) and adverse events such as acute HF (3.8% vs 6.2%; P = .395) were similar between HFpEF and HFrEF patients. Freedom from recurrent atrial arrhythmia was not significantly different in HFpEF vs HFrEF patients (33.9% vs 32.6%; adjusted hazard ratio 1.47; 95% confidence interval 0.72-3.01), with similar improvements in NYHA functional class (-0.32 vs -0.19; P = .135) and MAFSI symptom severity (-0.23 vs -0.09; P = .116) after ablation. Catheter ablation of AF seems to have similar effectiveness in patients with HF, regardless of presence of systolic dysfunction. There were no significant differences in procedural characteristics, arrhythmia-free recurrence, or functional improvements between patients with HFpEF and those with HFrEF. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

[Chronic outcome of patients with paroxysmal atrial fibrillation post catheter ablation].

PubMed

Lin, Yu-bi; Xia, Yun-long; Gao, Lian-jun; Chu, Zhen-liang; Cong, Pei-xin; Chang, Dong; Yin, Xiao-meng; Zhang, Shu-long; Yang, Dong-Hui; Yang, Yan-Zong

2009-12-01

High short-term successful rate was reported for catheter ablation in patients with paroxysmal atrial fibrillation (AF), we analyzed the long-term outcome (success rate, anticoagulation therapy and embolism event, anti-arrhythmic therapy and death post procedure) of catheter ablation for paroxysmal AF in this study. From January 2000 to December 2004, 106 consecutive patients with drug-refractory paroxysmal AF underwent catheter ablation and were followed-up for (60.7 + or - 11.8) months. Segmental pulmonary vein isolation (SPVI) was routinely performed by radiofrequency energy under the guidance of circular mapping catheter. The patients were followed up with 24 h-holter, ECG, telephone or letter. Data on recurrence of AF, the anticoagulation medication and the incidence of embolism, anti-arrhythmic therapy were obtained. There were 9 patients lost to follow up. In the remaining 97 patients [65 males, (54.8 + or - 11.2) years old], 3 cases died from cancer, sinus rhythm was maintained in 68 patients (Group S, 72.3%) and AF recurrence evidenced in 26 patients (Group R, 27.7%). In Group S, 56 patients (82.4%) discontinued anticoagulation medication, and 12 patients continued to take aspirin. There was no embolism event in Group S during follow-up. In Group R, 1 patient continued to take warfarin; 11 patients continued to take aspirin and 2 patients suffered from cerebral embolism. Anticoagulation medication was discontinued in 14 patients (53.8%) and 1 patient suffered form cerebral embolism. The incidence of embolism event in Group R is significantly higher than in Group S (P < 0.01). More patients discontinued anti-arrhythmic medication in Group S than in Group R (80.9% vs. 56.0%, P < 0.05). Catheter ablation is associated with satisfactory long-term success rate, reduced anti-arrhythmia medication, improved quality of life in patients with paroxysmal AF.

Clinical predictors of cardiac magnetic resonance late gadolinium enhancement in patients with atrial fibrillation.

PubMed

Chrispin, Jonathan; Ipek, Esra Gucuk; Habibi, Mohammadali; Yang, Eunice; Spragg, David; Marine, Joseph E; Ashikaga, Hiroshi; Rickard, John; Berger, Ronald D; Zimmerman, Stefan L; Calkins, Hugh; Nazarian, Saman

2017-03-01

This study aims to examine the association of clinical co-morbidities with the presence of left atrial (LA) late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). Previous studies have established the severity of LA LGE to be associated with atrial fibrillation (AF) recurrence following AF ablation. We sought to determine whether baseline clinical characteristics were associated with LGE extent among patients presenting for an initial AF ablation. The cohort consisted of 179 consecutive patients with no prior cardiac ablation procedures who underwent pre-procedure LGE-CMR. The extent of LA LGE for each patient was calculated using the image intensity ratio, normalized to the mean blood pool intensity, corresponding to a bipolar voltage ≤0.3 mV. The association of LGE extent with baseline clinical characteristics was examined using non-parametric and multivariable models. The mean age of the cohort was 60.9 ± 9.6 years and 128 (72%) were male. In total, 56 (31%) patients had persistent AF. The mean LA volume was 118.4 ± 41.6 mL, and the mean LA LGE extent was 14.1 ± 10.4%. There was no association with any clinical variables with LGE extent by quartiles in the multivariable model. Extent of LGE as a continuous variable was positively, but weakly associated with LA volume in a multivariable model adjusting for age, body mass index, AF persistence, and left ventricular ejection fraction (1.5% scar/mL, P = 0.038). In a cohort of patients presenting for initial AF ablation, the presence of pre-ablation LA LGE extent was weakly, but positively associated with increasing LA volume. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Safety and Efficacy of Switching Anticoagulation to Aspirin Three Months after Successful Radiofrequency Catheter Ablation of Atrial Fibrillation

PubMed Central

Uhm, Jae-Sun; Won, Hoyoun; Joung, Boyoung; Nam, Gi-Byoung; Choi, Kee-Joon; Lee, Moon-Hyoung; Kim, You-Ho

2014-01-01

Purpose Although current guidelines recommend continuing the same antithrombotic strategy regardless of rhythm control after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), anticoagulation has a risk of major bleeding. We evaluated the safety of switching warfarin to aspirin in patients with successful AF ablation. Materials and Methods Among 721 patients who underwent RFCA of AF, 608 patients (age, 57.3±10.9 years; 77.0% male, 75.5% paroxysmal AF) who had no evidence of AF recurrence at 3 months post-RFCA were included. We compared the thromboembolic and hemorrhagic events in patients for whom warfarin was switched to aspirin (ASA group; n=296) and patients who were kept on warfarin therapy (W group; n=312). Results There were no significant differences in CHA2DS2-VASc or HAS-BLED scores between the groups. In 30 patients in the ASA group and 37 patients in W group, AF recurred and warfarin was restarted or maintained during the 18.0±12.2 months of follow-up. There were no significant differences in thromboembolic (0.3% vs. 1.0%, p=0.342) and major bleeding incidences (0.7% vs. 0.6%, p=0.958) between ASA and W groups during the follow-up period. In the 259 patients with a CHA2DS2-VASc score ≥2, there were no significant differences in thromboembolism (0.8% and 2.2%, p=0.380) or major bleeding incidences (0.8% and 1.4%, p=0.640) between ASA and W groups. Conclusion Switching warfarin to aspirin 3 months after successful RFCA of AF could be as safe and efficacious as long-term anticoagulation even in patients with CHA2DS2-VASc score ≥2. However, strict rhythm monitoring cannot be overemphasized. PMID:25048480

Temporal trends of in-hospital complications associated with catheter ablation of atrial fibrillation in the United States: An update from Nationwide Inpatient Sample database (2011-2014).

PubMed

Tripathi, Byomesh; Arora, Shilpkumar; Kumar, Varun; Abdelrahman, Mohamed; Lahewala, Sopan; Dave, Mihir; Shah, Mahek; Tan, Bryan; Savani, Sejal; Badheka, Apurva; Gopalan, Radha; Shantha, Ghanshyam Palamaner Subash; Viles-Gonzalez, Juan; Deshmukh, Abhishek

2018-05-01

Catheter ablation is widely accepted intervention for atrial fibrillation (AF) refractory to antiarrhythmic drugs, but limited data are available regarding contemporary trends in major complications and in-hospital mortality due to the procedure. This study was aimed at exploring the temporal trends of in-hospital mortality, major complications, and impact of hospital volume on frequency of AF ablation-related outcomes. The Nationwide Inpatient Sample database was utilized to identify the AF patients treated with catheter ablation. In-hospital death and common complications including vascular access complications, cardiac perforation and/or tamponade, pneumothorax, stroke, and transient ischemic attack, were identified using International Classification of Disease (ICD-9-CM) codes. In-hospital mortality rate of 0.15% and overall complication rate of 5.46% were noted among AF ablation recipients (n = 50,969). Significant increase in complications during study period (relative increase 56.37%, P-trend < 0.001) was observed. Cardiac (2.65%), vascular (1.33%), and neurological (1.05%) complications were most common. On multivariate analysis (odds ratio [OR]; 95% confidence interval [95% CI]; P value), significant predictors of complications were female sex (OR = 1.40; CI = 1.17-1.68; P value < 0.001), high burden of comorbidity as indicated by Charlson Comorbidity Index ≥2 (OR = 2.84; CI = 2.29-3.52; P value < 0.001), and low hospital volume (< 50 procedures). Our study noted a decline in AF ablation-related hospitalizations and complications associated with the procedure. These findings largely reflect shifting trends of outpatient performance of the procedure and increasing safety profile due to improved institutional expertise and catheter techniques. © 2018 Wiley Periodicals, Inc.

Temporal trends in safety and complication rates of catheter ablation for atrial fibrillation.

PubMed

Muthalaly, Rahul G; John, Roy M; Schaeffer, Benjamin; Tanigawa, Shinichi; Nakamura, Tomofumi; Kapur, Sunil; Zei, Paul C; Epstein, Laurence M; Tedrow, Usha B; Michaud, Gregory F; Stevenson, William G; Koplan, Bruce A

2018-06-01

Atrial fibrillation (AF) ablation is increasingly common, but is associated with potential major complications. Technology, experience, and protocols have evolved significantly in recent times, and may have impacted procedural safety. We sought to compare AF ablation safety profiles, including complication rates and fluoroscopy times in a "modern" versus "historical" cohort. We evaluated consecutive patients undergoing AF ablation from a modern cohort (MC) from 2014 to 2015 and a historic cohort (HC) from 2009 to 2011 for complications. Major complications were categorized according to Heart Rhythm Society guidelines. We included 1,425 patients, 726 in the HC and 699 in the MC. The MC was older, had more OSA and less valvular AF. Fifty-two (3.5%) procedures suffered major complications across the cohorts, with significantly fewer in the MC (5.0% vs. 2.3%, P  =  0.007). The largest reductions were seen in vascular, hemorrhagic, ischemic stroke, and perforation/tamponade related complications. Periprocedural antiplatelets drugs (aHR 2.1 [95 CI 1.1-3.9], P  =  0.02) and force-sensing catheters (aHR 0.4 [95 CI 0.2-0.9], P  =  0.03) were independently related to major complication rates. Direct oral anticoagulants and uninterrupted anticoagulation were not associated with complications. There was a decrease in both fluoroscopy (-17.4 minutes [95 CI 19.2-15.6], P < 0.0001) and radiofrequency ablation times (-561 seconds [95CI -750 to -371], P < 0.0001). The safety profile of AF ablation has improved significantly in less than a decade. © 2018 Wiley Periodicals, Inc.

Randomized ablation strategies for the treatment of persistent atrial fibrillation: RASTA study.

PubMed

Dixit, Sanjay; Marchlinski, Francis E; Lin, David; Callans, David J; Bala, Rupa; Riley, Michael P; Garcia, Fermin C; Hutchinson, Mathew D; Ratcliffe, Sarah J; Cooper, Joshua M; Verdino, Ralph J; Patel, Vickas V; Zado, Erica S; Cash, Nancy R; Killian, Tony; Tomson, Todd T; Gerstenfeld, Edward P

2012-04-01

The single-procedure efficacy of pulmonary vein isolation (PVI) is less than optimal in patients with persistent atrial fibrillation (AF). Adjunctive techniques have been developed to enhance single-procedure efficacy in these patients. We conducted a study to compare 3 ablation strategies in patients with persistent AF. Subjects were randomized as follows: arm 1, PVI + ablation of non-PV triggers identified using a stimulation protocol (standard approach); arm 2, standard approach + empirical ablation at common non-PV AF trigger sites (mitral annulus, fossa ovalis, eustachian ridge, crista terminalis, and superior vena cava); or arm 3, standard approach + ablation of left atrial complex fractionated electrogram sites. Patients were seen at 6 weeks, 6 months, and 1 year; transtelephonic monitoring was performed at each visit. Antiarrhythmic drugs were discontinued at 3 to 6 months. The primary study end point was freedom from atrial arrhythmias off antiarrhythmic drugs at 1 year after a single-ablation procedure. A total of 156 patients (aged 59±9 years; 136 males; AF duration, 47±50 months) participated (arm 1, 55 patients; arm 2, 50 patients; arm 3, 51 patients). Procedural outcomes (procedure, fluoroscopy, and PVI times) were comparable between the 3 arms. More lesions were required to target non-PV trigger sites than a complex fractionated electrogram (33±9 versus 22±9; P<0.001). The primary end point was achieved in 71 patients and was worse in arm 3 (29%) compared with arm 1 (49%; P=0.04) and arm 2 (58%; P=0.004). These data suggest that additional substrate modification beyond PVI does not improve single-procedure efficacy in patients with persistent AF. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00379301.

The burden of proof: The current state of atrial fibrillation prevention and treatment trials.

PubMed

Zakeri, Rosita; Van Wagoner, David R; Calkins, Hugh; Wong, Tom; Ross, Heather M; Heist, E Kevin; Meyer, Timothy E; Kowey, Peter R; Mentz, Robert J; Cleland, John G; Pitt, Bertram; Zannad, Faiez; Linde, Cecilia

2017-05-01

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3-5, 2015. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Ventricular fibrillation occurring after atrioventricular node ablation despite minimal difference between pre- and post-ablation heart rates.

PubMed

Squara, F; Theodore, G; Scarlatti, D; Ferrari, E

2017-02-01

We report the case of an 82-year-old man presenting with ventricular fibrillation (VF) occurring acutely after atrioventricular node (AVN) ablation. This patient had severe valvular cardiomyopathy, chronic atrial fibrillation (AF), and underwent prior to the AVN ablation a biventricular implantable cardiac defibrillator positioning. The VF was successfully cardioverted with one external electrical shock. What makes this presentation original is that the pre-ablation spontaneous heart rate in AF was slow (84 bpm), and that VF occurred after ablation despite a minimal heart rate drop of only 14 bpm. VF is the most feared complication of AVN ablation, but it had previously only been described in case of acute heart rate drop after ablation of at least 30 bpm (and more frequently>50 bpm). This case report highlights the fact that VF may occur after AVN ablation regardless of the heart rate drop, rendering temporary fast ventricular pacing mandatory whatever the pre-ablation heart rate. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Non-invasive identification of stable rotors and focal sources for human atrial fibrillation: mechanistic classification of atrial fibrillation from the electrocardiogram.

PubMed

Jones, Aled R; Krummen, David E; Narayan, Sanjiv M

2013-09-01

To develop electrocardiogram (ECG) tools to quantify the number of sources for atrial fibrillation (AF), i.e. spatially stable rotors and focal impulses, and whether they lie in right or left atrium. Intracardiac mapping has recently shown that paroxysmal and persistent AF is sustained by rotors or focal sources that are stable in location and thus targets for limited ablation [focal impulse and rotor modulation (FIRM)] to eliminate AF. Importantly, the numbers and locations of concurrent sources determine both the complexity of AF and the approach for ablation. In 36 AF patients (n = 29 persistent, 63 ± 9 years) in the CONventional ablation with or without Focal Impulse and Rotor Modulation (CONFIRM) trial, we developed phase lock (PL) to quantify spatial repeatability of ECG 'F-waves' between leads over time. Phase lock spectrally quantifies the angle θ between F-wave voltages in planes formed by ECG leads I, aVF, and V1 at successive points in time. We compared PL with ECG spectral dominant frequency (DF) and organizational index (OI) to characterize stable rotors and focal sources validated by intracardiac FIRM mapping. Focal impulse and rotor modulation ablation alone at ≤3 sources acutely terminated and rendered AF non-inducible or substantially slowed AF in 31 of 36 patients. Receiver operating characteristics of PL for this endpoint had area under the curve (AUC) = 0.72, and the optimum cut-point (PL = 0.09) had 74% sensitivity, 92% positive predictive value (PPV). Receiver operating characteristics areas for OI and DF were 0.50 and 0.58, respectively. Left (n = 28) or right (n = 3) atrial sources were localized by PL with AUC = 0.85, sensitivity 100%, PPV 30%, and negative predictive value 100%. Spectral DF provided AUC = 0.79. Notably, PL did not comigrate with diagnosis of paroxysmal or persistent AF (P = NS), unlike ECG DF. The novel metric of ECG PL identifies patients with fewer (≤3) or greater numbers of stable rotors/focal sources for AF, validated by intracardiac FIRM mapping, and localized them to right or left atria. These data open the possibility of using 12-lead ECG analyses to classify AF mechanistically and plan procedures for right- or left-sided FIRM ablation.

Benefits of Atrial Substrate Modification Guided by Electrogram Similarity and Phase Mapping Techniques to Eliminate Rotors and Focal Sources Versus Conventional Defragmentation in Persistent Atrial Fibrillation.

PubMed

Lin, Yenn-Jiang; Lo, Men-Tzung; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Liao, Jo-Nan; Lin, Chin-Yu; Kuo, Huan-Yu; Chang, Yi-Chung; Lin, Chen; Tuan, Ta-Chuan; Vincent Young, Hsu-Wen; Suenari, Kazuyoshi; Dan Do, Van Buu; Raharjo, Suunu Budhi; Huang, Norden E; Chen, Shih-Ann

2016-11-01

This prospective study compared the efficacy of atrial substrate modification guided by a nonlinear phase mapping technique with that of conventional substrate ablation. The optimal ablation strategy for persistent atrial fibrillation (AF) was unknown. In phase 1 study, we applied a cellular automation technique to simulate the electrical wave propagation to improve the phase mapping algorithm, involving analysis of high-similarity electrogram regions. In addition, we defined rotors and focal AF sources, using the physical parameters of the divergence and curvature forces. In phase 2 study, we enrolled 68 patients with persistent AF undergoing substrate modification into 2 groups, group-1 (n = 34) underwent similarity index (SI) and phase mapping techniques; group-2 (n = 34) received complex fractionated atrial electrogram ablation with commercially available software. Group-1 received real-time waveform similarity measurements in which a phase mapping algorithm was applied to localize the sources. We evaluated the single-procedure freedom from AF. In group-1, we identified an average of 2.6 ± 0.89 SI regions per chamber. These regions involved rotors and focal sources in 65% and 77% of patients in group-1, respectively. Group-1 patients had shorter ablation procedure times, higher termination rates, and significant reduction in AF recurrence compared to group-2 and a trend toward benefit for all atrial arrhythmias. Multivariate analysis showed that substrate mapping using nonlinear similarity and phase mapping was the independent predictor of freedom from AF recurrence (hazard ratio: 0.26; 95% confidence interval: 0.09 to 0.74; p = 0.01). Our study showed that for persistent AF ablation, a specified substrate modification guided by nonlinear phase mapping could eliminate localized re-entry and non-pulmonary focal sources after pulmonary vein isolation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Does periprocedural anticoagulation management of atrial fibrillation affect the prevalence of silent thromboembolic lesion detected by diffusion cerebral magnetic resonance imaging in patients undergoing radiofrequency atrial fibrillation ablation with open irrigated catheters? Results from a prospective multicenter study.

PubMed

Di Biase, Luigi; Gaita, Fiorenzo; Toso, Elisabetta; Santangeli, Pasquale; Mohanty, Prasant; Rutledge, Neal; Yan, Xue; Mohanty, Sanghamitra; Trivedi, Chintan; Bai, Rong; Price, Justin; Horton, Rodney; Gallinghouse, G Joseph; Beheiry, Salwa; Zagrodzky, Jason; Canby, Robert; Leclercq, Jean François; Halimi, Franck; Scaglione, Marco; Cesarani, Federico; Faletti, Riccardo; Sanchez, Javier; Burkhardt, J David; Natale, Andrea

2014-05-01

Silent cerebral ischemia (SCI) has been reported in 14% of cases after catheter ablation of atrial fibrillation (AF) with radiofrequency (RF) energy and discontinuation of warfarin before AF ablation procedures. The purpose of this study was to determine whether periprocedural anticoagulation management affects the incidence of SCI after RF ablation using an open irrigated catheter. Consecutive patients undergoing RF ablation for AF without warfarin discontinuation and receiving heparin bolus before transseptal catheterization (group I, n = 146) were compared with a group of patients who had protocol deviation in terms of maintaining the therapeutic preprocedural international normalized ratio (patients with subtherapeutic INR) and/or failure to receive pretransseptal heparin bolus infusion and/or ≥2 consecutive ACT measurements <300 seconds (noncompliant population, group II, n = 134) and with a group of patients undergoing RF ablation with warfarin discontinuation bridged with low molecular weight heparin (group III, n = 148). All patients underwent preablation and postablation (within 48 hours) diffusion magnetic resonance imaging. SCI was detected in 2% of patients (3/146) in group I, 7% (10/134) in group II, and 14% (21/148) in group III (P <.001). "Therapeutic INR" was strongly associated with a lower prevalence of postprocedural silent cerebral ischemia (SCI). Multivariable analysis demonstrated nonparoxysmal AF (odds ratio 3.8, 95% confidence interval 1.5-9.7, P = .005) and noncompliance to protocol (odds ratio 2.8, 95% confidence interval 1.5-5.1, P <.001] to be significant predictors of ischemic events. Strict adherence to an anticoagulation protocol significantly reduces the prevalence of SCI after catheter ablation of AF with RF energy. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Comparison of resource utilization of pulmonary vein isolation: cryoablation versus RF ablation with three-dimensional mapping in the Value PVI Study.

PubMed

DeVille, J Brian; Svinarich, J Thomas; Dan, Dan; Wickliffe, Andrew; Kantipudi, Charan; Lim, Hae W; Plummer, Lisa; Baker, James; Kowalski, Marcin; Baydoun, Hassan; Jenkins, Mark; Chang-Sing, Peter

2014-06-01

Point-to-point focal radiofrequency (RF) catheter ablation for aberrant pulmonary vein triggers that manifest into atrial fibrillation (AF) is the traditional method for treating symptomatic drug-resistant paroxysmal AF (PAF) when an ablation procedure is warranted. More recently, pulmonary vein isolation (PVI) using the cryoballoon has been demonstrated to be safe and effective (STOP AF clinical trial). Currently, two small studies have reviewed the procedural efficiency when comparing cryoballoon to focal RF catheter ablation procedures; however, no multicenter study has yet reported on this comparison of the two types of ablation catheters. A multicenter retrospective chart extraction and evaluation was conducted at seven geographically mixed cardiac care centers. The study examined procedural variables during ablation for PVI in PAF patients. In several procedural measurements, the two modalities were comparable in efficiencies, including: acute PVI >96%; length of hospital stay at approximately 27 hours; and about 30% usage of adenosine after procedural testing. However, when compared to RF catheters, the cryoballoon procedure demonstrated a 13% reduction in laboratory occupancy time (247 min vs 283 min), a 13% reduction in procedure time (174 min vs 200 min), and a 21% reduction in fluoroscopy time (33 min vs 42 min). Additionally, when comparing the material usage of both cryoballoon and RF catheters, the cryoballoon used more radiopaque contrast agent (78 cc vs 29 cc) while using less intraprocedural saline (1234 cc vs 2386 cc), intracardiac echocardiography (88% vs 99%), three-dimensional electroanatomic mapping (30% vs 87%), and fewer transseptal punctures (1.5 vs 1.9). This study is the first United States multicenter examination to report the procedural comparisons between the cryoballoon and focal RF catheters when used for the treatment of PAF patients. In this hospital chart review study, potential advantages were found when operating the cryoballoon with regard to hospital resource allocation. There was no statistical difference between cryoballoon and RF catheters for acute PVI success during the ablation procedure.

Wireless monitoring of reconstructed 12-lead ECG in atrial fibrillation patients enables differential diagnosis of recurrent arrhythmias.

PubMed

Vukajlovic, Dejan; Gussak, Ihor; George, Samuel; Simic, Goran; Bojovic, Bosko; Hadzievski, Ljupco; Stojanovic, Bojan; Angelkov, Lazar; Panescu, Dorin

2011-01-01

Differential diagnosis of symptomatic events in post-ablation atrial fibrillation (AF) patients (pts) is important; in particular, accurate, reliable detection of AF or atrial flutter (AFL) is essential. However, existing remote monitoring devices usually require attached leads and are not suitable for prolonged monitoring; moreover, most do not provide sufficient information to assess atrial activity, since they generally monitor only 1-3 ECG leads and rely on RR interval variability for AF diagnosis. A new hand-held, wireless, symptom-activated event monitor (CardioBip; CB) does not require attached leads and hence can be conveniently used for extended periods. Moreover, CB provides data that enables remote reconstruction of full 12-lead ECG data including atrial signal information. We hypothesized that these CB features would enable accurate remote differential diagnosis of symptomatic arrhythmias in post-ablation AF pts. 21 pts who underwent catheter ablation for AF were instructed to make a CB transmission (TX) whenever palpitations, lightheadedness, or similar symptoms occurred, and at multiple times daily when asymptomatic, during a 60 day post-ablation time period. CB transmissions (TXs) were analyzed blindly by 2 expert readers, with differences adjudicated by consensus. 7 pts had no symptomatic episodes during the monitoring period. 14 of 21 pts had symptomatic events and made a total of 1699 TX, 164 of which were during symptoms. TX quality was acceptable for rhythm diagnosis and atrial activity in 96%. 118 TX from 10 symptomatic pts showed AF (96 TX from 10 pts) or AFL (22 TX from 3 pts), and 46 TX from 9 pts showed frequent PACs or PVCs. No other arrhythmias were detected. Five pts made symptomatic TX during AF/AFL and also during PACs/PVCs. Use of CB during symptomatic episodes enabled detection and differential diagnosis of symptomatic arrhythmias. The ability of CB to provide accurate reconstruction of 12 L ECGs including atrial activity, combined with its ease of use, makes it suitable for long-term surveillance for recurrent AF in post-ablation patients.

Early Efficacy Analysis of Biatrial Ablation versus Left and Simplified Right Atrial Ablation for Atrial Fibrillation Treatment in Patients with Rheumatic Heart Disease.

PubMed

Liu, Hong; Chen, Lin; Xiao, Yingbin; Ma, Ruiyan; Hao, Jia; Chen, Baicheng; Qin, Chuan; Cheng, Wei

2015-08-01

Atrial fibrillation (AF) is the most common sustained arrhythmia. About 60% of patients with rheumatic heart disease have persistent AF. A total of 197 patients underwent valve replacement concomitant bipolar radiofrequency ablation (BRFA). Patients were divided into the biatrial ablation group and the simplified right atrial ablation group. In biatrial ablation group, the patients underwent a complete left and right atrial ablation. In simplified right atrial ablation group, the patients underwent a complete left atrial ablation and a simplified right atrial ablation. The conversion of sinus rhythm (SR) was high in both groups during the follow-up period. In the simplified right atrial ablation group, SR conversion rate was 88.29% at discharge. At six months and 12 months after surgery, 87.39% of patients and 86.49% of patients were in SR free of antiarrhythmic drugs, respectively. While in the biatrial ablation group, SA conversion rate was 89.53% at discharge. Percentage of patients in SR free of antiarrhythmic drugs was 88.37% and 88.37% at six months and 12 months after surgery, respectively. Echocardiography showed left atrial diameter decreased significantly after the surgery in the two groups. The ejection fraction and fractional shortening were improved significantly, without significant differences between the two groups. The results suggest that the concomitant left atrial and simplified right atrial BRFA for AF in patients undergoing valve replacement can achieve similar early efficiency as biatrial ablation. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Pulmonary vein anatomy predicts freedom from atrial fibrillation using remote magnetic navigation for circumferential pulmonary vein ablation.

PubMed

Sohns, Christian; Sohns, Jan M; Bergau, Leonard; Sossalla, Samuel; Vollmann, Dirk; Lüthje, Lars; Staab, Wieland; Dorenkamp, Marc; Harrison, James L; O'Neill, Mark D; Lotz, Joachim; Zabel, Markus

2013-08-01

Multidetector computed tomography (MDCT) is frequently used to guide circumferential pulmonary vein ablation (PVA) for treatment of atrial fibrillation (AF) as it offers accurate visualization of the left atrial (LA) and pulmonary vein (PV) anatomy. This study aimed to identify if PV anatomy is associated with outcomes following PVA using remote magnetic navigation (RMN). We analysed data from 138 consecutive patients and 146 ablation procedures referred for PVA due to drug-refractory symptomatic AF (age 63 ± 11 years; 57% men; 69% paroxysmal AF). The RMN using the stereotaxis system and open-irrigated 3.5 mm ablation catheters was used in all procedures. Prior to PVA, all patients underwent electrocardiogram-gated 64-MDCT for assessment of LA dimensions, PV anatomy, and electro-anatomical image integration during the procedure. Regular PV anatomy was found in 68%, a common left PV ostium was detected in 26%, and variant anatomy of the right PVs was detected in 6%. After a mean follow-up of 337 ± 102 days, 63% of the patients maintained sinus rhythm after the initial ablation, and 83% when including repeat PVA. Although acutely successful PV isolation did not differ between anatomical subgroups (regular 3.5 ± 0.8 vs. variant 3.2 ± 1.3; P = 0.31), AF recurrence was significantly higher in patients with non-regular PV anatomy (P = 0.04, hazard ratio 1.72). Pulmonary vein anatomy did not influence complication rates. Pulmonary vein anatomy assessed by MDCT is a good predictor of AF recurrence after PVA using RMN.

Spatial Relationship of Focal Impulses, Rotors and Low Voltage Zones in Patients With Persistent Atrial Fibrillation.

PubMed

Schade, Anja; Nentwich, Karin; Costello-Boerrigter, Lisa C; Halbfass, Philipp; Mueller, Patrick; Roos, Markus; Barth, Sebastian; Krug, Joachim; Szoelloesi, Geza-Atilla; Lapp, Harald; Deneke, Thomas

2016-05-01

Focal impulses (FI) and rotors are sources associated with the initiation and maintenance of atrial fibrillation (AF). Their ablation results in a lower recurrence rate. The aim of this study was to characterize for the first time the spatial relationship between such sources and atrial low voltage zones (LVZ) representing fibrosis. Twenty-five consecutive patients undergoing their first ablation for persistent AF were included. Voltage mapping of both atria was done during AF. Endocardial mapping of FI and rotors (sources) was performed using a basket catheter and displayed using RhythmView(TM) (Topera Inc.) before ablation. Spatial relationship of LVZ and sources was analyzed. LVZs covered 13 ± 12% of right atrial (RA) endocardial surface and 33 ± 25% of left atrial (LA) endocardial surface. The median number of sources was 1 [1-3] in RA and 3 [1-4] in LA. Of LA sources, 18 (30%) were definitely not associated with LVZs or pulmonary vein (PV) antra. Of RA sources, 32 (84%) were remote from LVZ. During ablation of such sources substantial cycle length (CL) prolongation or AF conversion occurred in 11/23 patients (48%). Altogether, 8/11 (73%) of these pertinent sources were located remotely from LVZ and PV antra. There is a wide discrepancy in distribution of LVZ areas and sites of identified rotors. Site and incidence of FIRM sources appear to be unpredictable with atrial substrate mapping. Further prospective, randomized studies are necessary to elucidate the impact of additional ablation of such sources in patients with persistent or longstanding persistent AF. © 2016 Wiley Periodicals, Inc.

Termination of atrial spiral waves by traction into peripheral non 1:1 conducting regions - A numerical study.

PubMed

Rozner, Amit; Zlochiver, Sharon

2016-11-01

Atrial ablation has been recently utilized to treat atrial fibrillation (AF) by isolation or destruction of arrhythmia drivers. In chronic or persistent AF patients these drivers often consist of one or few rotors at unknown locations, and several ablations are commonly conducted before arrhythmia is terminated. However, the irreversible damage done to the tissue may lead to AF recurrence. We propose an alternative strategy to terminate rotor activity by its attraction into a non 1:1 conducting region. The feasibility of the method was numerically tested in 2D models of chronic AF human atrial tissue. Left-to-right gradients of either acetylcholine (ACh) or potassium conductance were employed to generate regions of 1:1 and non 1:1 conduction, characterized by their dominant frequency (DF) ratios. Spiral waves were established in the 1:1 conducting region and raster scanning was employed using a stimulating probe to attract the spiral wave tip. The probe was then linearly moved towards the boundary between the two regions. Successful attraction of spiral waves to the probe was demonstrated when the probe was <8mm from the spiral wave tip. Maximal traction velocity without loss of anchoring increased in a non-linear way with increasing values of ACh. Success rate of spiral wave termination was over 90% for regional DF ratios of as low as 1:1.2. Given that normally much higher ratios are measured in physiological atrial tissues, we envision this technique to provide a feasible, safer alternative to ablation procedures performed in persistent AF patients. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Efficacy of catheter ablation of atrial fibrillation beyond HATCH score.

PubMed

Tang, Ri-Bo; Dong, Jian-Zeng; Long, De-Yong; Yu, Rong-Hui; Ning, Man; Jiang, Chen-Xi; Sang, Cai-Hua; Liu, Xiao-Hui; Ma, Chang-Sheng

2012-10-01

HATCH score is an established predictor of progression from paroxysmal to persistent atrial fibrillation (AF). The purpose of this study was to determine if HATCH score could predict recurrence after catheter ablation of AF. The data of 488 consecutive paroxysmal AF patients who underwent an index circumferential pulmonary veins (PV) ablation were retrospectively analyzed. Of these patients, 250 (51.2%) patients had HATCH score = 0, 185 (37.9%) patients had HATCH score = 1, and 53 (10.9%) patients had HATCH score ≥ 2 (28 patients had HATCH score = 2, 23 patients had HATCH score = 3, and 2 patients had HATCH score = 4). The patients with HATCH score ≥ 2 had significantly larger left atrium size, the largest left ventricular end systolic diameter, and the lowest ejection fraction. After a mean follow-up of (823 ± 532) days, the recurrence rates were 36.4%, 37.8% and 28.3% from the HATCH score = 0, HATCH score = 1 to HATCH score ≥ 2 categories (P = 0.498). Univariate analysis revealed that left atrium size, body mass index, and failure of PV isolation were predictors of AF recurrence. After adjustment for body mass index, left atrial size and PV isolation, the HATCH score was not an independent predictor of recurrence (HR = 0.92, 95% confidence interval = 0.76 - 1.12, P = 0.406) in multivariate analysis. HATCH score has no value in prediction of AF recurrence after catheter ablation.

Identification of Left Atrial Appendage Thrombi in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation Using Intra-Cardiac Echocardiography and Cardiac Computed Tomography.

PubMed

Ikegami, Yukinori; Tanimoto, Kojiro; Inagawa, Kohei; Shiraishi, Yasuyuki; Fuse, Jun; Sakamoto, Munehisa; Momiyama, Yukihiko; Takatsuki, Seiji

2017-12-25

Intracardiac echocardiography (ICE) and cardiac computed tomography (CCT), in addition to standard transesophageal echocardiography (TEE), have been used to identify left atrial (LA) thrombi prior to ablation for atrial fibrillation (AF). The clinical advantages of this, however, remain unclear. This study therefore investigated the advantages of additional pre-procedural LA appendage (LAA) thrombus evaluation using ICE and the clinical value of CCT in persistent and long-standing persistent AF.Methods and Results:We analyzed data from 108 consecutive patients with persistent and long-standing persistent AF who were scheduled to undergo AF ablation. TEE was performed within 24 h prior to ablation. ICE was performed for 97 patients in whom a thrombus was not detected on TEE. CCT was performed in 95 patients. Thrombus or sludge was detected on TEE in 11 patients (10.3%), for whom ablation was cancelled. Four additional patients were diagnosed with LAA thrombus on ICE. When TEE and ICE were used as the reference for thrombus detection, the sensitivity, specificity, positive predictive value, and negative predictive value of CCT for identifying contrast defects in the LAA were 100%, 81.0%, 40.7%, and 100%, respectively. ICE combined with TEE increased the detection rate of LAA thrombi in patients with persistent and long-standing persistent AF. Moreover, CCT had high sensitivity and negative predictive value for LAA thrombus detection.

Outcomes after cryoballoon or radiofrequency ablation for persistent atrial fibrillation: a multicentric propensity-score matched study.

PubMed

Boveda, Serge; Providência, Rui; Defaye, Pascal; Pavin, Dominique; Cebron, Jean-Pierre; Anselme, Frederic; Halimi, Franck; Khoueiry, Ziad; Combes, Nicolas; Combes, Stephane; Jacob, Sophie; Albenque, Jean-Paul; Sousa, Pedro

2016-11-01

Recent data show no benefit of additional ablation beyond pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF). Evidence suggests that radiofrequency energy (RF) and cryoballoon (CRYO) have comparable efficacy for PVI. We aimed to assess the outcomes after a single catheter ablation procedure, comparing PVI using CRYO vs. RF ablation for PVI plus additional ablation in a cohort of patients with persistent AF. In this prospective multicenter propensity score-matched comparison, 59 consecutive patients undergoing CRYO ablation of persistent AF were matched to 59 patients treated with RF from November 2010 to June 2012. During a mean follow-up of 15.6 ± 11.5 months, 43.2 % of patients presented atrial arrhythmia relapse after a blanking period of 3 months, which was comparable between the two groups (40.7 % in CRYO vs. 45.8 % in RF, Log rank P = 0.14; HR = 0.67, 95 %CI 0.38-1.16, P = 0.15), despite the fact that 52.5 % of RF patients add additional complex fractionated atrial electrogram ablation, as well as left atrial linear ablation in over two-thirds (roof line in 67.8 % and mitral isthmus in 32.2 %). On multivariate Cox regression, only AF duration in years (HR = 1.10, 95 %CI 1.01-1.10, P = 0.04) was a predictor of relapse. Patients undergoing RF ablation presented a numerically, but non-significantly, lower complication rate (6.8 vs 10.2 %, P = 0.51). In our multicenter experience, freedom from atrial arrhythmias was comparable among matched patients treated with CRYO and RF, despite non-significant trends in favor of RF in terms of complications, at the cost of longer procedure times.

Atrial Tachycardias Following Atrial Fibrillation Ablation

PubMed Central

Sághy, László; Tutuianu, Cristina; Szilágyi, Judith

2015-01-01

One of the most important proarrhythmic complications after left atrial (LA) ablation is regular atrial tachycardia (AT) or flutter. Those tachycardias that occur after atrial fibrillation (AF) ablation can cause even more severe symptoms than those from the original arrhythmia prior to the index ablation procedure since they are often incessant and associated with rapid ventricular response. Depending on the method and extent of LA ablation and on the electrophysiological properties of underlying LA substrate, the reported incidence of late ATs is variable. To establish the exact mechanism of these tachycardias can be difficult and controversial but correlates with the ablation technique and in the vast majority of cases the mechanism is reentry related to gaps in prior ablation lines. When tachycardias occur, conservative therapy usually is not effective, radiofrequency ablation procedure is mostly successful, but can be challenging, and requires a complex approach. PMID:25308808

Post-procedural evaluation of catheter contact force characteristics

NASA Astrophysics Data System (ADS)

Koch, Martin; Brost, Alexander; Kiraly, Atilla; Strobel, Norbert; Hornegger, Joachim

2012-03-01

Minimally invasive catheter ablation of electric foci, performed in electrophysiology labs, is an attractive treatment option for atrial fibrillation (AF) - in particular if drug therapy is no longer effective or tolerated. There are different strategies to eliminate the electric foci inducing the arrhythmia. Independent of the particular strategy, it is essential to place transmural lesions. The impact of catheter contact force on the generated lesion quality has been investigated recently, and first results are promising. There are different approaches to measure catheter-tissue contact. Besides traditional haptic feedback, there are new technologies either relying on catheter tip-to-tissue contact force or on local impedance measurements at the tip of the catheter. In this paper, we present a novel tool for post-procedural ablation point evaluation and visualization of contact force characteristics. Our method is based on localizing ablation points set during AF ablation procedures. The 3-D point positions are stored together with lesion specific catheter contact force (CF) values recorded during the ablation. The force records are mapped to the spatial 3-D positions, where the energy has been applied. The tracked positions of the ablation points can be further used to generate a 3-D mesh model of the left atrium (LA). Since our approach facilitates visualization of different force characteristics for post-procedural evaluation and verification, it has the potential to improve outcome by highlighting areas where lesion quality may be less than desired.

Simple Model for Identifying Critical Regions in Atrial Fibrillation

NASA Astrophysics Data System (ADS)

Christensen, Kim; Manani, Kishan A.; Peters, Nicholas S.

2015-01-01

Atrial fibrillation (AF) is the most common abnormal heart rhythm and the single biggest cause of stroke. Ablation, destroying regions of the atria, is applied largely empirically and can be curative but with a disappointing clinical success rate. We design a simple model of activation wave front propagation on an anisotropic structure mimicking the branching network of heart muscle cells. This integration of phenomenological dynamics and pertinent structure shows how AF emerges spontaneously when the transverse cell-to-cell coupling decreases, as occurs with age, beyond a threshold value. We identify critical regions responsible for the initiation and maintenance of AF, the ablation of which terminates AF. The simplicity of the model allows us to calculate analytically the risk of arrhythmia and express the threshold value of transversal cell-to-cell coupling as a function of the model parameters. This threshold value decreases with increasing refractory period by reducing the number of critical regions which can initiate and sustain microreentrant circuits. These biologically testable predictions might inform ablation therapies and arrhythmic risk assessment.

Towards multispectral endoscopic imaging of cardiac lesion assessment and classification for cardiac ablation therapy

NASA Astrophysics Data System (ADS)

Park, Soo Young; Singh-Moon, Rajinder P.; Hendon, Christine P.

2018-02-01

Pulmonary vein (PV) isolation is a critical procedure for the treatment and termination of atrial fibrillation (AF). The success of such treatment depends on the extent of tissue damage, where partial lesions can allow abnormal electrical conduction and risk relapse of AF. Proper evaluation of lesion delivery and ablation line continuity remains challenging with current techniques and in part limit procedural efficacy. A tool for direct visualization of endo-myocardial lesions in vivo could potentially reduce ambiguity in treatment location and extent and improve the overall fidelity of lesion sets. In this work, we introduce a method for wide-field visualization of myocardial tissue including the discernment of ablated and non-ablated regions using an endoscopic multispectral imaging system (EMIS). The system was designed to fit the working channel of most commercial sheathes (<4 Fr) and supported quadruple-wavelength reflectance imaging through a flexible fiber-bundle. A total of 50 endocardial lesions were created and imaged on nine swine hearts, ex vivo in addition to 15 lesions on human LA samples near PV regions. A pixel-wise linear discriminant analysis algorithm was developed to classify regions of ablation treatment based on calibrated EMI maps. Results show good agreement of treatment severity and spatial extent compared to post-hoc tissue vital staining.

Minimally invasive surgery for atrial fibrillation

PubMed Central

Suwalski, Piotr

2013-01-01

Atrial fibrillation (AF) remains the most common cardiac arrhythmia, affecting nearly 2% of the general population worldwide. Minimally invasive surgical ablation remains one of the most dynamically evolving fields of modern cardiac surgery. While there are more than a dozen issues driving this development, two seem to play the most important role: first, there is lack of evidence supporting percutaneous catheter based approach to treat patients with persistent and long-standing persistent AF. Paucity of this data offers surgical community unparalleled opportunity to challenge guidelines and change indications for surgical intervention. Large, multicenter prospective clinical studies are therefore of utmost importance, as well as honest, clear data reporting. Second, a collaborative methodology started a long-awaited debate on a Heart Team approach to AF, similar to the debate on coronary artery disease and transcatheter valves. Appropriate patient selection and tailored treatment options will most certainly result in better outcomes and patient satisfaction, coupled with appropriate use of always-limited institutional resources. The aim of this review, unlike other reviews of minimally invasive surgical ablation, is to present medical professionals with two distinctly different, approaches. The first one is purely surgical, Standalone surgical isolation of the pulmonary veins using bipolar energy source with concomitant amputation of the left atrial appendage—a method of choice in one of the most important clinical trials on AF—The Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST) Trial. The second one represents the most complex approach to this problem: a multidisciplinary, combined effort of a cardiac surgeon and electrophysiologist. The Convergent Procedure, which includes both endocardial and epicardial unipolar ablation bonds together minimally invasive endoscopic surgery with electroanatomical mapping, to deliver best of the two worlds. One goal remains: to help those in urgent need for everlasting relief. PMID:24251031

Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion affects the outcomes after catheter ablation for atrial fibrillation.

PubMed

Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru

2018-04-24

The a-wave in left atrial pressure (LAP) is often not observed after cardioversion (CV). We hypothesized that repeated atrial fibrillation (AF) occurs in patients who do not show a-wave pattern after CV. We investigated the impact of "LAP pattern without a-wave" on the outcome after catheter ablation (CA) for AF. We studied 100 patients (64 males, age 66 ± 8 years, 42 with non-paroxysmal AF) who underwent CA for AF. Sustained- or induced-AF were terminated with internal CV, and LAP was measured during sinus rhythm (SR) after CV. LAP pattern without a-wave was defined as absence of a-wave (the "a-wave" was defined as a protruding part by 0.2 mmHg or more from the baseline) in LAP wave form. AF was terminated with CV in all patients. Recurrent AF was detected in 35/100 (35%) during the follow-up period (13.1 ± 7.8 month). Univariate analysis revealed higher prevalence of LAP pattern without a-wave (71 vs. 17%, P < 0.0001), larger left atrial volume, elevated E wave, and decreased deceleration time as significant variables. On multivariate analysis, LAP pattern without a-wave was only independently associated with recurrent AF (P = 0.0014, OR 9.865, 95% CI 2.327-54.861). Moreover, patients with LAP pattern without a-wave had a higher risk of recurrent AF than patients with a-wave (25/36 patients, 69 vs. 10/64 patients, 16%, log-rank P < 0.0001). Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion could predict recurrence after catheter ablation for AF.

Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management.

PubMed

Margulescu, Andrei D; Mont, Lluis

2017-08-01

Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.

Achieving Bidirectional Long Delays In Pulmonary Vein Antral Lines Prior To Bidirectional Block In Patients With Paroxysmal Atrial Fibrillation (The Bi-Bi Technique For Atrial Fibrillation Ablation).

PubMed

Mina, Adel F; Warnecke, Nicholas L

2016-01-01

Background: Pulmonary Vein Antral isolation (PVAI) is currently the standard of care for both paroxysmal and persistent atrial fibrillation ablation. Reconnection to the pulmonary vein is the most common cause of recurrence of atrial fibrillation. Achieving the endpoint of bidirectional block (BDB) for cavotricuspid isthmus dependant flutter has improved our outcomes for atrial flutter ablation. With this we tried to achieve long delays in the pulmonary veins antral lines prior to complete isolation comparable to those delays found in patient with bidirectional block of atrial flutter lines. Study Objective: The objective of this paper was to evaluate feasibility and efficacy of achieving Bidirectional long delays in pulmonary vein antral lines prior to Bidirectional Block in patient with paroxysmal atrial fibrillation. Method: A retrospective analysis was performed on patients who had paroxysmal atrial fibrillation procedures at Unity Point Methodist from January 2015 to January 2016. 20 consecutive patients with paroxysmal atrial fibrillation who had AF ablation using the Bi-Bi technique were evaluated. Result: Mean age was 63, number of antiarrhythmic used prior to ablation was 1.4, mean left atrial size was 38 mm. Mean chads score was 1.3. Mean EF was 53%. Long delays in the left antral circumferential lines were achieved with mean delay of 142 milliseconds +/-100. Also long delays in the right antral circumferential lines were achieved with mean delay of 150 milliseconds +/-80. 95 % (19/20) of patients were free of any atrial arrhythmias and were off antiarrhythmic medications for AF post procedure. There was only one transient complication in one patient who developed a moderate pericardial effusion that was successfully drained with no hemodynamic changes. The only patient who had recurrence was found to have asymptomatic AF with burden on his device <1%, this patient was also found to have non PV triggers for his AF. In patients with only PV triggered AF success rate was 100%. Conclusion: Achievement of Bidirectional long delays in pulmonary vein antral lines prior to Bidirectional Block in patient with paroxysmal atrial fibrillation is feasible and highly effective technique in this small cohort of patients studied. We also outlined the procedure in details.

Computationally efficient method for localizing the spiral rotor source using synthetic intracardiac electrograms during atrial fibrillation.

PubMed

Shariat, M H; Gazor, S; Redfearn, D

2015-08-01

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is an extremely costly public health problem. Catheter-based ablation is a common minimally invasive procedure to treat AF. Contemporary mapping methods are highly dependent on the accuracy of anatomic localization of rotor sources within the atria. In this paper, using simulated atrial intracardiac electrograms (IEGMs) during AF, we propose a computationally efficient method for localizing the tip of the electrical rotor with an Archimedean/arithmetic spiral wavefront. The proposed method deploys the locations of electrodes of a catheter and their IEGMs activation times to estimate the unknown parameters of the spiral wavefront including its tip location. The proposed method is able to localize the spiral as soon as the wave hits three electrodes of the catheter. Our simulation results show that the method can efficiently localize the spiral wavefront that rotates either clockwise or counterclockwise.

Isolation of the posterior left atrium for patients with persistent atrial fibrillation: routine adenosine challenge for dormant posterior left atrial conduction improves long-term outcome.

PubMed

McLellan, Alex J A; Prabhu, Sandeep; Voskoboinik, Alex; Wong, Michael C G; Walters, Tomos E; Pathik, Bhupesh; Morris, Gwilym M; Nisbet, Ashley; Lee, Geoffrey; Morton, Joseph B; Kalman, Jonathan M; Kistler, Peter M

2017-12-01

Catheter ablation to achieve posterior left atrial wall (PW) isolation may be performed as an adjunct to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF). We aimed to determine whether routine adenosine challenge for dormant posterior wall conduction improved long-term outcome. A total of 161 patients with persistent AF (mean age 59 ± 9 years, AF duration 6 ± 5 years) underwent catheter ablation involving circumferential PVI followed by PW isolation. Posterior left atrial wall isolation was performed with a roof and inferior wall line with the endpoint of bidirectional block. In 54 patients, adenosine 15 mg was sequentially administered to assess reconnection of the pulmonary veins and PW. Sites of transient reconnection were ablated and adenosine was repeated until no further reconnection was present. Holter monitoring was performed at 6 and 12 months to assess for arrhythmia recurrence. Posterior left atrial wall isolation was successfully achieved in 91% of 161 patients (procedure duration 191 ± 49 min, mean RF time 40 ± 19 min). Adenosine-induced reconnection of the PW was demonstrated in 17%. The single procedure freedom from recurrent atrial arrhythmia was superior in the adenosine challenge group (65%) vs. no adenosine challenge (40%, P < 0.01) at a mean follow-up of 19 ± 8 months. After multiple procedures, there was significantly improved freedom from AF between patients with vs. without adenosine PW challenge (85 vs. 65%, P = 0.01). Posterior left atrial wall isolation in addition to PVI is a readily achievable ablation strategy in patients with persistent AF. Routine adenosine challenge for dormant posterior wall conduction was associated with an improvement in the success of catheter ablation for persistent AF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions please email: journals.permissions@oup.com.

Two-year clinical follow-up after pulmonary vein isolation using high-intensity focused ultrasound (HIFU) and an esophageal temperature-guided safety algorithm.

PubMed

Neven, Kars; Metzner, Andreas; Schmidt, Boris; Ouyang, Feifan; Kuck, Karl-Heinz

2012-03-01

High-intensity frequency ultrasound (HIFU) can achieve pulmonary vein isolation (PVI), but severe complications have happened. An esophageal temperature (ET)-guided safety algorithm was implemented. We investigated medium-term outcome. After left atrial access, HIFU was applied until complete PVI. The safety algorithm was as follows: ≤3 complete ablations per pulmonary vein, early abortion when ET ≥40.0°C, use of Power Modulation at ET >39.0°C or when after 20 to 30 seconds no change in PV electrograms: to reduce the ablation temperature in the surrounding tissue, acoustic power is switched on and off with a frequency of 1 Hz; in all first ablations, use of Power Modulation after 50% of programmed time. Touch-up radiofrequency ablation when PVI failed. Follow-up included interviews and Holter electrocardiograms. Recurrence was defined as atrial fibrillation (AF) >30 seconds without a blanking period. A total of 28 symptomatic patients (18 males, age 63 years), with paroxysmal AF (n = 19) and persistent AF (n = 9) were included. After a median follow-up of 738 days, 22 of the 28 patients (79%) were free of AF without antiarrhythmic drugs. After 1 repeat procedure with radiofrequency ablation, 5 patients remained free of AF. The complications were as follows: 1 lethal atrial-to-esophageal fistula at day 31, 1 pericardial effusion at day 48, 1 unexplained death at day 49, and 2 persistent phrenic nerve palsies with full recovery within 12 months. Two-year follow-up after PVI using HIFU and an ET-guided safety algorithm shows success rates similar to those of radiofrequency-based procedures but with higher complication rates. Importantly, the ET-guided safety algorithm failed to prevent severe complications. HIFU does not meet safety standards required for the treatment of AF, and this led to a halt of its clinical use. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

THE MECHANISM OF LESION FORMATION BY FOCUSED ULTRASOUND ABLATION CATHETER FOR TREATMENT OF ATRIAL FIBRILLATION

PubMed Central

Sinelnikov, Y.D.; Fjield, T.; Sapozhnikov, O.A.

2009-01-01

The application of therapeutic ultrasound for the treatment of atrial fibrillation (AF) is investigated. The results of theoretical and experimental investigation of ultrasound ablation catheter are presented. The major components of the catheter are the high power cylindrical piezoelectric element and parabolic balloon reflector. Thermal elevation in the ostia of pulmonary veins is achieved by focusing the ultrasound beam in shape of a torus that transverses the myocardial tissue. High intensity ultrasound heating in the focal zone results in a lesion surrounding the pulmonary veins that creates an electrical conduction blocks and relief from AF symptoms. The success of the ablation procedure largely depends on the correct choice of reflector geometry and ultrasonic power. We present a theoretical model of the catheter’s acoustic field and bioheat transfer modeling of cardiac lesions. The application of an empirically derived relation between lesion formation and acoustic power is shown to correlate with the experimental data. Developed control methods combine the knowledge of theoretical acoustics and the thermal lesion formation simulations with experiment and thereby establish rigorous dosimetry that contributes to a safe and effective ultrasound ablation procedure. PMID:20161431

Evolution of Force Sensing Technologies.

PubMed

Shah, Dipen

2017-06-01

In order to Improve the procedural success and long-term outcomes of catheter ablation techniques for atrial fibrillation (AF), an Important unfulfilled requirement is to create durable electrophysiologically complete lesions. Measurement of contact force (CF) between the catheter tip and the target tissue can guide physicians to optimise both mapping and ablation procedures. Contact force can affect lesion size and clinical outcomes following catheter ablation of AF. Force sensing technologies have matured since their advent several years ago, and now allow the direct measurement of CF between the catheter tip and the target myocardium in real time. In order to obtain complete durable lesions, catheter tip spatial stability and stable contact force are important. Suboptimal energy delivery, lesion density/contiguity and/or excessive wall thickness of the pulmonary vein-left atrial (PV-LA) junction may result in conduction recovery at these sites. Lesion assessment tools may help predict and localise electrical weak points resulting in conduction recovery during and after ablation. There is increasing clinical evidence to show that optimal use of CF sensing during ablation can reduce acute PV re-conduction, although prospective randomised studies are desirable to confirm long-term favourable clinical outcomes. In combination with optimised lesion assessment tools, contact force sensing technology has the potential to become the standard of care for all patients undergoing AF catheter ablation.

Atrial Fibrillation Radiofrequency Ablation: Safety Using Contact Force Catheter In A Low-Volume Centre.

PubMed

Vaccari Md, Diego; Giacopelli MSc, Daniele; Rocchetto MSc, Eros; Vittadello Md, Sabina; Mantovan Md, Roberto; Neri Md, Gianfilippo

2014-01-01

The tip-to-tissue contact force (CF) has been identified as a potential determinant of lesion quality during radiofrequency (RF) ablation. The aim of this paper is to report the experience of a single low-volume centre in the atrial fibrillation (AF) ablation procedure with an RF catheter capable of measuring this parameter. CF data and their possible implications on patient safety are presented. Thirty-nine consecutive patients suffering of paroxysmal or permanent AF received percutaneous ablation with the novel catheter studied. Procedural characteristics, CF applied and safety events related to the procedure were reported. During RF application the mean CF value was 17 ± 3 g, with a maximum mean value of 37 ± 8 g. CF value never exceeded 62 g and in the 74% of the RF applications ranged between 10 g and 30 g. No complication related to the catheter manipulation or to the energy delivered was observed. This study of a single centre with a low level of experience in AF ablation suggests that the ability to measure CF may provide additional useful information to the operator. It ensures uniform ablations, with little variability in the catheter manipulations, and it avoids excessive contact forces increasing the patient safety.

Long-term outcome of catheter ablation in atrial fibrillation patients with coexistent metabolic syndrome and obstructive sleep apnea: impact of repeat procedures versus lifestyle changes.

PubMed

Mohanty, Sanghamitra; Mohanty, Prasant; DI Biase, Luigi; Bai, Rong; Trivedi, Chintan; Santangeli, Pasquale; Santoro, Francesco; Hongo, Richard; Hao, Steven; Beheiry, Salwa; Burkhardt, David; Gallinghouse, Joseph G; Horton, Rodney; Sanchez, Javier E; Bailey, Shane; Hranitzky, Patrick M; Zagrodzky, Jason; Natale, Andrea

2014-09-01

Metabolic syndrome (MS) and obstructive sleep apnea (OSA) are well-known independent risk factors for atrial fibrillation (AF) recurrence. This study evaluated ablation outcome in AF patients with coexistent MS and OSA and influence of lifestyle modifications (LSM) on arrhythmia recurrence. We included 1,257 AF patients undergoing first catheter ablation (30% paroxysmal AF). Patients having MS + OSA were classified into Group 1 (n = 126; 64 ± 8 years; 76% male). Group 2 (n = 1,131; 62 ± 11 years; 72% male) included those with either MS (n = 431) or OSA (n = 112; no CPAP users) or neither of these comorbidities (n = 588). Patients experiencing recurrence after first procedure were divided into 2 subgroups; those having sporadic events (frequency < 2 months) remained on previously ineffective antiarrhythmic drugs (AAD) and aggressive LSM, while those with persistent arrhythmia (incessant or ≥2 months) underwent repeat ablation. After 34 ± 8 months of first procedure, 66 (52%) in Group 1 and 386 (34%) in Group 2 had recurrence (P < 0.001). Recurrence rate in only-MS, only-OSA, and without MS/OSA groups were 40%, 38%, and 29%, respectively. Patients with MS + OSA experienced substantially higher recurrence compared to those with lone MS or OSA (52% vs. 40% vs. 38%; P = 0.036). Of the 452 patients having recurrence, 250 underwent redo-ablation and 194 remained on AAD and LSM. At 20 ± 6 months, 76% of the redo group remained arrhythmia-free off AAD whereas 74% of the LSM group were free from recurrence (P = 0.71), 33% of which were off AAD. MS and OSA have additive negative effect on arrhythmia recurrence following single procedure. Repeat ablation or compliant LSM increase freedom from recurrent AF. © 2014 Wiley Periodicals, Inc.

Assessment of atrial fibrillation and vulnerability in patients with Wolff-Parkinson-White syndrome using two-dimensional speckle tracking echocardiography.

PubMed

Li, Jing-Jie; Wei, Fang; Chen, Ju-Gang; Yu, Yan-Wei; Gu, Hong-Yue; Jiang, Rui; Wu, Xiu-Li; Sun, Qian

2014-01-01

The aim was to assess atrial fibrillation (AF) and vulnerability in Wolff-Parkinson-White (WPW) syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE). All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. Results showed significant differences in both body mass index (BMI) and supraventricular tachycardia (SVT) duration between WPW patients and DAVNP patients (both P<0.05). Echocardiography revealed that the maximum left atrial volume (LAVmax) and the left ventricular mass index (LVMI) in diastole increased noticeably in patients with WPW compared to patients with DAVNP both before and after ablation (all P<0.05). Before ablation, there were obvious differences in the levels of SRs, SRe, and SRa from the 4-chamber view (LA) in the WPW patients group compared with patients in the DAVNP group (all P<0.05). In the AF group, there were significant differences in the levels of systolic strain rate (SRs), early diastolic strain rate (SRe), and late diastolic strain rate (SRa) from the 4-chamber view (LA) both before and after ablation (all P<0.05). In the non-AF group, there were decreased SRe levels from the 4-chamber view (LA/RA) pre-ablation compared to post-ablation (all P<0.05). Our findings provide convincing evidence that WPW syndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period.

Right atrium positioning for exposure of right pulmonary veins during off-pump atrial fibrillation ablation.

PubMed

Suwalski, Grzegorz; Emery, Robert; Mróz, Jakub; Kaczejko, Kamil; Gryszko, Leszek; Cwetsch, Andrzej; Skrobowski, Andrzej

2017-06-01

Concomitant surgical ablation of atrial fibrillation (AF) is recommended for patients undergoing off-pump coronary revascularization in the presence of this arrhythmia. Achievement of optimal visualization of pulmonary veins while maintaining stable haemodynamic conditions is crucial for proper completion of the ablation procedure. This study evaluates the safety and feasibility of right atrial positioning using a suction-based cardiac positioner as opposed to compressive manoeuvres for exposure during off-pump surgical ablation for AF. Thirty-four consecutive patients underwent pulmonary vein isolation, ganglionated plexi ablation and left atrial appendage occlusion during off-pump coronary artery bypass grafting. Right atrial suction positioning was used to visualize right pulmonary veins. Safety and feasibility end points were analysed intraoperatively and in the early postoperative course. In all patients, right atrial positioning created optimal conditions to complete transverse and oblique sinus blunt dissection, correct placement of a bipolar ablation probe, detection and ablation of ganglionated plexi and conduction block assessment. In all patients, this entire right-sided ablation procedure was completed with a single exposure manoeuvre. Feasibility end points were achieved in all study patients. This report documents the safety and feasibility of right atrial exposure using a suction-based cardiac positioner to complete ablation for AF concomitant with off-pump coronary revascularization. This technique may be widely adopted to create stable haemodynamic conditions and optimal visualization of the right pulmonary veins. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Outcome of stand-alone thoracoscopic epicardial left atrial posterior box isolation with bipolar radiofrequency energy for longstanding persistent atrial fibrillation.

PubMed

Compier, M G; Braun, J; Tjon, A; Zeppenfeld, K; Klautz, R J M; Schalij, M J; Trines, S A

2016-02-01

Catheter ablation of longstanding (> 1 year) persistent atrial fibrillation (AF) is associated with poor outcome. This might be due to remodelling and fibrosis formation, mainly located in the posterior left atrial (LA) wall. Therefore, we adopted a thoracoscopic epicardial box isolation of the posterior left atrium using bipolar RF energy with intraoperative testing of conduction block. Bilateral thoracoscopic box isolation was performed with a bipolar RF clamp. Entrance block was defined as absence of a conducted electrogram within the box, while exit block was confirmed by pacing at 10.0 V/2 ms. Ablation outcome was evaluated after 3, 6, 12 and 24 months with 12-lead ECGs and 24-hour Holter recordings. Twenty-five consecutive patients were included (58 ± 7 years, persistent AF duration 1.8 ± 0.9 years). Entrance block was achieved in all patients and exit block confirmed if sinus rhythm was achieved. After 17 ± 7 months, 76 % of the patients (n = 19) were free of AF recurrence. One patient died within 1 month and was considered an ablation failure. Four patients with AF recurrences regained sinus rhythm with additional catheter ablation or antiarrhythmic drugs. Treatment of longstanding persistent AF with thoracoscopic epicardial LA posterior box isolation using bipolar RF energy with intraoperative testing of conduction block is feasible and highly effective.

Features of intrinsic ganglionated plexi in both atria after extensive pulmonary isolation and their clinical significance after catheter ablation in patients with atrial fibrillation.

PubMed

Kurotobi, Toshiya; Shimada, Yoshihisa; Kino, Naoto; Ito, Kazato; Tonomura, Daisuke; Yano, Kentaro; Tanaka, Chiharu; Yoshida, Masataka; Tsuchida, Takao; Fukumoto, Hitoshi

2015-03-01

The features of intrinsic ganglionated plexi (GP) in both atria after extensive pulmonary vein isolation (PVI) and their clinical implications have not been clarified in patients with atrial fibrillation (AF). The purpose of this study was to assess the features of GP response after extensive PVI and to evaluate the relationship between GP responses and subsequent AF episodes. The study population consisted of 216 consecutive AF patients (104 persistent AF) who underwent an initial ablation. We searched for the GP sites in both atria after an extensive PVI. GP responses were determined in 186 of 216 patients (85.6%). In the left atrium, GP responses were observed around the right inferior GP in 116 of 216 patients (53.7%) and around the left inferior GP in 57 of 216 (26.4%). In the right atrium, GP responses were observed around the posteroseptal area: inside the CS in 64 of 216 patients (29.6%), at the CS ostium in 150 of 216 (69.4%), and in the lower right atrium in 45 of 216 (20.8%). The presence of a positive GP response was an independent risk factor for AF recurrence (hazard ratio 4.04, confidence interval 1.48-11.0) in patients with paroxysmal, but not persistent, AF. The incidence of recurrent atrial tachyarrhythmias in patients with paroxysmal AF with a positive GP response was 51% vs 8% in those without a GP response (P = .002). The presence of GP responses after extensive PVI was significantly associated with increased AF recurrence after ablation in patients with paroxysmal AF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Box Isolation of Fibrotic Areas (BIFA): A Patient-Tailored Substrate Modification Approach for Ablation of Atrial Fibrillation.

PubMed

Kottkamp, Hans; Berg, Jan; Bender, Roderich; Rieger, Andreas; Schreiber, Doreen

2016-01-01

Catheter ablation strategies beyond pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF) are less well defined. Increasing clinical data indicate that atrial fibrosis is a critical common left atrial (LA) substrate in AF patients (pts). We applied a new substrate modification concept according to the individual fibrotic substrate as estimated from electroanatomic voltage mapping (EAVM) in 41 pts undergoing catheter ablation of AF. First, EAVM during sinus rhythm was done in redo cases of 10 pts with paroxysmal AF despite durable PVI. Confluent low-voltage areas (LVA) were found in all pts and were targeted with circumferential isolation, so-called box isolation of fibrotic areas (BIFA). This strategy led to stable sinus rhythm in 9/10 pts and was transferred prospectively to first procedures of 31 pts with nonparoxysmal AF. In 13 pts (42%), no LVA (<0.5 mV) were identified, and only PVI was performed. In 18 pts (58%), additional BIFA strategies were applied (posterior box in 5, anterior box in 7, posterior plus anterior box in 5, no box in 1 due to diffuse fibrosis). Mean follow-up was 12.5 ± 2.4 months. Single-procedure freedom from AF/atrial tachycardia was achieved in 72.2% of pts and in 83.3% of pts with 1.17 procedures/patient. In approximately 40% of pts with nonparoxysmal AF, no substantial LVA were identified, and PVI alone showed high success rate. In pts with paroxysmal AF despite durable PVI and in approximately 60% of pts with nonparoxysmal AF, individually localized LVA were identified and could be targeted successfully with the BIFA strategy. © 2015 Wiley Periodicals, Inc.

Machine learning methods for locating re-entrant drivers from electrograms in a model of atrial fibrillation

NASA Astrophysics Data System (ADS)

McGillivray, Max Falkenberg; Cheng, William; Peters, Nicholas S.; Christensen, Kim

2018-04-01

Mapping resolution has recently been identified as a key limitation in successfully locating the drivers of atrial fibrillation (AF). Using a simple cellular automata model of AF, we demonstrate a method by which re-entrant drivers can be located quickly and accurately using a collection of indirect electrogram measurements. The method proposed employs simple, out-of-the-box machine learning algorithms to correlate characteristic electrogram gradients with the displacement of an electrogram recording from a re-entrant driver. Such a method is less sensitive to local fluctuations in electrical activity. As a result, the method successfully locates 95.4% of drivers in tissues containing a single driver, and 95.1% (92.6%) for the first (second) driver in tissues containing two drivers of AF. Additionally, we demonstrate how the technique can be applied to tissues with an arbitrary number of drivers. In its current form, the techniques presented are not refined enough for a clinical setting. However, the methods proposed offer a promising path for future investigations aimed at improving targeted ablation for AF.

Planning the Safety of Atrial Fibrillation Ablation Registry Initiative (SAFARI) as a Collaborative Pan-Stakeholder Critical Path Registry Model: a Cardiac Safety Research Consortium "Incubator" Think Tank.

PubMed

Al-Khatib, Sana M; Calkins, Hugh; Eloff, Benjamin C; Packer, Douglas L; Ellenbogen, Kenneth A; Hammill, Stephen C; Natale, Andrea; Page, Richard L; Prystowsky, Eric; Jackman, Warren M; Stevenson, William G; Waldo, Albert L; Wilber, David; Kowey, Peter; Yaross, Marcia S; Mark, Daniel B; Reiffel, James; Finkle, John K; Marinac-Dabic, Danica; Pinnow, Ellen; Sager, Phillip; Sedrakyan, Art; Canos, Daniel; Gross, Thomas; Berliner, Elise; Krucoff, Mitchell W

2010-01-01

Atrial fibrillation (AF) is a major public health problem in the United States that is associated with increased mortality and morbidity. Of the therapeutic modalities available to treat AF, the use of percutaneous catheter ablation of AF is expanding rapidly. Randomized clinical trials examining the efficacy and safety of AF ablation are currently underway; however, such trials can only partially determine the safety and durability of the effect of the procedure in routine clinical practice, in more complex patients, and over a broader range of techniques and operator experience. These limitations of randomized trials of AF ablation, particularly with regard to safety issues, could be addressed using a synergistically structured national registry, which is the intention of the SAFARI. To facilitate discussions about objectives, challenges, and steps for such a registry, the Cardiac Safety Research Consortium and the Duke Clinical Research Institute, Durham, NC, in collaboration with the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, organized a Think Tank meeting of experts in the field. Other participants included the National Heart, Lung and Blood Institute, the Centers for Medicare and Medicaid Services, the Agency for Healthcare Research and Quality, the Society of Thoracic Surgeons, the AdvaMed AF working group, and additional industry representatives. The meeting took place on April 27 to 28, 2009, at the US Food and Drug Administration headquarters in Silver Spring, MD. This article summarizes the issues and directions presented and discussed at the meeting. Copyright 2010 Mosby, Inc. All rights reserved.

Presence and stability of rotors in atrial fibrillation: evidence and therapeutic implications

PubMed Central

Guillem, María S.; Climent, Andreu M.; Rodrigo, Miguel; Fernández-Avilés, Francisco; Atienza, Felipe; Berenfeld, Omer

2016-01-01

Rotor-guided ablation has opened new perspectives into the therapy of atrial fibrillation (AF). Analysis of the spatio-temporal cardiac excitation patterns in the frequency and phase domains has demonstrated the importance of rotors in research models of AF, however, the dynamics and role of rotors in human AF are still controversial. In this review, the current knowledge gained through research models and patient data that support the notion that rotors are key players in AF maintenance is summarized. We report and discuss discrepancies regarding rotor prevalence and stability in various studies, which can be attributed in part to methodological differences among mapping systems. Future research for validation and improvement of current clinical electrophysiology mapping technologies will be crucial for developing mechanistic-based selection and application of the best therapeutic strategy for individual AF patient, being it, pharmaceutical, ablative, or other approach. PMID:26786157

Surgical ablation for atrial fibrillation for two decades: are the results of new techniques equivalent to the Cox maze III procedure?

PubMed

Stulak, John M; Suri, Rakesh M; Burkhart, Harold M; Daly, Richard C; Dearani, Joseph A; Greason, Kevin L; Joyce, Lyle D; Park, Soon J; Schaff, Hartzell V

2014-05-01

A significant evolution has occurred in surgical ablation for atrial fibrillation (AF) toward alternate energy sources, lesion sets, and approaches, with the intent of simplifying the Cox maze III operation and maintaining similar outcomes. Because no large comparative studies with long-term follow-up exist, we have reviewed our experience. From January 1993 to January 2011, 1540 patients underwent surgical ablation for AF. The operations were performed in conjunction with repair of congenital heart disease in 351 (30%) and adult-acquired disease in 1189 patients (70%). In the 1189 patients, preoperative AF was paroxysmal in 598 (50%) and persistent in 591 (50%). The energy sources included cut and sew in 521 (44%), cryothermy in 267 (22%), radiofrequency in 262 (22%), and a combination in 139 patients (12%). The lesion sets included biatrial in 810 (68%), isolated pulmonary vein isolation in 269 (23%), and isolated left atrial in 110 (9%). AF ablation was performed during isolated mitral valve surgery in 516 patients (43%). The median follow-up was 33 months (maximum, 20.3 years), and late rhythm follow-up was available for 80%. The cut and sew Cox maze III procedure was superior at each follow-up interval (P = .01, P = .03, and P < .001). On multivariate analysis, the cut and sew maze procedure was independently associated with less risk of recurrent AF at a follow-up period of 1 to 5 years (hazard ratio, 0.4; 95% confidence interval, 0.24-0.69; P < .001) and >5 years (hazard ratio, 0.23; 95% confidence interval, 0.12-0.42; P < .001) for all patients. When performed during isolated mitral valve surgery, the cut and sew Cox maze III was also independently associated with less risk of recurrent AF at >5 years (hazard ratio, 0.23; 95% confidence interval, 0.08-0.66; P = .007). The cut and sew Cox maze III procedure appears to offer significantly greater freedom from AF without antiarrhythmic medications compared with alternate energy sources and lesion sets. Although alternate energy sources offer the advantage of quicker application and the possibility of minimally invasive applications, the Cox maze III operation arguably remains the reference standard for the surgical treatment of AF and should still be considered, especially for patients for whom AF ablation is of critical importance. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Efficacy and safety of cryoballoon ablation versus radiofrequency catheter ablation in atrial fibrillation: an updated meta-analysis

PubMed Central

Ma, Honglan; Sun, Dongdong; Luan, Hui; Feng, Wei; Zhou, Yaqiong; Wu, Jine; He, Caiyun

2017-01-01

Introduction Cryoballoon ablation (CBA) and irrigated radiofrequency catheter ablation (RFCA) are the main treatments for drug-refractory symptomatic atrial fibrillation (AF). Aim To compare the efficacy and safety between CBA and RFCA for the treatment of AF. Material and methods We searched the Embase and Medline databases for clinical studies published up to December 2016. Studies that satisfied our predefined inclusion criteria were included. Results After searching through the literature in the two major databases, 20 studies with a total of 9,141 patients were included in our study. The CBA had a significantly shorter procedure time (weighted mean difference (WMD) –30.38 min; 95% CI: –46.43 to –14.33, p = 0.0002) and non-significantly shorter fluoroscopy time (WMD –3.18 min; 95% CI: –6.43 to 0.07, p = 0.06) compared with RFCA. There was no difference in freedom from AF between CBA and RFCA (CBA 78.55% vs. RFCA 83.13%, OR = 1.15, 95% CI: 0.95–1.39, p = 0.14). The CBA was associated with a high risk of procedure-related complications (CBA 9.02% vs. RFCA 6.56%, OR = 1.56, 95% CI: 1.05–2.31, p = 0.03), especially phrenic nerve paralysis (PNP, OR = 10.72, 95% CI: 5.59–20.55, p < 0.00001). The risk of pericardial effusions/cardiac tamponade was low in the CBA group (CBA 1.05% vs. RFCA 1.86%, OR = 0.62, 95% CI: 0.41–0.93, p = 0.02). Conclusions For AF, CBA was as effective as RFCA. However, CBA had a shorter procedure time and a non-significantly shorter fluoroscopy time, a significantly high risk of PNP and a low incidence of pericardial effusions/cardiac tamponade compared with RFCA. PMID:29056997

Atrial Fibrillation Ablation Guided by a Novel Nonfluoroscopic Navigation System.

PubMed

Ballesteros, Gabriel; Ramos, Pablo; Neglia, Renzo; Menéndez, Diego; García-Bolao, Ignacio

2017-09-01

Rhythmia is a new nonfluoroscopic navigation system that is able to create high-density electroanatomic maps. The aim of this study was to describe the acute outcomes of atrial fibrillation (AF) ablation guided by this system, to analyze the volume provided by its electroanatomic map, and to describe its ability to locate pulmonary vein (PV) reconnection gaps in redo procedures. This observational study included 62 patients who underwent AF ablation with Rhythmia compared with a retrospective cohort who underwent AF ablation with a conventional nonfluoroscopic navigation system (Ensite Velocity). The number of surface electrograms per map was significantly higher in Rhythmia procedures (12 125 ± 2826 vs 133 ± 21 with Velocity; P < .001), with no significant differences in the total procedure time. The Orion catheter was placed for mapping in 99.5% of PV (95.61% in the control group with a conventional circular mapping catheter; P = .04). There were no significant differences in the percentage of PV isolation between the 2 groups. In redo procedures, an ablation gap could be identified on the activation map in 67% of the reconnected PV (40% in the control group; P = .042). The measured left atrial volume was lower than that calculated by computed tomography (109.3 v 15.2 and 129.9 ± 13.2 mL, respectively; P < .001). There were no significant differences in the number of complications. The Rhythmia system is effective for AF ablation procedures, with procedure times and safety profiles similar to conventional nonfluoroscopic navigation systems. In redo procedures, it appears to be more effective in identifying reconnected PV conduction gaps. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Simultaneous assessment of contact pressure and local electrical coupling index using robotic navigation.

PubMed

Dello Russo, Antonio; Fassini, Gaetano; Casella, Michela; Bologna, Fabrizio; Al-Nono, Osama; Colombo, Daniele; Biagioli, Viviana; Santangeli, Pasquale; Di Biase, Luigi; Zucchetti, Martina; Majocchi, Benedetta; Marino, Vittoria; Gallinghouse, Joseph J; Natale, Andrea; Tondo, Claudio

2014-06-01

Contact with cardiac tissue is a determinant of lesion efficacy during atrial fibrillation (AF) ablation. The Sensei®X Robotic Catheter System (Hansen Medical, CA) has been validated for contact force sensing. The electrical coupling index (ECI) from the EnSite Contact™ system (St. Jude Medical, MN) has been validated as an indicator of tissue contact. We aimed at analyzing ECI behavior during radiofrequency (RF) pulses maintaining a stable contact through the robotic navigation contact system. In 15 patients (age, 59 ± 12) undergoing AF ablation, pulmonary vein (PV) isolation was guided by the Sensei®X System, employing the Contact™ catheter. During the procedure, we assessed ECI changes associated with adequate contact based on the IntelliSense® force-sensing technology (Hansen Medical, CA. Baseline contact (27 ± 8 g/cm(2)) ECI value was 99 ± 13, whereas ECI values in a noncontact site (0 g/cm(2)) and in a light contact site (1-10 g/cm(2)) were respectively 66 ± 12 and 77 ± 10 (p < 0.0001). Baseline contact ECI values were not different depending on AF presentation (paroxysmal AF, 98 ± 9; persistent AF, 100 ± 9) or on cardiac rhythm (sinus rhythm, 97 ± 7; AF,101 ± 10). In all PVs, ECI was significantly reduced during and after ablation (ECI during RF, 56 ± 15; ECI after RF, 72 ± 16; p < 0.001). A mean reduction of 32.2% during RF delivery and 25.4% immediately after RF discontinuation compared with baseline ECI was observed. Successful PV isolation is associated with a significant decrease in ECI of at least 20 %. This may be used as a surrogate marker of effective lesion in AF ablation.

Investigating relationships between left atrial volume, symmetry, and sphericity

NASA Astrophysics Data System (ADS)

Menon, Prahlad G.; Nedios, Sotiris; Hindricks, Gerhard; Bollmann, Andreas

2016-03-01

Catheter ablation is a safe and effective therapy for drug-refractory patients symptomatic of atrial fibrillation (AF), with up to 80% of patients experiencing long-term arrhythmia-free survival. However, up to 20-40% of patients require more than one procedure in order to become arrhythmia-free. Therefore, appropriate patient selection is paramount to the effective implementation and long-term success of ablation therapy for patients with atrial fibrillation (AF). In this study, as a precursor to evaluating clinical significance of specific LA shape metrics as pre-procedural predictors of AF recurrence following ablative pulmonary vein isolation therapy, we report on a computational geometric analysis in a pilot cohort evaluating relationships between various patient-specific metrics of LA shape which might have such predictive value. This study specifically is focused on establishing the relationship between LA volume and sphericity, using a novel methodology for computing atrial sphericity based on regional shape.

Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial

PubMed Central

De Greef, Yves; Dekker, Lukas; Boersma, Lucas; Murray, Stephen; Wieczorek, Marcus; Spitzer, Stefan G.; Davidson, Neil; Furniss, Steve; Hocini, Mélèze; Geller, J. Christoph; Csanádi, Zoltan

2016-01-01

Abstract Aims This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. Methods and results A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16–72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (<3 W) ablations (15 vs. 23%, 5 vs. 10% and 2 vs. 7% in 4:1, 2:1, and 1:1 bipolar:unipolar energy modes, respectively). Mini-Mental State Exam was unchanged in all patients. Conclusion Atrial fibrillation ablation with PVAC GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. Trial registration ClinicalTrials.gov NCT01767558. PMID:26826134

Interest of waiting time for spontaneous early reconnection after cavotricuspid isthmus ablation: A monocentric randomized trial.

PubMed

Marchandise, Sébastien; Scavée, Christophe; Barbraud, Cynthia; de Meester de Ravenstein, Christophe; Balola Bagalwa, Mittérand; Goesaert, Cédric; Reis-Pinheiro, Ivone; le Polain de Waroux, Jean-Benoit

2017-12-01

The aim of this study was to determine the rate of recurrent atrial flutter (AFl) after isolated cavotricuspid isthmus (CTI) ablation and to evaluate the impact of a waiting period with the search for early resumption of the CTI block on the long-term outcome. Three hundred and nineteen consecutive patients referred for typical AFl ablation were randomly assigned to CTI ablation with continuous reevaluation of the CTI block during 30 minutes and early reablation if needed (waiting time [WT] + group, n  =  155) or to CTI ablation with no waiting period after proven bidirectional CTI block (WT - group, n  =  164). All patients were regularly followed-up. In the WT+ group, 10 patients (6%) presented a recovery across the CTI (time to recovery: 17 ± 7') and were reablated at the end of the waiting period. After a median follow-up of 21 months, the rate of recurrent AFl was significantly higher in the WT - group as compared to the WT+ group (11.6% [19/164] vs 2.5% [4/155], respectively; P  =  0.007). However, no significant differences in the subsequent rate of AF were observed between the two groups (29% [WT -] vs 32% [WT+], P  =  0.66). During the follow-up, 28 patients from the WT - group underwent a second ablation procedure (16 AFl redo and 12 AF ablation) versus 10 patients form the WT+ group (three AFl redo and seven AF ablation). Waiting 30 minutes after CTI ablation to check for early resumption and early reablation allows for decreasing significantly the rate of recurrent atrial flutter. © 2017 Wiley Periodicals, Inc.

Left Atrial Anatomy Relevant to Catheter Ablation

PubMed Central

Sánchez-Quintana, Damián; Cabrera, José Angel; Saremi, Farhood

2014-01-01

The rapid development of interventional procedures for the treatment of arrhythmias in humans, especially the use of catheter ablation techniques, has renewed interest in cardiac anatomy. Although the substrates of atrial fibrillation (AF), its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium (LA) has become a common therapeutic option for patients with this arrhythmia. Using ablation catheters, various isolation lines and focal targets are created, the majority of which are based on gross anatomical, electroanatomical, and myoarchitectual patterns of the left atrial wall. Our aim was therefore to review the gross morphological and architectural features of the LA and their relations to extracardiac structures. The latter have also become relevant because extracardiac complications of AF ablation can occur, due to injuries to the phrenic and vagal plexus nerves, adjacent coronary arteries, or the esophageal wall causing devastating consequences. PMID:25057427

Low Rates of Major Complications for Radiofrequency Ablation of Atrial Fibrillation Maintained Over 14 Years: A Single Centre Experience of 2750 Consecutive Cases.

PubMed

Voskoboinik, Aleksandr; Sparks, Paul B; Morton, Joseph B; Lee, Geoffrey; Joseph, Stephen A; Hawson, Joshua J; Kistler, Peter M; Kalman, Jonathan M

2018-02-03

Despite technological advances, studies continue to report high complication rates for atrial fibrillation (AF) ablation. We sought to review complication rates for AF ablation at a high-volume centre over a 14-year period and identify predictors of complications. We reviewed prospectively collected data from 2750 consecutive AF ablation procedures at our institution using radiofrequency energy (RF) between January 2004 and May 2017. All cases were performed under general anaesthetic with transoesophageal echocardiography (TEE), 3D-mapping and an irrigated ablation catheter. Double transseptal puncture was performed under TEE guidance. All patients underwent wide antral circumferential isolation of the pulmonary veins (30W anteriorly, 25W posteriorly) with substrate modification at operator discretion. Of 2255 initial and 495 redo procedures, ablation strategies were: pulmonary vein isolation (PVI) only 2097 (76.3%), PVI+lines 368 (13.4%), PVI+posterior wall 191 (6.9%), PVI+cavotricuspid isthmus 277 (10.1%). There were 23 major (0.84%) and 20 minor (0.73%) complications. Cardiac tamponade (five cases - 0.18%) and phrenic nerve palsy (one case - 0.04%) rates were very low. Major vascular complications necessitating surgery or blood transfusion occurred in five patients (0.18%). There were no cases of death, permanent disability, atrio-oesophageal fistulae or symptomatic pulmonary vein (PV) stenosis, although there were five TEE probe-related complications (0.18%). Female gender (OR 2.14; 95% CI 1.07-4.26) but not age >70 (OR 1.01) was the only multivariate predictor of complications. Atrial fibrillation ablation performed at a high-volume centre using RF can be achieved with a low major complication rate in a representative AF population over a sustained period of time. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

A Prospective Randomized Trial of Apixaban Dosing During Atrial Fibrillation Ablation: The AEIOU Trial.

PubMed

Reynolds, Matthew R; Allison, J Scott; Natale, Andrea; Weisberg, Ian L; Ellenbogen, Kenneth A; Richards, Mark; Hsieh, Wen-Hua; Sutherland, Julie; Cannon, Christopher P

2018-05-01

This study sought to determine whether uninterrupted apixaban would have similar rates of bleeding and thromboembolic events as does minimally interrupted apixaban at the time of atrial fibrillation (AF) ablation and to compare those results with rates in historical patients treated with uninterrupted warfarin. The safety, efficacy, and optimal dosing regimen for apixaban at the time of AF ablation are uncertain. This prospective, multicenter clinical trial enrolled 306 patients undergoing catheter ablation for nonvalvular AF and randomized 300 to uninterrupted versus minimally interrupted (holding 1 dose) periprocedural apixaban. A retrospective cohort of patients treated with uninterrupted warfarin at the same centers was matched to the apixaban-treated subjects for comparison. Endpoints included clinically significant bleeding, major bleeding, and nonhemorrhagic stroke or systemic embolism (SE) from the time of ablation through 30 days. There were no stroke or SE events. Clinically significant bleeding occurred in 11.3% of 150 evaluable patients on uninterrupted apixaban and 9.7% of 145 evaluable patients on interrupted apixaban (risk difference: 1.7% [95% confidence interval: -5.5% to 8.8%]; p = NS). Rates of major bleeding were 1.3% with uninterrupted apixaban, and 2.1% with interrupted (risk difference: -0.7%; p = NS). The rates of clinically significant and major bleeding were similar for all apixaban patients combined (10.5% and 1.7%), compared with the matched warfarin group (9.8% and 1.4%). Both uninterrupted and minimally interrupted apixaban at the time of AF ablation were associated with a very low rate of thromboembolic events, and rates of both major (<2%) and clinically significant bleeding were similar to uninterrupted warfarin. (Apixaban Evaluation of Interrupted Or Uninterrupted Anticoagulation for Ablation of Atrial Fibrillation [AEIOU]; NCT02608099). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

High incidence of echocardiographic abnormalities of the interatrial septum in patients undergoing ablation for atrial fibrillation.

PubMed

Schernthaner, Christiana; Danmayr, Franz; Daburger, Apollonia; Eichinger, Jörg; Hammerer, Matthias; Strohmer, Bernhard

2013-04-01

Atrial fibrosis or fatty deposition is known to increase the propensity for the development of atrial fibrillation (AF). Apart from the pulmonic veins, the interatrial septum (IAS) might play a role in the maintenance of AF. In contrast to left atrial anatomy and adjacent veins, the IAS cannot be visualized in detail with computed tomography. Thus, preprocedural transesophageal echocardiography (TEE) may provide important morphologic information beyond exclusion from atrial thrombi. The study comprised 108 consecutive patients (mean age 60 ± 11 years; 98 men). AF was paroxysmal in 91 (84%) and persistent in 17 (16%) patients. We investigated the morphological characteristics of the IAS by TEE in patients who underwent radiofrequency ablation of AF. The IAS was structurally abnormal in 46 (43%) patients, showing the following echocardiograhic findings: atrial septal hypermobility or aneurysm (n = 27) associated with a patent foramen ovale (PFO) (n = 11) or with a small atrial septal defect (ASD) (n = 2), a septal flap associated with a PFO or an ASD (n = 8), and an abnormally thickened IAS (n = 12). A thrombus in the left atrial appendage was discovered in only 2 (2%) patients. A structurally abnormal IAS was diagnosed in nearly half of the patients undergoing ablation therapy for AF. The information obtained by TEE is mandatory to exclude left atrial thrombi prior the ablation procedure. Moreover, detailed knowledge of morphologic characteristics of the IAS facilitates an optimized and safe performance of the transseptal puncture using long sheaths with large diameters. © 2012, Wiley Periodicals, Inc.

Developing the Safety of Atrial Fibrillation Ablation Registry Initiative (SAFARI) as a collaborative pan-stakeholder critical path registry model: a Cardiac Safety Research Consortium "Incubator" Think Tank.

PubMed

Al-Khatib, Sana M; Calkins, Hugh; Eloff, Benjamin C; Kowey, Peter; Hammill, Stephen C; Ellenbogen, Kenneth A; Marinac-Dabic, Danica; Waldo, Albert L; Brindis, Ralph G; Wilbur, David J; Jackman, Warren M; Yaross, Marcia S; Russo, Andrea M; Prystowsky, Eric; Varosy, Paul D; Gross, Thomas; Pinnow, Ellen; Turakhia, Mintu P; Krucoff, Mitchell W

2010-10-01

Although several randomized clinical trials have demonstrated the safety and efficacy of catheter ablation of atrial fibrillation (AF) in experienced centers, the outcomes of this procedure in routine clinical practice and in patients with persistent and long-standing persistent AF remain uncertain. Brisk adoption of this therapy by physicians with diverse training and experience highlights potential concerns regarding the safety and effectiveness of this procedure. Some of these concerns could be addressed by a national registry of AF ablation procedures such as the Safety of Atrial Fibrillation Ablation Registry Initiative that was initially proposed at a Cardiac Safety Research Consortium Think Tank meeting in April 2009. In January 2010, the Cardiac Safety Research Consortium, in collaboration with the Duke Clinical Research Institute, the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, held a follow-up meeting of experts in the field to review the construct and progress to date. Other participants included the National Heart, Lung, and Blood Institute; the Centers for Medicare and Medicaid Services; the Agency for Healthcare Research and Quality; the AdvaMed AF working group; and additional industry representatives. This article summarizes the discussions that occurred at the meeting of the state of the Safety of Atrial Fibrillation Ablation Registry Initiative, the identification of a clear pathway for its implementation, and the exploration of solutions to potential issues in the execution of this registry. Copyright © 2010 Mosby, Inc. All rights reserved.

Using Discrete Event Simulation to Model the Economic Value of Shorter Procedure Times on EP Lab Efficiency in the VALUE PVI Study.

PubMed

Kowalski, Marcin; DeVille, J Brian; Svinarich, J Thomas; Dan, Dan; Wickliffe, Andrew; Kantipudi, Charan; Foell, Jason D; Filardo, Giovanni; Holbrook, Reece; Baker, James; Baydoun, Hassan; Jenkins, Mark; Chang-Sing, Peter

2016-05-01

The VALUE PVI study demonstrated that atrial fibrillation (AF) ablation procedures and electrophysiology laboratory (EP lab) occupancy times were reduced for the cryoballoon compared with focal radiofrequency (RF) ablation. However, the economic impact associated with the cryoballoon procedure for hospitals has not been determined. Assess the economic value associated with shorter AF ablation procedure times based on VALUE PVI data. A model was formulated from data from the VALUE PVI study. This model used a discrete event simulation to translate procedural efficiencies into metrics utilized by hospital administrators. A 1000-day period was simulated to determine the accrued impact of procedure time on an institution's EP lab when considering staff and hospital resources. The simulation demonstrated that procedures performed with the cryoballoon catheter resulted in several efficiencies, including: (1) a reduction of 36.2% in days with overtime (422 days RF vs 60 days cryoballoon); (2) 92.7% less cumulative overtime hours (370 hours RF vs 27 hours cryoballoon); and (3) an increase of 46.7% in days with time for an additional EP lab usage (186 days RF vs 653 days cryoballoon). Importantly, the added EP lab utilization could not support the time required for an additional AF ablation procedure. The discrete event simulation of the VALUE PVI data demonstrates the potential positive economic value of AF ablation procedures using the cryoballoon. These benefits include more days where overtime is avoided, fewer cumulative overtime hours, and more days with time left for additional usage of EP lab resources.

Robotic assistance and general anaesthesia improve catheter stability and increase signal attenuation during atrial fibrillation ablation.

PubMed

Malcolme-Lawes, Louisa C; Lim, Phang Boon; Koa-Wing, Michael; Whinnett, Zachary I; Jamil-Copley, Shahnaz; Hayat, Sajad; Francis, Darrel P; Kojodjojo, Pipin; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa

2013-01-01

Recurrent arrhythmias after ablation procedures are often caused by recovery of ablated tissue. Robotic catheter manipulation systems increase catheter tip stability which improves energy delivery and could produce more transmural lesions. We tested this assertion using bipolar voltage attenuation as a marker of lesion quality comparing robotic and manual circumferential pulmonary vein ablation for atrial fibrillation (AF). Twenty patients were randomly assigned to robotic or manual AF ablation at standard radiofrequency (RF) settings for our institution (30 W 60 s manual, 25 W 30 s robotic, R30). A separate group of 10 consecutive patients underwent robotic ablation at increased RF duration, 25 W for 60 s (R60). Lesions were marked on an electroanatomic map before and after ablation to measure distance moved and change in bipolar electrogram amplitude during RF. A total of 1108 lesions were studied (761 robotic, 347 manual). A correlation was identified between voltage attenuation and catheter movement during RF (Spearman's rho -0.929, P < 0.001). The ablation catheter was more stable during robotic RF; 2.9 ± 2.3 mm (R30) and 2.6 ± 2.2 mm (R60), both significantly less than the manual group (4.3 ± 3.0 mm, P < 0.001). Despite improved stability, there was no difference in signal attenuation between the manual and R30 group. However, there was increased signal attenuation in the R60 group (52.4 ± 19.4%) compared with manual (47.7 ± 25.4%, P = 0.01). When procedures under general anaesthesia (GA) and conscious sedation were analysed separately, the improvement in signal attenuation in the R60 group was only significant in the procedures under GA. Robotically assisted ablation has the capability to deliver greater bipolar voltage attenuation compared with manual ablation with appropriate selection of RF parameters. General anaesthesia confers additional benefits of catheter stability and greater signal attenuation. These findings may have a significant impact on outcomes from AF ablation procedures.

Optimizing radiofrequency ablation of paroxysmal and persistent atrial fibrillation by direct catheter force measurement-a case-matched comparison in 198 patients.

PubMed

Sigmund, Elisabeth; Puererfellner, Helmut; Derndorfer, Michael; Kollias, Georgios; Winter, Siegmund; Aichinger, Josef; Nesser, Hans-Joachim; Martinek, Martin

2015-02-01

Sufficient electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). We assessed the impact of direct catheter force measurement on acute procedural parameters and outcome of RFCA for paroxysmal and persistent atrial fibrillation (AF). Ninety-nine consecutive patients (70% men) with paroxysmal (63.6%) or persistent AF underwent left atrial RFCA using a 3.5-mm open-irrigated-tip (OIT) catheter with contact force measurement capabilities (group 1). For comparison a case-matched cohort with standard OIT catheters was used (99 patients; group 2). Case matching included gender, type of AF, number or RFCA procedures, and type of procedure. Procedural data showed a significant decline in radiofrequency ablation time from 52 ± 20 to 44 ± 16 minutes (P = 0.003) with a remarkable mean reduction in overall procedure time of 34 minutes (P = 0.0001; 225.8 ± 53.1 vs 191.9 ± 53.3 minutes). In parallel, the total fluoroscopy time could be significantly reduced from 28.5 ± 11.0 to 19.9 ± 9.3 minutes (P = 0.0001) as well as fluoroscopy dose from 74.1 ± 58.0 to 56.7 ± 38.9 Gy/cm(2) (P = 0.016). Periprocedural complications were similar in both groups. The use of contact force sensing technology is able to significantly reduce ablation, procedure, and fluoroscopy times as well as dose in RFCA of AF in a mixed case-matched group of paroxysmal and persistent AF. Energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Additionally 12-month outcome data showed increased efficacy. Such time saving and equally safe technology may have a relevant impact on laboratory management and increased cost effectiveness. © 2014 Wiley Periodicals, Inc.

Radiofrequency and microwave energy sources in surgical ablation of atrial fibrillation: a comparative analysis.

PubMed

Topkara, Veli K; Williams, Mathew R; Barili, Fabio; Bastos, Renata; Liu, Judy F; Liberman, Elyse A; Russo, Mark J; Oz, Mehmet C; Argenziano, Michael

2006-01-01

Due to its complexity and risk of bleeding, the Maze III procedure has been largely replaced by surgical ablation for atrial fibrillation (AF) using alternative energy sources. Radiofrequency (RF) and microwave (MW) are the most commonly used energy forms. In this study, we sought to compare these energy modalities in terms of clinical outcomes. Two hundred five patients underwent surgical ablation of AF, from October 1999 to May 2004 at our institution via an endocardial approach. Patients were categorized into 2 groups: RF and MW. Baseline characteristics, operative details, and clinical outcomes were compared between the 2 groups. Rhythm success was defined as freedom from AF and atrial flutter as determined by postoperative electrocardiograms. One hundred twenty patients (58.5%) were ablated using RF, whereas 85 (41.5%) were ablated with MW. Most of the patients had persistent AF in both the RF and MW groups (85.7% versus 80.0%, respectively; P = .363). Intraoperative left atrial size was 6.4 +/- 1.7 cm for the RF group and 6.4 +/- 1.7 cm for the MW group (P = .820). Postoperative rhythm success at 6 and 12 months was 72.4% versus 71.4% (P +/- .611) and 75.0% versus 66.7% (P = .909) for the RF and MW groups, respectively. Hospital length of stay was comparable for both groups (15.4 +/- 14.0 versus 13.3 +/- 13.9 days; P = .307). Postoperative survival at 6 months, 1 year, and 3 years was 90.4%, 89.5%, and 86.1% for RF patients compared to 87.9%, 86.5%, and 84.4% for MW patients, respectively (log rank P = .490). RF and MW energy forms yield comparable postoperative rhythm success, hospital length of stay, and postoperative survival. Both sources are rapid, safe, and effective alternatives to "cut and sew" techniques for surgical treatment of AF.

The definition of success in atrial fibrillation ablation surgery.

PubMed

Hunter, Steven

2014-01-01

In spite of recent attempts to define and clarify the treatment endpoints in atrial fibrillation (AF) ablation surgery, the definition of success has remained blurred. It is of importance to address the burden of AF in the non-symptomatic population. Thromboembolic events invariably blight the outcomes, therefore freedom from stroke must be incorporated into any definition of success and guidelines. It is essential to meticulously study the long-term outcomes of an unsuccessful treatment as a supplement to the definition of success.

Interatrial block and interatrial septal thickness in patients with paroxysmal atrial fibrillation undergoing catheter ablation: Long-term follow-up study.

PubMed

Gul, Enes E; Pal, Raveen; Caldwell, Jane; Boles, Usama; Hopman, Wilma; Glover, Benedict; Michael, Kevin A; Redfearn, Damian; Simpson, Chris; Abdollah, Hoshiar; Baranchuk, Adrian

2017-07-01

Interatrial block (IAB) is a strong predictor of recurrence of atrial fibrillation (AF). IAB is a conduction delay through the Bachman region, which is located in the upper region of the interatrial space. During IAB, the impulse travels from the right atrium to the interatrial septum (IAS) and coronary sinus to finally reach the left atrium in a caudocranial direction. No relation between the presence of IAB and IAS thickness has been established yet. To determine whether a correlation exists between the degree of IAB and the thickness of the IAS and to determine whether IAS thickness predicts AF recurrence. Sixty-two patients with diagnosis of paroxysmal AF undergoing catheter ablation were enrolled. IAB was defined as P-wave duration ≥120 ms. IAS thickness was measured by cardiac computed tomography. Among 62 patients with paroxysmal AF, 45 patients (72%) were diagnosed with IAB. Advanced IAB was diagnosed in 24 patients (39%). Forty-seven patients were male. During a mean follow-up period of 49.8 ± 22 months (range 12-60 months), 32 patients (51%) developed AF recurrence. IAS thickness was similar in patients with and without IAB (4.5 ± 2.0 mm vs. 4.0 ± 1.4 mm; p = .45) and did not predict AF. Left atrial size was significantly enlarged in patients with IAB (40.9 ± 5.7 mm vs. 37.2 ± 4.0 mm; p = .03). Advanced IAB predicted AF recurrence after the ablation (OR: 3.34, CI: 1.12-9.93; p = .03). IAS thickness was not significantly correlated to IAB and did not predict AF recurrence. IAB as previously demonstrated was an independent predictor of AF recurrence. © 2016 Wiley Periodicals, Inc.

Safety and Efficacy of Cryoballoon Ablation for Paroxysmal Atrial Fibrillation in Japan　- Results From the Japanese Prospective Post-Market Surveillance Study.

PubMed

Okumura, Ken; Matsumoto, Kazuo; Kobayashi, Yoshinori; Nogami, Akihiko; Hokanson, Robert B; Kueffer, Fred

2016-07-25

Outcomes of cryoballoon ablation for paroxysmal atrial fibrillation (PAF) have been reported in the Western countries but not in Japan. The CRYO-Japan PMS study was a single-arm, observational, multicenter, prospective study of the 2nd-generation cryoballoon Arctic Front Advance(TM). We evaluated device- and procedure-related complications and clinical outcomes at 6 months. The 616 patients (male, 72%; mean age, 63±11 years) were enrolled from 33 Japanese hospitals. Of all patients, 610 had PAF, and procedural data were analyzed in 607. A subset of 328 patients was followed for 6 months for the primary efficacy analysis. AF recurrence outside the 3-month blanking period or repeat ablation was considered treatment failure. Pulmonary vein isolation was achieved in 606/607 patients (99.8%); 1 patient (0.3%) had a repeat ablation during the blanking period. Freedom from AF at 6 months was 88.4% (95% CI: 84.1-91.6%). Device- and/or procedure-related adverse events included phrenic nerve injury unresolved at hospital discharge in 9/616 patients (1.5%), which resolved within 6 months in 7, pericardial effusion in 5/616 (0.8%), and tamponade in 4/616 (0.6%). One non-device-related death from pneumonia was reported 6 days post-procedure. Cryoballoon ablation is safe and effective for Japanese PAF patients, with 88.4% AF freedom at 6 months post-ablation. (Circ J 2016; 80: 1744-1749).

The Impact of Transforming Growth Factor-β1 Level on Outcome After Catheter Ablation in Patients With Atrial Fibrillation.

PubMed

Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru

2017-04-01

Transforming growth factor-β 1 (TGF-β 1 ) is an important factor that induces atrial fibrosis and atrial fibrillation (AF). The purpose of this study was to evaluate the association between TGF-β 1 level and clinical factors before catheter ablation (CA), and to investigate the impact of TGF-β 1 level on the outcome after CA for AF. This prospective study included 151 patients (persistent AF group: n = 59, paroxysmal AF [PAF] group: n = 54, and control group: n = 38). All patients who underwent CA for AF were followed up for 12 months. The PAF group had the highest TGF-β 1 levels in all patients. An early recurrence of AF (ERAF: defined as episodes of atrial tachyarrhythmia within a 3-month blanking period) was detected in 60 patients (53%). Recurrent AF after the blanking period was detected in 36 patients (32%). On multivariate analysis, low TGF-β 1 level was the only independent factor associated with recurrent AF. Moreover, the AF recurrence ratio was higher in the low TGF-β 1 group (< 12.56 ng/mL) than in the high TGF-β 1 group (16 of 29 patients, 55% vs. 20 of 84 patients, 24%, P = 0.002 by log-rank test). PAF was associated with a higher TGF-β 1 level. Moreover, lower TGF-β 1 level in AF patients could be a cause of recurrent AF after CA. © 2017 Wiley Periodicals, Inc.

Safety and efficacy of switching anticoagulation to aspirin three months after successful radiofrequency catheter ablation of atrial fibrillation.

PubMed

Uhm, Jae-Sun; Won, Hoyoun; Joung, Boyoung; Nam, Gi-Byoung; Choi, Kee-Joon; Lee, Moon-Hyoung; Kim, You-Ho; Pak, Hui-Nam

2014-09-01

Although current guidelines recommend continuing the same antithrombotic strategy regardless of rhythm control after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), anticoagulation has a risk of major bleeding. We evaluated the safety of switching warfarin to aspirin in patients with successful AF ablation. Among 721 patients who underwent RFCA of AF, 608 patients (age, 57.3±10.9 years; 77.0% male, 75.5% paroxysmal AF) who had no evidence of AF recurrence at 3 months post-RFCA were included. We compared the thromboembolic and hemorrhagic events in patients for whom warfarin was switched to aspirin (ASA group; n=296) and patients who were kept on warfarin therapy (W group; n=312). There were no significant differences in CHA₂DS₂-VASc or HAS-BLED scores between the groups. In 30 patients in the ASA group and 37 patients in W group, AF recurred and warfarin was restarted or maintained during the 18.0±12.2 months of follow-up. There were no significant differences in thromboembolic (0.3% vs. 1.0%, p=0.342) and major bleeding incidences (0.7% vs. 0.6%, p=0.958) between ASA and W groups during the follow-up period. In the 259 patients with a CHA₂DS₂-VASc score≥2, there were no significant differences in thromboembolism (0.8% and 2.2%, p=0.380) or major bleeding incidences (0.8% and 1.4%, p=0.640) between ASA and W groups. Switching warfarin to aspirin 3 months after successful RFCA of AF could be as safe and efficacious as long-term anticoagulation even in patients with CHA₂DS₂-VASc score≥2. However, strict rhythm monitoring cannot be overemphasized.

Sensitivity of reentrant driver localization to electrophysiological parameter variability in image-based computational models of persistent atrial fibrillation sustained by a fibrotic substrate

NASA Astrophysics Data System (ADS)

Deng, Dongdong; Murphy, Michael J.; Hakim, Joe B.; Franceschi, William H.; Zahid, Sohail; Pashakhanloo, Farhad; Trayanova, Natalia A.; Boyle, Patrick M.

2017-09-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, causing morbidity and mortality in millions worldwide. The atria of patients with persistent AF (PsAF) are characterized by the presence of extensive and distributed atrial fibrosis, which facilitates the formation of persistent reentrant drivers (RDs, i.e., spiral waves), which promote fibrillatory activity. Targeted catheter ablation of RD-harboring tissues has shown promise as a clinical treatment for PsAF, but the outcomes remain sub-par. Personalized computational modeling has been proposed as a means of non-invasively predicting optimal ablation targets in individual PsAF patients, but it remains unclear how RD localization dynamics are influenced by inter-patient variability in the spatial distribution of atrial fibrosis, action potential duration (APD), and conduction velocity (CV). Here, we conduct simulations in computational models of fibrotic atria derived from the clinical imaging of PsAF patients to characterize the sensitivity of RD locations to these three factors. We show that RDs consistently anchor to boundaries between fibrotic and non-fibrotic tissues, as delineated by late gadolinium-enhanced magnetic resonance imaging, but those changes in APD/CV can enhance or attenuate the likelihood that an RD will anchor to a specific site. These findings show that the level of uncertainty present in patient-specific atrial models reconstructed without any invasive measurements (i.e., incorporating each individual's unique distribution of fibrotic tissue from medical imaging alongside an average representation of AF-remodeled electrophysiology) is sufficiently high that a personalized ablation strategy based on targeting simulation-predicted RD trajectories alone may not produce the desired result.

Non-invasive prediction of catheter ablation outcome in persistent atrial fibrillation by fibrillatory wave amplitude computation in multiple electrocardiogram leads.

PubMed

Zarzoso, Vicente; Latcu, Decebal G; Hidalgo-Muñoz, Antonio R; Meo, Marianna; Meste, Olivier; Popescu, Irina; Saoudi, Nadir

2016-12-01

Catheter ablation (CA) of persistent atrial fibrillation (AF) is challenging, and reported results are capable of improvement. A better patient selection for the procedure could enhance its success rate while avoiding the risks associated with ablation, especially for patients with low odds of favorable outcome. CA outcome can be predicted non-invasively by atrial fibrillatory wave (f-wave) amplitude, but previous works focused mostly on manual measures in single electrocardiogram (ECG) leads only. To assess the long-term prediction ability of f-wave amplitude when computed in multiple ECG leads. Sixty-two patients with persistent AF (52 men; mean age 61.5±10.4years) referred for CA were enrolled. A standard 1-minute 12-lead ECG was acquired before the ablation procedure for each patient. F-wave amplitudes in different ECG leads were computed by a non-invasive signal processing algorithm, and combined into a mutivariate prediction model based on logistic regression. During an average follow-up of 13.9±8.3months, 47 patients had no AF recurrence after ablation. A lead selection approach relying on the Wald index pointed to I, V1, V2 and V5 as the most relevant ECG leads to predict jointly CA outcome using f-wave amplitudes, reaching an area under the curve of 0.854, and improving on single-lead amplitude-based predictors. Analysing the f-wave amplitude in several ECG leads simultaneously can significantly improve CA long-term outcome prediction in persistent AF compared with predictors based on single-lead measures. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Peri-procedural interrupted oral anticoagulation for atrial fibrillation ablation: comparison of aspirin, warfarin, dabigatran, and rivaroxaban

PubMed Central

Winkle, Roger A.; Mead, R. Hardwin; Engel, Gregory; Kong, Melissa H.; Patrawala, Rob A.

2014-01-01

Aims Atrial fibrillation ablation requires peri-procedural oral anticoagulation (OAC) to prevent thromboembolic events. There are several options for OAC. We evaluate peri-procedural AF ablation complications using a variety of peri-procedural OACs. Methods and results We examined peri-procedural OAC and groin, bleeding, and thromboembolic complications for 2334 consecutive AF ablations using open irrigated-tip radiofrequency (RF) catheters. Pre-ablation OAC was warfarin in 1113 (47.7%), dabigatran 426 (18.3%), rivaroxaban 187 (8.0%), aspirin 472 (20.2%), and none 136 (5.8%). Oral anticoagulation was always interrupted and intraprocedural anticoagulation was unfractionated heparin (activated clotting time, ACT = 237 ± 26 s). Pre- and post-OAC drugs were the same for 1591 (68.2%) and were different for 743 (31.8%). Following ablation, 693 (29.7%) were treated with dabigatran and 291 (12.5%) were treated with rivaroxaban. There were no problems changing from one OAC pre-ablation to another post-ablation. Complications included 12 (0.51%) pericardial tamponades [no differences for dabigatran (P = 0.457) or rivaroxaban (P = 0.163) compared with warfarin], 12 (0.51%) groin complications [no differences for rivaroxaban (P = 0.709) and fewer for dabigatran (P = 0.041) compared with warfarin]. Only 5 of 2334 (0.21%) required blood transfusions. There were two strokes (0.086%) and no transient ischaemic attacks (TIAs) in the first 48 h post-ablation. Three additional strokes (0.13%), and two TIAs (0.086%) occurred from 48 h to 30 days. Only one stroke had a residual deficit. Compared with warfarin, the neurologic event rate was not different for dabigatran (P = 0.684) or rivaroxaban (P = 0.612). Conclusion Using interrupted OAC, low target intraprocedural ACT, and irrigated-tip RF, the rate of peri-procedural groin, haemorrhagic, and thromboembolic complications was extremely low. There were only minimal differences between OACs. Low-risk patients may remain on aspirin/no OAC pre-ablation. There are no problems changing from one OAC pre-ablation to another post-ablation. PMID:25115168

Surgical perspectives in the management of atrial fibrillation

PubMed Central

Kyprianou, Katerina; Pericleous, Agamemnon; Stavrou, Antonio; Dimitrakaki, Inetzi A; Challoumas, Dimitrios; Dimitrakakis, Georgios

2016-01-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia and a huge public health burden associated with significant morbidity and mortality. For decades an increasing number of patients have undergone surgical treatment of AF, mainly during concomitant cardiac surgery. This has sparked a drive for conducting further studies and researching this field. With the cornerstone Cox-Maze III “cut and sew” procedure being technically challenging, the focus in current literature has turned towards less invasive techniques. The introduction of ablative devices has revolutionised the surgical management of AF, moving away from the traditional surgical lesions. The hybrid procedure, a combination of catheter and surgical ablation is another promising new technique aiming to improve outcomes. Despite the increasing number of studies looking at various aspects of the surgical management of AF, the literature would benefit from more uniformly conducted randomised control trials. PMID:26839656

Characteristics of atrial fibrillation cycle length predict restoration of sinus rhythm by catheter ablation.

PubMed

Di Marco, Luigi Yuri; Raine, Daniel; Bourke, John P; Langley, Philip

2013-09-01

Successful termination of atrial fibrillation (AF) during catheter ablation (CA) is associated with arrhythmia-free follow-up. Preablation factors such as mean atrial fibrillation cycle length (AFCL) predict the likelihood of AF termination during ablation but recurring patterns and AFCL stability have not been evaluated. To investigate novel predictors of acute and postoperative ablation outcomes from intracardiac electrograms: (1) recurring AFCL patterns and (2) localization index (LI) of the instantaneous fibrillatory rate distribution. Sixty-two patients with AF (32 paroxysmal AF; 45 men; age 57 ± 10 years) referred for CA were enrolled. One-minute electrogram was recorded from coronary sinus (CS; 5 bipoles) and right atrial appendage (HRA; 2 bipoles). Atrial activations were detected automatically to derive the AFCL and instantaneous fibrillatory rate (inverse of AFCL) time series. Recurring AFCL patterns were quantified by using recurrence plot indices (RPIs): percentage determinism, entropy of determinism, and maximum diagonal length. AFCL stability was determined by using the LI. The CA outcome predictivity of individual indices was assessed. Patients with terminated atrial fibrillation (T-AF) had higher RPI (P < .05 in CS7-8) and LI than did those with nonterminated atrial fibrillation (P < .005 in CS3-4; P < .05 in CS5-6, CS7-8, and HRA). Patients free of arrhythmia after 3-month follow-up had higher RPI and LI (all P < .05 in CS7-8). All indices except percentage determinism predicted T-AF in CS7-8 (area under the curve [AUC] ≥ 0.71; odds ratio [OR] ≥ 4.50; P < .05). The median AFCL and LI predicted T-AF in HRAD (AUC ≥ 0.75; OR ≥ 7.76; P < .05). The RPI and LI predicted 3-month follow-up in CS7-8 (AUC ≥ 0.68; OR ≥ 4.17; P < .05). AFCL recurrence and stability indices could be used in selecting patients more likely to benefit from CA. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Catheter Ablation versus Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation (CASA-AF): study protocol for a randomised controlled trial.

PubMed

Khan, Habib Rehman; Kralj-Hans, Ines; Haldar, Shouvik; Bahrami, Toufan; Clague, Jonathan; De Souza, Anthony; Francis, Darrel; Hussain, Wajid; Jarman, Julian; Jones, David Gareth; Mediratta, Neeraj; Mohiaddin, Raad; Salukhe, Tushar; Jones, Simon; Lord, Joanne; Murphy, Caroline; Kelly, Joanna; Markides, Vias; Gupta, Dhiraj; Wong, Tom

2018-02-20

Atrial fibrillation is the commonest arrhythmia which raises the risk of heart failure, thromboembolic stroke, morbidity and death. Pharmacological treatments of this condition are focused on heart rate control, rhythm control and reduction in risk of stroke. Selective ablation of cardiac tissues resulting in isolation of areas causing atrial fibrillation is another treatment strategy which can be delivered by two minimally invasive interventions: percutaneous catheter ablation and thoracoscopic surgical ablation. The main purpose of this trial is to compare the effectiveness and safety of these two interventions. Catheter Ablation versus Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation (CASA-AF) is a prospective, multi-centre, randomised controlled trial within three NHS tertiary cardiovascular centres specialising in treatment of atrial fibrillation. Eligible adults (n = 120) with symptomatic, long-standing, persistent atrial fibrillation will be randomly allocated to either catheter ablation or thoracoscopic ablation in a 1:1 ratio. Pre-determined lesion sets will be delivered in each treatment arm with confirmation of appropriate conduction block. All patients will have an implantable loop recorder (ILR) inserted subcutaneously immediately following ablation to enable continuous heart rhythm monitoring for at least 12 months. The devices will be programmed to detect episodes of atrial fibrillation and atrial tachycardia ≥ 30 s in duration. The patients will be followed for 12 months, completing appropriate clinical assessments and questionnaires every 3 months. The ILR data will be wirelessly transmitted daily and evaluated every month for the duration of the follow-up. The primary endpoint in the study is freedom from atrial fibrillation and atrial tachycardia at the end of the follow-up period. The CASA-AF Trial is a National Institute for Health Research-funded study that will provide first-class evidence on the comparative efficacy, safety and cost-effectiveness of thoracoscopic surgical ablation and conventional percutaneous catheter ablation for long-standing persistent atrial fibrillation. In addition, the results of the trial will provide information on the effects on patients' quality of life. ISRCTN Registry, ISRCTN18250790 . Registered on 24 April 2015.

Contact force sensing for ablation of persistent atrial fibrillation: A randomized, multicenter trial.

PubMed

Conti, Sergio; Weerasooriya, Rukshen; Novak, Paul; Champagne, Jean; Lim, Hong Euy; Macle, Laurent; Khaykin, Yaariv; Pantano, Alfredo; Verma, Atul

2018-02-01

Impact of contact force sensing (CFS) on ablation of persistent atrial fibrillation (PeAF) is unknown. The purpose of the TOUCH AF (Therapeutic Outcomes Using Contact force Handling during Ablation of Persistent Atrial Fibrillation) randomized trial was to compare CFS-guided ablation to a CFS-blinded strategy. Patients (n = 128) undergoing first-time ablation for persistent AF were randomized to a CFS-guided vs CFS-blinded strategy. In the CFS-guided procedure, operators visualized real-time force data. In the blinded procedure, force data were hidden. Wide antral pulmonary vein isolation plus a roof line were performed. Patients were followed at 3, 6, 9, and 12 months with clinical visit, ECG, and 48-hour Holter monitoring. The primary endpoint was cumulative radiofrequency (RF) time for all procedures. Atrial arrhythmia >30 seconds after 3 months was a recurrence. PeAF was continuous for 26 weeks (interquartile range [IQR] 13-52), and left atrial size was 45 ± 5 mm. Force in the CFS-blinded and CFS-guided arms was 12 g [IQR 6-20] and 14 g [IQR 9-20] (P = .10), respectively. Total RF time did not differ between CFS-guided and CFS-blinded groups (49 ± 14 min vs 50 ± 20 min, respectively; P = .70). Single procedure freedom from atrial arrhythmia was 60% in the CFS-guided arm and 63% in the CFS-blinded arm off drugs. Lesions with gaps were associated with significantly less force (11.4 g [IQR 6-19] vs 13.2 g [IQR 8-20], respectively; P = .0007) and less force-time integral (174 gs [IQR 91-330] vs 210 gs [IQR 113-388], respectively; P <.001). CFS-guided ablation resulted in no difference to RF time or 12-month outcome. Lower force/force-time integral was associated with significantly more gaps. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Feasibility, Safety and Efficacy of a Novel Pre-Shaped Nitinol Esophageal Deviator to Successfully Deflect the Esophagus and Ablate Left Atrium without Esophageal Temperature Rise during Atrial Fibrillation Ablation - The DEFLECT GUT study.

PubMed

Parikh, Valay; Swarup, Vijay; Hantla, Jacob; Vuddanda, Venkat; Dar, Tawseef; Yarlagadda, Bharath; Di Biase, Luigi; Al-Ahmad, Amin; Natale, Andrea; Lakkireddy, Dhanunjaya

2018-04-17

Esophageal thermal injury is a feared complication of radiofrequency ablation (RFA) for atrial fibrillation (AF). Rise in luminal esophageal temperature (LET) limits the ability to deliver RF energy on posterior wall of LA. The aim of this registry was to evaluate feasibility, safety and efficacy of a mechanical esophageal deviation (ED) tool during AF ablation. We evaluated 687 patients who underwent RFA for AF. In 209 patients, EsoSure® was used to deflect esophagus away from ablation site. Propensity-score matching was performed to obtain 180 patients each in ED and non-ED arms. ED was used for LET rise seen in 61.7% (111/180) patients and was used if esophagus was in the line of ablation on fluoroscopy in 38.3% (69/180) patients. The mean deviation of trailing edge of esophagus with EsoSure® was 2.45 ± 0.9 cm (range: 1-4.5 cm). LET rise >1°C was significantly lower in ED than non-ED group (3% vs 79.4%, p<0.001). Mean LET rise (ED 0.34 ± 0.59 vs non-ED 1.66 ± 0.54, p<0.001). Intra-procedural success of PVAI, was slightly improved in ED arm than in non-ED arm without statistical significance. AF recurrence was lower in ED arm at 3-month, 6-month and 1-year follow-up than non-ED arm. No ED-related complications were noted. Mechanical displacement of esophagus with EsoSure® appears to be feasible, safe and efficacious in enabling adequate RF energy delivery to posterior wall of LA without significant LET rise and obvious clinical signs of esophageal injury. Copyright © 2018. Published by Elsevier Inc.

Usefulness of Doppler assessment of pulmonary vein and left atrial appendage flow following pulmonary vein isolation of chronic atrial fibrillation in predicting recovery of left atrial function.

PubMed

Donal, Erwan; Grimm, Richard A; Yamada, Hirotsugu; Kim, Yong Jin; Marrouche, Nassir; Natale, Andrea; Thomas, James D

2005-04-15

Atrial fibrillation (AF) is a widespread condition that causes significant morbidity and mortality. Recently, pulmonary venous (PV) isolation using radiofrequency ablation has been used successfully to exclude the pulmonary venous ostia, resulting in correction of AF. Further, miniaturized high-frequency ultrasound phased-array transducers currently provide Doppler and 2-dimensional imaging during the ablation procedure. We examined atrial function and its determinants using intracardiac echocardiography before and after PV isolation in 45 patients who had chronic AF (56 +/- 11 years old). PV, left atrial (LA) appendage, and mitral and tricuspid flows were recorded. Recovery of booster pump function (defined by the presence of mitral inflow A wave, LA appendage a-wave, and PV A-reversal wave velocities >10 cm/s) was observed in 39 of 45 patients (86.6%). PV flow systolic wave before and after ablation correlated with the degree of LA booster pump function after PV isolation. An early systolic PV flow peak velocity >57.47 cm/s predicted "good" LA booster pump function recovery with 96% specificity. Diastolic LA appendage emptying in AF correlated (p <0.001) and predicted good LA booster pump function with 92% specificity for velocities >46.4 cm/s. Thus, monitoring LA function during PV isolation for chronic AF is feasible. Most patients recovered LA booster pump function immediately after PV isolation, and the degree of recovery correlated with LA reservoir function. Preserved reservoir function during AF is predictive of satisfactory recovery of booster pump function after PV isolation.

Endurance Sport Activity and Risk of Atrial Fibrillation – Epidemiology, Proposed Mechanisms and Management

PubMed Central

Vicedomini, Gabriele; Pappone, Carlo

2014-01-01

There is evidence for a higher prevalence of atrial fibrillation (AF) in athletes engaged in long-term endurance sports training compared with the general population. Although atrial anatomic adaptations, alterations in autonomic nervous system, chronic systemic inflammation and fibrosis have been proposed as potential mechanisms, they remain speculative. Medical therapy with long-term antiarrhythmic agents or ‘pill in the pocket’ medications is hampered by limitations, such as sports eligibility and interference with exercise tolerance. AF ablation represents a valid therapeutic option with results similar to these achieved in other patients. Nevertheless, further clinical trials are needed to confirm whether endurance sport practice affects the maintenance of sinus rhythm following catheter ablation of AF. PMID:26835059

Limited left atrial surgical ablation effectively treats atrial fibrillation but decreases left atrial function.

PubMed

Compier, Marieke G; Tops, Laurens F; Braun, Jerry; Zeppenfeld, Katja; Klautz, Robert J; Schalij, Martin J; Trines, Serge A

2017-04-01

Limited left atrial (LA) surgical ablation with bipolar radiofrequency is considered to be an effective procedure for treatment of atrial fibrillation (AF). We studied whether limited LA surgical ablation concomitant to cardiac surgery is able to maintain LA function. Thirty-six consecutive patients (age 66 ± 12 years, 53% male, 78% persistent AF) scheduled for valve surgery and/or coronary revascularization and concomitant LA surgical ablation were included. Epicardial pulmonary vein isolation (PVI) and additional endo-epicardial lines were performed using bipolar radiofrequency. An age- and gender-matched control group (n = 36, age 66 ± 9 years, 69% male, 81% paroxysmal AF) was selected from patients undergoing concomitant epicardial PVI only. Left atrial dimensions and function were assessed on two-dimensional echocardiography preoperatively and at 3- and 12-month follow-up. Sinus rhythm (SR) maintenance was 67% for limited LA ablation and 81% for PVI at 1-year follow-up (P = 0.18). Left atrial volume decreased from 72 ± 21 to 50 ± 14 mL (31%, P < 0.01) after limited LA ablation and from 65 ± 23 to 56 ± 20 mL (14%, P < 0.01) after PVI. Atrial transport function was restored in 54% of patients in SR after limited LA ablation compared with 100% of patients in SR after PVI. Atrial strain and contraction parameters (LA ejection fraction, A-wave velocity, reservoir function, and strain rate) significantly decreased after limited LA ablation. After PVI, strain and contraction parameters remained unchanged. Even limited LA ablation decreased LA volume, contraction, transport function, and compliance, indicating both reverse remodelling combined with significant functional deterioration. In contrast, surgical PVI decreased LA volume while function remained unchanged. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Outcomes of atrioesophageal fistula following catheter ablation of atrial fibrillation treated with surgical repair versus esophageal stenting.

PubMed

Mohanty, Sanghamitra; Santangeli, Pasquale; Mohanty, Prasant; Di Biase, Luigi; Trivedi, Chintan; Bai, Rong; Horton, Rodney; Burkhardt, J David; Sanchez, Javier E; Zagrodzky, Jason; Bailey, Shane; Gallinghouse, Joseph G; Hranitzky, Patrick M; Sun, Albert Y; Hongo, Richard; Beheiry, Salwa; Natale, Andrea

2014-06-01

Atrioesophageal fistula (AEF) is a rare but devastating complication of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Surgical repair and esophageal stents are available treatment options for AEF. We report outcomes of these 2 management strategies. Nine patients with AEF post-RFCA for AF were included in this study. AEF was diagnosed based on symptoms and chest CT imaging. Of the 9 patients, 5 received stents and 4 underwent surgical repair of fistula. AF ablation was performed under general anesthesia (n = 4) or conscious sedation (n = 5). During ablation, RF power was maintained between 25 and 35 Watts in areas close to the esophagus and energy delivery discontinued when esophageal temperature reached 38 °C. Seven patients underwent ablation with 3.5-mm open-irrigated catheter, 1 with 8-mm nonirrigated catheter, and 1 had surgical epicardial ablation. Seven patients received proton pump inhibitor and sucralfate before and after procedure. AEF symptoms developed within 2–6 weeks from ablation. Esophageal stenting was performed in 5 patients (median age 58 years, median time from RFCA 4 weeks) and 4 underwent surgical repair (median age 54 years, median time from RFCA 4 weeks) within 2–4 hours from diagnosis. All 5 patients receiving stents died within 1 week of the procedure due to cerebral embolism, septic shock, or respiratory failure. On the other hand, the 4 patients that received surgical repair were alive at median follow-up of 2.1 years (P = 0.005). Esophageal stenting should be discouraged and prompt surgical repair is crucial for survival in patients with atrioesophageal fistula.

Electrophysiological characteristics of the Marshall bundle in humans

PubMed Central

Han, Seongwook; Joung, Boyoung; Scanavacca, Mauricio; Sosa, Eduardo; Chen, Peng-Sheng; Hwang, Chun

2010-01-01

BACKGROUND Marshall bundles (MBs) are the muscle bundles within the ligament of Marshall. OBJECTIVE This trial sought to the electrophysiological characteristics of the MB and the anatomical connections between MB and left atrium (LA) in patients with persistent atrial fibrillation (AF). METHODS We enrolled 72 patients (male:female 59:13, age 59.9 ± 9.4 years) who underwent MB mapping and ablation for AF. MB mapping was done via an endocardial or epicardial approach during sinus rhythm and AF. RESULTS Recordings were successful in 64 of 72 patients (89%). A single connection was noted in 11 of 64 patients between the MB and the coronary sinus (CS) muscle sleeves. The MB recordings showed distinct MB potentials with a proximal-to-distal activation pattern during sinus rhythm. During AF, organized passive activations and dissociated slow MB ectopic activities were commonly observed in this type of connection. Double connections to both CS and LA around left pulmonary veins were noted in 23 of 64 patients (36%). After the ablation of the distal connection, MB recording showed typical double potentials as in single connection. Multiple connections were noted in 30 of 64 patients (47%). During sinus rhythm, the earliest activation was in the middle of the MB. The activation patterns were irregular and variable in each patient. During AF, rapid and fractionated complex activations were noted in all patients of this group. CONCLUSION We documented 3 different types of MB–LA connections. Rapid and fractionated activations were most commonly observed in the MB that had multiple LA connections. PMID:20188860

Two years outcome in patients with persistent atrial fibrillation after pulmonary vein isolation using the second-generation 28-mm cryoballoon.

PubMed

Tscholl, Verena; Lsharaf, Abdullah Khaled-A; Lin, Tina; Bellmann, Barbara; Biewener, Sebastian; Nagel, Patrick; Suhail, Saba; Lenz, Klaus; Landmesser, Ulf; Roser, Mattias; Rillig, Andreas

2016-09-01

The efficacy of the second-generation cryoballoon (CB) in patients with paroxysmal atrial fibrillation (AF) has been demonstrated previously. Data on the efficacy of CB ablation in patients with persistent AF are sparse. The aim of this study was to evaluate the 2-year success rate of pulmonary vein isolation in patients with persistent AF using the second-generation CB. Fifty consecutive patients (mean age 64.6 ± 9.9 years; 19 women [38%]) with persistent AF were included in this analysis. The mean follow-up period was 22 ± 11 months. All patients were ablated using the second-generation 28-mm CB. Isolation of the pulmonary veins was confirmed using a spiral mapping catheter. In all patients, follow-up was obtained using 24-hour Holter monitoring or via interrogation of an implanted loop recorder or pacemaker. The mean left atrial diameter was 43.6 ± 5.6 mm, the mean CHA2DS2-VASc score was 2.8 ± 1.5, and the mean HAS-BLED score was 2.1 ± 1.2. The mean fluoroscopy time was 25.8 ± 9 minutes, and the mean procedural time was 146.4 ± 37.8 minutes. After 22 ± 11 months, the frequency of arrhythmia recurrence was 22 of 50 (44%) in the overall group (paroxysmal AF 6 of 22 [27%]; persistent AF 16 of 22 [73%]). No major complications occurred. Aneurysma spurium not requiring surgical intervention occurred in 1 (2%) patient. No phrenic nerve palsy was observed. Two years' results after pulmonary vein isolation using the second-generation CB in patients with persistent AF are promising. The clinical success rate appears to be similar to the reported success rates of radiofrequency ablation for the treatment of persistent AF. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Remote Magnetic versus Manual Navigation for Radiofrequency Ablation of Paroxysmal Atrial Fibrillation: Long-Term, Controlled Data in a Large Cohort.

PubMed

Kataria, Vikas; Berte, Benjamin; Vandekerckhove, Yves; Tavernier, Rene; Duytschaever, Mattias

2017-01-01

Purpose. We aimed to study long-term outcome after pulmonary vein isolation (PVI) guided by remote magnetic navigation (RMN) and provided comparative data to outcome after manual navigation (MAN). Methods. Three hundred thirty-six patients with symptomatic paroxysmal AF underwent PVI by irrigated point-by-point radiofrequency (RF) ablation (RMN, n = 114 versus MAN, n = 222). Patients were followed up with symptom guided rhythm monitoring for a period up to 43 months. The end point of the study was freedom from repeat ablation after a single procedure and without antiarrhythmic drug treatment (ADT). Results. At the end of follow-up (median 26.3 months), freedom from repeat ablation was comparable between RMN and MAN (70.9% versus 69.5%, p = 0.61). At repeat, mean number of reconnected veins was 2.4 ± 1.2 in RMN versus 2.6 ± 1.0 in MAN ( p = 0.08). The majority of repeat procedures occurred during the first year (82.1% in RMN versus 78.5% in MAN; p = 0.74). Conclusion. On the long term (up to 3 years) and in a large cohort of patients with paroxysmal AF, RMN-guided PVI is as effective as MAN guided PVI. In both strategies the majority of repeat procedures occurred during the first year after index procedure.

Remote Magnetic versus Manual Navigation for Radiofrequency Ablation of Paroxysmal Atrial Fibrillation: Long-Term, Controlled Data in a Large Cohort

PubMed Central

Berte, Benjamin; Vandekerckhove, Yves; Tavernier, Rene

2017-01-01

Purpose. We aimed to study long-term outcome after pulmonary vein isolation (PVI) guided by remote magnetic navigation (RMN) and provided comparative data to outcome after manual navigation (MAN). Methods. Three hundred thirty-six patients with symptomatic paroxysmal AF underwent PVI by irrigated point-by-point radiofrequency (RF) ablation (RMN, n = 114 versus MAN, n = 222). Patients were followed up with symptom guided rhythm monitoring for a period up to 43 months. The end point of the study was freedom from repeat ablation after a single procedure and without antiarrhythmic drug treatment (ADT). Results. At the end of follow-up (median 26.3 months), freedom from repeat ablation was comparable between RMN and MAN (70.9% versus 69.5%, p = 0.61). At repeat, mean number of reconnected veins was 2.4 ± 1.2 in RMN versus 2.6 ± 1.0 in MAN (p = 0.08). The majority of repeat procedures occurred during the first year (82.1% in RMN versus 78.5% in MAN; p = 0.74). Conclusion. On the long term (up to 3 years) and in a large cohort of patients with paroxysmal AF, RMN-guided PVI is as effective as MAN guided PVI. In both strategies the majority of repeat procedures occurred during the first year after index procedure. PMID:28386560

[Combined left atrial appendage percutaneous closure and atrial fibrillation ablation: a single center experience].

PubMed

Pelissero, Elisa; Giuggia, Marco; Todaro, Maria Chiara; Trapani, Giuseppe; Giordano, Benedetta; Senatore, Gaetano

2017-12-01

We evaluated long-term safety and efficacy of concomitant left atrial appendage (LAA) closure and atrial fibrillation (AF) ablation. From February 2013 to June 2017, all patients referred for AF ablation and LAA closure (group 1) were enrolled in the study and compared with a matched control group undergoing AF ablation only (group 2). Pulmonary vein isolation was achieved in all cases with radiofrequency or cryoballoon. LAA was occluded with Watchman or Amplatzer Cardiac Plug or Amulet (ACP) devices. All patients were treated with oral anticoagulation therapy for at least 3 months after the procedure ("blanking period"), and then switched to dual antiplatelet therapy with aspirin and clopidogrel for other 3 months, and then to single antiplatelet therapy with aspirin in case of LAA closure, while group 2 was treated with long-term oral anticoagulation therapy according to CHA2DS2-VASc score. Follow-up was performed with transesophageal echocardiography and clinical visit at 3, 6 and 12 months after the procedure. AF burden was evaluated by loop recorder or pacemaker interrogation in all patients. Overall, 42 patients were enrolled, 21 in each group. Mean age was 66.86 ± 10.35 years in group 1 vs 68.42 ± 10.61 in group 2 (p=NS); mean CHA2DS2-VASc score was 2.8 ± 1.22 in group 1 vs 2.01 ± 0.93 in group 2 (p=NS), mean HAS-BLED score was 3.2 ± 0.83 in group 1 vs 3.1 ± 0.95 in group 2 (p=NS). Persistent AF was present in 80% of patients in group 1 and in 85% in group 2. LAA closure was successful in all cases (14 Watchman, 7 ACP devices). Procedural and fluoroscopy times were shorter in group 2 (68 ± 17 vs 52 ± 15 min, p <0.05; 23 ± 5 vs 18 ± 3 min, p <0.05, respectively). No procedural complications were observed in group 2, while in group 1 one case of self-terminating pericardial effusion and one arteriovenous fistula were observed. At a mean follow-up of 14.93 ± 10.05 months, complete seal of LAA was documented in all patients, with neither dislocations nor thromboembolic events. Similarly, no long-term complications were observed in group 2. Maintenance of sinus rhythm was overlapping, with an AF relapse rate of 36% in group 1 vs 38% in group 2 (p=NS). Combined LAA percutaneous closure and AF ablation appears to be feasible in high-risk patients.

Noninvasive evaluation of reverse atrial remodeling after catheter ablation of atrial fibrillation by P wave dispersion.

PubMed

Fujimoto, Yuhi; Yodogawa, Kenji; Takahashi, Kenta; Tsuboi, Ippei; Hayashi, Hiroshi; Uetake, Shunsuke; Iwasaki, Yu-Ki; Hayashi, Meiso; Miyauchi, Yasushi; Shimizu, Wataru

2017-11-01

Atrial fibrillation (AF) itself creates structural and electrophysiological changes such as atrial enlargement, shortening of refractory period and decrease in conduction velocity, called "atrial remodeling", promoting its persistence. Although the remodeling process is considered to be reversible, it has not been elucidated in detail. The aim of this study was to assess the feasibility of P wave dispersion in the assessment of reverse atrial remodeling following catheter ablation of AF. Consecutive 126 patients (88 males, age 63.0 ± 10.4 years) who underwent catheter ablation for paroxysmal AF were investigated. P wave dispersion was calculated from the 12 lead ECG before, 1 day, 1 month, 3 months and 6 months after the procedure. Left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular ejection fraction (LVEF), transmitral flow velocity waveform (E/A), and tissue Doppler (E/e') on echocardiography, plasma B-type natriuretic peptide (BNP) concentrations, serum creatinine, and estimated glomerular filtration rate (eGFR) were also measured. Of all patients, 103 subjects remained free of AF for 1 year follow-up. In these patients, P wave dispersion was not changed 1 day and 1 month after the procedure. However, it was significantly decreased at 3 and 6 months (50.1 ± 14.8 to 45.4 ± 14.4 ms, p < 0.05, 45.2 ± 9.9 ms, p < 0.05, respectively). Plasma BNP concentrations, LAD and LAVI were decreased (81.1 ± 103.8 to 44.8 ± 38.3 pg/mL, p < 0.05, 38.2 ± 5.7 to 35.9 ± 5.6 mm, p < 0.05, 33.3 ± 14.2 to 29.3 ± 12.3 mL/m 2 , p < 0.05) at 6 months after the procedure. There were no significant changes in LVEF, E/A, E/e', serum creatinine, and eGFR during the follow up period. P wave dispersion was decreased at 3 and 6 months after catheter ablation in patients without recurrence of AF. P wave dispersion is useful for assessment of reverse remodeling after catheter ablation of AF.

Meta-analysis of efficacy and safety of apixaban and uninterrupted apixaban therapy compared to vitamin K antagonists in patients undergoing catheter ablation for atrial fibrillation.

PubMed

Ukaigwe, Anene; Shrestha, Pragya; Karmacharya, Paras; Hussain, Sarah K; Samii, Soraya; Gonzalez, Mario D; Wolbrette, Deborah; Naccarrelli, Gerald V

2017-03-01

Apixaban is a Factor Xa inhibitor increasingly being used for stroke prevention in atrial fibrillation (AF). Although several studies have been done, the efficacy and safety of apixaban during the peri-procedural period of AF ablation remains unclear. We sought to systematically review pooled data from these various studies to evaluate thromboembolic and bleeding risks in patients undergoing catheter ablation for AF who are treated with apixaban (interrupted and uninterrupted). Studies comparing anticoagulation with apixaban or vitamin K antagonists (VKA) in patients undergoing ablation for AF were identified via an electronic search of MEDLINE, EMBASE, clinical trials.gov, and Cochrane Library from inception to January 2016. Study-specific risk ratios were calculated and combined with a fixed-effects model meta-analysis. In the analysis of 2100 pooled patients, thromboembolic complications (TE) occurred in 14/778 (1.80 %) patients in the apixaban group (AG) compared to 20/1322 patients in the VKA group (RR 1.03, 95 % CI 0.55-1.90, p = 0.93, I 2  = 0 %). Major bleeding occurred in 9/778 (1.2 %) of the AG compared to 20/1322 (1.51 %) in the VKA group (RR 1.03, 95 % CI 0.55-1.90, p = 0.93, I 2  = 0 %). In uninterrupted apixaban group (uAG), TE occurred in 4/585 (0.68 %) patients in the uAG compared to 6/910 (0.66 %) in VKA group (RR 0.86, 95 % CI 0.25-2.95, p = 0.81, I 2  = 0 %). Major bleeding occurred in 5/585 (0.85 %) in uAG compared to 7/910 (0.77 %) in the VKA group (RR 1.20, 95 % CI 0.37-3.88, p = 0.76, I 2  = 0 %). Our study demonstrates patients treated with apixaban and VKA during the peri-procedural period for AF ablation have similar rates of TE and bleeding complications. Interrupted and uninterrupted apixaban strategies were associated with similar outcomes.

An approach to ablate and pace:AV junction ablation and pacemaker implantation performed concurrently from the same venous access site.

PubMed

Issa, Ziad F

2007-09-01

Atrioventricular junction (AVJ) ablation combined with permanent pacemaker implantation (the "ablate and pace" approach) remains an acceptable alternative treatment strategy for symptomatic, drug-refractory atrial fibrillation (AF) with rapid ventricular response. This case series describes the feasibility and safety of catheter ablation of the AVJ via a superior vena caval approach performed during concurrent dual-chamber pacemaker implantation. A total of 17 consecutive patients with symptomatic, drug-refractory, paroxysmal AF underwent combined AVJ ablation and dual-chamber pacemaker implantation procedure using a left axillary venous approach. Two separate introducer sheaths were placed into the axillary vein. The first sheath was used for implantation of the pacemaker ventricular lead, which was then connected to the pulse generator. Subsequently, a standard ablation catheter was introduced through the second axillary venous sheath and used for radiofrequency (RF) ablation of the AVJ. After successful ablation, the catheter was withdrawn and the pacemaker atrial lead was advanced through that same sheath and implanted in the right atrium. Catheter ablation of the AVJ was successfully achieved in all patients. The median number of RF applications required to achieve complete AV block was three (range 1-10). In one patient, AV conduction recovered within the first hour after completion of the procedure, and AVJ ablation was then performed using the conventional femoral venous approach. There were no procedural complications. Catheter ablation of the AVJ can be performed successfully and safely via a superior vena caval approach in patients undergoing concurrent dual-chamber pacemaker implantation.

Impact of Radiofrequency Ablation of Atrial Fibrillation on Pulmonary Vein Cross Sectional Area: Implications for the Diagnosis of Pulmonary Vein Stenosis.

PubMed

Jazayeri, Mohammad-Ali; Vanga, Subba Reddy; Vuddanda, Venkat; Turagam, Mohit; Parikh, Valay; Lavu, Madhav; Bommana, Sudharani; Atkins, Donita; Nath, Jayant; Rosamond, Thomas; Vacek, James; Madhu Reddy, Y; Lakkireddy, Dhanunjaya

2017-01-01

Restoration of normal sinus rhythm by radiofrequency ablation (RFA) in atrial fibrillation (AF) patients can result in a reduction of left atrial (LA) volume and pulmonary vein (PV) dimensions. It is not clear if this PV size reduction represents a secondary effect of overall LA volume reduction or true PV stenosis. We assessed the relationship between LA volume reduction and PV orifice area pre- and post-RFA. A retrospective cohort study was conducted at a tertiary care academic hospital. Pre- and post-RFA cardiac computed tomography (CT) studies of 100 consecutive AF patients were reviewed. Studies identifying obvious segmental PV narrowing were excluded. Left atrial volumes and PV orifice cross-sectional areas (PVOCA) were measured using proprietary software from the CT scanner vendor (GE Healthcare, Waukesha, WI). The cohort had a mean age of 60 ± 8 years, 73% were male, and 90% were Caucasian. Non-paroxysmal AF was present in 76% of patients with a mean duration from diagnosis to RFA of 55 ± 54 months. Mean procedural time was 244 ± 70 min. AF recurred in 27% at 3 month follow-up. Pre-RFA LA volumes were 132 ± 60 ml and mean PVOCA was 2.89 ± 2.32 cm 2 . In patients with successful ablation, mean LA volume decreased by 10% and PVOCA decreased by 21%. PVOCA was significantly reduced in patients with successful RFA compared to those who had recurrence (2.18 ± 1.12 vs. 2.8 ± 1.9 cm 2 , p = 0.04) but reduction in LA volume between groups was not significant (118 ± 42 vs. 133 ± 54 ml, p=0.15). The study demonstrates that both PV orifice dimensions and LA volume are reduced after successful AF ablation. These data warrant a reassessment of criteria for diagnosing PV stenosis based on changes in PV caliber alone, ideally incorporating LA volume changes.

Remotely controlled steerable sheath improves result and procedural parameters of atrial fibrillation ablation with magnetic navigation.

PubMed

Errahmouni, Abdelkarim; Latcu, Decebal Gabriel; Bun, Sok-Sithikun; Rijo, Nicolas; Dugourd, Céline; Saoudi, Nadir

2015-07-01

The magnetic navigation (MN) system may be coupled with a new advancement system that fully controls both the catheter and a robotic deflectable sheath (RSh) or with a fixed-curve sheath and a catheter-only advancement system (CAS). We aimed to compare these approaches for atrial fibrillation (AF) ablation. Atrial fibrillation ablation patients (45, 23 paroxysmal and 22 persistent) performed with MN-RSh (RSh group) were compared with a control group (37, 18 paroxysmal and19 persistent) performed with MN-CAS (CAS group). Setup duration was measured from the procedure's start to operator transfer to control room. Ablation step duration was defined as the time from the beginning of the first radiofrequency (RF) pulse to the end of the last one and was separately acquired for the left and the right pulmonary vein (PV) pairs. Clinical characteristics, left atrial size, and AF-type distribution were similar between the groups. Setup duration as well as mapping times was also similar. Ablation step duration for the left PVs was similar, but was shorter for the right PVs in RSh group (46 ± 9 vs. 63 ± 12 min, P < 0.0001). Radiofrequency delivery time (34 ± 9 vs. 40 ± 11 min, P = 0.007) and procedure duration (227 ± 36 vs. 254 ± 62 min, P = 0.01) were shorter in RSh group. No complication occurred in RSh group. During follow-up, there were five recurrences (11%) in RSh group and 11 (29%) in CAS group (P = 0.027). The use of the RSh for AF ablation with MN is safe and improves outcome. Right PV isolation is faster, RF delivery time and procedure time are reduced. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Localization of gaps during redo ablations of paroxysmal atrial fibrillation: Preferential patterns depending on the choice of cryoballoon ablation or radiofrequency ablation for the initial procedure.

PubMed

Galand, Vincent; Pavin, Dominique; Behar, Nathalie; Auffret, Vincent; Fénéon, Damien; Behaghel, Albin; Daubert, Jean-Claude; Mabo, Philippe; Martins, Raphaël P

2016-11-01

Pulmonary vein (PV) isolation, using cryoballoon or radiofrequency ablation, is the cornerstone therapy for symptomatic paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drugs. One-third of the patients have recurrences, mainly due to PV reconnections. To describe the different locations of reconnection sites in patients who had previously undergone radiofrequency or cryoballoon ablation, and to compare the characteristics of the redo procedures in both instances. Demographic data and characteristics of the initial ablation (cryoballoon or radiofrequency) were collected. Number and localization of reconduction gaps, and redo characteristics were reviewed. Seventy-four patients scheduled for a redo ablation of paroxysmal AF were included; 38 had been treated by radiofrequency ablation and 36 by cryoballoon ablation during the first procedure. For the initial ablation, procedural and fluoroscopy times were significantly shorter for cryoballoon ablation (147.8±52.6min vs. 226.6±64.3min [P<0.001] and 37.0±17.7min vs. 50.8±22.7min [P=0.005], respectively). Overall, an identical number of gaps was found during redo procedures of cryoballoon and radiofrequency ablations. However, a significantly higher number of gaps were located in the right superior PV for patients first ablated with radiofrequency (0.9±1.0 vs. 0.5±0.9; P=0.009). Gap localization displayed different patterns. Although not significant, redo procedures of cryoballoon ablation were slightly shorter and needed shorter durations of radiofrequency to achieve PV isolation. During redo procedures, gap localization pattern is different for patients first ablated with cryoballoon or radiofrequency ablation, and right superior PV reconnections occur more frequently after radiofrequency ablation. Redo ablation of a previous cryoballoon ablation appears to be easier. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Real-time rotational ICE imaging of the relationship of the ablation catheter tip and the esophagus during atrial fibrillation ablation.

PubMed

Helms, Adam; West, J Jason; Patel, Amit; Mounsey, J Paul; DiMarco, John P; Mangrum, J Michael; Ferguson, John D

2009-02-01

Atrioesophageal fistula is a rare complication of atrial fibrillation (AF) ablation that should be avoided. We investigated whether rotational intracardiac echocardiography (ICE) can help to minimize ablation close to the esophagus. We studied 41 patients referred for catheter ablation of refractory AF. A rotational ICE catheter was inserted into the (LA) to determine the location of the esophagus. The esophagus was identified to be either adjacent to the pulmonary vein (PV) ostium or to a cuff 2 cm outside the ostium. Circumferential ablation was performed at the PV ostium, with the exact ablation location determined by ICE. The relationship of the catheter tip to the esophagus was imaged during energy delivery, allowing interruption when respiration moved the tip closer to the esophagus. Out of 41 patients, the esophagus was seen near left-sided PVs in 32 and near right-sided PVs in three patients. The median distance from LA endocardium to esophagus was 2.2 mm (range, 1.4-6 mm). In 21 of 35 patients with a closely related esophagus, ablation over the esophagus was avoided by ablating either lateral or medial to the esophagus. In 14 patients, the esophagus could not be avoided, and risk was minimized by limiting lesion size. Significant movement (>10 mm) of the esophagus during the procedure occurred in 3/41 cases. Rotational ICE can accurately determine the distance of ablation sites from the esophagus. Real-time imaging of the relationship of the ablation catheter tip to the esophagus may reduce the incidence of esophageal injury.

A New Era in the Surgical Treatment of Atrial Fibrillation

PubMed Central

Melby, Spencer J.; Zierer, Andreas; Bailey, Marci S.; Cox, James L.; Lawton, Jennifer S.; Munfakh, Nabil; Crabtree, Traves D.; Moazami, Nader; Huddleston, Charles B.; Moon, Marc R.; Damiano, Ralph J.

2006-01-01

Background/Objective: While the Cox-Maze procedure remains the gold standard for the surgical treatment of atrial fibrillation (AF), the use of ablation technology has revolutionized the field. To simplify the procedure, our group has replaced most of the incisions with bipolar radiofrequency ablation lines. The purpose of this study was to examine results using bipolar radiofrequency in 130 patients undergoing a full Cox-Maze procedure, a limited Cox-Maze procedure, or pulmonary vein isolation alone. Methods: A retrospective review was performed of patients who underwent a Cox-Maze procedure (n = 100), utilizing bipolar radiofrequency ablation, a limited Cox-Maze procedure (n = 7), or pulmonary vein isolation alone (n = 23). Follow-up was available on 129 of 130 patients (99%). Results: Pulmonary vein isolation was confirmed by intraoperative pacing in all patients. Cross-clamp time in the lone Cox-Maze procedure patients was 44 ± 21 minutes, and 104 ± 42 minutes for the Cox-Maze procedure with a concomitant procedure, which was shortened considerably from our traditional cut-and-sew Cox-Maze procedure times (P < 0.05). There were 4 postoperative deaths in the Cox-Maze procedure group and 1 in the pulmonary vein isolation group. The mean follow-up was 13 ± 10, 23 ± 15, and 9 ± 10 months for the Cox-Maze IV, the pulmonary vein isolation, and the limited Cox-Maze procedure groups, respectively. At last follow-up, freedom from AF was 90% (85 of 94), 86% (6 of 7), and 59% (10 of 17) in the in the Cox-Maze procedure group, limited Cox-Maze procedure group, and pulmonary vein isolation alone group, respectively. Conclusions: The use of bipolar radiofrequency ablation to replace Cox-Maze incisions was safe and effective at controlling AF. Pulmonary vein isolation alone was much less effective, and should be used cautiously in this population. PMID:16998367

The Role Of Contact Force In Atrial Fibrillation Ablation.

PubMed

Nakagawa, Hiroshi; Jackman, Warren M

2014-01-01

During radiofrequency (RF) ablation, low electrode-tissue contact force (CF) is associated with ineffective RF lesion formation, whereas excessive CF may increase the risk of steam pop and perforation. Recently, ablation catheters using two technologies have been developed to measure real-time catheter-tissue CF. One catheter uses three optical fibers to measure microdeformation of a deformable body in the catheter tip. The other catheter uses a small spring connecting the ablation tip electrode to the catheter shaft with a magnetic transmitter and sensors to measure microdeflection of the spring. Pre-clinical experimental studies have shown that 1) at constant RF power and application time, RF lesion size significantly increases with increasing CF; 2) the incidence of steam pop and thrombus also increase with increasing CF; 3) modulating RF power based on CF (i.e, high RF power at low CF and lower RF power at high CF) results in a similar and predictable RF lesion size. In clinical studies in patients undergoing pulmonary vein (PV) isolation, CF during mapping in the left atrium and PVs showed a wide range of CF and transient high CF. The most common high CF site was located at the anterior/rightward left atrial roof, directly beneath the ascending aorta. There was a poor relationship between CF and previously used surrogate parameters for CF (unipolar or bipolar atrial potential amplitude and impedance). Patients who underwent PV isolation with an average CF of <10 g experienced higher AF recurrence, whereas patients with ablation using an average CF of > 20g had lower AF recurrence. AF recurred within 12 months in 6 of 8 patients (75%) who had a mean Force-Time Integral (FTI, area under the curve for contact force vs. time) < 500 gs. In contrast, AF recurred in only 4 of 13 patients (21%) with ablation using a mean FTI >1000 gs. In another study, controlling RF power based on CF prevented steam pop and impedance rise without loss of lesion effectiveness. These studies confirm that CF is a major determinant of RF lesion size and future systems combining CF, RF power and application time may provide real-time assessment of lesion formation.

Catheter ablation of asymptomatic longstanding persistent atrial fibrillation: impact on quality of life, exercise performance, arrhythmia perception, and arrhythmia-free survival.

PubMed

Mohanty, Sanghamitra; Santangeli, Pasquale; Mohanty, Prasant; Di Biase, Luigi; Holcomb, Shawna; Trivedi, Chintan; Bai, Rong; Burkhardt, David; Hongo, Richard; Hao, Steven; Beheiry, Salwa; Santoro, Francesco; Forleo, Giovanni; Gallinghouse, Joseph G; Horton, Rodney; Sanchez, Javier E; Bailey, Shane; Hranitzky, Patrick M; Zagrodzky, Jason; Natale, Andrea

2014-10-01

Impact of catheter ablation on exercise performance, quality of life (QoL) and symptom perception in asymptomatic longstanding persistent AF (LSP-AF) patients has not been reported yet. Sixty-one consecutive patients (mean age 62 ±13 years, 71% males) with asymptomatic LSP-AF undergoing first catheter ablation were enrolled. Extended pulmonary vein antrum isolation plus ablation of complex fractionated atrial electrograms and nonpulmonary vein triggers was performed in all. QoL survey was taken at baseline and 12-months postablation, using Short Form-36 (SF-36). Information on arrhythmia perception was obtained using a standard questionnaire and corroborating symptoms with documented evidence of arrhythmia. Exercise tests were performed on 38 patients at baseline and 5 months after procedure. Recurrence was assessed using event recorder, cardiology evaluation, electrocardiogram, and 7-day holter monitoring. After 20 ± 5 months follow-up, 36 (57%) patients remained recurrence-free off-AAD. Of the 25 patients experiencing recurrence, 21 (84%) were symptomatic. Compared to baseline, follow-up SF-36 scores improved significantly in many measures. For patients with successful ablation, physical component summary (PCS) and mental component summary (MCS) demonstrated substantial improvement ( 64.2 ± 22.3 to 70.1 ± 18.6 [P = 0.041]; PCS: 62.6 ± 18.4 to 70.0 ± 14.4 [P = 0.032]). Postablation exercise study in recurrence-free patients showed significant reduction in resting and peak heart rate (75 ± 11 vs. 90 ± 17 and 132 ± 20 vs. 154.5 ± 36, respectively, P < 0.001), increase in peak oxygen pulse (13.4 ± 3 vs. 18.9 ± 16 mL/beat, Δ5.5 ± 15, P = 0.001), peak VO2 /kg (19.7 ± 5 to 23.4 ± 13 mL/kg/min [Δ 3.7 ± 10, P = 0.043]), and corresponding MET (5.6 ± 1 to 6.7 ± 4 [Δ1.1 ± 3, P = 0.03]). No improvement was observed in patients with failed procedures. Successful ablation improves exercise performance and QoL in asymptomatic LSP-AF patients. © 2014 Wiley Periodicals, Inc.

Multimodal Examination of Atrial Fibrillation Substrate: Correlation of Left Atrial Bipolar Voltage Using Multi-Electrode Fast Automated Mapping, Point-by-Point Mapping, and Magnetic Resonance Image Intensity Ratio.

PubMed

Zghaib, Tarek; Keramati, Ali; Chrispin, Jonathan; Huang, Dong; Balouch, Muhammad A; Ciuffo, Luisa; Berger, Ronald D; Marine, Joseph E; Ashikaga, Hiroshi; Calkins, Hugh; Nazarian, Saman; Spragg, David D

2018-01-01

Bipolar voltage mapping, as part of atrial fibrillation (AF) ablation, is traditionally performed in a point-by-point (PBP) approach using single-tip ablation catheters. Alternative techniques for fibrosis-delineation include fast-anatomical mapping (FAM) with multi-electrode circular catheters, and late gadolinium-enhanced magnetic-resonance imaging (LGE-MRI). The correlation between PBP, FAM, and LGE-MRI fibrosis assessment is unknown. In this study, we examined AF substrate using different modalities (PBP, FAM, and LGE-MRI mapping) in patients presenting for an AF ablation. LGE-MRI was performed pre-ablation in 26 patients (73% males, age 63±8years). Local image-intensity ratio (IIR) was used to normalize myocardial intensities. PBP- and FAM-voltage maps were acquired, in sinus rhythm, prior to ablation and co-registered to LGE-MRI. Mean bipolar voltage for all 19,087 FAM voltage points was 0.88±1.27mV and average IIR was 1.08±0.18. In an adjusted mixed-effects model, each unit increase in local IIR was associated with 57% decrease in bipolar voltage (p<0.0001). IIR of >0.74 corresponded to bipolar voltage <0.5 mV. A total of 1554 PBP-mapping points were matched to the nearest FAM-point. In an adjusted mixed-effects model, log-FAM bipolar voltage was significantly associated with log-PBP bipolar voltage (ß=0.36, p<0.0001). At low-voltages, FAM-mapping distribution was shifted to the left compared to PBP-mapping; at intermediate voltages, FAM and PBP voltages were overlapping; and at high voltages, FAM exceeded PBP-voltages. LGE-MRI, FAM and PBP-mapping show good correlation in delineating electro-anatomical AF substrate. Each approach has fundamental technical characteristics, the awareness of which allows proper assessment of atrial fibrosis.

Stand alone totally endoscopic epimyocardial ablation in patients with persistent atrial fibrillation and significant atrial dilatation.

PubMed

Wagner, Florian Mathias; Pecha, Simon; Conradi, Lenard; Reichenspurner, Hermann

2015-05-01

To analyze safety and efficacy of surgical totally endoscopic epimyocardial ablation in patients (pts) turned down for interventional catheter therapy due to long-standing persistent atrial fibrillation (pAF) combined with significant atrial dilatation (> 5 cm). Since December 2010, 15 pts were referred for surgical ablation due to persistent AF combined with biatrial dilatation (left atrium [LA] 5.0 ± 0.6 cm). Mean age was 52 ± 6 years, body mass index (BMI) 38 ± 6, duration of AF 2.8 ± 1.2 years, left ventricular end diastolic diameter (LVEDD) 5.8 cm ± 0.6 cm. Ablation was performed via a bilateral endoscopic approach using bipolar RF energy application. Monitoring was achieved by an event recorder (Reveal XT Medtronic, Inc., Minneapolis, MN, USA) or repeated 24-hours Holter electrocardiogram. All pts successfully received bilateral pulmonary vein isolation + box lesion + trigonal lesion + left atrial appendage resection. Mean duration of procedure was 235 ± 70 minutes. There was no intraoperative complication; however, one patient had persistent left phrenic nerve palsy. Mean hospital stay was 4 ± 2 days, mean follow-up time was 21 ± 11 months. Incidence of sinus rhythm (SR) was 67, 73, and 80% at discharge, three months, and 12 months follow-up. Mean LA diameter was reduced from 58.1 mm ± 6.0 mm preoperative to 49.7 mm ± 5.4 mm (p = 0.004) at 12 months follow-up. Incidence of SR was 86% at latest follow-up (mean time 21 months). All pts currently in SR (13/15 = 86%) are of class I or III antiarrhythmic drugs. Totally endoscopic left atrial ablation including left atrial resection can safely be performed. It achieved excellent rates of SR restoration in patients with long-standing persistent AF combined with significant atrial dilatation. © 2015 Wiley Periodicals, Inc.

Efficacy and Safety of Uninterrupted Low-Intensity Warfarin for Radiofrequency Catheter Ablation of Atrial Fibrillation in the Elderly.

PubMed

Xing, Yangbo; Xu, Buyun; Xu, Chao; Peng, Fang; Yang, Biao; Qiu, Yufang; Sun, Yong; Wang, Shengkai; Guo, Hangyuan

2017-09-01

No previous studies exist investigating the optimal intensity of uninterrupted anticoagulation with warfarin during radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in the elderly. Evaluate the efficacy and safety of continuous low-intensity warfarin therapy throughout the periprocedural period of RFCA for AF in the elderly. This is a prospective randomized study. We enrolled AF patients (age ≥ 70 years) who underwent first-time RFCA for AF. Enrolled patients were randomized to group A and group B. The international normalized ratios before ablation were maintained at 1.5 to 2.0 and 2.0 to 2.5 in group A and B, respectively. Primary end points were periprocedural thromboembolic complications and major bleeding. Secondary end points included periprocedural asymptomatic cerebral emboli (ACE) and minor bleeding. A total of 101 patients were enrolled in our study (group A: 52; group B: 49). Baseline characteristics were well balanced between the 2 groups. Only 1 patient suffered from stroke in group B. No major bleeding events occurred in either group. The incidence of new ACE lesions was comparable between the 2 groups (11.5% vs 8.2%, P = 0.82). Minor bleeding occurred in 1 of 52 (1.9%) patients in group A and in 5 of 49 (10.2%) patients in group B ( P = 0.10). Uninterrupted low-intensity warfarin for RFCA of AF might be as effective as standard-intensity warfarin in preventing periprocedural thromboembolic complications and might be associated with fewer bleeding events in the elderly.

Pacemaker implantation after catheter ablation for atrial fibrillation.

PubMed

Deshmukh, Abhishek J; Yao, Xiaoxi; Schilz, Stephanie; Van Houten, Holly; Sangaralingham, Lindsey R; Asirvatham, Samuel J; Friedman, Paul A; Packer, Douglas L; Noseworthy, Peter A

2016-01-01

Sinus node dysfunction requiring pacemaker implantation is commonly associated with atrial fibrillation (AF), but may not be clinically apparent until restoration of sinus rhythm with ablation or cardioversion. We sought to determine frequency, time course, and predictors for pacemaker implantation after catheter ablation, and to compare the overall rates to a matched cardioversion cohort. We conducted a retrospective analysis using a large US commercial insurance database and identified 12,158 AF patients who underwent catheter ablation between January 1, 2005 and December 31, 2012. Over an average of 2.4 years of follow-up, 5.6 % of the patients underwent pacemaker implantation. Using the Cox proportional hazards models, we found that risk of risks of pacemaker implantation was associated with older age (50-64 and ≥65 versus <50 years), female gender, higher CHADS2 score (≥2 and 1 versus 0), higher Charlson index (≥2 versus 0-1), certain baseline comorbidities (conduction disorder, coronary atherosclerosis, and congestive heart failure), and the year of ablation. There was no significant difference in the risk of pacemaker implantation between ablation patients and propensity score (PS)-matched cardioversion groups (3.5 versus. 4.1 % at 1 year and 8.8 versus 8.3 % at 5 years). Overall, pacemaker implantation occurs in about 1/28 patients within 1 year of catheter ablation. The overall implantation rate decreased between 2005 and 2012. Furthermore, the risk after ablation is similar to cardioversion, suggesting that patients require pacing due to a common underlying electrophysiologic substrate, rather than the ablation itself.

Effect of left atrial volume and pulmonary vein anatomy on outcome of nMARQ™ catheter ablation of paroxysmal atrial fibrillation.

PubMed

Stabile, Giuseppe; Anselmino, Matteo; Soldati, Ezio; De Ruvo, Ermengildo; Solimene, Francesco; Iuliano, Assunta; Sciarra, Luigi; Bongiorni, Maria Grazia; Calò, Leonardo; Gaita, Fiorenzo

2017-03-01

Left atrial volume (LA) and pulmonary vein (PV) anatomy may potentially relate to technical challenges in achieving stable and effective catheter position in case of atrial fibrillation (AF) ablation by means of "one-shot" catheters. The aim of this study was to investigate whether LA volume and PV anatomy, evaluated by computed tomography (CT) or magnetic resonance (MR) prior to ablation, predict acute and midterm outcome of AF ablation by nMARQ™. We included 75 patients (mean age 58 ± 11 years, 67 % male) with symptomatic paroxysmal AF. All patients underwent CT/MR scanning prior to catheter ablation to evaluate LA volume and PV anatomy. All the patients underwent PV isolation by nMARQ™, an open-irrigated mapping and radiofrequency (RF) decapolar ablation catheter. Ablation was guided by electroanatomic mapping allowing RF energy delivery in the antral region of PVs from ten irrigated electrodes simultaneously. Mean LA volume was 75 ± 40 ml. A normal anatomy (4 PVs) was documented in 40 (53 %) patients and abnormal anatomy (common truncus or accessory PVs) in 35 patients. Mean procedural and fluoroscopy times were 94 ± 55 and 8 ± 5 min, respectively, without significant differences among patients with normal or abnormal anatomy (92 ± 45 vs 95 ± 64 min, p = 0.85 and 6 ± 3 vs 8 ± 4 min, p = 0.65, respectively). Mean ablation time was 14 ± 3 min, and 99 % of the targeted veins were isolated with a mean of 23 ± 5 RF pulses per patient. After a mean follow-up of 17 ± 8 months, 23 (31 %) patients had an atrial arrhythmia recurrence. Neither LA volume nor PV anatomy was a predictor of outcome. LA volume and PV anatomy did not affect procedural data and outcome in patients who underwent PV isolation by an open-irrigated mapping and RF decapolar ablation catheter.

Impact of Catheter Ablation for Paroxysmal Atrial Fibrillation in Patients With Sick Sinus Syndrome　- Important Role of Non-Pulmonary Vein Foci.

PubMed

Hayashi, Kentaro; Fukunaga, Masato; Yamaji, Kyohei; An, Yoshimori; Nagashima, Michio; Hiroshima, Kenichi; Ohe, Masatsugu; Makihara, Yu; Yamashita, Kennosuke; Ando, Kenji; Iwabuchi, Masashi; Goya, Masahiko

2016-01-01

The clinical efficacy of catheter ablation (CA) for paroxysmal atrial fibrillation (PAF) in patients with sick sinus syndrome (SSS) and the mechanism and predictors of recurrence are not yet completely elucidated. Of 963 consecutive patients who underwent PAF ablation during the study period, a total of 108 patients with SSS (SSS group) and 108 matched controls without SSS (non-SSS group) were followed up. During the follow-up period (mean, 32.8±17.5 months), the SSS group had significantly higher AF recurrence rate since the last procedure than the non-SSS group (26.9% vs. 12.0%; P=0.02). The SSS group had significantly higher prevalence of non-pulmonary vein (non-PV) foci than the non-SSS group (25.9% vs. 13.9%; P=0.027). On multivariate analysis congestive heart failure (HR, 13.7; 95% CI: 1.57-119; P=0.02) and non-PV foci (HR, 5.75; 95% CI: 1.69-19.6; P=0.005) were independent predictors of recurrence following CA in the SSS group. In the SSS group, 88 patients had bradycardia-tachycardia syndrome without prior permanent pacemaker implantation. Of these, 6 required pacemaker implantation because of AF and sinus pause recurrence. Patients with SSS are at higher risk of AF recurrence after CA. Non-PV foci are associated with AF recurrence following PAF with SSS.

Application of Traditional Chinese Medicine in Treatment of Atrial Fibrillation

PubMed Central

Dong, Yan; Yao, Kuiwu; Jiang, Wenrui

2017-01-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia, which is related to many cardiac and cerebral vascular diseases, especially stroke. It can therefore increase cardiovascular mortality and all-cause death. The current treatments of AF remain to be western drugs and radiofrequency ablation which are limited by the tolerance of patients, adverse side effects, and high recurrence rate, especially for the elderly. On the contrary, traditional Chinese medicine (TCM) with long history of use involves various treatment methods, including Chinese herbal medicines (CHMs) or bioactive ingredients, Chinese patent medicines, acupuncture, Qigong, and Tai Chi Chuan. With more and more researches reported, the active roles of TCM in AF management have been discovered. Then it is likely that TCM would be effective preventive means and valuable additional remedy for AF. The potential mechanisms further found by numerous experimental studies showed the distinct characteristics of TCM. Some CHMs or bioactive ingredients are atrial-selective, while others are multichannel and multifunctional. Therefore, in this review we summarized the treatment strategies reported in TCM, with the purpose of providing novel ideas and directions for AF management. PMID:28243308

High Voltage Guided Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation.

PubMed

Boles, Usama; Gul, Enes E; Enriquez, Andres; Lee, Howard; Riegert, Dave; Andres, Adrian; Baranchuk, Adrian; Redfearn, Damian; Glover, Benedict; Simpson, Chris; Abdollah, Hoshiar; Michael, Kevin

2017-01-01

Ablation of the pulmonary vein (PV) antrum using an electroanatomic mapping system is standard of care for point-by-point pulmonary vein isolation (PVI). Focused ablation at critical areas is more likely to achieve intra-procedural PV isolation and decrease the likelihood for reconnection and recurrence of atrial fibrillation (AF). Therefore this prospective pilot study is to investigate the short-term outcome of a voltage-guided circumferential PV ablation (CPVA) strategy. We recruited patients with a history of paroxysmal atrial fibrillation (AF). The EnSite NavX system (St. Jude Medical, St Paul, Minnesota, USA) was employed to construct a three-dimensional geometry of the left atrium (LA) and voltage map. CPVA was performed; with radiofrequency (RF) targeting sites of highest voltage first in a sequential clockwise fashion then followed by complete the gaps in circumferential ablation. Acute and short-term outcomes were compared to a control group undergoing conventional standard CPVA using the same 3D system. Follow-up was scheduled at 3, 6 and 12 months. Thirty-four paroxysmal AF patients with a mean age of 40 years were included. Fourteen patients (8 male) underwent voltage mapping and 20 patients underwent empirical, non-voltage guided standard CPVA. A mean of 54 ± 12 points per PV antrum were recorded. Mean voltage for right and left PVs antra were 1.7±0.1 mV and 1.9±0.2 mV, respectively. There was a trend towards reduced radiofrequency time (40.9±17.4 vs. 48.1±15.5 mins; p=0.22). Voltage-guided CPVA is a promising strategy in targeting critical points for PV isolation with a lower trend of AF recurrence compared with a standard CPVA in short-term period. Extended studies to confirm these findings are warranted.

Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.

PubMed

Matsuda, Hisao; Parwani, Abdul Shokor; Attanasio, Philipp; Huemer, Martin; Wutzler, Alexander; Blaschke, Florian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

2016-09-01

Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV.

Remote navigation systems in electrophysiology.

PubMed

Schmidt, Boris; Chun, Kyoung Ryul Julian; Tilz, Roland R; Koektuerk, Buelent; Ouyang, Feifan; Kuck, Karl-Heinz

2008-11-01

Today, atrial fibrillation (AF) is the dominant indication for catheter ablation in big electrophysiologists (EP) centres. AF ablation strategies are complex and technically challenging. Therefore, it would be desirable that technical innovations pursue the goal to improve catheter stability to increase the procedural success and most importantly to increase safety by helping to avoid serious complications. The most promising technical innovation aiming at the aforementioned goals is remote catheter navigation and ablation. To date, two different systems, the NIOBE magnetic navigation system (MNS, Stereotaxis, USA) and the Sensei robotic navigation system (RNS, Hansen Medical, USA), are commercially available. The following review will introduce the basic principles of the systems, will give an insight into the merits and demerits of remote navigation, and will further focus on the initial clinical experience at our centre with focus on pulmonary vein isolation (PVI) procedures.

Robust tracking of a virtual electrode on a coronary sinus catheter for atrial fibrillation ablation procedures

NASA Astrophysics Data System (ADS)

Wu, Wen; Chen, Terrence; Strobel, Norbert; Comaniciu, Dorin

2012-02-01

Catheter tracking in X-ray fluoroscopic images has become more important in interventional applications for atrial fibrillation (AF) ablation procedures. It provides real-time guidance for the physicians and can be used as reference for motion compensation applications. In this paper, we propose a novel approach to track a virtual electrode (VE), which is a non-existing electrode on the coronary sinus (CS) catheter at a more proximal location than any real electrodes. Successful tracking of the VE can provide more accurate motion information than tracking of real electrodes. To achieve VE tracking, we first model the CS catheter as a set of electrodes which are detected by our previously published learning-based approach.1 The tracked electrodes are then used to generate the hypotheses for tracking the VE. Model-based hypotheses are fused and evaluated by a Bayesian framework. Evaluation has been conducted on a database of clinical AF ablation data including challenging scenarios such as low signal-to-noise ratio (SNR), occlusion and nonrigid deformation. Our approach obtains 0.54mm median error and 90% of evaluated data have errors less than 1.67mm. The speed of our tracking algorithm reaches 6 frames-per-second on most data. Our study on motion compensation shows that using the VE as reference provides a good point to detect non-physiological catheter motion during the AF ablation procedures.2

[Impact of CHA2DS2 VASc score on substrate for persistent atrial fibrillation and outcome post catheter ablation of atrial fibrillation].

PubMed

Ribo, Tang; Jianzeng, Dong; Xiaohui, Liu; Meisheng, Shang; Ronghui, Yu; Deyong, Long; Xin, Du; Junping, Kang; Jiahui, Wu; Man, Ning; Caihua, Sang; Chenxi, Jiang; Rong, Bai; Songnan, Li; Yan, Yao; Songnan, Wen; Changsheng, Ma

2015-08-01

To explore if CHA2DS2 VASc score can predict substrate for persistent atrial fibrillation ( AF) and outcome post catheter ablation of AF. From January 2011 to December 2012,116 patients underwent catheter ablation of persistent AF in our department and were enrolled in this study. CHA2DS2VASc score was calculated as follows: two points were assigned for a history of stroke or transient ischemic attack and age ≥ 75 and 1 point each was assigned for age ≥ 65, a history of hypertension, diabetes,recent cardiac failure, vessel disease, female. Left atrial geometry ( LA) was reconstructed with a 3.5 mm tip ablation catheter with fill-in threshold 10 in CARTO system. The mapping catheter was stabled at each endocardial location for at least 3 seconds for recording. The electrogram recordings at each endocardial location were analyzed with a custom software embedded in the CARTO mapping system. Interval confidence level (ICL) was used to characterize complex fractionated atrial electrograms (CFAEs) . As the default setting of the software, ICL more than or equal to 7 was considered sites with a highly repetitive CFAEs complex. CFAEs index was defined as the fraction of area of ICL more than or equal to 7 to the left atrial surface. The CFAEs index and outcome of catheter ablation among different CHA2DS2VASc groups were compared. Of the 116 patients, CHA2DS2VASc was 0 in 33 patients, 1 in 31 patients and ≥ 2 in 52 patients. Left atrial surface ((121.2 ± 18.9) cm2, (133.6 ± 23.8) cm2, (133.9 ± 16.1) cm2, P = 0.008), left atrial volume ((103.6 ± 24.8) ml, (118.3 ± 27.8) ml, (120.9 ± 20.9) ml, P = 0.005) and CFAEs index (44.6% ± 22.4%, 54.2% ± 22.2%, 58.7% ± 23.1%, P = 0.023) increased in proportion with increasing CHA2DS2VASc. ICLmax, ICLmin and CFAEs spatial distribution were similar among the three groups. During the mean follow-up of (13 ± 8) months, the recurrence rate were 36.4%, 35.5%, 55.8% among the three groups (P = 0.025). A high CHA2DS2VASc score is associated with extensive AF substrate and higher recurrence rate post catheter ablation of persistent AF.

Obstructive Sleep Apnoea and Atrial Fibrillation

PubMed Central

Zhang, Ling; Hou, Yuemei; Po, Sunny S

2015-01-01

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is associated with significant morbidity and mortality. Obstructive sleep apnoea (OSA) is common among patients with AF. Growing evidence suggests that OSA is associated with the initiation and maintenance of AF. This association is independent of obesity, body mass index and hypertension. OSA not only promotes initiation of AF but also has a significant negative impact on the treatment of AF. Patients with untreated OSA have a higher AF recurrence rate with drug therapy, electrical cardioversion and catheter ablation. Treatment with continuous positive airway pressure (CPAP) has been shown to improve AF control in patients with OSA. In this article, we will review and discuss the pathophysiological mechanisms of OSA that may predispose OSA patients to AF as well as the standard and emerging therapies for patients with both OSA and AF. PMID:26835094

Integration of intracardiac echocardiography and computed tomography during atrial fibrillation ablation: Combining ultrasound contours obtained from the right atrium and ventricular outflow tract.

PubMed

Nakamura, Kohki; Naito, Shigeto; Kaseno, Kenichi; Nakatani, Yosuke; Sasaki, Takehito; Anjo, Naofumi; Yamashita, Eiji; Kumagai, Koji; Funabashi, Nobusada; Kobayashi, Yoshio; Oshima, Shigeru

2017-02-01

We aimed to optimize the acquisition of the left atrial (LA) and pulmonary vein (PV) ultrasound contours for more accurate integration of intracardiac echocardiography (ICE) and computed tomography (CT) using the CARTO ® 3 system during atrial fibrillation (AF) ablation. Eighty-five AF patients underwent integration of ICE and CT using (1) the LA roof and posterior wall contours acquired from the right atrium (RA), (2) all LA/PV contours from the RA (Whole-RA-integration), (3) the LA roof/posterior wall contours from the RA and right ventricular outflow tract (RVOT) (Posterior-RA/RV-integration), and (4) all LA/PV contours from the RA and RVOT (Whole-RA/RV-integration). The integration accuracy was compared using the (1) surface registration error, (2) distances between the three-dimensional CT and eight specific sites on the anterior, posterior, superior, and inferior aspects of the right and left circumferential PV isolation lines, and (3) registration score: a score of 0 or 1 was assigned for whether or not each specific site was visually aligned with the CT, and summed for each method (0 best, 8 worst). Posterior-RA/RV-integration revealed a significantly lower surface registration error (1.30±0.15mm) than Whole-RA- and Whole-RA/RV-integration (p<0.001). The mean distances of the eight specific sites and the registration score for Posterior-RA/RV-integration (median 1.26mm and 2, respectively) were significantly smaller than those for the other integration approaches (p<0.001). Image integration with the LA roof and posterior wall contours acquired from the RA and RVOT may provide greater accuracy for catheter navigation with three-dimensional CT during AF ablation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Stability of rotors and focal sources for human atrial fibrillation: focal impulse and rotor mapping (FIRM) of AF sources and fibrillatory conduction.

PubMed

Swarup, Vijay; Baykaner, Tina; Rostamian, Armand; Daubert, James P; Hummel, John; Krummen, David E; Trikha, Rishi; Miller, John M; Tomassoni, Gery F; Narayan, Sanjiv M

2014-12-01

Several groups report electrical rotors or focal sources that sustain atrial fibrillation (AF) after it has been triggered. However, it is difficult to separate stable from unstable activity in prior studies that examined only seconds of AF. We applied phase-based focal impulse and rotor mapping (FIRM) to study the dynamics of rotors/sources in human AF over prolonged periods of time. We prospectively mapped AF in 260 patients (169 persistent, 61 ± 12 years) at 6 centers in the FIRM registry, using baskets with 64 contact electrodes per atrium. AF was phase mapped (RhythmView, Topera, Menlo Park, CA, USA). AF propagation movies were interpreted by each operator to assess the source stability/dynamics over tens of minutes before ablation. Sources were identified in 258 of 260 of patients (99%), for 2.8 ± 1.4 sources/patient (1.8 ± 1.1 in left, 1.1 ± 0.8 in right atria). While AF sources precessed in stable regions, emanating activity including spiral waves varied from collision/fusion (fibrillatory conduction). Each source lay in stable atrial regions for 4,196 ± 6,360 cycles, with no differences between paroxysmal versus persistent AF (4,290 ± 5,847 vs. 4,150 ± 6,604; P = 0.78), or right versus left atrial sources (P = 0.26). Rotors and focal sources for human AF mapped by FIRM over prolonged time periods precess ("wobble") but remain within stable regions for thousands of cycles. Conversely, emanating activity such as spiral waves disorganize and collide with the fibrillatory milieu, explaining difficulties in using activation mapping or signal processing analyses at fixed electrodes to detect AF rotors. These results provide a rationale for targeted ablation at AF sources rather than fibrillatory spiral waves. © 2014 Wiley Periodicals, Inc.

Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction: The CAMERA-MRI Study.

PubMed

Prabhu, Sandeep; Taylor, Andrew J; Costello, Ben T; Kaye, David M; McLellan, Alex J A; Voskoboinik, Aleksandr; Sugumar, Hariharan; Lockwood, Siobhan M; Stokes, Michael B; Pathik, Bhupesh; Nalliah, Chrishan J; Wong, Geoff R; Azzopardi, Sonia M; Gutman, Sarah J; Lee, Geoffrey; Layland, Jamie; Mariani, Justin A; Ling, Liang-Han; Kalman, Jonathan M; Kistler, Peter M

2017-10-17

Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy. The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF. This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months. A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093). AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of ventricular fibrosis on CMR. This outcome challenges the current treatment paradigm that rate control is the appropriate strategy in patients with AF and LVSD. (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction [CAMERA-MRI]; ACTRN12613000880741). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Loss of pace capture on the ablation line: a new marker for complete radiofrequency lesions to achieve pulmonary vein isolation.

PubMed

Steven, Daniel; Reddy, Vivek Y; Inada, Keiichi; Roberts-Thomson, Kurt C; Seiler, Jens; Stevenson, William G; Michaud, Gregory F

2010-03-01

Catheter ablation procedures for atrial fibrillation (AF) often involve circumferential antral isolation of pulmonary veins (PV). Inability to reliably identify conduction gaps on the ablation line necessitates placing additional lesions within the intended lesion set. This pilot study investigated the relationship between loss of pace capture directly along the ablation line and electrogram criteria for PV isolation (PVI). Using a 3-dimensional anatomic mapping system and irrigated-tip radiofrequency (RF) ablation catheter, lesions were placed in the PV antra to encircle ipsilateral vein pairs until pace capture at 10 mA/2 ms no longer occurred along the line. During ablation, a circular mapping catheter was placed in an ipsilateral PV, but the electrograms were not revealed until loss-of-pace capture. The procedural end point was PVI (entrance and exit block). Thirty patients (57 +/- 12 years; 15 male [50%]) undergoing PVI in 2 centers (3 primary operators) were included (left atrial diameter 40 +/- 4 mm, left ventricular ejection fraction 60 +/- 7%). All patients reached the end points of complete PVI and loss of pace capture. When PV electrograms were revealed after loss of pace capture along the line, PVI was present in 57 of 60 (95%) vein pairs. In the remaining 3 of 60 (5%) PV pairs, further RF applications achieved PVI. The procedure duration was 237 +/- 46 minutes, with a fluoroscopy time of 23 +/- 9 minutes. Analysis of the blinded PV electrograms revealed that even after PVI was achieved, additional sites of pace capture were present on the ablation line in 30 of 60 (50%) of the PV pairs; 10 +/- 4 additional RF lesions were necessary to fully achieve loss of pace capture. After ablation, the electrogram amplitude was lower at unexcitable sites (0.25 +/- 0.15 mV vs. 0.42 +/- 0.32 mV, P < .001), but there was substantial overlap with pace capture sites, suggesting that electrogram amplitude lacks specificity for identifying pace capture sites. Complete loss of pace capture directly along the circumferential ablation line correlates with entrance block in 95% of vein pairs and can be achieved without circular mapping catheter guidance. Thus, pace capture along the ablation line can be used to identify conduction gaps. Interestingly, more RF ablation energy was required to achieve loss of pace capture along the ablation line than for entrance block into PVs. Further study is warranted to determine whether this method results in more durable ablation lesions that reduce recurrence of AF. Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Factors affecting basket catheter detection of real and phantom rotors in the atria: A computational study.

PubMed

Martinez-Mateu, Laura; Romero, Lucia; Ferrer-Albero, Ana; Sebastian, Rafael; Rodríguez Matas, José F; Jalife, José; Berenfeld, Omer; Saiz, Javier

2018-03-01

Anatomically based procedures to ablate atrial fibrillation (AF) are often successful in terminating paroxysmal AF. However, the ability to terminate persistent AF remains disappointing. New mechanistic approaches use multiple-electrode basket catheter mapping to localize and target AF drivers in the form of rotors but significant concerns remain about their accuracy. We aimed to evaluate how electrode-endocardium distance, far-field sources and inter-electrode distance affect the accuracy of localizing rotors. Sustained rotor activation of the atria was simulated numerically and mapped using a virtual basket catheter with varying electrode densities placed at different positions within the atrial cavity. Unipolar electrograms were calculated on the entire endocardial surface and at each of the electrodes. Rotors were tracked on the interpolated basket phase maps and compared with the respective atrial voltage and endocardial phase maps, which served as references. Rotor detection by the basket maps varied between 35-94% of the simulation time, depending on the basket's position and the electrode-to-endocardial wall distance. However, two different types of phantom rotors appeared also on the basket maps. The first type was due to the far-field sources and the second type was due to interpolation between the electrodes; increasing electrode density decreased the incidence of the second but not the first type of phantom rotors. In the simulations study, basket catheter-based phase mapping detected rotors even when the basket was not in full contact with the endocardial wall, but always generated a number of phantom rotors in the presence of only a single real rotor, which would be the desired ablation target. Phantom rotors may mislead and contribute to failure in AF ablation procedures.

Factors affecting basket catheter detection of real and phantom rotors in the atria: A computational study

PubMed Central

Romero, Lucia; Rodríguez Matas, José F.; Berenfeld, Omer; Saiz, Javier

2018-01-01

Anatomically based procedures to ablate atrial fibrillation (AF) are often successful in terminating paroxysmal AF. However, the ability to terminate persistent AF remains disappointing. New mechanistic approaches use multiple-electrode basket catheter mapping to localize and target AF drivers in the form of rotors but significant concerns remain about their accuracy. We aimed to evaluate how electrode-endocardium distance, far-field sources and inter-electrode distance affect the accuracy of localizing rotors. Sustained rotor activation of the atria was simulated numerically and mapped using a virtual basket catheter with varying electrode densities placed at different positions within the atrial cavity. Unipolar electrograms were calculated on the entire endocardial surface and at each of the electrodes. Rotors were tracked on the interpolated basket phase maps and compared with the respective atrial voltage and endocardial phase maps, which served as references. Rotor detection by the basket maps varied between 35–94% of the simulation time, depending on the basket’s position and the electrode-to-endocardial wall distance. However, two different types of phantom rotors appeared also on the basket maps. The first type was due to the far-field sources and the second type was due to interpolation between the electrodes; increasing electrode density decreased the incidence of the second but not the first type of phantom rotors. In the simulations study, basket catheter-based phase mapping detected rotors even when the basket was not in full contact with the endocardial wall, but always generated a number of phantom rotors in the presence of only a single real rotor, which would be the desired ablation target. Phantom rotors may mislead and contribute to failure in AF ablation procedures. PMID:29505583

Electrogram morphology recurrence patterns during atrial fibrillation.

PubMed

Ng, Jason; Gordon, David; Passman, Rod S; Knight, Bradley P; Arora, Rishi; Goldberger, Jeffrey J

2014-11-01

Traditional mapping of atrial fibrillation (AF) is limited by changing electrogram morphologies and variable cycle lengths. We tested the hypothesis that morphology recurrence plot analysis would identify sites of stable and repeatable electrogram morphology patterns. AF electrograms recorded from left atrial (LA) and right atrial (RA) sites in 19 patients (10 men; mean age 59 ± 10 years) before AF ablation were analyzed. Morphology recurrence plots for each electrogram recording were created by cross-correlation of each automatically detected activation with every other activation in the recording. A recurrence percentage, the percentage of the most common morphology, and the mean cycle length of activations with the most recurrent morphology were computed. The morphology recurrence plots commonly showed checkerboard patterns of alternating high and low cross-correlation values, indicating periodic recurrences in morphologies. The mean recurrence percentage for all sites and all patients was 38 ± 25%. The highest recurrence percentage per patient averaged 83 ± 17%. The highest recurrence percentage was located in the RA in 5 patients and in the LA in 14 patients. Patients with sites of shortest mean cycle length of activations with the most recurrent morphology in the LA and RA had ablation failure rates of 25% and 100%, respectively (hazard ratio 4.95; P = .05). A new technique to characterize electrogram morphology recurrence demonstrated that there is a distribution of sites with high and low repeatability of electrogram morphologies. Sites with rapid activation of highly repetitive morphology patterns may be critical to sustaining AF. Further testing of this approach to map and ablate AF sources is warranted. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Pulmonary Vein Isolation with the Cryoballoon Technique: Feasibility, Procedural Outcomes, and Adoption in the Real World: Data from One Shot Technologies TO Pulmonary Vein Isolation (1STOP) Project.

PubMed

Padeletti, Luigi; Curnis, Antonio; Tondo, Claudio; Lunati, Maurizio; Porcellini, Stefano; Verlato, Roberto; Sciarra, Luigi; Senatore, Gaetano; Catanzariti, Domenico; Leoni, Loira; Landolina, Maurizio; Delise, Pietro; Iacopino, Saverio; Pieragnoli, Paolo; Arena, Giuseppe

2017-01-01

Catheter ablation (CA) is recommended for patients with drug refractory symptomatic atrial fibrillation (AF). "One Shot" catheters have been introduced to simplify CA and cryoballoon ablation (CBA) is spreading rapidly. Few real-world data are available on standard clinical practice, mainly from single-center experience. We aimed to evaluate clinical settings, demographics, and acute procedural outcomes in a large cohort of patients treated with CBA. A total of 903 patients (73% male, mean age 59 ± 11) underwent pulmonary vein CBA. Correlations between the patient's inclusion time and clinical characteristics, procedure duration, acute success rate, and intraprocedural complications were evaluated. Seventy-seven percent of patients were affected by paroxysmal AF and 23% by persistent AF. Overall, acute success rate was 97.9% and periprocedural complications were observed in 35 (3.9%) patients, 13 (1.4%) of which were classified as major complications. With respect to the patient's inclusion time analysis, an increase in treatment of persistent AF was observed, a significant decrease in CBA times (procedure, ablation, and fluoroscopy: 136.0 ± 46.5 minutes, 28.8 ± 19.6 minutes, and 34.3 ± 15.4 minutes, respectively) was observed, with comparable acute success rate and intraprocedural complications over time. The rate of major complications was extremely low (1.4%); no death, atrioesophageal fistula, stroke, or other major periinterventional or late complications occurred. This series represents the largest experience of CBA in the treatment of AF that also describes the adoption curve of this relatively recent technology. CBA showed an excellent safety profile when performed in a large real-world clinical setting, with satisfactory acute success rate and, on average, short procedural times. clinicaltrials.gov (NCT01007474). © 2016 Wiley Periodicals, Inc.

Estimating the Prevalence of Atrial Fibrillation from A Three-Class Mixture Model for Repeated Diagnoses

PubMed Central

Li, Liang; Mao, Huzhang; Ishwaran, Hemant; Rajeswaran, Jeevanantham; Ehrlinger, John; Blackstone, Eugene H.

2016-01-01

Atrial fibrillation (AF) is an abnormal heart rhythm characterized by rapid and irregular heart beat, with or without perceivable symptoms. In clinical practice, the electrocardiogram (ECG) is often used for diagnosis of AF. Since the AF often arrives as recurrent episodes of varying frequency and duration and only the episodes that occur at the time of ECG can be detected, the AF is often underdiagnosed when a limited number of repeated ECGs are used. In studies evaluating the efficacy of AF ablation surgery, each patient undergo multiple ECGs and the AF status at the time of ECG is recorded. The objective of this paper is to estimate the marginal proportions of patients with or without AF in a population, which are important measures of the efficacy of the treatment. The underdiagnosis problem is addressed by a three-class mixture regression model in which a patient’s probability of having no AF, paroxysmal AF, and permanent AF is modeled by auxiliary baseline covariates in a nested logistic regression. A binomial regression model is specified conditional on a subject being in the paroxysmal AF group. The model parameters are estimated by the EM algorithm. These parameters are themselves nuisance parameters for the purpose of this research, but the estimators of the marginal proportions of interest can be expressed as functions of the data and these nuisance parameters and their variances can be estimated by the sandwich method. We examine the performance of the proposed methodology in simulations and two real data applications. PMID:27983754

Estimating the prevalence of atrial fibrillation from a three-class mixture model for repeated diagnoses.

PubMed

Li, Liang; Mao, Huzhang; Ishwaran, Hemant; Rajeswaran, Jeevanantham; Ehrlinger, John; Blackstone, Eugene H

2017-03-01

Atrial fibrillation (AF) is an abnormal heart rhythm characterized by rapid and irregular heartbeat, with or without perceivable symptoms. In clinical practice, the electrocardiogram (ECG) is often used for diagnosis of AF. Since the AF often arrives as recurrent episodes of varying frequency and duration and only the episodes that occur at the time of ECG can be detected, the AF is often underdiagnosed when a limited number of repeated ECGs are used. In studies evaluating the efficacy of AF ablation surgery, each patient undergoes multiple ECGs and the AF status at the time of ECG is recorded. The objective of this paper is to estimate the marginal proportions of patients with or without AF in a population, which are important measures of the efficacy of the treatment. The underdiagnosis problem is addressed by a three-class mixture regression model in which a patient's probability of having no AF, paroxysmal AF, and permanent AF is modeled by auxiliary baseline covariates in a nested logistic regression. A binomial regression model is specified conditional on a subject being in the paroxysmal AF group. The model parameters are estimated by the Expectation-Maximization (EM) algorithm. These parameters are themselves nuisance parameters for the purpose of this research, but the estimators of the marginal proportions of interest can be expressed as functions of the data and these nuisance parameters and their variances can be estimated by the sandwich method. We examine the performance of the proposed methodology in simulations and two real data applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Revisiting pulmonary vein isolation alone for persistent atrial fibrillation: A systematic review and meta-analysis.

PubMed

Voskoboinik, Aleksandr; Moskovitch, Jeremy T; Harel, Nadav; Sanders, Prashanthan; Kistler, Peter M; Kalman, Jonathan M

2017-05-01

Early studies demonstrated relatively low success rates for pulmonary vein isolation (PVI) alone in patients with persistent atrial fibrillation (PeAF). However, the advent of new technologies and the observation that additional substrate ablation does not improve outcomes have created a new focus on PVI alone for treatment of PeAF. The purpose of this study was to systematically review the recent medical literature to determine current medium-term outcomes when a PVI-only approach is used for PeAF. An electronic database search (MEDLINE, Embase, Web of Science, PubMed, Cochrane) was performed in August 2016. Only studies of PeAF patients undergoing a "PVI only" ablation strategy using contemporary radiofrequency (RF) technology or second-generation cryoballoon (CB2) were included. A random-effects model was used to assess the primary outcome of pooled single-procedure 12-month arrhythmia-free survival. Predictors of recurrence were also examined and a meta-analysis performed if ≥4 studies examined the parameter. Fourteen studies of 956 patients, of whom 45.2% underwent PVI only with RF and 54.8% with CB2, were included. Pooled single-procedure 12-month arrhythmia-free survival was 66.7% (95% confidence interval [CI] 60.8%-72.2%), with the majority of patients (80.5%) off antiarrhythmic drugs. Complication rates were very low, with cardiac tamponade occurring in 5 patients (0.6%) and persistent phrenic nerve palsy in 5 CB2 patients (0.9% of CB2). Blanking period recurrence (hazard ratio 4.68, 95% CI 1.70-12.9) was the only significant predictor of recurrence. A PVI-only strategy in PeAF patients with a low prevalence of structural heart disease using contemporary technology yields excellent outcomes comparable to those for paroxysmal AF ablation. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Surgical treatment of atrial fibrillation: a review.

PubMed

Hiari, Nadine

2011-01-01

Atrial fibrillation is the most commonly sustained arrhythmia in man. While it affects millions of patients worldwide, its incidence will markedly increase with an aging population. Primary goals of AF therapy are to (1) reduce embolic complications, particularly stroke, (2) alleviate symptoms, and (3) prevent long-term heart remodelling. These have been proven to be a challenge as there are major limitations in our knowledge of the pathological and electrophysiological mechanisms underlying AF. Although advances continue to be made in the medical management of this condition, pharmacotherapy is often unsuccessful. Because of the high recurrence rate of AF despite antiarrhythmic drug therapy for maintenance of sinus rhythm and the adverse effects of these drugs, there has been growing interest in nonpharmacological strategies. Surgery for treatment of AF has been around for some time. The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation and has more than 90% success in eliminating atrial fibrillation. Although the cut and sew maze is very effective, it has been superseded by newer operations that rely on alternate energy sources to create lines of conduction block. In addition, the evolution of improved ablation technology and instrumentation has facilitated the development of minimally invasive approaches. In this paper, the rationale for surgical ablation for atrial fibrillation and the different surgical techniques that were developed will be explored. In addition, it will detail the new approaches to surgical ablation of atrial fibrillation that employ alternate energy sources.

Venous hemostasis postcatheter ablation of atrial fibrillation while under therapeutic levels of oral and intravenous anticoagulation.

PubMed

Issa, Ziad F; Amr, Bashar S

2015-11-01

Catheter ablation of atrial fibrillation (AF) requires utilizing multiple venous femoral sheaths in conjunction with aggressive periprocedural anticoagulation, which can lead to increased risk of vascular access complications. The objective of this study is to evaluate the safety and efficacy of the "figure-of-eight" ("F-8") suture technique for femoral venous hemostasis while on therapeutic doses of intravenous anticoagulation at the time of sheath removal. In this case-control analysis, 376 consecutive patients underwent AF ablation while on uninterrupted oral anticoagulation and received intraprocedural heparin. In the first 253 patients (the control group), manual pressure was used for femoral venous hemostasis after reversal of heparin effects. The subsequent 123 patients (the F-8 group) had femoral venous hemostasis using the F-8 suture technique and while under therapeutic heparin effects. The F-8 subcutaneous suture technique achieved adequate venous hemostasis in 98.4% of patients. As compared to the control group, there was significantly less frequent utilization of the FemoStop compression assist device (1.2 vs. 16.8%, p < 0.0001) and in a significantly shorter interval (6.8 ± 5.7 vs. 50.7 ± 12.2 min, p < 0.0001). Vascular access complications and thromboembolic events occurred in 9.8% in the F-8 group vs. 13.0% in the control group (p = 0.678). Immediate hemostasis of the femoral venous access sites after insertion of multiple sheaths for AF ablation in the presence of anticoagulation can be safely and effectively achieved using the F-8 suture technique. This technique helps minimize the period of inadequate anticoagulation immediately following ablation and shortens the time required to achieve adequate hemostasis.

Safety and feasibility of leadless pacemaker in patients undergoing atrioventricular node ablation for atrial fibrillation.

PubMed

Yarlagadda, Bharath; Turagam, Mohit K; Dar, Tawseef; Jangam, Pragna; Veerapaneni, Vaishnavi; Atkins, Donita; Bommana, Sudharani; Friedman, Paul; Deshmukh, Abhishek J; Doshi, Rahul; Reddy, Vivek Y; Dukkipati, Srinivas R; Natale, Andrea; Lakkireddy, Dhanunjaya

2018-03-01

Atrioventricular node (AVN) ablation and permanent pacing is an established strategy for rate control in the management of symptomatic atrial fibrillation (AF). Leadless pacemakers (LPs) can overcome some of the short-term and long-term limitations of conventional transvenous pacemakers (CTPs). The purpose of this study was to compare the feasibility and safety of LP with those of single-chamber CTP in patients with AF undergoing AVN ablation. We conducted a multicenter observational study of patients undergoing AVN ablation and pacemaker implantation (LP vs single-chamber CTP) between February 2014 and November 2016. The primary efficacy end points were acceptable sensing (R wave ≥5.0 mV) and pacing thresholds (≤2.0 V at 0.4 ms) at follow-up. Safety end points included device-related major and minor (early ≤1 month, late >1 month) adverse events. A total of 127 patients with LP (n = 60) and CTP (n = 67) were studied. The median follow-up was 12 months (interquartile range 12-18 months). Ninety-five percent of the LP group and 97% of the CTP group met the primary efficacy end point at follow-up (57 of 60 vs 65 of 67; P = .66). There was 1 major adverse event (loss of pacing and sensing) in the LP group and 2 (lead dislodgement) in the CTP group (1 of 60 vs 2 of 67; P = 1.00). There were 6 minor adverse events (5 early and 1 late) in the LP group and 3 (early) in the CTP group (6 of 60 vs 3 of 67; P = .30). Our results demonstrate the feasibility and safety of LP compared with CTP in patients undergoing AVN ablation for AF. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Atrial fibrillation ablation using remote magnetic navigation and the risk of atrial-esophageal fistula: international multicenter experience.

PubMed

Danon, Asaf; Shurrab, Mohammed; Nair, Krishnakumar Mohanan; Latcu, Decebal Gabriel; Arruda, Mauricio S; Chen, Xu; Szili-Torok, Tamas; Rossvol, Ole; Wissner, Eric E; Lashevsky, Ilan; Crystal, Eugene

2015-08-01

Remote magnetic navigation (RMN) has been used in various electrophysiological procedures, including atrial fibrillation (AF) ablation. Atrial-esophageal fistula (AEF) is one of most disastrous complications of AF ablation. We aimed to evaluate the incidence of AEF during AF ablation using RMN in comparison to manual ablation. We conducted the first international survey among RMN operators for assessment of the prevalence of AEF and procedural parameters affecting the risk. Data from parallel survey of AEF among Canadian interventional electrophysiologists (CIE) using only manual catheters served as control. Fifteen RMN operators (who performed 3637 procedures) and 25 manual CIE operators (7016 procedures) responded to the survey. RMN operators were more experienced than CIE operators (16.3 ± 8.3 vs. 9.2 ± 5.4 practice years in electrophysiology, p = 0.007). The maximal energy output in the posterior wall was higher in the operator using RMN (33 ± 5 vs. 28.6 ± 4.9 W; p = 0.02). Other parameters including use of preprocedural images, irrigated catheter, pump flow rate, esophageal temperature monitoring, intracardiac echocardiography (ICE), and general anesthesia were similar. CIE operators administered proton-pump inhibitors postoperatively significantly more than RMN operators (76 vs. 35%, p = 0.01). AEF was reported in 5 of the 7016 patients in the control group (0.07%) but in none of the RMN group (p = 0.11). AEF is a rare complication and its evaluation necessitates large-scale studies. Although no AEF case with RMN was reported in this large study or previously on the literature, the rarity of this complication prevents firm conclusion about the risk.

3 Tesla MRI-detected brain lesions after pulmonary vein isolation for atrial fibrillation: results of the MACPAF study.

PubMed

Haeusler, Karl Georg; Koch, Lydia; Herm, Juliane; Kopp, Ute A; Heuschmann, Peter U; Endres, Matthias; Schultheiss, Heinz-Peter; Schirdewan, Alexander; Fiebach, Jochen B

2013-01-01

Left atrial catheter ablation (LACA) is an established therapeutic approach to abolish symptomatic atrial fibrillation (AF). Based on the prospective MACPAF study (clinicaltrials.gov NCT01061931) we report the rate of ischemic brain lesions postablation and their impact on cognitive function. Patients with symptomatic paroxysmal AF were randomized to LACA using the Arctic Front® or the HD Mesh Ablator® catheter. All patients underwent brain MRI at 3 Tesla, neurological, and neuropsychological examinations within 48 hours prior and after the ablation procedure. There was no clinically evident stroke in 37 patients (mean age 62.4 ± 8.4 years; 41% female; median CHADS2 score 1 [IQR 0-2]) after LACA but high-resolution diffusion-weighted imaging (DWI) detected new ischemic lesions in 15 (41%) patients after LACA. Four (27%) of the HD Mesh Ablator® patients and 11 (50%) of the Arctic Front® patients suffered a silent ischemic lesion (P = 0.19). In these 15 patients, there was a nonsignificant trend toward lower cardiac ejection fraction (P = 0.07) and AF episodes during LACA (P = 0.09), while activated clotting time levels, number of energy applications, periprocedural electrocardioversion or CHADS(2) score had no impact. Lesion volumes varied from 5 to 150 mm(3) and 1 to 5 lesions were detected per patient. However, acute brain lesions had no effect on cognitive performance immediately after LACA. Of the DWI lesions postablation 82% were not detectable on FLAIR images 6-9 months postablation. According to 3 Tesla high-resolution DWI, ischemic brain lesions after LACA were common but not associated with impaired cognitive function after the ablation procedure. © 2012 Wiley Periodicals, Inc.

Validation of a novel CARTOSEG™ segmentation module software for contrast-enhanced computed tomography-guided radiofrequency ablation in patients with atrial fibrillation.

PubMed

Imanli, Hasan; Bhatty, Shaun; Jeudy, Jean; Ghzally, Yousra; Ume, Kiddy; Vunnam, Rama; Itah, Refael; Amit, Mati; Duell, John; See, Vincent; Shorofsky, Stephen; Dickfeld, Timm M

2017-11-01

Visualization of left atrial (LA) anatomy using image integration modules has been associated with decreased radiation exposure and improved procedural outcome when used for guidance of pulmonary vein isolation (PVI) in atrial fibrillation (AF) ablation. We evaluated the CARTOSEG™ CT Segmentation Module (Biosense Webster, Inc.) that offers a new CT-specific semiautomatic reconstruction of the atrial endocardium. The CARTOSEG™ CT Segmentation Module software was assessed prospectively in 80 patients undergoing AF ablation. Using preprocedural contrast-enhanced computed tomography (CE-CT), cardiac chambers, coronary sinus (CS), and esophagus were semiautomatically segmented. Segmentation quality was assessed from 1 (poor) to 4 (excellent). The reconstructed structures were registered with the electroanatomic map (EAM). PVI was performed using the registered 3D images. Semiautomatic reconstruction of the heart chambers was successfully performed in all 80 patients with AF. CE-CT DICOM file import, semiautomatic segmentation of cardiac chambers, esophagus, and CS was performed in 185 ± 105, 18 ± 5, 119 ± 47, and 69 ± 19 seconds, respectively. Average segmentation quality was 3.9 ± 0.2, 3.8 ± 0.3, and 3.8 ± 0.2 for LA, esophagus, and CS, respectively. Registration accuracy between the EAM and CE-CT-derived segmentation was 4.2 ± 0.9 mm. Complications consisted of one perforation (1%) which required pericardiocentesis, one increased pericardial effusion treated conservatively (1%), and one early termination of ablation due to thrombus formation on the ablation sheath without TIA/stroke (1%). All targeted PVs (n  =  309) were successfully isolated. The novel CT- CARTOSEG™ CT Segmentation Module enables a rapid and reliable semiautomatic 3D reconstruction of cardiac chambers and adjacent anatomy, which facilitates successful and safe PVI. © 2017 Wiley Periodicals, Inc.

Atrial Electrogram Fractionation Distribution before and after Pulmonary Vein Isolation in Human Persistent Atrial Fibrillation-A Retrospective Multivariate Statistical Analysis.

PubMed

Almeida, Tiago P; Chu, Gavin S; Li, Xin; Dastagir, Nawshin; Tuan, Jiun H; Stafford, Peter J; Schlindwein, Fernando S; Ng, G André

2017-01-01

Purpose: Complex fractionated atrial electrograms (CFAE)-guided ablation after pulmonary vein isolation (PVI) has been used for persistent atrial fibrillation (persAF) therapy. This strategy has shown suboptimal outcomes due to, among other factors, undetected changes in the atrial tissue following PVI. In the present work, we investigate CFAE distribution before and after PVI in patients with persAF using a multivariate statistical model. Methods: 207 pairs of atrial electrograms (AEGs) were collected before and after PVI respectively, from corresponding LA regions in 18 persAF patients. Twelve attributes were measured from the AEGs, before and after PVI. Statistical models based on multivariate analysis of variance (MANOVA) and linear discriminant analysis (LDA) have been used to characterize the atrial regions and AEGs. Results: PVI significantly reduced CFAEs in the LA (70 vs. 40%; P < 0.0001). Four types of LA regions were identified, based on the AEGs characteristics: (i) fractionated before PVI that remained fractionated after PVI (31% of the collected points); (ii) fractionated that converted to normal (39%); (iii) normal prior to PVI that became fractionated (9%) and; (iv) normal that remained normal (21%). Individually, the attributes failed to distinguish these LA regions, but multivariate statistical models were effective in their discrimination ( P < 0.0001). Conclusion: Our results have unveiled that there are LA regions resistant to PVI, while others are affected by it. Although, traditional methods were unable to identify these different regions, the proposed multivariate statistical model discriminated LA regions resistant to PVI from those affected by it without prior ablation information.

Prevalence and predictors of low voltage zones in the left atrium in patients with atrial fibrillation.

PubMed

Huo, Yan; Gaspar, Thomas; Pohl, Matthias; Sitzy, Judith; Richter, Utz; Neudeck, Sebastian; Mayer, Julia; Kronborg, Mads Brix; Piorkowski, Christopher

2017-06-10

To describe the extent and distribution of low voltage zones (LVZ) in a large cohort of patients undergoing ablation for paroxysmal and persistent atrial fibrillation (AF), and to explore baseline predictors of LVZ in these patients. Consecutive patients who underwent a bipolar voltage map guided AF ablation, were enrolled. Voltage maps were conducted for each patient using 3-dimensional electroanatomical mapping system and LVZ were defined as areas of bipolar voltage < 0.5 mV. A total of 539 patients (309 male, age 65 ± 10 years) were included. Low voltage zones was present in 58 out of 292 patients with paroxysmal and 134 out of 247 persistent AF (P < 0.001). The area of LVZ was larger in patients with persistent as compare to paroxysmal AF, 5 cm2 (IQR 3-18.6) vs. 12.1 cm2 (IQR 3.6-28.5), P = 0.026, respectively. In the multivariate analysis age (OR 1.07, 95%CI 1.05-1.10, P < 0.001), female gender (OR 2.18, 95%CI 1.38-3.43, P = 0.001), sinoatrial node dysfunction (OR 3.90, 95%CI 1.24-12.21, P = 0.020), larger surface area of left atrium pr. cm2 (OR 1.01, 95%CI 1.00-1.02, P = 0.016), and persistent AF (OR 5.03, 95%CI 3.20-7.90, P<0.001) were associated with presence of LVZ. In a large cohort of patients undergoing ablation for AF, the prevalence of LVZ was higher and LVZ areas larger in patients with persistent as compared with paroxysmal AF. The most frequent localization of LVZ was anterior wall, septum and posterior wall. Presence of LVZ was associated with higher age, female gender, larger LA surface area, and sinoatrial node dysfunction. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Impact of number of co-existing rotors and inter-electrode distance on accuracy of rotor localization☆,☆☆

PubMed Central

Aronis, Konstantinos N.; Ashikaga, Hiroshi

2018-01-01

Background Conflicting evidence exists on the efficacy of focal impulse and rotor modulation on atrial fibrillation ablation. A potential explanation is inaccurate rotor localization from multiple rotors coexistence and a relatively large (9–11 mm) inter-electrode distance (IED) of the multi-electrode basket catheter. Methods and results We studied a numerical model of cardiac action potential to reproduce one through seven rotors in a two-dimensional lattice. We estimated rotor location using phase singularity, Shannon entropy and dominant frequency. We then spatially downsampled the time series to create IEDs of 2–30 mm. The error of rotor localization was measured with reference to the dynamics of phase singularity at the original spatial resolution (IED = 1 mm). IED has a significant impact on the error using all the methods. When only one rotor is present, the error increases exponentially as a function of IED. At the clinical IED of 10 mm, the error is 3.8 mm (phase singularity), 3.7 mm (dominant frequency), and 11.8 mm (Shannon entropy). When there are more than one rotors, the error of rotor localization increases 10-fold. The error based on the phase singularity method at the clinical IED of 10 mm ranges from 30.0 mm (two rotors) to 96.1 mm (five rotors). Conclusions The magnitude of error of rotor localization using a clinically available basket catheter, in the presence of multiple rotors might be high enough to impact the accuracy of targeting during AF ablation. Improvement of catheter design and development of high-density mapping catheters may improve clinical outcomes of FIRM-guided AF ablation. PMID:28988690

Prospective randomized comparison of rotational angiography with three-dimensional reconstruction and computed tomography merged with electro-anatomical mapping: a two center atrial fibrillation ablation study.

PubMed

Anand, Rishi; Gorev, Maxim V; Poghosyan, Hermine; Pothier, Lindsay; Matkins, John; Kotler, Gregory; Moroz, Sarah; Armstrong, James; Nemtsov, Sergei V; Orlov, Michael V

2016-08-01

To compare the efficacy and accuracy of rotational angiography with three-dimensional reconstruction (3DATG) image merged with electro-anatomical mapping (EAM) vs. CT-EAM. A prospective, randomized, parallel, two-center study conducted in 36 patients (25 men, age 65 ± 10 years) undergoing AF ablation (33 % paroxysmal, 67 % persistent) guided by 3DATG (group 1) vs. CT (group 2) image fusion with EAM. 3DATG was performed on the Philips Allura Xper FD 10 system. Procedural characteristics including time, radiation exposure, outcome, and navigation accuracy were compared between two groups. There was no significant difference between the groups in total procedure duration or time spent for various procedural steps. Minor differences in procedural characteristics were present between two centers. Segmentation and fusion time for 3DATG or CT-EAM was short and similar between both centers. Accuracy of navigation guided by either method was high and did not depend on left atrial size. Maintenance of sinus rhythm between the two groups was no different up to 24 months of follow-up. This study did not find superiority of 3DATG-EAM image merge to guide AF ablation when compared to CT-EAM fusion. Both merging techniques result in similar navigation accuracy.

Long-term follow-up of patients with paroxysmal atrial fibrillation and severe left atrial scarring: comparison between pulmonary vein antrum isolation only or pulmonary vein isolation combined with either scar homogenization or trigger ablation.

PubMed

Mohanty, Sanghamitra; Mohanty, Prasant; Di Biase, Luigi; Trivedi, Chintan; Morris, Eli Hamilton; Gianni, Carola; Santangeli, Pasquale; Bai, Rong; Sanchez, Javier E; Hranitzky, Patrick; Gallinghouse, G Joseph; Al-Ahmad, Amin; Horton, Rodney P; Hongo, Richard; Beheiry, Salwa; Elayi, Claude S; Lakkireddy, Dhanunjaya; Madhu Reddy, Yaruva; Viles Gonzalez, Juan F; Burkhardt, J David; Natale, Andrea

2017-11-01

Left atrial (LA) scarring, a consequence of cardiac fibrosis is a powerful predictor of procedure-outcome in atrial fibrillation (AF) patients undergoing catheter ablation. We sought to compare the long-term outcome in patients with paroxysmal AF (PAF) and severe LA scarring identified by 3D mapping, undergoing pulmonary vein isolation (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI+ ablation of the non-PV triggers. Totally, 177 consecutive patients with PAF and severe LA scarring were included. Patients underwent PVAI only (n = 45, Group 1), PVAI+ scar homogenization (n = 66, Group 2) or PVAI+ ablation of non-PV triggers (n = 66, Group 3) based on operator's choice. Baseline characteristics were similar across the groups. After first procedure, all patients were followed-up for a minimum of 2 years. The success rate at the end of the follow-up was 18% (8 pts), 21% (14 pts), and 61% (40 pts) in Groups 1, 2, and 3, respectively. Cumulative probability of AF-free survival was significantly higher in Group 3 (overall log-rank P <0.01, pairwise comparison 1 vs. 3 and 2 vs. 3 P < 0.01). During repeat procedures, non-PV triggers were ablated in all. After average 1.5 procedures, the success rates were 28 (62%), 41 (62%), and 56 (85%) in Groups 1, 2, and 3, respectively (log-rank P< 0.001). In patients with PAF and severe LA scarring, PVAI+ ablation of non-PV triggers is associated with significantly better long-term outcome than PVAI alone or PVAI+ scar homogenization. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

Rotational Angiography Based Three-Dimensional Left Atrial Reconstruction: A New Approach for Transseptal Puncture.

PubMed

Koektuerk, Buelent; Yorgun, Hikmet; Koektuerk, Oezlem; Turan, Cem H; Gorr, Eduard; Horlitz, Marc; Turan, Ramazan G

2016-02-01

Rotational angiography is a well-known method for the three-dimensional (3-D) reconstruction of left atrium and pulmonary veins during left-sided atrial arrhythmia ablation procedures. In our study, we aimed to review our experience in transseptal puncture (TSP) using 3-D rotational angiography. We included a total of 271 patients who underwent atrial fibrillation ablation using cryoballoon. Rotational angiography was performed to get the three-dimensional left atrial and pulmonary vein reconstructions using cardiac C-arm computed tomography. The image reconstruction was made using the DynaCT Cardiac software (Siemens, Erlangen, Germany). The mean age of the study population was 61 ± 10 years. The indications for left atrial arrhythmia ablation were paroxysmal AF in 140 patients (52%) and persistent AF patients in 131 (48%) patients. The success rate of TSP using only rotational guidance was (264/271 patients, 97.4%). In the remaining seven patients, transesophageal guidance was used after the initial attempt due to thick interatrial septum in five patients and difficult TSP due to abnormal anatomy and mild pericardial effusion in the remaining two patients. Mean fluoroscopy dosage of the rotational angiography was 4896.4 ± 825.3 μGym(2). The mean time beginning from femoral vein puncture to TSP was 12.3 ± 5.5 min. TSP guided by rotational angiography is a safe and effective method. Our results indicate that integration of rotational angiographic images into the real-time fluoroscopy can guide the TSP during the procedure. © 2015 John Wiley & Sons Ltd.

Causes and Predictors of Readmission in Patients With Atrial Fibrillation Undergoing Catheter Ablation: A National Population-Based Cohort Study.

PubMed

Arora, Shilpkumar; Lahewala, Sopan; Tripathi, Byomesh; Mehta, Varshil; Kumar, Varun; Chandramohan, Divya; Lemor, Alejandro; Dave, Mihir; Patel, Nileshkumar; Patel, Nilay V; Palamaner Subash Shantha, Ghanshyam; Viles-Gonzalez, Juan; Deshmukh, Abhishek

2018-06-15

Reducing readmission after catheter ablation (CA) in atrial fibrillation (AF) is important. We utilized National Readmission Data (NRD) 2010-2014. AF was identified by International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnostic code 427.31 in the primary field, while first CA of AF was identified via ICD-9 -procedure code 37.34. Any admission within 30 or 90 days of index admission was considered a readmission. Cox proportional hazard regression was used to adjust for confounders. The primary outcomes were 30- and 90-day readmissions and the secondary outcome was AF recurrence. In total, 1 128 372 patients with AF were identified from January 1, 2010 to September 30, 2014. Of which 37 360 (3.3%) underwent CA. Patients aged ≥65 years and female sex were less likely to receive CA for AF. Overall, 10.9% and 16.5% of CA patients were readmitted within 30 and 90 days post-CA, respectively. Most common causes of readmissions were arrhythmia (AF, atrial flutter), heart failure, pulmonary causes (pneumonia, chronic obstructive pulmonary disease) and bleeding complications (gastrointestinal bleed, intracranial hemorrhage). Patients with diabetes mellitus, heart failure, coronary artery disease (CAD), chronic pulmonary and kidney disease, prior stroke/transient ischemic attack (TIA), female sex, length of stay ≥2 and disposition to the facility were prone to higher 30- and 90-day readmissions post-CA. Predictors of increase in AF recurrence post-CA were female sex, diabetes mellitus, chronic pulmonary disease, and length of stay ≥2. Trends of 90-day readmission and AF recurrence were found to improve over the study period. We identified several demographic and clinical factors associated with the use of CA in AF, and short-term outcomes of the same, which could potentially help in the patient selection and improve outcomes. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Prevalence and mechanism of rotor activation identified during atrial fibrillation by noncontact mapping: Lack of evidence for a role in the maintenance of atrial fibrillation.

PubMed

Yamabe, Hiroshige; Kanazawa, Hisanori; Ito, Miwa; Kaneko, Shozo; Ogawa, Hisao

2016-12-01

It remains unclear whether atrial fibrillation (AF) is maintained by the rotor. We evaluated the role of the rotor and examined its mechanism. Among 75 patients with AF (60 paroxysmal, 15 persistent AF) who underwent 3-dimensional noncontact left atrial mapping during AF, we examined the prevalence and location of rotor activation and elucidated its mechanism. Catheter ablation was performed in a stepwise fashion (linear roof lesion and complex fractionated atrial electrogram ablation after pulmonary vein [PV) isolation) until AF termination. Rotor activation was observed in 11 patients (14.7%; 10 paroxysmal and 1 persistent AF) (tachycardia cycle length 160.0 ± 19.8 ms). Rotors were observed transiently (duration 6128 ± 9094 ms) during AF at the roof (n = 5), septum (n = 3), and ostium of the left superior PV (n = 3). Five rotors circulated in clockwise and 6 in counterclockwise directions. The length of the block line at the center of the rotor was 15.2 ± 6.9 mm. The electrograms at the block line showed low-amplitude multiple deflections (n = 7) or double potentials (n = 4), and the amplitudes during rotor activation were significantly lower than those during sinus rhythm (0.27 ± 0.18 mV vs 1.22 ± 0.92 mV; P < .01). No conduction disturbances were found during sinus rhythm, suggesting that the central line of block was formed functionally. AF was terminated by PV isolation alone without additional lesions in patients with rotors. Functionally formed rotor activation was observed during AF in a limited number of patients. These rotor activations may not be related to AF maintenance, but rather may reflect a transient organization of random propagation. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Gender differences in clinical presentation and 1-year outcomes in atrial fibrillation

PubMed Central

Schnabel, Renate B; Pecen, Ladislav; Ojeda, Francisco M; Lucerna, Markus; Rzayeva, Nargiz; Blankenberg, Stefan; Darius, Harald; Kotecha, Dipak; Caterina, Raffaele De; Kirchhof, Paulus

2017-01-01

Objectives Our objective was to examine gender differences in clinical presentation, management and prognosis of atrial fibrillation (AF) in a contemporary cohort. Methods In 6412 patients, 39.7% women, of the PREvention oF thromboembolic events – European Registry in Atrial Fibrillation, we examined gender differences in symptoms, risk factors, therapies and 1-year incidence of adverse outcomes. Results Men with AF were on average younger than women (mean±SD: 70.1±10.7 vs 74.1±9.7 years, p<0.0001). Women more frequently had at least one AF-related symptom at least occasionally compared with men (95.4% in women, 89.8% in men, p<0.0001). Prescription of oral anticoagulation was similar, with an increase of non-vitamin K antagonist oral anticoagulants from 5.9% to 12.6% in women and from 6.2% to 12.6% in men, p<0.0001 for both. Men were more frequently treated with electrical cardioversion and ablation (20.6% and 6.3%, respectively) than women (14.9% and 3.3%, respectively), p<0.0001. Women had 65% (OR: 0.35; 95% CI (0.22 to 0.56)) lower age-adjusted and country-adjusted odds of coronary revascularisation, 40% (OR: 0.60; (0.38 to 0.93)) lower odds of acute coronary syndrome and 20% (OR: 0.80; (0.68 to 0.96)) lower odds of heart failure at 1 year. There were no statistically significant gender differences in 1-year stroke/transient ischaemic attack/arterial thromboembolism and major bleeding events. Conclusion In a ‘real-world’ European AF registry, women were more symptomatic but less likely to receive invasive rhythm control therapy such as electrical cardioversion or ablation. Further study is needed to confirm that these differences do not disadvantage women with AF. PMID:28228467

Primary and key secondary results from the ROCKET AF trial, and their implications on clinical practice

PubMed Central

Shah, Rohan; Patel, Manesh R.

2016-01-01

Background: The safety and efficacy of the oral anticoagulant rivaroxaban were studied in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF trial). A number of subanalyses of the ROCKET AF trial have subsequently analyzed the use of rivaroxaban in special patient populations. Methods: The outcomes of the ROCKET AF trial were reviewed. The use of rivaroxaban in higher risk populations, as determined by the presence of co-morbidities included in the CHADS2 criteria, was analyzed. Requirements for dose adjustment in patients with renal impairment and in East Asian patients were described. Finally, clinical management challenges, including interruptions in therapy, drug discontinuation, management of bleeding events, drug interactions, and management of patients requiring cardioversion/ablation were reviewed. Results: Rivaroxaban is efficacious in high-risk populations, including elderly patients, patients with diabetes, heart failure, history of stroke, prior myocardial infarction, or peripheral arterial disease (PAD). Patients with PAD have a higher risk of bleeding with rivaroxaban compared with warfarin. East Asian populations do not require a dose adjustment for rivaroxaban, while a reduced dose of 15 mg daily is required for patients with moderate renal impairment. Rivaroxaban remains effective with temporary interruptions in therapy and in patients requiring cardioversion/ablation. Rates of major bleeding and subsequent outcomes were similar in patients on warfarin and rivaroxaban, although rates of gastrointestinal bleeding were higher with rivaroxaban. Concurrent use of antiarrhythmic therapy was not associated with adverse outcomes. Conclusions: Rivaroxaban represents an efficacious alternative to warfarin in high-risk patients with AF. Dose adjustment is required for patients with moderate renal impairment. Rivaroxaban can be used safely in a number of challenging clinical management scenarios although the concurrent use of amiodarone requires more study. PMID:27555569

Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial.

PubMed

De Greef, Yves; Dekker, Lukas; Boersma, Lucas; Murray, Stephen; Wieczorek, Marcus; Spitzer, Stefan G; Davidson, Neil; Furniss, Steve; Hocini, Mélèze; Geller, J Christoph; Csanádi, Zoltan

2016-05-01

This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16-72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (<3 W) ablations (15 vs. 23%, 5 vs. 10% and 2 vs. 7% in 4:1, 2:1, and 1:1 bipolar:unipolar energy modes, respectively). Mini-Mental State Exam was unchanged in all patients. Atrial fibrillation ablation with PVAC GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. ClinicalTrials.gov NCT01767558. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

The identification of conduction gaps after pulmonary vein isolation using a new electroanatomic mapping system.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Matsuda, Yasuhiro; Okuno, Shota; Ohashi, Takuya; Tsuji, Aki; Mano, Toshiaki

2017-11-01

The reconnection of left atrial-pulmonary vein (LA-PV) conduction after the initial procedure of pulmonary vein (PV) isolation is not rare, and is one of the main cause of atrial fibrillation (AF) recurrence after PV isolation. We investigated feasibility of a new ultrahigh-resolution mapping system using a 64-pole small basket catheter for the identification of LA-PV conduction gaps. This prospective study included 31 consecutive patients (20 with persistent AF) undergoing a second ablation after a PV isolation procedure with LA-PV reconnected conduction at any of the 4 PVs. An LA-PV map was created using the mapping system, and ablation was performed at the estimated gap location. The propagation map identified 54 gaps from 39 ipsilateral PV pairs, requiring manual electrogram reannotation for 23 gaps (43%). Gaps at the anterior and carinal regions of left and right ipsilateral PVs required manual electrogram reannotation more frequently than the other regions. The voltage map could identify the gap only in 19 instances (35%). Electrophysiological properties of the gaps (multiple gaps in the same ipsilateral PVs, conduction time, velocity, width, and length) did not differ between those needing and not needing manual electrogram reannotation. During the gap ablation, either the activation sequence alteration or elimination of PV potentials was observed using a circular catheter placed in the PV, suggesting that all the identified gaps were correct. This new electroanatomic mapping system visualized all the LA-PV gaps in patients undergoing a second AF ablation. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Validation of a novel mapping system and utility for mapping complex atrial tachycardias.

PubMed

Honarbakhsh, S; Hunter, R J; Dhillon, G; Ullah, W; Keating, E; Providencia, R; Chow, A; Earley, M J; Schilling, R J

2018-03-01

This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT). Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps. The left atrium was paced from four sites to demonstrate focal activation. ATs were mapped with the mechanism confirmed by conventional mapping, entrainment, and response to ablation. Twenty-two patients were included in the study (16 with AT and 6 with AF initially who terminated to AT during ablation). In total, 172 maps were created with the mapping system. It correctly identified atrial-pacing sites in all paced maps. It accurately mapped 9 focal/microreentrant and 18 macroreentrant ATs both in the left and right atrium. A third and fourth observer independently identified the sites of atrial pacing and the AT mechanism from the CARTOFINDER maps, while being blinded to the conventional activation maps. This novel mapping system was effectively validated by mapping focal activation patterns from atrial-paced beats. The system was also effective in mapping complex wavefront patterns in a range of ATs in patients with scarred atria. The system may therefore be of practical use in the mapping and ablation of AT and could have potential for mapping wavefront activations in AF. © 2018 Wiley Periodicals, Inc.

Interatrial septum thickness and difficulty with transseptal puncture during redo catheter ablation of atrial fibrillation.

PubMed

Tomlinson, David R; Sabharwal, Nikant; Bashir, Yaver; Betts, Timothy R

2008-12-01

Patients undergoing catheter ablation for atrial fibrillation (AF) frequently require redo procedures, but there are no data reporting interatrial septum thickness (IAS) and difficulty during repeat transseptal puncture (TSP). Patients undergoing two separate AF ablation procedures had preprocedural fossa ovalis (FO) thickness measured using transesophageal echocardiography (TEE). "Difficult" TSP was defined by two observers as requiring excessive force, or conversion to TEE guidance. The study comprised 42 patients (37 male) with mean+/-SD age 55+/-9 years. Mean FO thickness was significantly greater at the time of redo TSP (2.2+/-1.6 mm vs 2.6+/-1.5 mm at redo, P=0.03); however, this finding was limited to those who underwent initial dual transseptal sheath procedures, FO thickness 2.0+/-1.5 mm and 2.5+/-1.4 mm for TEE 1 and 2, respectively (P=0.048). There was a trend for more frequent difficult redo TSP procedures, 7/42 (17%; 95% confidence interval [CI] 8-31) redo, versus 4/42 (10%; 95% CI 3-23) first TSP. On univariate analysis, FO thickness was not predictive of TSP difficulty; the only predictor of difficult redo TSP was diabetes. IAS thickness at the FO increased following catheter ablation of AF, yet on subgroup analysis this was limited to initial procedures utilizing dual transseptal sheaths. There was a trend toward more frequent difficulty during redo TSP, yet this was not associated with FO thickening. Diabetes may predispose to difficulty during redo TSP; this finding requires confirmation in a larger study population.

Recurring patterns of atrial fibrillation in surface ECG predict restoration of sinus rhythm by catheter ablation.

PubMed

Di Marco, Luigi Yuri; Raine, Daniel; Bourke, John P; Langley, Philip

2014-11-01

Non-invasive tools to help identify patients likely to benefit from catheter ablation (CA) of atrial fibrillation (AF) would facilitate personalised treatment planning. To investigate atrial waveform organisation through recurrence plot indices (RPI) and their ability to predict CA outcome. One minute 12-lead ECG was recorded before CA from 62 patients with AF (32 paroxysmal AF; 45 men; age 57±10 years). Organisation of atrial waveforms from i) TQ intervals in V1 and ii) QRST suppressed continuous AF waveforms (CAFW), were quantified using RPI: percentage recurrence (PR), percentage determinism (PD), entropy of recurrence (ER). Ability to predict acute (terminating vs. non-terminating AF), 3-month and 6-month postoperative outcome (AF vs. AF free) were assessed. RPI either by TQ or CAFW analysis did not change significantly with acute outcome. Patients arrhythmia-free at 6-month follow-up had higher organisation in TQ intervals by PD (p<0.05) and ER (p<0.005) and both were significant predictors of 6-month outcome (PD (AUC=0.67, p<0.05) and ER (AUC=0.72, p<0.005)). For paroxysmal AF cases, all RPI predicted 3-month (AUC(ER)=0.78, p<0.05; AUC(PD)=0.79, p<0.05; AUC(PR)=0.80, p<0.01) and 6-month (AUC(ER)=0.81, p<0.005; AUC(PD)=0.75, p<0.05; AUC(PR)=0.71, p<0.05) outcome. CAFW-derived RPIs did not predict acute or postoperative outcomes. Higher values of any RPI from TQ (values greater than 25th percentile of preoperative distribution) were associated with decreased risk of AF relapse at follow-up (hazard ratio ≤0.52, all p<0.05). Recurring patterns from preprocedural 1-minute recordings of ECG TQ intervals were significant predictors of CA 6-month outcome. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited "Jackhammer Esophagus": A New Complication Due to Vagal Nerve Stimulation?

PubMed

Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

2015-10-01

Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM.

Rotor Meandering Contributes to Irregularity in Electrograms during Atrial Fibrillation

PubMed Central

Zlochiver, Sharon; Yamazaki, Masatoshi; Kalifa, Jerome; Berenfeld, Omer

2010-01-01

Radiofrequency ablation therapy of atrial fibrillation (AF) recently incorporated the analysis of dominant frequency (DF) and/or electrogram fractionation for guidance. However, the relationships between DF, fractionation and spatio-temporal characteristics of the AF source remain unclear. We hypothesize that meandering reentrant AF source contributes to the wave fractionation and is reflected in the power spectrum of local electrograms elsewhere in the rotor’s surroundings. Methods Meandering rotors as AF sources were simulated in 2D models of human atrial tissue and recorded in isolated sheep hearts. Non-dominant elements of the signals were differentiated from the dominant elements using singular value decomposition, whereby the purely periodic constituent (PC) relating to the rotor’s DF was eliminated rendering a residual constituent (RC) that consisted of all other activity. Results Spectral analysis of the decomposed constituents revealed peaks corresponding to the meandering frequency of the rotor tip, the magnitudes of which were proportional to the size of, and the distance to the rotor core. Similar analyses on epicardial optical signals and electrograms from isolated sheep hearts, as well as human complex fractionated atrial electrograms demonstrated applicability of the approach. Conclusion Increased meandering of the rotor driving AF reduces activation periodicity and increases fractionation. The spectral manifestation of the rotor activity beyond the meandering region makes it possible to characterize AF source stability, as well as DF in humans using electrode mapping. PMID:18534369

The impact of the CartoSound® image directly acquired from the left atrium for integration in atrial fibrillation ablation.

PubMed

Kaseno, Kenichi; Hisazaki, Kaori; Nakamura, Kohki; Ikeda, Etsuko; Hasegawa, Kanae; Aoyama, Daisetsu; Shiomi, Yuichiro; Ikeda, Hiroyuki; Morishita, Tetsuji; Ishida, Kentaro; Amaya, Naoki; Uzui, Hiroyasu; Tada, Hiroshi

2018-04-14

Intracardiac echocardiographic (ICE) imaging might be useful for integrating three-dimensional computed tomographic (CT) images for left atrial (LA) catheter navigation during atrial fibrillation (AF) ablation. However, the optimal CT image integration method using ICE has not been established. This study included 52 AF patients who underwent successful circumferential pulmonary vein isolation (CPVI). In all patients, CT image integration was performed after the CPVI with the following two methods: (1) using ICE images of the LA derived from the right atrium and right ventricular outflow tract (RA-merge) and (2) using ICE images of the LA directly derived from the LA added to the image for the RA-merge (LA-merge). The accuracy of these two methods was assessed by the distances between the integrated CT image and ICE image (ICE-to-CT distance), and between the CT image and actual ablated sites for the CPVI (CT-to-ABL distance). The mean ICE-to-CT distance was comparable between the two methods (RA-merge = 1.6 ± 0.5 mm, LA-merge = 1.7 ± 0.4 mm; p = 0.33). However, the mean CT-to-ABL distance was shorter for the LA-merge (2.1 ± 0.6 mm) than RA-merge (2.5 ± 0.8 mm; p < 0.01). The LA, especially the left-sided PVs and LA roof, was more sharply delineated by direct LA imaging, and whereas the greatest CT-to-ABL distance was observed at the roof portion of the left superior PV (3.7 ± 2.8 mm) after the RA-merge, it improved to 2.6 ± 1.9 mm after the LA-merge (p < 0.01). Additional ICE images of the LA directly acquired from the LA might lead to a greater accuracy of the CT image integration for the CVPI.

Impact of number of co-existing rotors and inter-electrode distance on accuracy of rotor localization.

PubMed

Aronis, Konstantinos N; Ashikaga, Hiroshi

Conflicting evidence exists on the efficacy of focal impulse and rotor modulation on atrial fibrillation ablation. A potential explanation is inaccurate rotor localization from multiple rotors coexistence and a relatively large (9-11mm) inter-electrode distance (IED) of the multi-electrode basket catheter. We studied a numerical model of cardiac action potential to reproduce one through seven rotors in a two-dimensional lattice. We estimated rotor location using phase singularity, Shannon entropy and dominant frequency. We then spatially downsampled the time series to create IEDs of 2-30mm. The error of rotor localization was measured with reference to the dynamics of phase singularity at the original spatial resolution (IED=1mm). IED has a significant impact on the error using all the methods. When only one rotor is present, the error increases exponentially as a function of IED. At the clinical IED of 10mm, the error is 3.8mm (phase singularity), 3.7mm (dominant frequency), and 11.8mm (Shannon entropy). When there are more than one rotors, the error of rotor localization increases 10-fold. The error based on the phase singularity method at the clinical IED of 10mm ranges from 30.0mm (two rotors) to 96.1mm (five rotors). The magnitude of error of rotor localization using a clinically available basket catheter, in the presence of multiple rotors might be high enough to impact the accuracy of targeting during AF ablation. Improvement of catheter design and development of high-density mapping catheters may improve clinical outcomes of FIRM-guided AF ablation. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of Echocardiography in the Management and Prognosis of Atrial Fibrillation

PubMed Central

Silverman, David I; Ayirala, Srilatha R; Manning, Warren J

2012-01-01

Echocardiography plays a longstanding and vital role in the management of atrial fibrillation (AF). Advances in 2D imaging, Doppler echocardiography and strain imaging have all contributed to major progress in AF treatment. Echocardiographically measured left atrial (LA) volume is a powerful predictor of maintenance of sinus rhythm following cardioversion as well as risk of thrombus formation and thromboembolism. Doppler derived parameters of atrial mechanical function including atrial ejection force provide related prognostic information. Transesophageal echocardiocardiograpy (TEE) guided cardioversion of AF allows for rapid conversion to sinus rhythm without prolonged oral anticoagulation, and TEE serves as a useful tool during catheter ablation of AF and atrial flutter. Newer measures derived from speckle tracking offer great promise in further improving the care of patients with AF. PMID:28496715

Trends in hospitalization for atrial fibrillation: epidemiology, cost, and implications for the future.

PubMed

Sheikh, Azfar; Patel, Nileshkumar J; Nalluri, Nikhil; Agnihotri, Kanishk; Spagnola, Jonathan; Patel, Aashay; Asti, Deepak; Kanotra, Ritesh; Khan, Hafiz; Savani, Chirag; Arora, Shilpkumar; Patel, Nilay; Thakkar, Badal; Patel, Neil; Pau, Dhaval; Badheka, Apurva O; Deshmukh, Abhishek; Kowalski, Marcin; Viles-Gonzalez, Juan; Paydak, Hakan

2015-01-01

Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide and the most common arrhythmia leading to hospitalization. Due to a substantial increase in incidence and prevalence of AF over the past few decades, it attributes to an extensive economic and public health burden. The increasing number of hospitalizations, aging population, anticoagulation management, and increasing trend for disposition to a skilled facility are drivers of the increasing cost associated with AF. There has been significant progress in AF management with the release of new oral anticoagulants, use of left atrial catheter ablation, and novel techniques for left atrial appendage closure. In this article, we aim to review the trends in epidemiology, hospitalization, and cost of AF along with its future implications on public health. Published by Elsevier Inc.

Short-Term Heparin Kinetics during Catheter Ablation of Atrial Fibrillation.

PubMed

Gabus, Vincent; Rollin, Anne; Maury, Philippe; Forclaz, Andrei; Pascale, Patrizio; Dhutia, Harshil; Bisch, Laurence; Pruvot, Etienne

2015-10-01

Percutaneous catheter ablation of atrial fibrillation (CA-AF) is a treatment option for symptomatic drug-refractory atrial fibrillation (AF). CA-AF carries a risk for thromboembolic complications that has been minimized by the use of intraprocedural intravenous unfractionated heparin (UFH). The optimal administration of UFH as well as its kinetics are not well established and need to be precisely determined. A total 102 of consecutive patients suffering from symptomatic drug-refractory AF underwent CA-AF. The mean age was 61 ± 10 years old. After transseptal puncture of the fossa ovalis, weight-adjusted UFH bolus (100 U/kg) was infused. A significant increase in activated clotting time (ACT) was observed from an average value of 100 ± 27 seconds at baseline, to 355 ± 94 seconds at 10 min (T10), to 375 ± 90 seconds at 20 min (T20). Twenty-four patients failed to reach the targeted ACT value of ≥300 seconds at T10 and more than half of these remained with subtherapeutic ACT values at T20. This subset of patients showed similar clinical characteristics and amount of UFH but were more frequently prescribed preprocedural vitamin K1 than the rest of the study population. In a typical intervention setting, UFH displays unexpected slow anticoagulation kinetics in a significant proportion of procedures up to 20 minutes after infusion. These findings support the infusion of UFH before transseptal puncture or any left-sided catheterization with early ACT measurements to identify patients with delayed kinetics. They are in line with recent guidelines to perform CA-AF under therapeutic anticoagulation. © 2015 Wiley Periodicals, Inc.

An E/e' ratio on echocardiography predicts the existence of left atrial low-voltage areas and poor outcomes after catheter ablation for atrial fibrillation.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Ohashi, Takuya; Uematsu, Masaaki

2018-05-01

An elevated left atrial pressure has been reported to play an important role in the development of atrial remodelling in atrial fibrillation (AF) patients. The study aimed at elucidating the association between the diastolic early transmitral flow velocity/mitral annular velocity (E/e', a non-invasive surrogate of left atrial pressure) and left atrial low-voltage-area existence, and the prognostic impact of the E/e' on procedural outcomes in patients undergoing AF ablation. Total of 215 consecutive patients were divided into 3 groups based on the estimated left atrial pressure: normal (E/e' < 8.0, n = 58), undetermined (E/e' = 8.0-14.0, n = 114), and elevated (E/e' > 14.0, n = 43). Left atrial endocardial voltage mapping was performed following pulmonary vein isolation. Patients with a high E/e' more frequently had low-voltage areas (E/e' < 8.0, 31%, E/e' = 8.0-14.0, 35%; E/e' > 14.0, 67%; P = 0.0001). After adjusting for other correlates, a high E/e' was an independent predictor of low-voltage-area existence (HR = 1.11, 95% CI = 1.02-1.21, P = 0.017). During a mean follow-up period of 12 ± 6 months, recurrent atrial tachyarrhythmias occurred in 22 (10%) patients after multiple (1.4 ± 0.5) procedures. Patients with an E/e' > 14 had more frequent recurrent atrial tachyarrhythmias after multiple ablation procedures than those with an E/e' ≤ 14 (23% vs. 7%, P = 0.001). A high E/e' obtained by pre-ablation echocardiography was associated with a left atrial arrhythmogenic substrate in patients undergoing AF ablation. Furthermore, a high E/e' predicted poor procedural outcomes after pulmonary vein isolation.

Adenosine triphosphate-guided pulmonary vein isolation for atrial fibrillation: the UNmasking Dormant Electrical Reconduction by Adenosine TriPhosphate (UNDER-ATP) trial.

PubMed

Kobori, Atsushi; Shizuta, Satoshi; Inoue, Koichi; Kaitani, Kazuaki; Morimoto, Takeshi; Nakazawa, Yuko; Ozawa, Tomoya; Kurotobi, Toshiya; Morishima, Itsuro; Miura, Fumiharu; Watanabe, Tetsuya; Masuda, Masaharu; Naito, Masaki; Fujimoto, Hajime; Nishida, Taku; Furukawa, Yoshio; Shirayama, Takeshi; Tanaka, Mariko; Okajima, Katsunori; Yao, Takenori; Egami, Yasuyuki; Satomi, Kazuhiro; Noda, Takashi; Miyamoto, Koji; Haruna, Tetsuya; Kawaji, Tetsuma; Yoshizawa, Takashi; Toyota, Toshiaki; Yahata, Mitsuhiko; Nakai, Kentaro; Sugiyama, Hiroaki; Higashi, Yukei; Ito, Makoto; Horie, Minoru; Kusano, Kengo F; Shimizu, Wataru; Kamakura, Shiro; Kimura, Takeshi

2015-12-07

Most of recurrent atrial tachyarrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation (AF) are due to reconnection of PVs. The aim of the present study was to evaluate whether elimination of adenosine triphosphate (ATP)-induced dormant PV conduction by additional energy applications during the first ablation procedure could reduce the incidence of recurrent atrial tachyarrhythmias. We randomly assigned 2113 patients with paroxysmal, persistent, or long-lasting AF to either ATP-guided PVI (1112 patients) or conventional PVI (1001 patients). The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of Vaughan Williams class I or III antiarrhythmic drugs at 1 year with the blanking period of 90 days post ablation. Among patients assigned to ATP-guided PVI, 0.4 mg/kg body weight of ATP provoked dormant PV conduction in 307 patients (27.6%). Additional radiofrequency energy applications successfully eliminated dormant conduction in 302 patients (98.4%). At 1 year, 68.7% of patients in the ATP-guided PVI group and 67.1% of patients in the conventional PVI group were free from the primary endpoint, with no significant difference (adjusted hazard ratio [HR] 0.89; 95% confidence interval [CI] 0.74-1.09; P = 0.25). The results were consistent across all the prespecified subgroups. Also, there was no significant difference in the 1-year event-free rates from repeat ablation for any atrial tachyarrhythmia between the groups (adjusted HR 0.83; 95% CI 0.65-1.08; P = 0.16). In the catheter ablation for AF, we found no significant reduction in the 1-year incidence of recurrent atrial tachyarrhythmias by ATP-guided PVI compared with conventional PVI. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Catheter ablation for atrial fibrillation on uninterrupted direct oral anticoagulants: A safe approach.

PubMed

Sawhney, V; Shaukat, M; Volkova, E; Jones, N; Providencia, R; Honarbakhsh, S; Dhillon, G; Chow, A; Lowe, M; Lambiase, P; Dhinoja, M; Sporton, S; Earley, M J; Schilling, R J; Hunter, R J

2018-05-16

Current consensus guidelines suggest DOACs are interrupted peri-procedurally for catheter ablation (CA) of AF. However, this may predispose patients to thromboembolic complications. This study investigates the safety of CA for AF on uninterrupted DOACs compared to uninterrupted warfarin. Single centre, retrospective study of consecutive patients undergoing CA for AF. All patients were heparinised prior to trans-septal puncture with a target activated clotting time (ACT) of 300-350 seconds. Patients who had procedures performed on continuous DOAC were compared to those on continuous warfarin. Clinical, procedural data and complications occurring up to 3 months were analysed from a prospective registry with additional review of electronic health records. 1884 procedures were performed over 28 months: 761(609 patients) on uninterrupted warfarin and 1123(900 patients) on uninterrupted DOAC (rivaroxaban 64%, apixaban 32% and dabigatran 4%). There was no difference in the composite end point of death, thromboembolism or major bleeding complication(2.2% vs 1.4%, p = 0.20). There was no difference in the complications comprising this including tamponade, haematoma, pseudoaneurysm, transfusion(p-values 0.28, 0.13, 0.45 and 0.36). There were no strokes, TIAs or other thromboembolic complications. There was no difference between groups in the proportion of tamponades requiring reversal of oral anticoagulation, the volume of blood lost, the proportion transfused, or the proportion drained percutaneously(p-values 0.50, 0.51, 0.36, 0.38). Catheter ablation for AF can be performed safely and effectively in patients anticoagulated with DOACs and heparinised with a therapeutic ACT. There is no increased risk of peri-procedural bleeding when compared to uninterrupted warfarin. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Atrial fibrillation in patients with gastroesophageal reflux disease: A comprehensive review

PubMed Central

Roman, Crina; Bruley des Varannes, Stanislas; Muresan, Lucian; Picos, Alina; Dumitrascu, Dan L

2014-01-01

AIM: To analyze the potential relationship between gastroesophageal reflux disease (GERD) and the development of atrial fibrillation (AF). METHODS: Using the key words “atrial fibrillation and gastroesophageal reflux”, “atrial fibrillation and esophagitis, peptic”, “atrial fibrillation and hernia, hiatal” the PubMed, EMBASE, Cochrane Library, OVIDSP, WILEY databases were screened for relevant publications on GERD and AF in adults between January 1972-December 2013. Studies written in languages other than English or French, studies not performed in humans, reviews, case reports, abstracts, conference presentations, letters to the editor, editorials, comments and opinions were not taken into consideration. Articles treating the subject of radiofrequency ablation of AF and the consecutive development of GERD were also excluded. RESULTS: Two thousand one hundred sixty-one titles were found of which 8 articles met the inclusion criteria. The presence of AF in patients with GERD was reported to be between 0.62%-14%, higher compared to those without GERD. Epidemiological data provided by these observational studies showed that patients with GERD, especially those with more severe GERD-related symptoms, had an increased risk of developing AF compared with those without GERD, but a causal relationship between GERD and AF could not be established based on these studies. The mechanisms of AF as a consequence of GERD remain largely unknown, with inflammation and vagal stimulation playing a possible role in the development of these disorders. Treatment with proton pomp inhibitors may improve symptoms related to AF and facilitate conversion to sinus rhythm. CONCLUSION: Although links between AF and GERD exist, large randomized clinical studies are required for a better understanding of the relationship between these two entities. PMID:25071357

Left atrial thrombus and dense spontaneous echocardiographic contrast in patients on continuous direct oral anticoagulant therapy undergoing catheter ablation of atrial fibrillation: Comparison of dabigatran, rivaroxaban, and apixaban.

PubMed

Wu, Michael; Gabriels, James; Khan, Mohammad; Shaban, Nada; D'Amato, Salvatore; Liu, Christopher F; Markowitz, Steven M; Ip, James E; Thomas, George; Singh, Parmanand; Lerman, Bruce; Patel, Apoor; Cheung, Jim W

2018-04-01

Left atrial thrombus (LAT) and dense spontaneous echocardiographic contrast (SEC) detected by transesophageal echocardiography (TEE) in patients on continuous direct oral anticoagulants (DOAC) therapy before catheter ablation of atrial fibrillation (AF) or atrial flutter (AFL) have been described. We sought to compare rates of TEE-detected LAT and dense SEC among patients taking different DOACs. We evaluated 609 consecutive patients from 3 tertiary hospitals (median age 65 years; interquartile range 58-71 years; 436 (72%) men) who were on ≥4 weeks of continuous DOAC therapy (dabigatran, n = 166 [27%]; rivaroxaban, n = 257 [42%]; or apixaban, n = 186 [31%]) undergoing TEE before catheter ablation of AF/AFL. Demographic, clinical, and TEE data were collected for each patient. Despite ≥4 weeks of continuous DOAC therapy, 17 patients (2.8%) had LAT and 15 patients (2.5%) had dense SEC detected by TEE. The rates of LAT were 3.0%, 3.5%, and 1.6% for patients on dabigatran, rivaroxaban, and apixaban, respectively (P = .482). The rates of dense SEC were 1.2%, 3.5%, and 2.2% for patients on dabigatran, rivaroxaban, and apixaban, respectively (P = .299). Congestive heart failure (odds ratio 4.4; 95% confidence interval 1.6-12; P = .003) and moderate/severe left atrial enlargement (odds ratio 3.1; 95% confidence interval 1.1-8.6; P = .026) were independent predictors of LAT. In this study, ∼3% of patients on continuous DOAC therapy had LAT detected before catheter ablation of AF/AFL. Specific DOAC therapy did not significantly affect the rates of LAT detection. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Atrial fibrillation and stroke: the evolving role of rhythm control.

PubMed

Patel, Taral K; Passman, Rod S

2013-06-01

Atrial fibrillation (AF) remains a major risk factor for stroke. Unfortunately, clinical trials have failed to demonstrate that a strategy of rhythm control--therapy to maintain normal sinus rhythm (NSR)--reduces stroke risk. The apparent lack of benefit of rhythm control likely reflects the difficulty in maintaining NSR using currently available therapies. However, there are signals from several trials that the presence of NSR is indeed beneficial and associated with better outcomes related to stroke and mortality. Most electrophysiologists feel that as rhythm control strategies continue to improve, the crucial link between rhythm control and stroke reduction will finally be demonstrated. Therefore, AF specialists tend to be aggressive in their attempts to maintain NSR, especially in patients who have symptomatic AF. A step-wise approach from antiarrhythmic drugs to catheter ablation to cardiac surgery is generally used. In select patients, catheter ablation or cardiac surgery may supersede antiarrhythmic drugs. The choice depends on the type of AF, concurrent heart disease, drug toxicity profiles, procedural risks, and patient preferences. Regardless of strategy, given the limited effectiveness of currently available rhythm control therapies, oral anticoagulation is still recommended for stroke prophylaxis in AF patients with other stroke risk factors. Major challenges in atrial fibrillation management include selecting patients most likely to benefit from rhythm control, choosing specific antiarrhythmic drugs or procedures to achieve rhythm control, long-term monitoring to gauge the efficacy of rhythm control, and determining which (if any) patients may safely discontinue anticoagulation if long-term NSR is achieved.

Comparison of PV signal quality using a novel circular mapping and ablation catheter versus a standard circular mapping catheter.

PubMed

von Bary, Christian; Fredersdorf-Hahn, Sabine; Heinicke, Norbert; Jungbauer, Carsten; Schmid, Peter; Riegger, Günter A; Weber, Stefan

2011-08-01

Recently, new catheter technologies have been developed for atrial fibrillation (AF) ablation. We investigate the diagnostic accuracy of a circular mapping and pulmonary vein ablation catheter (PVAC) compared with a standard circular mapping catheter (Orbiter) and the influence of filter settings on signal quality. After reconstruction of the left atrium by three-dimensional atriography, baseline PV potentials (PVP) were recorded consecutively with PVAC and Orbiter in 20 patients with paroxysmal AF. PVPs were compared and attributed to predefined anatomical PV segments. Ablation was performed in 80 PVs using the PVAC. If isolation of the PVs was assumed, signal assessment of each PV was repeated with the Orbiter. If residual PV potentials could be uncovered, different filter settings were tested to improve mapping quality of the PVAC. Ablation was continued until complete PV isolation (PVI) was confirmed with the Orbiter. Baseline mapping demonstrated a good correlation between the Orbiter and PVAC. Mapping accuracy using the PVAC for mapping and ablation was 94% (74 of 79 PVs). Additional mapping with the Orbiter improved the PV isolation rate to 99%. Adjustment of filter settings failed to improve quality of the PV signals compared with standard filter settings. Using the PVAC as a stand-alone strategy for mapping and ablation, one should be aware that in some cases, different signal morphology mimics PVI isolation. Adjustment of filter settings failed to improve signal quality. The use of an additional mapping catheter is recommended to become familiar with the particular signal morphology during the first PVAC cases or whenever there is a doubt about successful isolation of the pulmonary veins.

Outcomes of repeat catheter ablation using magnetic navigation or conventional ablation.

PubMed

Akca, Ferdi; Theuns, Dominic A M J; Abkenari, Lara Dabiri; de Groot, Natasja M S; Jordaens, Luc; Szili-Torok, Tamas

2013-10-01

After initial catheter ablation, repeat procedures could be necessary. This study evaluates the efficacy of the magnetic navigation system (MNS) in repeat catheter ablation as compared with manual conventional techniques (MANs). The results of 163 repeat ablation procedures were analysed. Ablations were performed either using MNS (n = 84) or conventional manual ablation (n = 79). Procedures were divided into four groups based on the technique used during the initial and repeat ablation procedure: MAN-MAN (n = 66), MAN-MNS (n = 31), MNS-MNS (n = 53), and MNS-MAN (n = 13). Three subgroups were analysed: supraventricular tachycardias (SVTs, n = 68), atrial fibrillation (AF, n = 67), and ventricular tachycardias (VT, n = 28). Recurrences were assessed during 19 ± 11 months follow-up. Overall, repeat procedures using MNS were successful in 89.0% as compared with 96.2% in the MAN group (P = ns). The overall recurrence rate was significantly lower using MNS (25.0 vs. 41.4%, P = 0.045). Acute success and recurrence rates for the MAN-MAN, MAN-MNS, MNS-MNS, and MNS-MAN groups were comparable. For the SVT subgroup a higher acute success rate was achieved using MAN (87.9 vs. 100.0%, P = 0.049). The use of MNS for SVT is associated with longer procedure times (205 ± 82 vs. 172 ± 69 min, P = 0.040). For AF procedure and fluoroscopy times were longer (257 ± 72 vs. 185 ± 64, P = 0.001; 59.5 ± 19.3 vs. 41.1 ± 18.3 min, P < 0.001). Less fluoroscopy was used for MNS-guided VT procedures (22.8 ± 14.7 vs. 41.2 ± 10.9, P = 0.011). Our data suggest that overall MNS is comparable with MAN in acute success after repeat catheter ablation. However, MNS is related to fewer recurrences as compared with MAN.

Difference Between Dormant Conduction Sites Revealed by Adenosine Triphosphate Provocation and Unipolar Pace-Capture Sites Along the Ablation Line After Pulmonary Vein Isolation.

PubMed

Kogawa, Rikitake; Okumura, Yasuo; Watanabe, Ichiro; Sonoda, Kazumasa; Sasaki, Naoko; Takahashi, Keiko; Iso, Kazuki; Nagashima, Koichi; Ohkubo, Kimie; Nakai, Toshiko; Kunimoto, Satoshi; Hirayama, Atsushi

2016-01-01

Dormant pulmonary vein (PV) conduction revealed by adenosine/adenosine triphosphate (ATP) provocation test and exit block to the left atrium by pacing from the PV side of the ablation line ("pace and ablate" method) are used to ensure durable pulmonary vein isolation (PVI). However, the mechanistic relation between ATP-provoked PV reconnection and the unexcitable gap along the ablation line is unclear.Forty-five patients with atrial fibrillation (AF) (paroxysmal: 31 patients, persistent: 14 patients; age: 61.1 ± 9.7 years) underwent extensive encircling PVI (EEPVI, 179 PVs). After completion of EEPVI, an ATP provocation test (30 mg, bolus injection) and unipolar pacing (output, 10 mA; pulse width, 2 ms) were performed along the previous EEPVI ablation line to identify excitable gaps. Dormant conduction was revealed in 29 (34 sites) of 179 PVs (16.2%) after EEP-VI (22/45 patients). Pace capture was revealed in 59 (89 sites) of 179 PVs (33.0%) after EEPVI (39/45 patients), and overlapping sites, ie, sites showing both dormant conduction and pace capture, were observed in 22 of 179 (12.3%) PVs (17/45 patients).Some of the ATP-provoked dormant PV reconnection sites were identical to the sites with excitable gaps revealed by pace capture, but most of the PV sites were differently distributed, suggesting that the main underling mechanism differs between these two forms of reconnection. These findings also suggest that performance of the ATP provocation test followed by the "pace and ablate" method can reduce the occurrence of chronic PV reconnections.

Impact of Body Mass Index on Plasma N-Terminal ProB-Type Natriuretic Peptides in Chinese Atrial Fibrillation Patients without Heart Failure

PubMed Central

Zheng, Li-hui; Wu, Ling-min; Yao, Yan; Chen, Wen-sheng; Bao, Jing-ru; Huang, Wen; Shi, Rui; Zhang, Kui-jun; Zhang, Shu

2014-01-01

Background An inverse relationship between body mass index (BMI) and circulating levels of N-terminal proB-type natriuretic peptide (NT-proBNP) has been demonstrated in subjects with and without heart failure. Obesity also has been linked with increased incidence of atrial fibrillation (AF), but its influence on NT-proBNP concentrations in AF patients remains unclear. This study aimed to investigate the effect of BMI on NT-proBNP levels in AF patients without heart failure. Methods A total of 239 consecutive patients with AF undergoing catheter ablation were evaluated. Levels of NT-proBNP and clinical characteristics were compared in overweight or obese (BMI≥25 kg/m2) and normal weight (BMI<25 kg/m2) patients. Results Of 239 patients, 129 (54%) were overweight or obese. Overweight or obese patients were younger, more likely to have a history of nonparoxysmal AF, hypertension, and diabetes mellitus. Levels of NT-proBNP were significantly lower in overweight or obese than in normal weight subjects (P<0.05). The relationship of obesity and decreased NT-proBNP levels persisted in subgroup of hypertension, both gender and both age levels (≥65 yrs and <65 yrs).Multivariate linear regression identified BMI as an independent negative correlate of LogNT-proBNP level. Conclusions An inverse relationship between BMI and plasma NT-proBNP concentrations have been demonstrated in AF patients without heart failure. Overweight or obese patients with AF appear to have lower NT-proBNP levels than normal weight patients. PMID:25144363

Clinical impact of an open-irrigated radiofrequency catheter with direct force measurement on atrial fibrillation ablation.

PubMed

Martinek, Martin; Lemes, Christine; Sigmund, Elisabeth; Derndorfer, Michael; Aichinger, Josef; Winter, Siegmund; Nesser, Hans-Joachim; Pürerfellner, Helmut

2012-11-01

Electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5-mm open-irrigated-tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Relationship between diastolic ventricular dysfunction and subclinical sleep-disordered breathing in atrial fibrillation ablation candidates.

PubMed

Kaitani, Kazuaki; Kondo, Hirokazu; Hanazawa, Koji; Onishi, Naoaki; Hayama, Yukiko; Tsujimura, Akira; Kuroda, Maiko; Nishimura, Shunsuke; Yoshikawa, Yusuke; Takahashi, Yusuke; Amano, Masashi; Imamura, Sari; Tamaki, Yodo; Enomoto, Soichiro; Miyake, Makoto; Tamura, Toshihiro; Motooka, Makoto; Izumi, Chisato; Nakagawa, Yoshihisa

2016-07-01

Sleep-disordered breathing (SDB) is recognized as a primary factor or mediator of atrial fibrillation (AF). We hypothesized that the severity of SDB among AF ablation candidates would be associated with left ventricular diastolic dysfunction (LVDD) even for subclinical SDB. A total of 246 patients hospitalized for initial pulmonary vein isolation (PVI) were analyzed. Known SDB cases were excluded. We measured the oxygen desaturation index (ODI) by pulse oximetry overnight as an indicator of SDB, and classified SDB severity by 3 % ODI as normal (ODI < 5 events/h), mild (ODI ≤ 5 to <15 events/h), or moderate-to-severe (ODI ≥15 events/h). The LVDD was assessed by echocardiography using combined categories with tissue Doppler imaging and left atrial (LA) volume measurement. Among the participants, 42 patients (17.1 %) had LVDD. The prevalence of LVDD increased with the SDB severity from 8.6 % (normal) to 12.7 % (mild) to 40.0 % (moderate-to-severe SDB) (p < 0.0001). In the multivariate logistic regression analysis, the odds ratio of having LVDD in the moderate-to-severe SDB group (ODI ≥ 15) vs. normal group (ODI < 5) was 5.96 (95 % CI, 2.10-19.00, P = 0.006). The presence of moderate-to-severe SDB in AF ablation candidates adversely affected LV diastolic function even during a subclinical state of SDB.

Association Between Local Bipolar Voltage and Conduction Gap Along the Left Atrial Linear Ablation Lesion in Patients With Atrial Fibrillation.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Mano, Toshiaki

2017-08-01

A bipolar voltage reflects a thick musculature where formation of a transmural lesion may be hard to achieve. The purpose of this study was to explore the association between local bipolar voltage and conduction gap in patients with persistent atrial fibrillation (AF) who underwent atrial roof or septal linear ablation. This prospective observational study included 42 and 36 consecutive patients with persistent AF who underwent roof or septal linear ablations, respectively. After pulmonary vein isolation, left atrial linear ablations were performed, and conduction gap sites were identified and ablated after first-touch radiofrequency application. Conduction gap(s) after the first-touch roof and septal linear ablation were observed in 13 (32%) and 19 patients (53%), respectively. Roof and septal area voltages were higher in patients with conduction gap(s) than in those without (roof, 1.23 ± 0.77 vs 0.73 ± 0.42 mV, p = 0.010; septal, 0.96 ± 0.43 vs 0.54 ± 0.18 mV, p = 0.001). Trisected regional analyses revealed that the voltage was higher at the region with a conduction gap than at the region without. Complete conduction block across the roof and septal lines was not achieved in 3 (7%) and 6 patients (17%), respectively. Patients in whom a linear conduction block could not be achieved demonstrated higher ablation area voltage than those with a successful conduction block (roof, 1.91 ± 0.74 vs 0.81 ± 0.51 mV, p = 0.001; septal, 1.15 ± 0.56 vs 0.69 ± 0.31 mV, p = 0.006). In conclusion, a high regional bipolar voltage predicts failure to achieve conduction block after left atrial roof or septal linear ablation. In addition, the conduction gap was located at the preserved voltage area. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of radiofrequency catheter ablation on left ventricular structure and function in patients with atrial fibrillation: a meta-analysis.

PubMed

Zhu, Pengju; Zhang, Yong; Jiang, Peiqing; Wang, Zhongsu; Wang, Jiangrong; Yin, Xiangcui; Hou, Yinglong

2014-08-01

Radiofrequency catheter ablation (RFCA) is an effective therapy for atrial fibrillation (AF). This study was designed to investigate the effects of RFCA on left ventricular (LV) structure and function in AF patients. A systematic literature search in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials was performed to identify trials involving changes of LV structure and function in AF patients undergoing RFCA. Effect size was expressed as weighted mean difference (WMD) with 95% confidence interval (CI). LV end-diastolic diameter (LVEDD), LV end-systolic diameter (LVESD), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were estimated. A total of 21 trials including 1,135 participants were qualified for this meta-analysis. Compared to the baseline values, there were significant decreases in LVEDV (WMD, -6.39 ml; 95%CI, -12.46 to -0.33) and LVESV (WMD, -6.39 ml; 95%CI, -11.35 to -1.42) and a significant improvement in LVEF (WMD, 6.23%; 95%CI, 3.70 to 8.75), but no significant changes were observed in LVEDD (WMD, -0.64 mm; 95%CI, -2.40 to 1.13) and LVESD (WMD, -0.38 mm; 95%CI, -1.32 to 0.56) after RFCA. Subgroup analysis demonstrated that patients with low LVEF (WMD, 11.90%; 95%CI, 9.16 to 14.64) gained more benefits than those with normal LVEF (WMD, 1.56%; 95%CI, 0.38 to 2.74). Besides, patients with chronic AF (WMD, 10.96%; 95%CI, 4.92 to 17.01) improved more than those with paroxysmal AF (WMD, 1.93%; 95%CI, -0.27 to 4.12). RFCA in AF patients could reverse LV structural remodeling and improve LV systolic function, especially in patients with low LVEF and chronic AF.

Polish and European management strategies in patients with atrial fibrillation. Data from the EURObservational Research Programme-Atrial Fibrillation General Registry Pilot Phase (EORP-AF Pilot).

PubMed

Lenarczyk, Radosław; Mitręga, Katarzyna; Mazurek, Michał; Janion, Marianna; Opolski, Grzegorz; Drożdż, Jarosław; Streb, Witold; Fuglewicz, Artur; Sokal, Adam; Laroche, Cécile; Lip, Gregory Y H; Kalarus, Zbigniew

2016-01-01

Despite continued efforts of the European Society of Cardiology (ESC) to unify management of patients with atrial fibrillation (AF) across Europe, interregional differences in guideline adherence are likely. The aim of the study was to compare treatment strategies depending on baseline characteristics of AF patients between Poland and other members of the European Union (EU). We analyzed the baseline data and treatment strategies in participants of the ESC registry: the EURObservational Research Programme-Atrial Fibrillation General Registry Pilot Phase. A total of 3119 consecutive patients with AF diagnosed within the last year were included in 67 centers from 9 countries, including 419 patients enrolled in 15 Polish centers. A rhythm control strategy was more frequent in Poland than in other EU countries (20.8% vs 11.9%; P <0.0001). Catheter ablation for AF was also used more frequently in Polish cardiology wards (13.9% vs 8.3%; P = 0.0017), while amiodarone at discharge was used less frequently (12.0% vs 22.7%; P <0.0001). In-hospital use of vitamin K antagonists (VKAs) and non-VKA anticoagulants was less frequent in Polish patients with a CHA2DS2-VASc score of 2 or higher than in patients from other EU countries (61.1% vs 79.0%; P <0.0001), but overall anticoagulation rates at discharge were similar to those in other countries (83.3% vs 82.6%). A rhythm control-oriented strategy in patients with AF with the use of ablation in cardiology wards is more frequent in Poland than in other EU countries. Similar to other EU countries, compliance with the ESC guidelines regarding anticoagulation in AF patients is suboptimal in Poland. Undertreatment was observed in a significant proportion of patients at high risk of stroke, while a large group of low-risk patients are overtreated. Differences between the types of recruiting centers in Poland and other EU countries might have influenced the results.

Incidences of esophageal injury during esophageal temperature monitoring: a comparative study of a multi-thermocouple temperature probe and a deflectable temperature probe in atrial fibrillation ablation.

PubMed

Kuwahara, Taishi; Takahashi, Atsushi; Takahashi, Yoshihide; Okubo, Kenji; Takagi, Katsumasa; Fujino, Tadashi; Kusa, Shigeki; Takigawa, Masateru; Watari, Yuji; Yamao, Kazuya; Nakashima, Emiko; Kawaguchi, Naohiko; Hikita, Hiroyuki; Sato, Akira; Aonuma, Kazutaka

2014-04-01

The study aim was to compare the incidence of esophageal injuries between different temperature probes in the monitoring of esophageal temperature during atrial fibrillation (AF) ablation. One hundred patients with drug-resistant AF were prospectively and randomly assigned into two groups according to the esophageal temperature probe used: the multi-thermocouple probe group (n = 50) and the deflectable temperature probe group (n = 50). Extensive pulmonary vein (PV) isolation was performed with a 3.5-mm open irrigated tip ablation catheter by using a radiofrequency (RF) power of 25-30 W. In both groups, the esophageal temperature thermocouple was placed on the area of the esophagus adjacent to the ablation site. When the esophageal temperature reached 42 °C, the RF energy delivery was stopped. Esophageal endoscopy was performed 1 day after the catheter ablation. No differences existed between the two groups in terms of clinical background and various parameters related to the catheter ablation, including RF delivery time and number of RF deliveries at an esophageal temperature of >42 °C. Esophageal lesions, such as esophagitis and esophageal ulcers, occurred in 10/50 (20 %) and 15/50 (30 %) patients in the multi-thermocouple and deflectable temperature probe groups, respectively (P = 0.25). Most lesions were mild to moderate injuries, and all were cured using conservative treatment. The incidence of esophageal injury was almost equal between the multi-thermocouple temperature probe and the deflectable temperature probe during esophageal temperature monitoring. Most of the esophageal lesions that developed during esophageal temperature monitoring were mild to moderate and reversible.

Remote magnetic versus manual catheter navigation for circumferential pulmonary vein ablation in patients with atrial fibrillation.

PubMed

Lüthje, Lars; Vollmann, Dirk; Seegers, Joachim; Dorenkamp, Marc; Sohns, Christian; Hasenfuss, Gerd; Zabel, Markus

2011-11-01

Only limited data exist on the clinical utility of remote magnetic navigation (RMN) for pulmonary vein (PV) ablation. Aim of this prospective study was to evaluate the safety and efficacy of RMN for PV isolation as compared to the manual (CON) approach. A total of 161 consecutive patients undergoing circumferential PV isolation were included. Open-irrigated 3.5 mm ablation catheters under the guidance of a mapping system were used. The catheter was navigated with the Stereotaxis Niobe II system in the RMN group (n = 107) and guided manually in the CON group (n = 54). Electrical isolation of all PVs was achieved in 90% of the patients in the RMN group and in 87% in the CON group (p = 0.6). All subjects were followed every 3 months by 7d Holter-ECG. At 12 months of follow-up, 53.5% (RMN) and 55.5% (CON) of the patients were free of any left atrial tachycardia/atrial fibrillation (AF) episode (p = 0.57). Free of symptomatic AF recurrence were 66.3% (RMN) and 62.1% (CON) of the subjects (p = 0.80). Use of RMN was associated with longer procedure duration (p < 0.0001), ablation times (p < 0.0001), and RF current application duration (p < 0.05). In contrast, fluoroscopy time was lower in the RMN group (p < 0.0001). Major complications occurred in 6 of 161 procedures (3.7%), with no significant difference between groups (p = 0.75). RMN-guided PV ablation provides comparable acute and long-term success rates as compared to manual navigation. Procedural complication rates are similar. The use of RMN is associated with markedly reduced fluoroscopy time, but prolonged ablation and procedure duration.

Single-ring ablation compared with standard circumferential pulmonary vein isolation using remote magnetic catheter navigation.

PubMed

Sohns, Christian; Bergau, Leonard; Seegers, Joachim; Lüthje, Lars; Vollmann, Dirk; Zabel, Markus

2014-10-01

In ablation of atrial fibrillation, the single-ring method aims for isolation of the posterior wall of the left atrium (LA) including the pulmonary veins (PVs) but avoiding posterior LA lesions. The aim of this randomized prospective study was to evaluate safety and efficacy of remote magnetic navigation (RMN)-guided single-ring ablation strategy as compared to standard RMN-guided circumferential PV ablation (PVA). Eighty consecutive patients undergoing PVA were enrolled prospectively and randomized equally into two study groups. RMN using the Stereotaxis system and open-irrigated 3.5-mm ablation catheters were used with a 3D mapping system in all procedures. Forty patients underwent RMN-guided single-ring ablation, and 40 patients received RMN-guided circumferential PVA. In the circumferential group, 3.3 ± 1.1 PVs were successfully isolated at the end of the procedure as compared to 3.1 ± 1.3 in the single-ring (box) group (p=0.38). All patients in the box group required additional posterior lesions in order to achieve electrical isolation of the PVs. Single-ring ablation was associated with longer procedure duration (p=0.01) and ablation time (p=0.001). After a single procedure, the proportion of patients free of any atrial tachycardia (AT)/atrial fibrillation (AF) episode at 12-month follow-up was 57 % in the box group and 58 % in the circ group. Using RMN, only minor complications have been observed. RMN-guided single-ring PVA provides comparable acute and long-term success rates as compared to RMN-guided circumferential PVA but requires additional posterior lesions to achieve PV isolation and increased procedure and ablation time. Procedural complication rates are low when using RMN.

Estimating Effective Dose from Phantom Dose Measurements in Atrial Fibrillation Ablation Procedures and Comparison of MOSFET and TLD Detectors in a Small Animal Dosimetry Setting

NASA Astrophysics Data System (ADS)

Anderson-Evans, Colin David

Two different studies will be presented in this work. The first involves the calculation of effective dose from a phantom study which simulates an atrial fibrillation (AF) ablation procedure. The second involves the validation of metal-oxide semiconducting field effect transistors (MOSFET) for small animal dosimetry applications as well as improved characterization of the animal irradiators on Duke University's campus. Atrial Fibrillation is an ever increasing health risk in the United States. The most common type of cardiac arrhythmia, AF is associated with increased mortality and ischemic cerebrovascular events. Managing AF can include, among other treatments, an interventional procedure called catheter ablation. The procedure involves the use of biplane fluoroscopy during which a patient can be exposed to radiation for as much as two hours or more. The deleterious effects of radiation become a concern when dealing with long fluoroscopy times, and because the AF ablation procedure is elective, it makes relating the risks of radiation ever more essential. This study hopes to quantify the risk through the derivation of dose conversion coefficients (DCCs) from the dose-area product (DAP) with the intent that DCCs can be used to provide estimates of effective dose (ED) for typical AF ablation procedures. A bi-plane fluoroscopic and angiographic system was used for the simulated AF ablation procedures. For acquisition of organ dose measurements, 20 diagnostic MOSFET detectors were placed at selected organs in a male anthropomorphic phantom, and these detectors were attached to 4 bias supplies to obtain organ dose readings. The DAP was recorded from the system console and independently validated with an ionization chamber and radiochromic film. Bi-plane fluoroscopy was performed on the phantom for 10 minutes to acquire the dose rate for each organ, and the average clinical procedure time was multiplied by each organ dose rate to obtain individual organ doses. The effective dose was computed by summing the product of each organ dose and the corresponding tissue weighting factor from the ICRP publication 103. Further risk calculations were done according to the BEIR VII Phase 2 report to obtain relative and lifetime attributable risks of cancer for an average AF ablation procedure. The ED was computed separately for the biplane fluoroscopic and angiographic system's 'low' and 'normal fluoro' automated settings, yielding 27.9 mSv and 45.6 mSv respectively for an average procedure time of 88.2 minutes. The corresponding DAP was 48.7 Gy cm2 and 79.1 Gy cm2 for low and normal settings respectively. The independently measured DAP was found to be within 0.1 % of that measured by the fluoroscopy system's onboard flat panel detectors. DCCs were calculated to be 0.573 and 0.577 for the respective low and normal settings. The results proved to be very closely matched, which was to be expected. The calculated cancer risks were fairly low due to the age of most patients (less than 5 incidences of solid tumor per 100,000 exposed for liver colon and stomach; 100-300 incidences per 100,000 exposed for lungs), but concern remains that longer procedures could increase the risk of erythema or other serious skin injuries. The second section of this thesis study involves the quantification and distribution of radiation dose in small animals undergoing irradiation in an orthovoltage x-ray unit. Extensive research is being done with small animals, particularly mice and rats, in fields such as cancer therapy, radiation biology and radiological countermeasures. Results and conclusion are often drawn from research based solely on manufacturer's specifications of the delivered dose rate without independent verification or adequate understanding of the machines' capabilities. Accurate radiation dose information is paramount when conducting research in this arena. Traditional methods of dosimetry, namely thermoluminescence dosimeters (TLDs) are challenging and often time consuming. This section hopes to show that in place of TLDs, MOSFETs can provide accurate, precise dose information comparable with TLDs and ionization chambers. Measurements of all three dosimeters are compared in a small animal irradiator in phantoms and in vivo. Measurements done with MOSFETs are shown to deviate by 2.5% from that of the ADCL calibrated ionization chamber while TLDs showed a 7% deviation. Dose distributions within a phantom is also measured using radiochromic film to estimate the attenuation and show that dose is not uniform throughout the mouse. A dose decrease of approximately 30% is observed in a water phantom, which was only slightly mitigated by a hardening the beam with additional filtration. A Bland-Altman plot was created to show that the MOSFETs and TLDs used to make the dose measurements are statistically equivalent. The results show that all measurements made over a range of doses fall within 1.96 standard deviations of the mean.

Novel pharmacological targets for the rhythm control management of atrial fibrillation.

PubMed

Burashnikov, Alexander; Antzelevitch, Charles

2011-12-01

Atrial fibrillation (AF) is a growing clinical problem associated with increased morbidity and mortality. Development of safe and effective pharmacological treatments for AF is one of the greatest unmet medical needs facing our society. In spite of significant progress in non-pharmacological AF treatments (largely due to the use of catheter ablation techniques), anti-arrhythmic agents (AADs) remain first line therapy for rhythm control management of AF for most AF patients. When considering efficacy, safety and tolerability, currently available AADs for rhythm control of AF are less than optimal. Ion channel inhibition remains the principal strategy for termination of AF and prevention of its recurrence. Practical clinical experience indicates that multi-ion channel blockers are generally more optimal for rhythm control of AF compared to ion channel-selective blockers. Recent studies suggest that atrial-selective sodium channel block can lead to safe and effective suppression of AF and that concurrent inhibition of potassium ion channels may potentiate this effect. An important limitation of the ion channel block approach for AF treatment is that non-electrical factors (largely structural remodeling) may importantly determine the generation of AF, so that "upstream therapy", aimed at preventing or reversing structural remodeling, may be required for effective rhythm control management. This review focuses on novel pharmacological targets for the rhythm control management of AF. Copyright © 2011 Elsevier Inc. All rights reserved.

Contemporary Atrial Fibrillation Management: A Comparison of the Current AHA/ACC/HRS, CCS, and ESC Guidelines.

PubMed

Andrade, Jason G; Macle, Laurent; Nattel, Stanley; Verma, Atul; Cairns, John

2017-08-01

In this article we compare and contrast the current recommendations, and highlight the important differences, in the American College of Cardiology/American Heart Association/Heart Rhythm Society, European Society of Cardiology, and Canadian Cardiovascular Society atrial fibrillation (AF) guidelines. Although many of the recommendations of the various societies are similar, there are important differences in the methodologies underlying their development and the specific content. Specifically, key differences can be observed in: (1) the definition of nonvalvular AF, which subsequently affects anticoagulation choices and candidacy for non-vitamin K antagonist oral anticoagulants; (2) the symptom score used to guide management decisions and longitudinal patient profiling; (3) the stroke risk stratification algorithm used to determine indications for oral anticoagulant therapy; (4) the role of acetylsalicylic acid in stroke prevention in AF; (5) the antithrombotic regimens used in the context of coronary artery disease, acute coronary syndromes, and percutaneous coronary intervention; (6) the rate control target and medications recommended to achieve the target; and (7) the role of "first-line" catheter ablation, open surgical ablation, and left atrial appendage exclusion. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Contemporary Management of Atrial Fibrillation: Update on Anticoagulation and Invasive Management Strategies

PubMed Central

Crandall, Mark A.; Bradley, David J.; Packer, Douglas L.; Asirvatham, Samuel J.

2009-01-01

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Its increasing prevalence, particularly among the elderly, renders it one of the most serious current medical epidemics. Several management questions confront the clinician treating a patient with AF: Should the condition be treated? Is the patient at risk of death or serious morbidity as a result of this diagnosis? If treatment is necessary, is rate control or rhythm control superior? Which patients need anticoagulation therapy, and for how long? This review of articles obtained by a search of the PubMed and MEDLINE databases presents the available evidence that can guide the clinician in answering these questions. After discussing the merits of available therapy, including medications aimed at controlling rate, rhythm, or both, we focus on the present status of ablative therapy for AF. Catheter ablation, particularly targeting the pulmonary veins, is being increasingly performed, although the precise indications for this approach and its effectiveness and safety are being actively investigated. We briefly discuss other invasive options that are less frequently used, such as pacemakers, defibrillators, left atrial appendage closure devices, and the surgical maze procedure. PMID:19567719

Atrial fibrillation and gastroesophageal reflux disease: the cardiogastric interaction.

PubMed

Linz, Dominik; Hohl, Mathias; Vollmar, Johanna; Ukena, Christian; Mahfoud, Felix; Böhm, Michael

2017-01-01

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and mortality. Multiple conditions like hypertension, heart failure, diabetes, sleep apnoea, and obesity play a role for the initiation and perpetuation of AF. Recently, a potential association between gastroesophageal reflux disease (GERD) and AF development has been proposed due to the close anatomic vicinity of the oesophagus and the left atrium. As an understanding of the association between acid reflux disease and AF may be important in the global multimodal treatment strategy to further improve outcomes in a subset of patients with AF, we discuss potential atrial arrhythmogenic mechanisms in patients with GERD, such as gastric and subsequent systemic inflammation, impaired autonomic stimulation, mechanical irritation due to anatomical proximity of the left atrium and the oesophagus, as well as common comorbidities like obesity and sleep-disordered breathing. Data on GERD and oesophageal lesions after AF-ablation procedures will be reviewed. Treatment of GERD to avoid AF or to reduce AF burden might represent a future treatment perspective but needs to be scrutinized in prospective trials. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Association of Left Atrial Function and Left Atrial Enhancement in Patients with Atrial Fibrillation: A Cardiac Magnetic Resonance Study

PubMed Central

Habibi, Mohammadali; Lima, Joao A.C.; Khurram, Irfan M.; Zimmerman, Stefan L.; Zipunnikov, Vadim; Fukumoto, Kotaro; Spragg, David; Ashikaga, Hiroshi; Rickard, John; Marine, Joseph E.; Calkins, Hugh; Nazarian, Saman

2015-01-01

Background Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. Methods and Results LA structure and function was measured in 90 AF patients (age 61 ± 10 years, 76% male) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain (PLAS), LA systolic strain rate (SR-s), and early (SR-ed) and late diastolic (SR-ld) strain rates were measured using cine-CMR images acquired during sinus rhythm. The degree of LGE was quantified. Compared to patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (LAVImax, 56 ± 17ml/m2 versus 49 ± 13ml/m2 p=0.036), and increased LGE (27.1± 11.7% versus 36.8 ± 14.8% p<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, PLAS, SR-s, SR-ed and SR-ld) were lower in patients with persistent AF (p< 0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared to AF patients (p<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, PLAS, SR-s, SR-ed, and SR-ld (p<0.05 for all). Conclusions Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking CMR may add important information regarding the physiological importance of LA fibrosis. PMID:25652181

Remote magnetic navigation for circumferential pulmonary vein ablation: single-catheter technique or additional use of a circular mapping catheter?

PubMed

Vollmann, Dirk; Lüthje, Lars; Seegers, Joachim; Sohns, Christian; Sossalla, Samuel; Sohns, Jan; Röver, Christian; Hasenfuß, Gerd; Zabel, Markus

2014-10-01

Remote magnetic navigation (RMN) is utilized for catheter guidance during pulmonary vein ablation (PVA). We aimed to determine whether the additional use of a circular mapping catheter (CMC) influences efficacy and outcome of RMN-guided PVA. A total of 80 consecutive subjects (65 % male, age 62 ± 9 years) underwent circumferential PVA with a 3D mapping system and an RMN-guided irrigated catheter. Procedural endpoint was complete PV isolation (PVI), total radiofrequency (RF) time >60 min, or procedure duration >5 h. PVI was defined as an entrance and/or exit block, diagnosed with a CMC within the PV ostium or by pacing via the roving RMN-guided catheter (single-catheter technique). Prolonged Holter monitoring after 3 and 6 months was used to detect atrial tachyarrhythmia (AT/AF) recurrences. Complete PVI was achieved in 56 % (45/80) of all subjects (isolated PVs per patient, 3.1 ± 1.2; RF time, 56.3 ± 17.2 min; procedure duration, 3.8 ± 0.8 h). Prospective validation of the single-catheter technique for diagnosing PVI demonstrated high concordance (94 %) with blinded CMC results. CMC use in first-time PVA was associated with similar total RF and procedure times but higher PV isolation rate. Upon multivariate analysis, CMC use, female gender, left PV, smaller PV ostium and repeat PVA predicted PVI during RMN-guided ablation. Persistent AF and mitral regurgitation at baseline and the number of non-isolated PVs predicted AT/AF recurrence during follow-up. Concomitant CMC use for first-time, RMN-guided PVA is associated with similar procedure duration but higher PV isolation rates as compared to a single-catheter approach. Since the number of isolated PVs predicts freedom from AT/AF, CMC utilization appears advisable for first-time, RMN-guided PVA.

Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy.

PubMed

Kim, Ki-Hun; Mohanty, Sanghamitra; Mohanty, Prasant; Trivedi, Chintan; Morris, Eli Hamilton; Santangeli, Pasquale; Bai, Rong; Al-Ahmad, Amin; Burkhardt, John David; Gallinghouse, Joseph G; Horton, Rodney; Sanchez, Javier E; Bailey, Shane; Hranitzky, Patrick M; Zagrodzky, Jason; Kim, Soo G; Di Biase, Luigi; Natale, Andrea

2017-08-01

Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known. This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30 μg/min) after PV isolation. Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P < 0.001], and most frequently originated from the right atrium (95 vs. 56%, P < 0.001). Other sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2 months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04]. Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.

Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation: The Randomized Alster-Lost-AF Trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation).

PubMed

Fink, Thomas; Schlüter, Michael; Heeger, Christian-Hendrik; Lemes, Christine; Maurer, Tilman; Reissmann, Bruno; Riedl, Johannes; Rottner, Laura; Santoro, Francesco; Schmidt, Boris; Wohlmuth, Peter; Mathew, Shibu; Sohns, Christian; Ouyang, Feifan; Metzner, Andreas; Kuck, Karl-Heinz

2017-07-01

Pulmonary vein isolation (PVI) for persistent atrial fibrillation is associated with limited success rates and often requires multiple procedures to maintain stable sinus rhythm. In the prospective and randomized Alster-Lost-AF trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation), we sought to assess, in patients with symptomatic persistent or long-standing persistent atrial fibrillation, the outcomes of initial ablative strategies comprising either stand-alone PVI (PVI-only approach) or a stepwise approach of PVI followed by complex fractionated atrial electrogram ablation and linear ablation (Substrate-modification approach). Patients were randomized 1:1 to stand-alone PVI or PVI plus substrate modification. The primary study end point was freedom from recurrence of any atrial tachyarrhythmia, outside a 90-day blanking period, at 12 months. A total of 124 patients were enrolled, with 118 patients included in the analysis (61 in the PVI-only group, 57 in the Substrate-modification group). Atrial tachyarrhythmias recurred in 28 PVI-only group patients and 24 Substrate-modification group patients, for 1-year freedom from tachyarrhythmia recurrence after a single ablation procedure of 54% (95% confidence interval, 43%-68%) in the PVI-only and 57% (95% confidence interval, 46%-72%) in the Substrate-modification group ( P =0.86). Twenty-four patients in the PVI-only group (39%) and 18 in the Substrate-modification group (32%) were without arrhythmia recurrence and off antiarrhythmic drug therapy at the end of the 12-month follow-up. In patients with persistent and long-standing persistent atrial fibrillation, no significant difference was observed in 12-month freedom from atrial tachyarrhythmias between an index ablative approach of stand-alone PVI and a stepwise approach of PVI plus complex fractionated atrial electrogram and linear ablation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00820625. © 2017 American Heart Association, Inc.

Novel robotic catheter manipulation system integrated with remote magnetic navigation for fully remote ablation of atrial tachyarrhythmias: a two-centre evaluation.

PubMed

Nölker, Georg; Gutleben, Klaus-Jürgen; Muntean, Bogdan; Vogt, Jürgen; Horstkotte, Dieter; Dabiri Abkenari, Lara; Akca, Ferdi; Szili-Torok, Tamas

2012-12-01

Studies have shown that remote magnetic navigation is safe and effective for ablation of atrial arrhythmias, although optimal outcomes often require frequent manual manipulation of a circular mapping catheter. The Vdrive robotic system ('Vdrive') was designed for remote navigation of circular mapping catheters to enable a fully remote procedure. This study details the first human clinical experience with remote circular catheter manipulation in the left atrium. This was a prospective, multi-centre, non-randomized consecutive case series that included patients presenting for catheter ablation of left atrial arrhythmias. Remote systems were used exclusively to manipulate both the circular mapping catheter and the ablation catheter. Patients were followed through hospital discharge. Ninety-four patients were included in the study, including 23 with paroxysmal atrial fibrillation (AF), 48 with persistent AF, and 15 suffering from atrial tachycardias. The population was predominately male (77%) with a mean age of 60.5 ± 11.7 years. The Vdrive was used for remote navigation between veins, creation of chamber maps, and gap identification with segmental isolation. The intended acute clinical endpoints were achieved in 100% of patients. Mean case time was 225.9 ± 70.5 min. Three patients (3.2%) crossed over to manual circular mapping catheter navigation. There were no adverse events related to the use of the remote manipulation system. The results of this study demonstrate that remote manipulation of a circular mapping catheter in the ablation of atrial arrhythmias is feasible and safe. Prospective randomized studies are needed to prove efficiency improvements over manual techniques.

Magnetic navigation in adults with atrial isomerism (heterotaxy syndrome) and supraventricular arrhythmias.

PubMed

Suman-Horduna, Irina; Babu-Narayan, Sonya V; Ueda, Akiko; Mantziari, Lilian; Gujic, Marko; Marchese, Procolo; Dimopoulos, Konstantinos; Gatzoulis, Michael A; Rigby, Michael L; Ho, Siew Yen; Ernst, Sabine

2013-06-01

We analysed the type and mechanism of supraventricular arrhythmias encountered in a series of symptomatic adults with atrial isomerism undergoing catheter ablation procedures. The study population included consecutive adults with atrial isomerism who had previously undergone surgical repair or palliation of the associated anomalies. Patients underwent electrophysiological study for symptomatic arrhythmia in our institution between 2010 and 2012 using magnetic navigation in conjunction with CARTO RMT and three-dimensional (3D) image integration. Eight patients (five females) with a median age of 33 years [interquartile range (IQR) 24-39] were studied. Access to the cardiac chambers of interest was obtained retrogradely via the aorta using remotely navigated magnetic catheters in six patients. Radiofrequency ablation successfully targeted twin atrioventricular (AV) nodal reentrant tachycardia in two patients, atrial fibrillation (AF) in three, focal atrial tachycardia (AT) mainly originating in the left-sided atrium in four patients, and macro-reentrant AT dependent on a right-sided inferior isthmus in three patients. The median fluoroscopy time was 3.0 min (IQR 2-11). After a median follow-up of 10 months (IQR 6-21), five of the ablated patients are free from arrhythmia; two patients experienced episodes of self-terminated AF and AT, respectively, within one month post-ablation; the remaining patient had only non-sustained AT during the electrophysiological study and was managed medically. Various supraventricular tachycardia mechanisms are possible in adults with heterotaxy syndrome, all potentially amenable to radiofrequency ablation. The use of remote magnetic navigation along with 3D mapping facilitated the procedures and resulted in a short radiation time.

Correlative anatomy for the electrophysiologist: ablation for atrial fibrillation. Part II: regional anatomy of the atria and relevance to damage of adjacent structures during AF ablation.

PubMed

Macedo, Paula G; Kapa, Suraj; Mears, Jennifer A; Fratianni, Amy; Asirvatham, Samuel J

2010-07-01

Ablation procedures for atrial fibrillation have become an established and increasingly used option for managing patients with symptomatic arrhythmia. The anatomic structures relevant to the pathogenesis of atrial fibrillation and ablation procedures are varied and include the pulmonary veins, other thoracic veins, the left atrial myocardium, and autonomic ganglia. Exact regional anatomic knowledge of these structures is essential to allow correlation with fluoroscopy and electrograms and, importantly, to avoid complications from damage of adjacent structures within the chest. We present this information as a series of 2 articles. In a prior issue, we have discussed the thoracic vein anatomy relevant to paroxysmal atrial fibrillation. In the present article, we focus on the atria themselves, the autonomic ganglia, and anatomic issues relevant for minimizing complications during atrial fibrillation ablation.

Primary and key secondary results from the ROCKET AF trial, and their implications on clinical practice.

PubMed

Shah, Rohan; Patel, Manesh R

2017-03-01

The safety and efficacy of the oral anticoagulant rivaroxaban were studied in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF trial). A number of subanalyses of the ROCKET AF trial have subsequently analyzed the use of rivaroxaban in special patient populations. The outcomes of the ROCKET AF trial were reviewed. The use of rivaroxaban in higher risk populations, as determined by the presence of co-morbidities included in the CHADS2 criteria, was analyzed. Requirements for dose adjustment in patients with renal impairment and in East Asian patients were described. Finally, clinical management challenges, including interruptions in therapy, drug discontinuation, management of bleeding events, drug interactions, and management of patients requiring cardioversion/ablation were reviewed. Rivaroxaban is efficacious in high-risk populations, including elderly patients, patients with diabetes, heart failure, history of stroke, prior myocardial infarction, or peripheral arterial disease (PAD). Patients with PAD have a higher risk of bleeding with rivaroxaban compared with warfarin. East Asian populations do not require a dose adjustment for rivaroxaban, while a reduced dose of 15 mg daily is required for patients with moderate renal impairment. Rivaroxaban remains effective with temporary interruptions in therapy and in patients requiring cardioversion/ablation. Rates of major bleeding and subsequent outcomes were similar in patients on warfarin and rivaroxaban, although rates of gastrointestinal bleeding were higher with rivaroxaban. Concurrent use of antiarrhythmic therapy was not associated with adverse outcomes. Rivaroxaban represents an efficacious alternative to warfarin in high-risk patients with AF. Dose adjustment is required for patients with moderate renal impairment. Rivaroxaban can be used safely in a number of challenging clinical management scenarios although the concurrent use of amiodarone requires more study.

Laser applications in surgery

PubMed Central

Azadgoli, Beina

2016-01-01

In modern medicine, lasers are increasingly utilized for treatment of a variety of pathologies as interest in less invasive treatment modalities intensifies. The physics behind lasers allows the same basic principles to be applied to a multitude of tissue types using slight modifications of the system. Multiple laser systems have been studied within each field of medicine. The term “laser” was combined with “surgery,” “ablation,” “lithotripsy,” “cancer treatment,” “tumor ablation,” “dermatology,” “skin rejuvenation,” “lipolysis,” “cardiology,” “atrial fibrillation (AF),” and “epilepsy” during separate searches in the PubMed database. Original articles that studied the application of laser energy for these conditions were reviewed and included. A review of laser therapy is presented. Laser energy can be safely and effectively used for lithotripsy, for the treatment of various types of cancer, for a multitude of cosmetic and reconstructive procedures, and for the ablation of abnormal conductive pathways. For each of these conditions, management with lasers is comparable to, and potentially superior to, management with more traditional methods. PMID:28090508

Atrial Fibrillation in Athletes: A Lesson in the Virtue of Moderation.

PubMed

Estes, N A Mark; Madias, Christopher

2017-09-01

Although the cardiovascular benefits of moderate exercise are well established, there is growing epidemiological support for the notion that high-intensity endurance athletics increases the risk of atrial fibrillation (AF). There are many gaps in evidence related to epidemiology and mechanisms of AF in endurance athletes. The proposed pathophysiological mechanisms include alterations of autonomic tone, electrical remodeling, anatomical remodeling, fibrosis, and inflammation. Clinical management of the athlete with AF often includes a period of decreased frequency, intensity, and duration of exercise with assessment for improvement in AF recurrence. Based on symptoms, a strategy of rate or rhythm control should be selected; however, due to side effects and intolerance of medications, ablation may be a preferred approach. The risks and benefits of anticoagulation for stroke prevention must be carefully assessed in the athlete with AF. All patients should be encouraged to be physically active with moderation; however, men should be advised of the higher risk of AF with long-term, high-intensity endurance training. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Catheter ablation versus medical therapy for patients with persistent atrial fibrillation: a systematic review and meta-analysis of evidence from randomized controlled trials.

PubMed

Chen, Chen; Zhou, Xinbin; Zhu, Min; Chen, Shenjie; Chen, Jie; Cai, Hongwen; Dai, Jin; Xu, Xiaoming; Mao, Wei

2018-06-01

The superiority of catheter ablation (CA) for persistent (and long-standing persistent) atrial fibrillation (AF) is currently not well defined. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the clinical outcomes of CA compared with medical therapy in persistent AF patients. We systematically searched PubMed, EMBASE, the Cochrane Library, and clinicaltrials.gov for RCTs comparing CA with medical therapy in patients with persistent AF. For CA vs medical rhythm control, the primary outcome was freedom from atrial arrhythmia. For CA vs medical rate control, the primary outcome was the change in the left ventricular ejection fraction (LVEF). Eight studies with a total of 809 patients were included in the final analysis. Compared with medical rhythm control, CA was superior in achieving freedom from atrial arrhythmia (RR 2.08, 95% CI [1.67, 2.58]; P < 0.00001). Similar result was found in CA arm without antiarrhythmic drug use after operation (RR 1.82, 95%CI [1.33, 2.49]; P = 0.0002). CA was also superior in reducing the probability of cardioversion (RR 0.59, 95%CI [0.46, 0.76]; P < 0.0001) and hospitalization (RR 0.54, 95%CI [0.39, 0.74]; P = 0.0002). Compared with the medical rate control in persistent AF patients with heart failure (HF), CA significantly improved the LVEF (MD 7.72, 95%CI [4.78, 10.67]; P < 0.00001) and reduced Minnesota Living with Heart Failure Questionnaire scores (MD 11.1395% CI [2.52-19.75]; P = 0.01). CA appeared to be superior to medical therapy in persistent AF patients and might be considered as a first-line therapy for some persistent AF patients especially for those with HF.

Predictors of chronic pulmonary vein reconnections after contact force-guided ablation: importance of completing electrical isolation with circumferential lines and creating sufficient ablation lesion densities.

PubMed

Nakamura, Kohki; Naito, Shigeto; Sasaki, Takehito; Minami, Kentaro; Take, Yutaka; Shimizu, Satoru; Yamaguchi, Yoshiaki; Yano, Toshiaki; Senga, Michiharu; Yamashita, Eiji; Sugai, Yoshinao; Kumagai, Koji; Funabashi, Nobusada; Oshima, Shigeru

2016-12-01

We aimed to identify the predictors of chronic pulmonary vein reconnections (CPVRs) after contact force (CF)-guided circumferential PV isolation (CPVI) of atrial fibrillation (AF). Forty-nine consecutive patients undergoing second ablation procedures for recurrent AF after CF-guided ablation were retrospectively studied. The CPVI was performed by point-by-point ablation with a target CF of 15-20 g. The incidence of CPVRs was evaluated along the right- and left-sided anterior and posterior CPVI regions (Ant-RPVs, Post-RPVs, Ant-LPVs, and Post-LPVs). CPVRs were observed in 30.6, 22.4, 20.4, and 32.7 % of patients along the Ant-RPVs, Post-RPVs, Ant-LPVs, and Post-LPVs, respectively (P = 0.436). In the multivariate logistic analyses, completing a left atrium-PV conduction block with touch-up ablation inside the initially estimated CPVI lines (Ant-RPVs, Post-RPVs, Ant-LPVs, Post-LPVs; odds ratio [OR] 5.747, 15.000, 207.619, 7.940; P = 0.032, 0.004, 0.034, 0.021) and region length (Post-LPVs; OR 3.183, P = 0.027) were positive predictors of CPVRs, while the mean CF (Ant-RPVs; OR 0.861, P = 0.045) and number of radiofrequency applications per unit length (Ant-LPVs, Post-LPVs; OR 0.038, 0.122; P = 0.034, 0.029) were negative predictors. At optimal cutoffs of 5.8 cm for the region length, 14.2 g for the mean CF, and 1.97/cm (Ant-LPVs) and 2.01/cm (Post-LPVs) for the radiofrequency application density, the sensitivity and specificity were 93.8 and 63.6 %, 60.0 and 76.5 %, 90.0 and 64.1 %, and 75.0 and 63.6 %, respectively. Completing PVI with circumferential lines without touch-up ablation and creating a sufficient density of radiofrequency ablation lesions on the lines with a sufficient CF may be necessary to prevent CPVRs after a CF-guided CPVI.

Atrial fibrillation and silent stroke: links, risks, and challenges.

PubMed

Hahne, Kathrin; Mönnig, Gerold; Samol, Alexander

2016-01-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia, with a projected number of 1 million affected subjects in Germany. Changes in age structure of the Western population allow for the assumption that the number of concerned people is going to be doubled, maybe tripled, by the year 2050. Large epidemiological investigations showed that AF leads to a significant increase in mortality and morbidity. Approximately one-third of all strokes are caused by AF and, due to thromboembolic cause, these strokes are often more severe than those caused by other etiologies. Silent brain infarction is defined as the presence of cerebral infarction in the absence of corresponding clinical symptomatology. Progress in imaging technology simplifies diagnostic procedures of these lesions and leads to a large amount of diagnosed lesions, but there is still no final conclusion about frequency, risk factors, and clinical relevance of these infarctions. The prevalence of silent strokes in patients with AF is higher compared to patients without AF, and several studies reported high incidence rates of silent strokes after AF ablation procedures. While treatment strategies to prevent clinically apparent strokes in patients with AF are well investigated, the role of anticoagulatory treatment for prevention of silent infarctions is unclear. This paper summarizes developments in diagnosis of silent brain infarction and its context to AF.

Increased atrial arrhythmia susceptibility induced by intense endurance exercise in mice requires TNFα

PubMed Central

Aschar-Sobbi, Roozbeh; Izaddoustdar, Farzad; Korogyi, Adam S.; Wang, Qiongling; Farman, Gerrie P.; Yang, FengHua; Yang, Wallace; Dorian, David; Simpson, Jeremy A.; Tuomi, Jari M.; Jones, Douglas L.; Nanthakumar, Kumaraswamy; Cox, Brian; Wehrens, Xander H.T.; Dorian, Paul; Backx, Peter H.

2015-01-01

Atrial fibrillation (AF) is the most common supraventricular arrhythmia that, for unknown reasons, is linked to intense endurance exercise. Our studies reveal that 6 weeks of swimming or treadmill exercise improves heart pump function and reduces heart-rates. Exercise also increases vulnerability to AF in association with inflammation, fibrosis, increased vagal tone, slowed conduction velocity, prolonged cardiomyocyte action potentials and RyR2 phosphorylation (CamKII-dependent S2814) in the atria, without corresponding alterations in the ventricles. Microarray results suggest the involvement of the inflammatory cytokine, TNFα, in exercised-induced atrial remodelling. Accordingly, exercise induces TNFα-dependent activation of both NFκB and p38MAPK, while TNFα inhibition (with etanercept), TNFα gene ablation, or p38 inhibition, prevents atrial structural remodelling and AF vulnerability in response to exercise, without affecting the beneficial physiological changes. Our results identify TNFα as a key factor in the pathology of intense exercise-induced AF. PMID:25598495

Dynamics of Endo- and Epicardial Focal Fibrillation Waves at the Right Atrium in a Patient With Advanced Atrial Remodelling.

PubMed

van der Does, Lisette J M E; Kik, Charles; Bogers, Ad J J C; Allessie, Maurits A; de Groot, Natasja M S

2016-10-01

Focal waves appear frequently at the epicardium during persistent atrial fibrillation (AF), however, the origin of these waves is under debate. We performed simultaneous endo-epicardial mapping of the right atrial wall during longstanding persistent AF in a patient undergoing cardiac surgery. During 10 seconds 53 and 59 focal waves appeared at random at respectively the endocardium and epicardium. Repetitive focal activity did not last longer than 3 cycles. Transmural asynchrony and conduction might be the origin of focal waves. Asynchronous propagation of fibrillation waves in 3 dimensions would stabilize the arrhythmia and could explain the limited success of persistent AF ablation. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Remote magnetic navigation with irrigated tip catheter for ablation of paroxysmal atrial fibrillation.

PubMed

Miyazaki, Shinsuke; Shah, Ashok J; Xhaët, Olivier; Derval, Nicolas; Matsuo, Seiichiro; Wright, Matthew; Nault, Isabelle; Forclaz, Andrei; Jadidi, Amir S; Knecht, Sébastien; Rivard, Lena; Liu, Xingpeng; Linton, Nick; Sacher, Frédéric; Hocini, Mélèze; Jaïs, Pierre; Haïssaguerre, Michel

2010-12-01

The remote magnetic navigation system (MNS) has been used with a nonirrigated magnetic catheter for atrial fibrillation (AF) ablation. The objective of this study was to evaluate the feasibility and efficiency of the newly available irrigated tip magnetic catheter for index pulmonary vein isolation (PVI) in patients with paroxysmal AF (PAF). Between January 2008 and June 2009, 30 consecutive patients with drug-resistant PAF underwent circular mapping catheter-guided PVI with MNS (MNS group). The outcomes were compared retrospectively with those of a conventional hand-controlled ablation technique during the same period in 44 consecutive patients (manual group). All 4 pulmonary veins were successfully isolated in both groups except in 4 patients in the MNS group. Radiofrequency and procedure duration were higher in the MNS group (60 ± 27 versus 43 ± 16 minutes; P = 0.0019) than in the manual group (246 ± 50 versus 153 ± 51 minutes; P < 0.0001). In the patients who underwent only PVI, total fluoroscopic time also was longer in the MNS group than in the manual group (58 ± 24 versus 40 ± 14 minutes; P = 0.0002). At 12-month follow-up after a single procedure, 69.0% of the patients in MNS group and 61.8% of patients in manual group were free of atrial tachyarrhythmia without antiarrhythmic drugs. There was no significant difference in the atrial tachyarrhythmia-free survival between the 2 groups (P = 0.961). Cardiac tamponade occurred in 1 patient in the manual group. In patients with PAF, MNS-guided PVI with the newly available irrigated tip magnetic catheter backed up with manual ablation whenever required is feasible. However, it requires longer ablation, fluoroscopy, and procedural times than the conventional approach in the early experience stage.

Impact of attributed audit on procedural performance in cardiac electrophysiology catheter laboratory.

PubMed

Sawhney, V; Volkova, E; Shaukat, M; Khan, F; Segal, O; Ahsan, S; Chow, A; Ezzat, V; Finlay, M; Lambiase, P; Lowe, M; Dhinoja, M; Sporton, S; Earley, M J; Hunter, R J; Schilling, R J

2018-06-01

Audit has played a key role in monitoring and improving clinical practice. However, audit often fails to drive change as summative institutional data alone may be insufficient to do so. We hypothesised that the practice of attributed audit, wherein each individual's procedural performance is presented will have a greater impact on clinical practice. This hypothesis was tested in an observational study evaluating improvement in fluoroscopy times for AF ablation. Retrospective analyses of fluoroscopy times in AF ablations at the Barts Heart Centre (BHC) from 2012-2017. Fluoroscopy times were compared pre- and post- the introduction of attributed audit in 2012 at St Bartholomew's Hospital (SBH). In order to test the hypothesis, this concept was introduced to a second group of experienced operators from the Heart Hospital (HH) as part of a merger of the two institutions in 2015 and change in fluoroscopy times recorded. A significant drop in fluoroscopy times (33.3 ± 9.14 to 8.95 ± 2.50, p < 0.0001) from 2012-2014 was noted after the introduction of attributed audit. At the time of merger, a significant difference in fluoroscopy times between operators from the two centres was seen in 2015. Each operator's procedural performance was shared openly at the audit meeting. Subsequent audits showed a steady decrease in fluoroscopy times for each operator with the fluoroscopy time (min, mean±SD) decreasing from 13.29 ± 7.3 in 2015 to 8.84 ± 4.8 (p < 0.0001) in 2017 across the entire group. Systematic improvement in fluoroscopy times for AF ablation procedures was noted byevaluating individual operators' performance. Attributing data to physicians in attributed audit can promptsignificant improvement and hence should be adopted in clinical practice.

Intracardiac echo-guided radiofrequency catheter ablation of atrial fibrillation in patients with atrial septal defect or patent foramen ovale repair: a feasibility, safety, and efficacy study.

PubMed

Lakkireddy, Dhanunjaya; Rangisetty, Umamahesh; Prasad, Subramanya; Verma, Atul; Biria, Mazda; Berenbom, Loren; Pimentel, Rhea; Emert, Martin; Rosamond, Thomas; Fahmy, Tamer; Patel, Dimpi; Di Biase, Luigi; Schweikert, Robert; Burkhardt, David; Natale, Andrea

2008-11-01

Intracardiac Echo-Guided Radiofrequency Catheter. Patients with atrial septal defect (ASD) are at higher risk for atrial fibrillation (AF) even after repair. Transseptal access in these patients is perceived to be difficult. We describe the feasibility, safety, and efficacy of pulmonary vein antral isolation (PVAI) in these patients. We prospectively compared post-ASD/patent foramen ovale (PFO) repair patients (group I, n = 45) with age-gender-AF type matched controls (group II, n = 45). All the patients underwent PVAI through a double transseptal puncture with a roving circular mapping catheter technique guided by intracardiac echocardiography (ICE). The short-term (3 months) and long-term (12 month) failure rates were assessed. In group I, 23 (51%) had percutaneous closure devices and 22 (49%) had a surgical closure. There was no significant difference between group I and II in the baseline characteristics. Intracardiac echo-guided double transseptal access was obtained in 98% of patients in group I and in 100% of patients in group II. PVAI was performed in all patients, with right atrial flutter ablation in 7 patients in group I and in 4 patients in group II. Over a mean follow-up of 15 +/- 4 months, group I had higher short-term (18% vs 13%, P = 0.77) and long-term recurrence (24% vs 18%, P = 0.6) than group II. There was no significant difference in the perioperative complications between the two groups. Echocardiography at 3 months showed interatrial communication in 2 patients in group I and 1 patient in group II, which resolved at 12 months. Percutaneous AF ablation using double transseptal access is feasible, safe, and efficacious in patients with ASD and PFO repairs.

Comparison of the origin and coupling interval between ectopy with and without atrial fibrillation initiation.

PubMed

Kanda, Takashi; Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Ohashi, Takuya; Uematsu, Masaaki

2018-01-01

Differentiation of atrial fibrillation (AF) trigger ectopy from other ectopy is often difficult. The purpose of this study was to compare the origin and coupling intervals (CI) between AF-trigger and non-AF-trigger ectopy. This study consisted of 120 patients with AF who underwent an initial ablation. Isoproterenol was infused up to 20μg/min to provoke ectopy and AF. We measured the CI of all ectopy provoked by an isoproterenol infusion. The %CI was calculated as the CI of the ectopy/P-P interval of the preceding 2 beats. A total of 117 patients had at least one ectopy, and AF was induced in 56 (47%) patients. Of the 276 ectopies observed in this study, 211 (76%) originated from pulmonary veins and 77 (28%) were AF-trigger ectopy. AF-trigger ectopy more frequently originated from pulmonary veins (PVs) (74 vs. 3, p<0.001) and had a significantly shorter CI (201±70ms vs. 365±147ms, p<0.001) and lower %CI (29±11% vs. 55±14%, p<0.001) than that of non-AF-trigger ectopy. A receiver operating characteristics analysis revealed that a %CI of 40% was the best cut-off value for differentiating whether it was an AF-trigger or not. The identified trigger group, including patients with provoked AF-trigger ectopy or ectopy with a low %CI (<40%), had a significantly better AF recurrence-free survival rate than the other group (88% vs. 65%, p=0.004). AF-trigger ectopy predominantly originated from PVs and had a short CI. These findings may be useful for estimating whether ectopies are an AF-trigger or not. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Morphologies of the atria and pulmonary veins in relation to lone atrial fibrillation progression: a dual-source computed tomography scan study.

PubMed

Liu, Xing-Peng; Xu, Xia; Tian, Ying; Tang, Ri-Bo; Yu, Rong-Hui; Long, De-Yong; Sang, Cai-Hua; Jiang, Chen-Xi; Ning, Man; Dong, Jian-Zeng; Ma, Chang-Sheng

2012-11-01

Atrial Remodeling and Lone Atrial Fibrillation. We sought to investigate the role of anatomic remodeling of the atria and pulmonary veins (PVs) in the progression of lone atrial fibrillation (AF) using dual-source computed tomography (DSCT). From 1,308 consecutive patients referred for an index ablation procedure for AF, we prospectively enrolled 29 consecutive patients with recently developed (<3 months) lone persistent AF (PsAF) and 23 consecutive patients with short-lasting (6-12 months) lone PsAF, all of whom had a history of paroxysmal AF (PAF). The control group consisted of 33 patients with lone PAF. On DSCT, the recently developed PsAF group showed more extensive atrial anatomic remodeling than the PAF group as shown by ∼40% higher spot biatrial volume, even though the mean duration of continuous AF was only 6 weeks. In contrast, the DSCT variables in the recently developed PsAF group and the short-lasting PsAF group were comparable, despite the fact that the mean duration of continuous AF in the latter group was 8 months. Series of cross-sectional areas of the ostial 1.5 cm of PV trunks were comparable in the PAF and PsAF groups in all but 3 ostial planes. A higher spot left atrial volume was the only independent factor associated with the progression of lone PAF to PsAF (OR: 1.06, 95% CI: 1.03-1.09, P<0.0001) on logistic regression. Prominent anatomic remodeling of the atria, rather than the PVs, underlies the mechanism of recent progression of lone paroxysmal AF to the persistent variety. © 2012 Wiley Periodicals, Inc.

[Predictive value of HATCH score on atrial fibrillation recurrence post radiofrequency catheter ablation].

PubMed

Miao, Dan-dan; Zang, Xiao-biao; Zhang, Shu-long; Gao, Lian-jun; Xia, Yun-long; Yin, Xiao-meng; Chang, Dong; Dong, Ying-xue; Yang, Yan-zong

2012-10-01

To determine the predictive value of HATCH score on recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). The data of 123 consecutive AF patients (74 paroxysmal and 49 persistent AF) who underwent RFCA between April 2009 and December 2010 in our department were retrospectively analyzed. Of theses patients, 65 (52.9%) patients had HATCH score = 0, 41 (33.3%) patients had HATCH score = 1, and 17 (13.8%) patients had HATCH score ≥ 2 (HATCH = 2 in 11 patients, HATCH = 3 in 5 patients, HATCH = 4 in 1 patient). The recurrence was defined as atrial tachyarrhythmia lasting more than 30 seconds after 3 months post RFCA. The patients were divided into recurrence group and no recurrence group. Relationship between HATCH score and recurrence was observed. There were 43 cases in recurrence group and 80 cases in no recurrence group. After 12 months follow-up, HATCH score was significant higher in recurrence group than in non-recurrence group [(0.91 ± 0.94) score vs. (0.53 ± 0.80) score, P < 0.05]. The ratio of patients with HATCH ≥ 2 in recurrence group was higher than in non-recurrence group [23.3% (10/43) vs. 8.8% (7/80), P < 0.01]. The sensitivity and specificity of HATCH ≥ 2 to define the risk of recurrence was 25.0%, 92.4% respectively. Cumulative non-recurrence rate of patients with HATCH score ≥ 2 was lower than patients with HATCH score = 0 and 1 (P < 0.05). Higher HATCH score is associated with increased risk of AF recurrence post RFCA.

2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation.

PubMed

Chiang, Chern-En; Wu, Tsu-Juey; Ueng, Kwo-Chang; Chao, Tze-Fan; Chang, Kuan-Cheng; Wang, Chun-Chieh; Lin, Yenn-Jiang; Yin, Wei-Hsian; Kuo, Jen-Yuan; Lin, Wei-Shiang; Tsai, Chia-Ti; Liu, Yen-Bin; Lee, Kun-Tai; Lin, Li-Jen; Lin, Lian-Yu; Wang, Kang-Ling; Chen, Yi-Jen; Chen, Mien-Cheng; Cheng, Chen-Chuan; Wen, Ming-Shien; Chen, Wen-Jone; Chen, Jyh-Hong; Lai, Wen-Ter; Chiou, Chuen-Wang; Lin, Jiunn-Lee; Yeh, San-Jou; Chen, Shih-Ann

2016-11-01

Atrial fibrillation (AF) is the most common sustained arrhythmia. Both the incidence and prevalence of AF are increasing, and the burden of AF is becoming huge. Many innovative advances have emerged in the past decade for the diagnosis and management of AF, including a new scoring system for the prediction of stroke and bleeding events, the introduction of non-vitamin K antagonist oral anticoagulants and their special benefits in Asians, new rhythm- and rate-control concepts, optimal endpoints of rate control, upstream therapy, life-style modification to prevent AF recurrence, and new ablation techniques. The Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology aimed to update the information and have appointed a jointed writing committee for new AF guidelines. The writing committee members comprehensively reviewed and summarized the literature, and completed the 2016 Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the Management of Atrial Fibrillation. This guideline presents the details of the updated recommendations, along with their background and rationale, focusing on data unique for Asians. The guidelines are not mandatory, and members of the writing committee fully realize that treatment of AF should be individualized. The physician's decision remains most important in AF management. Copyright © 2016. Published by Elsevier B.V.

Biomarkers of Inflammation, Thrombogenesis, and Collagen Turnover in Patients With Atrial Fibrillation.

PubMed

Jabati, Sallu; Fareed, Jawed; Liles, Jeffrey; Otto, Abigail; Hoppensteadt, Debra; Bontekoe, Jack; Phan, Trung; Walborn, Amanda; Syed, Mushabbar

2018-07-01

The purpose of this study was to determine whether there are any differences in the levels of inflammatory, thrombotic, and collagen turnover biomarkers between individuals with atrial fibrillation (AF) and healthy volunteers. Circulating plasma levels of plasminogen activator inhibitor 1 (PAI-1), CD40-ligand (CD40-L), nucleosomes (which are indicators of cell death), C-reactive protein (CRP), procollagen III N-terminal propeptide (PIIINP), procollagen III C-terminal propeptide (PIIICP), procollagen I N-terminal propeptide, tissue plasminogen activator, and von Willebrand factor were analyzed as potential biomarkers of AF. Baseline plasma was collected from patients with AF prior to ablation surgery at Loyola University Medical Center. Individuals with AF had statistically significantly increased levels of PAI-1, CD40-L, and nucleosomes, when compared to the normal population ( P < .0001). Additionally, there was a statistically significant increase in the CRP ( P = .01), PIIINP ( P = .04), and PIIICP ( P = .0008) when compared to normal individuals. From this study, it is concluded that the prothrombotic, inflammatory, and collagen turnover biomarkers PAI-1, CD40-L, nucleosomes, CRP, PIIICP, and PIIINP are elevated in AF.

3D patient-specific models for left atrium characterization to support ablation in atrial fibrillation patients.

PubMed

Valinoti, Maddalena; Fabbri, Claudio; Turco, Dario; Mantovan, Roberto; Pasini, Antonio; Corsi, Cristiana

2018-01-01

Radiofrequency ablation (RFA) is an important and promising therapy for atrial fibrillation (AF) patients. Optimization of patient selection and the availability of an accurate anatomical guide could improve RFA success rate. In this study we propose a unified, fully automated approach to build a 3D patient-specific left atrium (LA) model including pulmonary veins (PVs) in order to provide an accurate anatomical guide during RFA and without PVs in order to characterize LA volumetry and support patient selection for AF ablation. Magnetic resonance data from twenty-six patients referred for AF RFA were processed applying an edge-based level set approach guided by a phase-based edge detector to obtain the 3D LA model with PVs. An automated technique based on the shape diameter function was designed and applied to remove PVs and compute LA volume. 3D LA models were qualitatively compared with 3D LA surfaces acquired during the ablation procedure. An expert radiologist manually traced the LA on MR images twice. LA surfaces from the automatic approach and manual tracing were compared by mean surface-to-surface distance. In addition, LA volumes were compared with volumes from manual segmentation by linear and Bland-Altman analyses. Qualitative comparison of 3D LA models showed several inaccuracies, in particular PVs reconstruction was not accurate and left atrial appendage was missing in the model obtained during RFA procedure. LA surfaces were very similar (mean surface-to-surface distance: 2.3±0.7mm). LA volumes were in excellent agreement (y=1.03x-1.4, r=0.99, bias=-1.37ml (-1.43%) SD=2.16ml (2.3%), mean percentage difference=1.3%±2.1%). Results showed the proposed 3D patient-specific LA model with PVs is able to better describe LA anatomy compared to models derived from the navigation system, thus potentially improving electrograms and voltage information location and reducing fluoroscopic time during RFA. Quantitative assessment of LA volume derived from our 3D LA model without PVs is also accurate and may provide important information for patient selection for RFA. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel non-invasive algorithm to identify the origins of re-entry and ectopic foci in the atria from 64-lead ECGs: A computational study.

PubMed

Alday, Erick A Perez; Colman, Michael A; Langley, Philip; Zhang, Henggui

2017-03-01

Atrial tachy-arrhytmias, such as atrial fibrillation (AF), are characterised by irregular electrical activity in the atria, generally associated with erratic excitation underlain by re-entrant scroll waves, fibrillatory conduction of multiple wavelets or rapid focal activity. Epidemiological studies have shown an increase in AF prevalence in the developed world associated with an ageing society, highlighting the need for effective treatment options. Catheter ablation therapy, commonly used in the treatment of AF, requires spatial information on atrial electrical excitation. The standard 12-lead electrocardiogram (ECG) provides a method for non-invasive identification of the presence of arrhythmia, due to irregularity in the ECG signal associated with atrial activation compared to sinus rhythm, but has limitations in providing specific spatial information. There is therefore a pressing need to develop novel methods to identify and locate the origin of arrhythmic excitation. Invasive methods provide direct information on atrial activity, but may induce clinical complications. Non-invasive methods avoid such complications, but their development presents a greater challenge due to the non-direct nature of monitoring. Algorithms based on the ECG signals in multiple leads (e.g. a 64-lead vest) may provide a viable approach. In this study, we used a biophysically detailed model of the human atria and torso to investigate the correlation between the morphology of the ECG signals from a 64-lead vest and the location of the origin of rapid atrial excitation arising from rapid focal activity and/or re-entrant scroll waves. A focus-location algorithm was then constructed from this correlation. The algorithm had success rates of 93% and 76% for correctly identifying the origin of focal and re-entrant excitation with a spatial resolution of 40 mm, respectively. The general approach allows its application to any multi-lead ECG system. This represents a significant extension to our previously developed algorithms to predict the AF origins in association with focal activities.

Neurohumoral indicators of efficacy radiofrequency cardiac denervation

NASA Astrophysics Data System (ADS)

Evtushenko, A. V.; Evtushenko, V. V.; Saushkina, Yu. V.; Lishmanov, Yu. B.; Pokushalov, E. A.; Sergeevichev, D. S.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Anfinogenova, Ya. D.; Smyshlyaev, K. A.; Lotkov, A. I.; Kurlov, I. O.

2015-11-01

In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using 123I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

Feasibility, Process, and Outcomes of Cardiovascular Clinical Trial Data Sharing: A Reproduction Analysis of the SMART-AF Trial.

PubMed

Gay, Hawkins C; Baldridge, Abigail S; Huffman, Mark D

2017-12-01

Data sharing is as an expanding initiative for enhancing trust in the clinical research enterprise. To evaluate the feasibility, process, and outcomes of a reproduction analysis of the THERMOCOOL SMARTTOUCH Catheter for the Treatment of Symptomatic Paroxysmal Atrial Fibrillation (SMART-AF) trial using shared clinical trial data. A reproduction analysis of the SMART-AF trial was performed using the data sets, data dictionary, case report file, and statistical analysis plan from the original trial accessed through the Yale Open Data Access Project using the SAS Clinical Trials Data Transparency platform. SMART-AF was a multicenter, single-arm trial evaluating the effectiveness and safety of an irrigated, contact force-sensing catheter for ablation of drug refractory, symptomatic paroxysmal atrial fibrillation in 172 participants recruited from 21 sites between June 2011 and December 2011. Analysis of the data was conducted between December 2016 and April 2017. Effectiveness outcomes included freedom from atrial arrhythmias after ablation and proportion of participants without any arrhythmia recurrence over the 12 months of follow-up after a 3-month blanking period. Safety outcomes included major adverse device- or procedure-related events. The SMART AF trial participants' mean age was 58.7 (10.8) years, and 72% were men. The time from initial proposal submission to final analysis was 11 months. Freedom from atrial arrhythmias at 12 months postprocedure was similar compared with the primary study report (74.0%; 95% CI, 66.0-82.0 vs 76.4%; 95% CI, 68.7-84.1). The reproduction analysis success rate was higher than the primary study report (65.8%; 95% CI 56.5-74.2 vs 75.6%; 95% CI, 67.2-82.5). Adverse events were minimal and similar between the 2 analyses, but contact force range or regression models could not be reproduced. The feasibility of a reproduction analysis of the SMART-AF trial was demonstrated through an academic data-sharing platform. Data sharing can be facilitated through incentivizing collaboration, sharing statistical code, and creating more decentralized data sharing platforms with fewer restrictions to data access.

Robotic navigation and ablation.

PubMed

Malcolme-Lawes, L; Kanagaratnam, P

2010-12-01

Robotic technologies have been developed to allow optimal catheter stability and reproducible catheter movements with the aim of achieving contiguous and transmural lesion delivery. Two systems for remote navigation of catheters within the heart have been developed; the first is based on a magnetic navigation system (MNS) Niobe, Stereotaxis, Saint-Louis, Missouri, USA, the second is based on a steerable sheath system (Sensei, Hansen Medical, Mountain View, CA, USA). Both robotic and magnetic navigation systems have proven to be feasible for performing ablation of both simple and complex arrhythmias, particularly atrial fibrillation. Studies to date have shown similar success rates for AF ablation compared to that of manual ablation, with many groups finding a reduction in fluoroscopy times. However, the early learning curve of cases demonstrated longer procedure times, mainly due to additional setup times. With centres performing increasing numbers of robotic ablations and the introduction of a pressure monitoring system, lower power settings and instinctive driving software, complication rates are reducing, and fluoroscopy times have been lower than manual ablation in many studies. As the demand for catheter ablation for arrhythmias such as atrial fibrillation increases and the number of centres performing these ablations increases, the demand for systems which reduce the hand skill requirement and improve the comfort of the operator will also increase.

Impact of Tricuspid Regurgitation on the Success of Atrioventricular Node Ablation for Rate Control in Patients With Atrial Fibrillation: The Node Blast Study.

PubMed

Reddy, Yeruva Madhu; Gunda, Sampath; Vallakati, Ajay; Kanmanthareddy, Arun; Pillarisetti, Jayasree; Atkins, Donita; Bommana, Sudharani; Emert, Martin P; Pimentel, Rhea; Dendi, Raghuveer; Berenbom, Loren D; Lakkireddy, Dhanunjaya

2015-09-15

Atrioventricular node (AVN) ablation is an effective treatment for symptomatic patients with atrial arrhythmias who are refractory to rhythm and rate control strategies where optimal ventricular rate control is desired. There are limited data on the predictors of failure of AVN ablation. Our objective was to identify the predictors of failure of AVN ablation. This is an observational single-center study of consecutive patients who underwent AVN ablation in a large academic center. Baseline characteristics, procedural variables, and outcomes of AVN ablation were collected. AVN "ablation failure" was defined as resumption of AVN conduction resulting in recurrence of either rapid ventricular response or suboptimal biventricular pacing. A total of 247 patients drug refractory AF who underwent AVN ablation at our center with a mean age of 71 ± 12 years with 46% being males were included. Ablation failure was seen in 11 (4.5%) patients. There were no statistical differences between patients with "ablation failure" versus "ablation success" in any of the baseline clinical variables. Patients with moderate-to-severe tricuspid regurgitation (TR) were much more likely to have ablation failure than those with ablation success (8 [73%] vs 65 [27%]; p = 0.003). All 11 patients with ablation failure had a successful redo procedure, 9 with right and 2 with the left sided approach. On multivariate analysis, presence of moderate-to-severe TR was found to be the only predictor of failure of AVN ablation (odds ratio 9.1, confidence interval 1.99 to 42.22, p = 0.004). In conclusion, moderate-to-severe TR is a strong and independent predictor of failure of AVN ablation. Copyright © 2015 Elsevier Inc. All rights reserved.

Malignancy Associated Iatrogenic Iliopsoas Abscess -Venous Access Complication From Ablation Procedure.

PubMed

Iskandar, Sandia; Atoui, Moustapha; Rizwan Afzal, Muhammad; Lavu, Madhav; Reddy, Madhu; Lakkireddy, Dhanunjaya

2016-01-01

Iliopsoas abscess is a rare condition with a high rate of mortality and morbidity if left untreated. It can occur from hematogenous or lymphatic spread from distant structures or as a result of contiguous spread from adjacent structures. The disease typically occurs in patients with immunocompromised status and the symptoms can be non-specific.1,2 Generally, infectious complications from venous access during atrial fibrillation (AF) procedure are uncommon, and an iatrogenic iliopsoas abscess from percutaneous cardiac procedures has never been reported. We present the first case of iliopsoas abscess from an ablation procedure.

Modified radial v/s biatrial maze for atrial fibrillation in rheumatic valvular heart surgery.

PubMed

Sayed, Sajid A; Katewa, Ashish; Srivastava, Vivek; Jana, Sujit; Patwardhan, Anil M

2014-01-01

Atrial fibrillation (AF) is commonest sustained atrial arrhythmia producing high morbidity. Although Cox's Maze III procedure cures AF in majority, reduced atrial transport function (ATF) is a concern. Radial approach with ablation lines radial from sinus node towards atrioventricular annulii and parallel to atrial coronary arteries, has shown better ATF. Single blind open randomized prospective study of 80 patients was undertaken in two groups (40 each) of modified Cox's maze III and modified radial approach, to evaluate conversion to normal sinus rhythm (NSR) and ATF. Patients undergoing surgery for rheumatic valvular heart disease with continuous AF were prospectively randomized. Ablation lines were created with radiofrequency (RF) bipolar coagulation with cryoablation for the isthmal lesions and coronary sinus. Results were compared at 6 months and ATF was evaluated by atrial filling fraction (AFF) and A/E ratio on echocardiography. The rate of conversion to NSR in both groups was statistically insignificant by Fisher's exact test (p > 0.05). ATF was better in modified radial approach compared to modified Cox's Maze III (A/E compared by unpaired t test:0.52 ± 0.08 v/s 0.36 ± 0.10; p < 0.05. AFF compared using Mann Whitney U test: median AFF for radial group was 23 v/s 20 for biatrial group; p < 0.05). In patients with AF undergoing rheumatic valvular surgery, radiofrequency radial approach is as effective as modified Cox's maze III for conversion to NSR with better atrial transport function. Copyright © 2014 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Imaging before cryoablation of atrial fibrillation: is phrenic nerve palsy predictable?

PubMed

Canpolat, Uğur; Aytemir, Kudret; Hızal, Mustafa; Hazırolan, Tuncay; Yorgun, Hikmet; Sahiner, Levent; Kaya, Ergun Barış; Oto, Ali

2014-04-01

Multidetector computerized tomography (MDCT) with improved temporal and spatial resolution is one of the most commonly used non-invasive tests for evaluation of pulmonary veins (PVs) and adjacent structures before cryoablation of atrial fibrillation (AF). Identification of spatial neighbouring of phrenic nerves is important to decrease likelihood of phrenic nerve palsy (PNP). The purpose of our study is to clarify the course of right phrenic nerve, its relations to PVs using 64-slice MDCT, and effect on occurrence of PNP. A total of 162 patients underwent MDCT with 3D reconstruction of left atrium prior to cryoablation for AF. The location of the right pericardiophrenic artery (RPA) was identified on axial images and artery distance to the right upper PV (RUPV) ostium was measured in 3D image. Right pericardiophrenic artery was detectable in 145 of 162 (89.5%) patients (52.4% male, age 54.5 ± 10.1 years, and 80.7% paroxysmal AF). Acute procedural success rate was 96.2%. Mean procedural and fluoroscopy times were 74.4 ± 6.2 and 15.7 ± 4.3 min. Transient right PNP was developed in four (2.75%) patients. RUPV ostium to RPA distance was lower in patients with PNP (P = 0.033). In multivariate regression analysis, only RUPV ostium to RPA distance (odds ratio: 2.95; 95% confidence interval: 1.76-4.66, P = 0.001) was the independent predictor of PNP occurrence during cryoablation. Our results revealed that pre-ablation cardiac imaging with 64-slice MDCT adequately detected RPA bordering the phrenic nerve, which was an important determinant of PNP development during cryoballoon-based AF ablation.

Mechanisms of Atrial Fibrillation: Rotors, Ionic Determinants and Excitation Frequency

PubMed Central

Berenfeld, Omer; Jalife, José

2017-01-01

Summary Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans. However its mechanisms are poorly understood and AF therapy is often sub-optimal. This article reviews recent experimental, numerical and clinical data on dynamics of wave propagation during AF and its mechanistic link to ionic and structural properties of the atria. At the outset, we review numerical and optical mapping data suggesting that the sustained activity of periodic drivers (rotors) with exceedingly high dominant frequencies (DF) of excitation underlies the spatial dispersion and irregularity of activation rates that characterize AF. We show how optical mapping of the fibrillating atria in isolated normal sheep hearts has revealed that the rotors tend to localize in the left atrium (LA). We then discuss exciting new data in the sheep model of tachypacing induced AF demonstrating that the DF of paroxysmal AF episodes increases progressively over days or weeks during the transition to persistent AF (PeAF) and that the rate of the DF increase predicts the onset of PeAF. The data show that the DF increase during the transition may be explained by rotor acceleration secondary to upregulation of IK1 and downregulation of ICaL. The article concludes with a discussion on how translation of experimentally derived knowledge on the behavior and frequency of rotors may find its way into the clinic. We focus on studies in which the analysis of the spatial patterns of DF distribution in the atria of patients with paroxysmal vs persistent has increased our understanding of human AF and how that knowledge might contribute to improve the outcome of AF ablation procedures. PMID:26968663

The Role of Pharmacogenetics in Atrial Fibrillation Therapeutics: Is Personalized Therapy in Sight?

PubMed

Darbar, Dawood

2016-01-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide requiring therapy. Despite recent advances in catheter-based and surgical therapy, antiarrhythmic drugs (AADs) remain the mainstay of treatment for symptomatic AF. However, response in individual patients is highly variable with over half the patients treated with rhythm control therapy experiencing recurrence of AF within a year. Contemporary AADs used to suppress AF are incompletely and unpredictably effective and associated with significant risks of proarrhythmia and noncardiac toxicities. Furthermore, this "one-size" fits all strategy for selecting antiarrhythmics is based largely on minimizing risk of adverse effects rather than on the likelihood of suppressing AF. The limited success of rhythm control therapy is in part due to heterogeneity of the underlying substrate, interindividual differences in disease mechanisms, and our inability to predict response to AADs in individual patients. Genetic studies of AF over the past decade have revealed that susceptibility to and response to therapy for AF is modulated by the underlying genetic substrate. However, the bedside application of these new discoveries to the management of AF patients has thus far been disappointing. This may in part be related to our limited understanding about genetic predictors of drug response in general, the challenges associated with determining efficacy of response to AADs, and lack of randomized genotype-directed clinical trials. Nonetheless, recent studies have shown that common AF susceptibility risk alleles at the chromosome 4q25 locus modulated response to AADs, electrical cardioversion, and ablation therapy. This monograph discusses how genetic approaches to AF have not only provided important insights into underlying mechanisms but also identified AF subtypes that can be better targeted with more mechanism-based "personalized" therapy.

The Role of Pharmacogenetics in Atrial Fibrillation Therapeutics – Is Personalized Therapy in Sight?

PubMed Central

Darbar, Dawood

2015-01-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide requiring therapy. Despite recent advances in catheter-based and surgical therapy, antiarrhythmic drugs (AAD) remain the mainstay of treatment for symptomatic AF. However, response in individual patients is highly variable with over half the patients treated with rhythm control therapy experiencing recurrence of AF within a year. Contemporary AADs used to suppress AF are incompletely and unpredictably effective and associated with significant risks of proarrhythmia and non-cardiac toxicities. Furthermore, this ‘one-size’ fits all strategy for selecting antiarrhythmics is based largely on minimizing risk of adverse effects rather than on the likelihood of suppressing AF. The limited success of rhythm-control therapy is in part due to heterogeneity of the underlying substrate, interindividual differences in disease mechanisms, and our inability to predict response to AADs in individual patients. Genetic studies of AF over the last decade have revealed that susceptibility to and response to therapy for AF is modulated by the underlying genetic substrate. However, the bedside application of these new discoveries to the management of AF patients has thus far been disappointing. This may in part be related to our limited understanding about genetic predictors of drug response in general, the challenges associated with determining efficacy of response to AADs and lack of randomized genotype-directed clinical trials. Nonetheless, recent studies have shown that common AF susceptibility risk alleles at the chromosome 4q25 locus modulated response to AADs, electrical cardioversion and ablation therapy. This monograph discusses how genetic approaches to AF have not only provided important insights into underlying mechanisms but also identified AF sub-types that can be better targeted with more mechanism-based ‘personalized’ therapy. PMID:25970841

Anti-arrhythmic strategies for atrial fibrillation

PubMed Central

Grandi, Eleonora; Maleckar, Mary M.

2016-01-01

Atrial fibrillation (AF), the most common cardiac arrhythmia, is associated with increased risk of cerebrovascular stroke, and with several other pathologies, including heart failure. Current therapies for AF are targeted at reducing risk of stroke (anticoagulation) and tachycardia-induced cardiomyopathy (rate or rhythm control). Rate control, typically achieved by atrioventricular nodal blocking drugs, is often insufficient to alleviate symptoms. Rhythm control approaches include antiarrhythmic drugs, electrical cardioversion, and ablation strategies. Here, we offer several examples of how computational modeling can provide a quantitative framework for integrating multi scale data to: (a) gain insight into multi-scale mechanisms of AF; (b) identify and test pharmacological and electrical therapy and interventions; and (c) support clinical decisions. We review how modeling approaches have evolved and contributed to the research pipeline and preclinical development and discuss future directions and challenges in the field. PMID:27612549

A review: flexible, stretchable multifunctional sensors and actuators for heart arrhythmia therapy

NASA Astrophysics Data System (ADS)

Kang, Seung-Jo; Pak, James Jungho

2017-12-01

Cardiovascular disease is a very serious disease which results in about 30% of all global mortality. Atrial fibrillation (AF) causes rapid and irregular contractions resulting in stroke and cardiac arrest. AF is caused by abnormality of the heartbeat controlling electrical signal. Catheter ablation (CA) is often used to treat and remove the abnormal electrical source from the heart but it has limitations in sensing capability and spatial coverage. To overcome the limitations of the CA, new devices for improving the spatial capability have been reported. One of the most impressive methods is wrapping the heart surface with a flexible/stretchable film with an array of high-density multifunctional micro-sensors and actuators. With this technique, the overall heart surface may be diagnosed in real time and the AF may be treated much more effectively. The data acquisition from the array of multifunctional sensors is also very important for making the new devices useful. To operate the implanted device system, a battery is mostly used and it should be avoided to replace the battery by surgery. Therefore, various energy harvesting techniques or wireless energy transfer techniques to continuously feed the power to the system are under investigation. The development of these technologies was reviewed, and the current level of technology was reviewed and summarized.

Atrioventricular node functional remodeling induced by atrial fibrillation.

PubMed

Zhang, Youhua; Mazgalev, Todor N

2012-09-01

The atrioventricular node (AVN) plays a vital role in determining the ventricular rate during atrial fibrillation (AF). AF results in profound electrophysiological and structural remodeling in the atria as well as the sinus node. However, it is unknown whether AVN undergoes remodeling during AF. To determine whether AVN undergoes functional remodeling during AF. AVN conduction properties were studied in vitro in 9 rabbits with AF and 10 normal controls. A previously validated index of AVN dual-pathway electrophysiology, His-electrogram alternans, was used to monitor fast-pathway or slow-pathway (SP) AVN conduction in these experiments. AVN conduction properties were further studied in vivo in 7 dogs with chronic AF and 8 controls. Compared with the control rabbits, the rabbits with AF had a longer AVN conduction time (83 ± 16 ms vs 68 ± 7 ms; P <.01), longer AVN effective refractory period (141 ± 27 ms vs 100 ± 9 ms; P <.01), an earlier transition from fast-pathway to SP conduction (at a longer prematurity, 249 ± 60 ms vs 171 ± 24 ms; P <.01), and a slower ventricular rate during simulated AF (RR interval 249 ± 42 ms vs 202 ± 12 ms; P <.01). Notably, a larger proportion of conducted beats utilized the SP in AF preparations (92% ± 12% vs 63% ± 32%; P <.05). Long-term AF in dogs resulted in a longer atrioventricular conduction time and AVN effective refractory period and a slower ventricular rate during AF compared with the controls. Pronounced AVN functional electrophysiological remodeling occurs after long-term AF, which could lead to a spontaneous slowing of the ventricular rate. Furthermore, the SP dominance during AF underscores the effectiveness of its modification by ablation for ventricular rate control during AF. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Atrial Fibrillation: The Science behind Its Defiance

PubMed Central

Czick, Maureen E.; Shapter, Christine L.; Silverman, David I.

2016-01-01

Atrial fibrillation (AF) is the most prevalent arrhythmia in the world, due both to its tenacious treatment resistance, and to the tremendous number of risk factors that set the stage for the atria to fibrillate. Cardiopulmonary, behavioral, and psychological risk factors generate electrical and structural alterations of the atria that promote reentry and wavebreak. These culminate in fibrillation once atrial ectopic beats set the arrhythmia process in motion. There is growing evidence that chronic stress can physically alter the emotion centers of the limbic system, changing their input to the hypothalamic-limbic-autonomic network that regulates autonomic outflow. This leads to imbalance of the parasympathetic and sympathetic nervous systems, most often in favor of sympathetic overactivation. Autonomic imbalance acts as a driving force behind the atrial ectopy and reentry that promote AF. Careful study of AF pathophysiology can illuminate the means that enable AF to elude both pharmacological control and surgical cure, by revealing ways in which antiarrhythmic drugs and surgical and ablation procedures may paradoxically promote fibrillation. Understanding AF pathophysiology can also help clarify the mechanisms by which emerging modalities aiming to correct autonomic imbalance, such as renal sympathetic denervation, may offer potential to better control this arrhythmia. Finally, growing evidence supports lifestyle modification approaches as adjuncts to improve AF control. PMID:27699086

Incisional left atrial isolation for ablation of atrial fibrillation in mitral valve surgery.

PubMed

Graffigna, Angelo; Branzoli, Stefano; Sinelli, Stefano; Vigano, Mario

2009-01-01

The renewed interest in surgical techniques for atrial fibrillation (AF) limited to the left atrium has risen the importance of the original technique of left atrial isolation by means of surgical incision. Transmurality of lesions and cost containment are strong elements to be appreciated in this technique.

Atrial fibrillation in patients with gastroesophageal reflux disease: a comprehensive review.

PubMed

Roman, Crina; Bruley des Varannes, Stanislas; Muresan, Lucian; Picos, Alina; Dumitrascu, Dan L

2014-07-28

To analyze the potential relationship between gastroesophageal reflux disease (GERD) and the development of atrial fibrillation (AF). Using the key words "atrial fibrillation and gastroesophageal reflux", "atrial fibrillation and esophagitis, peptic", "atrial fibrillation and hernia, hiatal" the PubMed, EMBASE, Cochrane Library, OVIDSP, WILEY databases were screened for relevant publications on GERD and AF in adults between January 1972-December 2013. Studies written in languages other than English or French, studies not performed in humans, reviews, case reports, abstracts, conference presentations, letters to the editor, editorials, comments and opinions were not taken into consideration. Articles treating the subject of radiofrequency ablation of AF and the consecutive development of GERD were also excluded. Two thousand one hundred sixty-one titles were found of which 8 articles met the inclusion criteria. The presence of AF in patients with GERD was reported to be between 0.62%-14%, higher compared to those without GERD. Epidemiological data provided by these observational studies showed that patients with GERD, especially those with more severe GERD-related symptoms, had an increased risk of developing AF compared with those without GERD, but a causal relationship between GERD and AF could not be established based on these studies. The mechanisms of AF as a consequence of GERD remain largely unknown, with inflammation and vagal stimulation playing a possible role in the development of these disorders. Treatment with proton pomp inhibitors may improve symptoms related to AF and facilitate conversion to sinus rhythm. Although links between AF and GERD exist, large randomized clinical studies are required for a better understanding of the relationship between these two entities.

Making Better Scar: Emerging Approaches for Modifying Mechanical and Electrical Properties Following Infarction and Ablation

PubMed Central

Holmes, Jeffrey W.; Laksman, Zachary; Gepstein, Lior

2015-01-01

Following myocardial infarction (MI), damaged myocytes are replaced by collagenous scar tissue, which serves an important mechanical function – maintaining integrity of the heart wall against enormous mechanical forces – but also disrupts electrical function as structural and electrical remodeling in the infarct and borderzone predispose to re-entry and ventricular tachycardia. Novel emerging regenerative approaches aim to replace this scar tissue with viable myocytes. Yet an alternative strategy of therapeutically modifying selected scar properties may also prove important, and in some cases may offer similar benefits with lower risk or regulatory complexity. Here, we review potential goals for such modifications as well as recent proof-of-concept studies employing specific modifications, including gene therapy to locally increase conduction velocity or prolong the refractory period in and around the infarct scar, and modification of scar anisotropy to improve regional mechanics and pump function. Another advantage of scar modification techniques is that they have applications well beyond MI. In particular, ablation treats electrical abnormalities of the heart by intentionally generating scar to block aberrant conduction pathways. Yet in diseases such as atrial fibrillation (AF) where ablation can be extensive, treating the electrical disorder can significantly impair mechanical function. Creating smaller, denser scars that more effectively block conduction, and choosing the location of those lesions by balancing their electrical and mechanical impacts, could significantly improve outcomes for AF patients. We review some recent advances in this area, including the use of computational models to predict the mechanical effects of specific lesion sets and gene therapy for functional ablation. Overall, emerging techniques for modifying scar properties represents a potentially important important set of tools for improving patient outcomes across a range of heart diseases, whether used in place of or as an adjunct to regenerative approaches. PMID:26615948

Atrial Fibrillation and Heart Failure - Cause or Effect?

PubMed

Prabhu, Sandeep; Voskoboinik, Aleksandr; Kaye, David M; Kistler, Peter M

2017-09-01

There are emerging epidemics of atrial fibrillation (AF) and heart failure in most developed countries, with a significant health burden. Due to many shared pathophysiological mechanisms, which facilitate the maintenance of each condition, AF and heart failure co-exist in up to 30% of patients. In the circumstance where known structural causes of heart failure (such as myocardial infarction) are absent, patients presenting with both conditions present a unique challenge, particularly as the temporal relationship of each condition can often remain elusive from the clinical history. The question of whether the AF is driving, or significantly contributing to the left ventricular (LV) dysfunction, rather than merely a consequence of heart failure, has become ever more pertinent, especially as catheter ablation now offers a significant advancement over existing rhythm control strategies. This paper will review the inter-related physiological drivers of AF and heart failure before considering the implications from the outcomes of recent clinical trials in patients with AF and heart failure. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Contemporary stroke prevention strategies in 11 096 European patients with atrial fibrillation: a report from the EURObservational Research Programme on Atrial Fibrillation (EORP-AF) Long-Term General Registry.

PubMed

Boriani, Giuseppe; Proietti, Marco; Laroche, Cécile; Fauchier, Laurent; Marin, Francisco; Nabauer, Michael; Potpara, Tatjana; Dan, Gheorghe-Andrei; Kalarus, Zbigniew; Diemberger, Igor; Tavazzi, Luigi; Maggioni, Aldo P; Lip, Gregory Y H

2018-05-01

Contemporary data regarding atrial fibrillation (AF) management and current use of oral anticoagulants (OACs) for stroke prevention are needed. The EURObservational Research Programme on AF (EORP-AF) Long-Term General Registry analysed consecutive AF patients presenting to cardiologists in 250 centres from 27 European countries. From 2013 to 2016, 11 096 patients were enrolled (40.7% female; mean age 69 ± 11 years). At discharge, OACs were used in 9379 patients (84.9%), with non-vitamin K antagonists (NOACs) accounting for 40.9% of OACs. Antiplatelet therapy alone was used by 20% of patients, while no antithrombotic treatment was prescribed in 6.4%. On multivariable analysis, age, hypertension, previous ischaemic stroke, symptomatic AF and planned cardioversion or ablation were independent predictors of OAC use, whereas lone AF, previous haemorrhagic events, chronic kidney disease and admission for acute coronary syndrome (ACS) or non-cardiovascular causes independently predicted OAC non-use. Regarding the OAC type, coronary artery disease, history of heart failure, or valvular heart disease, planned cardioversion and non-AF reasons for admission independently predicted the use of vitamin K antagonists (VKAs). Wide variability among the European regions was observed in the use of NOACs, independently from other clinical factors. The EORP-AF Long-Term General Registry provides a full picture of contemporary use of OAC in European AF patients. The overall rate of OACs use was generally high (84.9%), and a series of factors were associated with the prescription of OAC. A significant geographical heterogeneity in prescription of NOACs vs. VKAs was evident.

[The clinical analysis of atrial fibrillation of 1 310 in patients in Urumqi of China].

PubMed

Guo, Xiaohua; Zhang, Yu; Xu, Guojun; Zhou, Xianhui; Li, Lei; Tang, Baopeng

2014-05-01

To investigate the clinical features and current therapy of atrial fibrillation (AF) of inpatients in Urumqi, China. The clinical data of inpatients diagnosed with AF from January, 2008 to December, 2012, in 12 hospitals in Urumqi were retrospectively analyzed. Totally 1 310 AF inpatients were enrolled in this study with the age of (64.8 ± 3.3) years old and a men to women ratio of 1.39. Most patients were in age groups of 61-70 years (26.5%) and 71-80 years (27.6%). More patients with paroxysmal AF were at cardiac function class I-II (75.2%), while more patients with persistent AF were at cardiac function class III-IV (31.0%) (both P values < 0.05). The most common co-morbidities of AF were hypertension (49.2%), coronary heart disease (38.5%), diabetes mellitus (20.1%). Compared with patients of chronic AF, the patients of paroxysmal AF had higher success rates in amiodarone conversation and sinus rhythm maintenance after ablation (44.8% vs 29.9%, 87.5% vs 68.9%, P values < 0.05). Among the 1 310 inpatients, 992 patients (75.7%) received antithrombotic therapy. There were statistically significant differences in CHA2DS2 score and incidence rate of cerebral infarction among patients receiving aspirin, warfarin or rivaroxaban/other anticoagulation drugs [2(1, 3) vs 3(2, 4) vs 3(2, 5) and 6.3% vs 23.8% vs 30.2%, both P values < 0.05]. Our results of AF inpatients' age, gender, related disease distribution, AF types, incidence of stoke, therapeutic and epidemiological features are in accordance with the domestic and abroad reports.

Late Outcome of Atrial Fibrillation Ablation Program at Unity Point Health Methodist in Peoria Illinois.

PubMed

Mina, Adel; Warnecke, Nicholas

2015-01-01

The objective of this study was to evaluate the long term efficacy and safety of the atrial fibrillation program at Unity Point Health Methodist in Peoria. A retrospective analysis was performed on patients who had atrial fibrillation procedures at Unity Point Methodist from February 19 th 2010 to September 26 th 2014. Patients were enrolled and information obtained through the patient's medical records. The study consisted of 53 patients, 65 percent of patients were paroxysmal, and 35 percent had chronic or persistent atrial fibrillation. The mean age was 66 +/- 23 (45 to 89 years). The average CHADS-Vasc Score is score is 2.13. Baseline co-morbidities included 34 individuals with HTN, 10 with Diabetes, and 4 with coronary artery disease. The average EF was 55% +/-25 (30% to 70%) and the average LA diameter 41 +/-15 mm (25-56). The average number of antiarrhythmic was 1.5 prior to ablation. After a mean follow-up of 28 ± 29 months (range, 3 to 57 months), freedom from AF was 94% overall (51 of 53 patients, including 52 were on antiarrhythmic drugs), 94% for paroxysmal AF (34 of 36 patients, including 24 of whom discontinued their antiarrhythmic drugs), and 94% for persistent AF (16 of 17 patients, including 9 no longer on antiarrhythmic drugs). 76 percent experienced a decrease in their antiarrhythmic medications of which 60 percent discontinued antiarrhythmic altogether. Out of the 53 patients, there were three major but completely reversible transient complications. Two of the complications were related to pericardial effusion that was successfully drained with no recurrence. The last complication was phrenic nerve injury in a patient who showed complete recovery 4 month after the procedure. Long-term results of atrial fibrillation ablation at Unity Point Health Methodist showed safety and efficacy of the program in the treatment of symptomatic atrial fibrillation in both paroxysmal and persistent groups.

Determining the Optimal Dose of Adenosine for Unmasking Dormant Pulmonary Vein Conduction Following Atrial Fibrillation Ablation: Electrophysiological and Hemodynamic Assessment. DORMANT-AF Study.

PubMed

Prabhu, Sandeep; Mackin, Vincent; McLellan, Alex J A; Phan, Tuong; McGlade, Desmond; Ling, Liang-Han; Peck, Kah Y; Voskoboinik, Alexandr; Pathik, Bupesh; Nalliah, Chrishan J; Wong, Geoff R; Azzopardi, Sonia M; Lee, Geoffrey; Mariani, Justin; Taylor, Andrew J; Kalman, Jonathan M; Kistler, Peter M

2017-01-01

ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT. The significance of adenosine induced dormant pulmonary vein (PV) conduction in atrial fibrillation (AF) ablation remains controversial. The optimal dose of adenosine to determine dormant PV conduction is yet to be systematically explored. ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT. Consecutive patients undergoing index AF ablation received 3 adenosine doses (12, 18, and 24 mg) in a randomized blinded order, immediately after pulmonary vein isolation (PVI). Electrophysiological (PR prolongation, AV block (AVB) and PV reconnection) and hemodynamic (BP) parameters were measured. A total, 339 doses (113/dose) assessed 191 PVs in 50 patients (66% male, 72% PAF, 52% hypertensive). Dormant PV conduction occurred in 28% of patients (16.5% [32] of PVs). All cases were associated with AVB (AVB: PV reconnection vs. no PV reconnection 100% vs. 83%, P = 0.007). AVB occurred more frequently at 24 mg versus 12 mg (92% vs. 82%, P = 0.019) but not versus 18 mg (91%, P = 0.62). AVB duration progressed between 12 mg (12.0 ± 8.9 seconds), 18 mg (16.1 ± 9.1 seconds, P = 0.001), and 24 mg (19.0 ± 9.3 seconds, P < 0.001) doses. MBP fell further at 24 mg (ΔMBP: 27 ± 12 mmHg) and 18 mg (26 ± 13 mmHg) doses compared to 12 mg (22 ± 10 mmHg vs., P < 0.001). A significant reduction in AVB in patients >110 kg (65% vs. 91% in 70-110 kg group, P < 0.001) in response to adenosine was seen. ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT. An adenosine dose producing AVB is required to unmask dormant PV conduction. AVB is significantly reduced in patients >110 kg. Weight and dosing variability may in part explain the conflicting results of studies evaluating the clinical utility of adenosine in PVI. © 2016 Wiley Periodicals, Inc.

Comparison of Left Atrial Voltage between Sinus Rhythm and Atrial Fibrillation in Association with Electrogram Waveform.

PubMed

Masuda, Masaharu; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Sunaga, Akihiro; Tsujimura, Takuya; Matsuda, Yasuhiro; Ohashi, Takuya; Uematsu, Masaaki

2017-05-01

The efficacy of low-voltage-guided ablation in addition to pulmonary vein (PV) isolation for atrial fibrillation (AF) has been reported with voltage mapping being performed during sinus rhythm (SR) or AF. The study aimed to compare the left atrial voltage between SR and AF in association with the electrogram waveform. This prospective observational study included 30 consecutive patients with persistent AF. After completion of PV isolation, electrogram points were taken during both SR and AF at the identical locations evenly throughout the left atrium. Electrograms were divided into two types: normal (sharp electrogram with ≤3 peaks or duration <50 ms) and fractionated (>3 peaks and duration ≥50 ms). During SR, 14 (47%) patients had low-voltage (0.5 mV) substrate with an area of 6.8 ± 4.5 cm 2 . In a total of 1,063 point pairs, 135 (13%) demonstrated a fractionated electrogram during SR and 483 (45%) during AF. The locations with fractionated electrograms during AF more frequently showed fractionation during SR compared to those with normal electrograms during AF (23% vs 5%, P < 0.0001), and had lower amplitude during SR (1.47 ± 1.29 mV vs 2.03 ± 1.19 mV, P < 0.0001). Electrogram amplitude was higher during SR than that during AF (1.77 ± 1.27 mV vs 0.96 ± 0.77 mV, P < 0.0001) with a weak correlation (r = 0.56, P < 0.0001). Subgroup analyses revealed that the correlation was relatively strong (r = 0.73, P < 0.0001) among the electrogram amplitudes with normal waveform during SR and AF. Significant differences in electrogram voltage and fractionation degree may exist between SR and AF at the same locations in patients with persistent AF. © 2017 Wiley Periodicals, Inc.

Pacing-induced chronic atrial fibrillation impairs sinus node function in dogs. Electrophysiological remodeling.

PubMed

Elvan, A; Wylie, K; Zipes, D P

1996-12-01

We assessed the effects of pacing-induced chronic atrial fibrillation (AF) on sinus node function, intra-atrial conduction, and atrial refractoriness. In 15 mongrel dogs (20 to 30 kg), AV nodal block was produced by radiofrequency catheter ablation, and a ventricular-inhibited (VVI) pacemaker (Minix 8330, Medtronic) was implanted and programmed to pace at 80 pulses per minute. In 11 of these dogs, right atrial endocardial pacing leads were connected to a pulse generator (Itrel 7432, Medtronic) and set at a rate of 20 Hz to induce AF. Corrected sinus node recovery time, P-wave duration, 24-hour Holter ECG to assess AF duration, maximal heart rate in response to isoproterenol (10 micrograms/min), intrinsic heart rate after administration of atropine (0.04 mg/kg) and propranolol (0.1 mg/kg), and atrial effective refractory periods (ERPs) were obtained at baseline (EPS-1) and after 2 to 6 weeks (EPS-2) of VVI pacing alone (n = 4) or VVI pacing and rapid atrial pacing (n = 11). At EPS-2, corrected sinus node recovery time and P-wave duration were prolonged, maximal heart rate and intrinsic heart rate were decreased, atrial ERPs were shortened, and the duration of AF was increased significantly compared with EPS-1. These changes partially reversed toward baseline 1 week after conversion to sinus rhythm. Sinus node function and AF inducibility observed in the control dogs that underwent ventricular pacing alone (n = 4) did not change. Pacing-induced chronic AF induces sinus node dysfunction, prolongs intra-atrial conduction time, shortens atrial refractoriness, and perpetuates AF, changes that reverse gradually after termination of AF.

Use of computed tomography to identify atrial fibrillation associated differences in left atrial wall thickness and density.

PubMed

Dewland, Thomas A; Wintermark, Max; Vaysman, Anna; Smith, Lisa M; Tong, Elizabeth; Vittinghoff, Eric; Marcus, Gregory M

2013-01-01

Left atrial (LA) tissue characteristics may play an important role in atrial fibrillation (AF) induction and perpetuation. Although frequently used in clinical practice, computed tomography (CT) has not been employed to describe differences in LA wall properties between AF patients and controls. We sought to noninvasively characterize AF-associated differences in LA tissue using CT. CT images of the LA were obtained in 98 consecutive patients undergoing AF ablation and in 89 controls. A custom software algorithm was used to measure wall thickness and density in four prespecified regions of the LA. On average, LA walls were thinner (-15.5%, 95% confidence interval [CI] -23.2 to -7.8%, P < 0.001) and demonstrated significantly lower density (-19.7 Hounsfield Units [HU], 95% CI -27.0 to -12.5 HU, P < 0.001) in AF patients compared to controls. In linear mixed models adjusting for demographics, clinical variables, and other CT measurements, the average LA, interatrial septum, LA appendage, and anterior walls remained significantly thinner in AF patients. After adjusting for the same potential confounders, history of AF was associated with reduced density in the LA anterior wall and increased density below the right inferior pulmonary vein and in the LA appendage. Application of an automated measurement algorithm to CT imaging of the atrium identified significant thinning of the LA wall and regional alterations in tissue density in patients with a history of AF. These findings suggest differences in LA tissue composition can be noninvasively identified and quantified using CT. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Online Measurement of Microembolic Signal Burden by Transcranial Doppler during Catheter Ablation for Atrial Fibrillation-Results of a Multicenter Trial.

PubMed

von Bary, Christian; Deneke, Thomas; Arentz, Thomas; Schade, Anja; Lehrmann, Heiko; Fredersdorf, Sabine; Baldaranov, Dobri; Maier, Lars; Schlachetzki, Felix

2017-01-01

Left atrial pulmonary vein isolation (PVI) is an accepted treatment option for patients with symptomatic atrial fibrillation (AF). This procedure can be complicated by stroke or silent cerebral embolism. Online measurement of microembolic signals (MESs) by transcranial Doppler (TCD) may be useful for characterizing thromboembolic burden during PVI. In this prospective multicenter trial, we investigated the burden, characteristics, and composition of MES during left atrial catheter ablation using a variety of catheter technologies. PVI was performed in a total of 42 patients using the circular-shaped multielectrode pulmonary vein ablation catheter (PVAC) technology in 23, an irrigated radiofrequency (IRF) in 14, and the cryoballoon (CB) technology in 5 patients. TCD was used to detect the total MES burden and sustained thromboembolic showers (TESs) of >30 s. During TES, the site of ablation within the left atrium was registered. MES composition was classified manually into "solid," "gaseous," or "equivocal" by off-line expert assessment. The total MES burden was higher when using IRF compared to CB (2,336 ± 1,654 vs. 593 ± 231; p  = 0.007) and showed a tendency toward a higher burden when using IRF compared to PVAC (2,336 ± 1,654 vs. 1,685 ± 2,255; p  = 0.08). TES occurred more often when using PVAC compared to IRF (1.5 ± 2 vs. 0.4 ± 1.3; p  = 0.04) and most frequently when ablation was performed close to the left superior pulmonary vein (LSPV). Of the MES, 17.004 (23%) were characterized as definitely solid, 13.204 (18%) as clearly gaseous, and 44.366 (59%) as equivocal. We investigated the burden and characteristics of MES during left atrial catheter ablation for AF. All ablation techniques applied in this study generated a relevant number of MES. There was a significant difference in total MES burden using IRF compared to CB and a tendency toward a higher burden using IRF compared to PVAC. The highest TES burden was found in the PVAC group, particularly during ablation close to the LSPV. The composition of thromboembolic particles was balanced. The impact of MES, TES, and composition of thromboembolic particles on neurological outcome needs to be evaluated further. (Clinical Trial Registration: Deutsches Register Klinischer Studien, https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003465. DRKS00003465.).

The value of basic research insights into atrial fibrillation mechanisms as a guide to therapeutic innovation: a critical analysis.

PubMed

Heijman, Jordi; Algalarrondo, Vincent; Voigt, Niels; Melka, Jonathan; Wehrens, Xander H T; Dobrev, Dobromir; Nattel, Stanley

2016-04-01

Atrial fibrillation (AF) is an extremely common clinical problem associated with increased morbidity and mortality. Current antiarrhythmic options include pharmacological, ablation, and surgical therapies, and have significantly improved clinical outcomes. However, their efficacy remains suboptimal, and their use is limited by a variety of potentially serious adverse effects. There is a clear need for improved therapeutic options. Several decades of research have substantially expanded our understanding of the basic mechanisms of AF. Ectopic firing and re-entrant activity have been identified as the predominant mechanisms for arrhythmia initiation and maintenance. However, it has become clear that the clinical factors predisposing to AF and the cellular and molecular mechanisms involved are extremely complex. Moreover, all AF-promoting and maintaining mechanisms are dynamically regulated and subject to remodelling caused by both AF and cardiovascular disease. Accordingly, the initial presentation and clinical progression of AF patients are enormously heterogeneous. An understanding of arrhythmia mechanisms is widely assumed to be the basis of therapeutic innovation, but while this assumption seems self-evident, we are not aware of any papers that have critically examined the practical contributions of basic research into AF mechanisms to arrhythmia management. Here, we review recent insights into the basic mechanisms of AF, critically analyse the role of basic research insights in the development of presently used anti-AF therapeutic options and assess the potential value of contemporary experimental discoveries for future therapeutic innovation. Finally, we highlight some of the important challenges to the translation of basic science findings to clinical application. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

The cox-maze procedure for lone atrial fibrillation: a single-center experience over 2 decades.

PubMed

Weimar, Timo; Schena, Stefano; Bailey, Marci S; Maniar, Hersh S; Schuessler, Richard B; Cox, James L; Damiano, Ralph J

2012-02-01

The Cox-Maze procedure (CMP) has achieved high success rates in the therapy of atrial fibrillation (AF) while becoming progressively less invasive. This report evaluates our experience with the CMP in the treatment of lone AF over 2 decades and compares the original cut-and-sew CMP-III to the ablation-assisted CMP-IV, which uses bipolar radiofrequency and cryoenergy to create the original lesion pattern. Data were collected prospectively on 212 consecutive patients (mean age, 53.5±10.4 years; 78% male) who underwent a stand-alone CMP from 1992 through 2010. The median duration of preoperative AF was 6 (interquartile range, 2.9-11.5) years, with 48% paroxysmal and 52% persistent or long-standing persistent AF. Univariate analysis with preoperative and perioperative variables used as covariates for the CMP-III (n=112) and the CMP-IV (n=100) was performed. Overall, 30-day mortality was 1.4%, with no intraoperative deaths. Freedom from AF was 93%, and freedom from AF off antiarrhythmics was 82%, at a mean follow-up time of 3.6±3.1 years. Freedom from symptomatic AF at 10 years was 85%. Only 1 late stroke occurred, with 80% of patients not receiving anticoagulation therapy. The less invasive CMP-IV had significantly shorter cross-clamp times (41±13 versus 92±26 minutes; P<0.001) while achieving high success rates, with 90% freedom from AF and 84% freedom from AF off antiarrhythmics at 2 years. The CMP, although simplified and shortened by alternative energy sources, has excellent results, even with improved follow-up and stricter definition of failure.

Spatial Relation Between Left Atrial Anatomical Contact Areas and Circular Activation in Persistent Atrial Fibrillation.

PubMed

Nakahara, Shiro; Yamaguchi, Takanori; Hori, Yuichi; Anjo, Naofumi; Hayashi, Akiko; Kobayashi, Sayuki; Komatsu, Takaaki; Sakai, Yoshihiko; Fukui, Akira; Tsuchiya, Takeshi; Taguchi, Isao

2016-05-01

Atrial low-voltage zones (LVZs) may be related to maintenance of atrial fibrillation (AF). The influence of left atrial (LA) contact areas (CoAs) on reentrant or rotor-like sources maintaining AF has not been investigated. Forty patients with persistent AF (PsAF) were analyzed. Three representative CoA regions in the LA (ascending aorta: anterior wall; descending aorta: left inferior pulmonary vein; and vertebrae: posterior wall) were visualized by enhanced CT. Using circular catheters, the LVZs (<0.5 mV) were assessed after restoration of SR, and local activation mapping and frequency domain analyses were performed after induction of AF. Circular activation during AF was visually defined as sites with ≥2 rotations by serial electrograms encompassing >80% of the mean AF cycle length. A pivot was defined as the core of the localized circular activation. Anterior (39/40 patients, 98%), left pulmonary vein antrum (27/40, 68%), and posterior (19/40, 48%) CoAs were identified, and 80% (68/85) of those sites were overlapped by or close (<3 mm) to LVZs. Thirty-six (90%) patients demonstrated circular activation (3.1±1.7 sites/patients) along with significantly higher organized dominant frequencies (6.3 ± 0.5 Hz, regularity-index: 0.26 [0.23-0.41]) within the LA, and the average electrogram amplitude of those pivots was 0.30 mV (0.18-0.52). Of those sites, 55% (66/120) were located at or close to CoA regions. Catheter ablation including of LVZs neighboring CoAs terminated AF in 9 (23%) patients. External anatomical structures contacting the LA may be related to unique conduction properties in diseased myocardium necessary for PsAF maintenance. © 2016 Wiley Periodicals, Inc.

Pulmonary vein isolation alone and combined with renal sympathetic denervation in chronic kidney disease patients with refractory atrial fibrillation.

PubMed

Kiuchi, Márcio G; Chen, Shaojie; E Silva, Gustavo R; Paz, Luis M R; Kiuchi, Tetsuaki; de Paula Filho, Ary G; Souto, Gladyston L L

2016-12-01

Atrial fibrillation (AF) commonly occurs in association with chronic kidney disease (CKD), resulting in adverse outcomes. Combining pulmonary vein isolation (PVI) and renal sympathetic denervation (RSD) may reduce the recurrence of AF in patients with CKD and hypertension. We considered that RSD could reduce the recurrence of AF in patients with CKD by modulating sympathetic hyperactivity. Our goal was to compare the impact of PVI + RSD with that of PVI alone in patients with concurrent AF and CKD. This was a single-center, prospective, longitudinal, randomized, double-blind study. Forty-five patients with controlled hypertension, symptomatic paroxysmal AF and/or persistent AF, stage 2 or 3 CKD, and a dual-chamber pacemaker were enrolled from January 2014 to January 2015. We assessed the 30-second recurrence of AF recorded by the pacemaker, 24-hour ambulatory blood pressure measurements, estimated glomerular filtration rate, albuminuria, echocardiographic parameters, and safety of RSD. No patient developed procedural or other complications. The ambulatory blood pressure measurements did not differ within the PVI + RSD group or between the PVI + RSD and PVI groups throughout the study. Significantly more patients in the PVI + RSD group than in the PVI group were free of AF at the 12-month follow-up evaluation. The PVI group had an unacceptable response to ablation with respect to changes in echocardiographic parameters, whereas these parameters improved in the PVI + RSD group. PVI + RSD were associated with a lower AF recurrence rate than PVI alone; it also improved renal function and some echocardiographic parameters. These encouraging data will serve as baseline information for further long-term studies on larger patient populations.

Linear ablation of right atrial free wall flutter: demonstration of bidirectional conduction block as an endpoint associated with long-term success.

PubMed

Snowdon, Richard L; Balasubramaniam, Richard; Teh, Andrew W; Haqqani, Haris M; Medi, Caroline; Rosso, Raphael; Vohra, Jitendra K; Kistler, Peter M; Morton, Joseph B; Sparks, Paul B; Kalman, Jonathan M

2010-05-01

Ablation for atypical atrial flutter (AFL) is often performed during tachycardia, with termination or noninducibility of AFL as the endpoint. Termination alone is, however, an inadequate endpoint for typical AFL ablation, where incomplete isthmus block leads to high recurrence rates. We assessed conduction block across a low lateral right atrial (RA) ablation line (LRA) from free wall scar to the inferior vena cava (IVC) or tricuspid annulus in 11 consecutive patients with atypical RA free wall flutter. LRA block was assessed following termination of AFL, by pacing from the ablation catheter in the low lateral RA posterior to the ablation line and recording the sequence and timing of activation anterior to the line with a duodecapole catheter, and vice versa for bidirectional block. LRA block resulted in a high to low activation pattern on the halo and a mean conduction time of 201 +/- 48 ms to distal halo. LRA conduction block was present in only 2 out of 6 patients after termination of AFL by ablation. Ablation was performed during sinus rhythm (SR) in 9 patients to achieve LRA conduction block. No recurrence of AFL was observed at long-term follow-up (22 +/- 12 months); 3 patients developed AF. Termination of right free wall flutter is often associated with persistent LRA conduction and additional radiofrequency ablation (RFA) in SR is usually required. Low RA pacing may be used to assess LRA conduction block and offers a robust endpoint for atypical RA free wall flutter ablation, which results in a high long-term cure rate.

Rotor meandering contributes to irregularity in electrograms during atrial fibrillation.

PubMed

Zlochiver, Sharon; Yamazaki, Masatoshi; Kalifa, Jérôme; Berenfeld, Omer

2008-06-01

Radiofrequency ablation therapy of atrial fibrillation (AF) recently incorporated the analysis of dominant frequency (DF) and/or electrogram fractionation for guidance. However, the relationships between DF, fractionation, and spatiotemporal characteristics of the AF source remain unclear. We hypothesize that a meandering reentrant AF source contributes to the wave fractionation and is reflected in the power spectrum of local electrograms elsewhere in the rotor's surroundings. Meandering rotors as AF sources were simulated in 2-dimensional models of human atrial tissue and recorded in isolated sheep hearts. Nondominant elements of the signals were differentiated from the dominant elements using singular value decomposition, whereby the purely periodic constituent (PC) relating to the rotor's DF was eliminated rendering a residual constituent (RC) that consisted of all other activity. Spectral analysis of the decomposed constituents revealed peaks corresponding to the meandering frequency of the rotor tip, the magnitudes of which were proportional to the size of and the distance to the rotor core. Similar analyses on epicardial optical signals and electrograms from isolated sheep hearts, as well as human complex fractionated atrial electrograms, showed applicability of the approach. Increased meandering of the rotor driving AF reduces activation periodicity and increases fractionation. The spectral manifestation of the rotor activity beyond the meandering region makes it possible to characterize AF source stability, as well as DF in humans using electrode mapping.

Comparison of health-related quality of life in patients with atrial fibrillation treated with catheter ablation or antiarrhythmic drug therapy: a systematic review and meta-analysis protocol.

PubMed

Allan, Katherine S; Henry, Shaunattonie; Aves, Theresa; Banfield, Laura; Victor, J Charles; Dorian, Paul; Healey, Jeff S; Andrade, Jason; Carroll, Sandra; McGillion, Michael

2017-08-21

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and causes patients considerable burden; symptoms such as palpitations and dyspnoea are common, leading to frequent emergency room visits. Patients with AF report reduced health-related quality of life (HQOL) compared with the general population; thus, treatments focus on the restoration of sinus rhythm to improve symptoms. Catheter ablation (CA) is a primary treatment strategy to treat AF-related burden in select patient populations; however, repeat procedures are often needed, there is a risk of major complications and the procedure is quite costly in comparison to medical therapy. As the outcomes after CA are mixed, an updated review that synthesises the available literature, on outcomes that matter to patients, is needed so that patients and their healthcare providers can make quality treatment decisions. The purpose of this review protocol is to extend previous findings by systematically analysing randomised controlled trials (RCTs) of CA in patients with AF and using meta-analytic techniques to identify the benefits and risks of CA with respect to HQOL and AF-related symptoms. We will include all RCTs that compare CA with antiarrhythmic drugs, or radiofrequency CA with cryoballoon CA, in patients with paroxysmal or persistent AF. To locate studies we will perform comprehensive electronic database searches from database inception to 4 April 2017, with no language restrictions. We will conduct a quantitative synthesis of the effect of CA on HQOL as well as AF-related symptoms and the number of CA procedures needed for success, using meta-analytic techniques. No ethical issues are foreseen and ethical approval is not required given that this is a protocol. The findings of the study will be reported at national and international conferences, and in a peer-reviewed journal using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In accordance with the guidelines, our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 6 March 2017 and was last updated on 6 March 2017 (registration number CRD42017057427). Any protocol amendments will be documented on the International Prospective Register of Systematic Reviews (PROSPERO) and in the final manuscript and indicated as such. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation - prospective study of 704 cases

PubMed Central

Mateos, José Carlos Pachón; Mateos, Enrique I Pachón; Peña, Tomas G Santillana; Lobo, Tasso Julio; Mateos, Juán Carlos Pachón; Vargas, Remy Nelson A; Pachón, Carlos Thiene C; Acosta, Juán Carlos Zerpa

2015-01-01

Introduction Although rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality. Objective This is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection. Methods Seven hundred and four patients (158 F/546M [22.4%/77.6%]; 52.8±14 [17-84] years old), with mean EF of 0.66±0.8 and drug-refractory atrial fibrillation were submitted to hybrid radiofrequency catheter ablation (conventional pulmonary vein isolation plus AF-Nests and background tachycardia ablation) with displacement of the esophagus as far as possible from the radiofrequency target by transesophageal echocardiography transducer handling. The esophageal luminal temperature was monitored without and with displacement in 25 patients. Results The mean esophageal displacement was 4 to 9.1cm (5.9±0.8 cm). In 680 of the 704 patients (96.6%), it was enough to allow complete and safe radiofrequency delivery (30W/40ºC/irrigated catheter or 50W/60ºC/8 mm catheter) without esophagus overlapping. The mean esophageal luminal temperature changes with versus without esophageal displacement were 0.11±0.13ºC versus 1.1±0.4ºC respectively, P<0.01. The radiofrequency had to be halted in 68% of the patients without esophageal displacement because of esophageal luminal temperature increase. There was no incidence of atrioesophageal fistula suspected or confirmed. Only two superficial bleeding caused by transesophageal echocardiography transducer insertion were observed. Conclusion Mechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid esophageal thermal lesion. In most cases, the esophageal displacement was sufficient to allow safe radiofrequency application without esophagus overlapping, being a convenient alternative in reducing the risk of atrioesophageal fistula. PMID:26107444

Neurohumoral indicators of efficacy radiofrequency cardiac denervation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evtushenko, A. V., E-mail: ave@cardio-tomsk.ru; Evtushenko, V. V.; Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk

In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes.more » The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.« less

Impact of steerable sheaths on contact forces and reconnection sites in ablation for persistent atrial fibrillation.

PubMed

Ullah, Waqas; Hunter, Ross J; McLean, Ailsa; Dhinoja, Mehul; Earley, Mark J; Sporton, Simon; Schilling, Richard J

2015-03-01

In preclinical studies, catheter contact force (CF) during radiofrequency ablation correlates with the subsequent lesion size. We investigated the impact of steerable sheaths on ablation CF, its consistency, and wide area circumferential ablation (WACA) line reconnection sites. Five thousand and sixty-four ablations were analyzed across 60 patients undergoing first-time ablation for persistent AF using a CF-sensing catheter: 19 manual nonsteerable sheath (Manual-NSS), 11 manual steerable sheath, and 30 robotic steerable sheath (Sensei, Hansen Medical Inc.) procedures were studied. Ablation CFs were higher in the steerable sheath groups for all left atrial ablations and also WACA ablations specifically (P < 0.006), but less consistent per WACA segment (P < 0.005). There were significant differences in the CFs around both WACAs by group: in the left WACA CFs were lower with Manual-NSS, other than at the anterior-inferior and posterior-superior regions, and lower in the right WACA, other than the anterior-superior region. There was a difference in the proportion of segments chronically reconnecting across groups: Manual-NSS 26.5%, manual steerable sheath 4.6%, robotic 12% (P < 0.0005). The left atrial appendage/PV ridge and right posterior wall were common sites of reconnection in all groups. Steerable sheaths increased ablation CF; however, there were region-specific heterogeneities in the extent of increment, with some segments where they failed to increase CF. Steerable sheath use was associated with reduced WACA-segment reconnection. It may be that the benefits of steerable sheath use in terms of higher CFs could be translated to improved clinical outcomes if regional weaknesses of this technology are taken into account during ablation procedures. © 2014 Wiley Periodicals, Inc.

Causal Scale of Rotors in a Cardiac System

NASA Astrophysics Data System (ADS)

Ashikaga, Hiroshi; Prieto-Castrillo, Francisco; Kawakatsu, Mari; Dehghani, Nima

2018-04-01

Rotors of spiral waves are thought to be one of the potential mechanisms that maintain atrial fibrillation (AF). However, disappointing clinical outcomes of rotor mapping and ablation to eliminate AF raise a serious doubt on rotors as a macro-scale mechanism that causes the micro-scale behavior of individual cardiomyocytes to maintain spiral waves. In this study, we aimed to elucidate the causal relationship between rotors and spiral waves in a numerical model of cardiac excitation. To accomplish the aim, we described the system in a series of spatiotemporal scales by generating a renormalization group, and evaluated the causal architecture of the system by quantifying causal emergence. Causal emergence is an information-theoretic metric that quantifies emergence or reduction between micro- and macro-scale behaviors of a system by evaluating effective information at each scale. We found that the cardiac system with rotors has a spatiotemporal scale at which effective information peaks. A positive correlation between the number of rotors and causal emergence was observed only up to the scale of peak causation. We conclude that rotors are not the universal mechanism to maintain spiral waves at all spatiotemporal scales. This finding may account for the conflicting benefit of rotor ablation in clinical studies.

Isthmus sites identified by Ripple Mapping are usually anatomically stable: A novel method to guide atrial substrate ablation?

PubMed

Luther, Vishal; Qureshi, Norman; Lim, Phang Boon; Koa-Wing, Michael; Jamil-Copley, Shahnaz; Ng, Fu Siong; Whinnett, Zachary; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa; Linton, Nick

2018-03-01

Postablation reentrant ATs depend upon conducting isthmuses bordered by scar. Bipolar voltage maps highlight scar as sites of low voltage, but the voltage amplitude of an electrogram depends upon the myocardial activation sequence. Furthermore, a voltage threshold that defines atrial scar is unknown. We used Ripple Mapping (RM) to test whether these isthmuses were anatomically fixed between different activation vectors and atrial rates. We studied post-AF ablation ATs where >1 rhythm was mapped. Multipolar catheters were used with CARTO Confidense for high-density mapping. RM visualized the pattern of activation, and the voltage threshold below which no activation was seen. Isthmuses were characterized at this threshold between maps for each patient. Ten patients were studied (Map 1 was AT1; Map 2: sinus 1/10, LA paced 2/10, AT2 with reverse CS activation 3/10; AT2 CL difference 50 ± 30 ms). Point density was similar between maps (Map 1: 2,589 ± 1,330; Map 2: 2,214 ± 1,384; P  =  0.31). RM activation threshold was 0.16 ± 0.08 mV. Thirty-one isthmuses were identified in Map 1 (median 3 per map; width 27 ± 15 mm; 7 anterior; 6 roof; 8 mitral; 9 septal; 1 posterior). Importantly, 7 of 31 (23%) isthmuses were unexpectedly identified within regions without prior ablation. AT1 was treated following ablation of 11/31 (35%) isthmuses. Of the remaining 20 isthmuses, 14 of 16 isthmuses (88%) were consistent between the two maps (four were inadequately mapped). Wavefront collision caused variation in low voltage distribution in 2 of 16 (12%). The distribution of isthmuses and nonconducting tissue within the ablated left atrium, as defined by RM, appear concordant between rhythms. This could guide a substrate ablative approach. © 2018 Wiley Periodicals, Inc.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation--prospective study of 704 cases.

PubMed

Mateos, José Carlos Pachón; Mateos, Enrique I Pachón; Peña, Tomas G Santillana; Lobo, Tasso Julio; Mateos, Juán Carlos Pachón; Vargas, Remy Nelson A; Pachón, Carlos Thiene C; Acosta, Juán Carlos Zerpa

2015-01-01

Although rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality. This is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection. Seven hundred and four patients (158 F/546M [22.4%/77.6%]; 52.8 ± 14 [17-84] years old), with mean EF of 0.66 ± 0.8 and drug-refractory atrial fibrillation were submitted to hybrid radiofrequency catheter ablation (conventional pulmonary vein isolation plus AF-Nests and background tachycardia ablation) with displacement of the esophagus as far as possible from the radiofrequency target by transesophageal echocardiography transducer handling. The esophageal luminal temperature was monitored without and with displacement in 25 patients. The mean esophageal displacement was 4 to 9.1cm (5.9 ± 0.8 cm). In 680 of the 704 patients (96.6%), it was enough to allow complete and safe radiofrequency delivery (30W/40ºC/irrigated catheter or 50W/60ºC/8 mm catheter) without esophagus overlapping. The mean esophageal luminal temperature changes with versus without esophageal displacement were 0.11 ± 0.13ºC versus 1.1 ± 0.4ºC respectively, P<0.01. The radiofrequency had to be halted in 68% of the patients without esophageal displacement because of esophageal luminal temperature increase. There was no incidence of atrioesophageal fistula suspected or confirmed. Only two superficial bleeding caused by transesophageal echocardiography transducer insertion were observed. Mechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid esophageal thermal lesion. In most cases, the esophageal displacement was sufficient to allow safe radiofrequency application without esophagus overlapping, being a convenient alternative in reducing the risk of atrioesophageal fistula.

[Left versus bi-atrial radiofrequency ablation in the treatment of atrial fibrillation].

PubMed

Wang, Jian-Gang; Meng, Xu; Li, Hui

2008-11-25

To evaluate the effectiveness of radiofrequency modified maze operation for the treatment of atrial fibrillation (AF) and compare the results of the left versus bi-atrial procedures. 305 patients of organic heart disease combined with AF, 117 males and 188 females, aged (53 +/- 10), that underwent cardiac valve operation (n = 293) and/or coronary artery bypass graft surgery (n = 14), received concomitant atrial fibrillation, bi-atrial (n = 160) or left atrial (n = 145) with a mean duration of (36 +/- 43) months. Follow-up was conducted for (28 +/- 5) (3 - 42) months. Thirteen patients (4.3%) died postoperatively: 7 died of multisystem and organ failure, 3 of low cardiac output, 1 of rupture of left ventricle, 1 of arrhythmia, and 1 of sudden death. During the follow-up, 1 patient died of heart failure, 1 of encephalorrhagia and 1 of unknown reason in the bi-atrial group. At the end of the procedure 223 patients (73.1%) had sinus rhythm, with a sinus rhythm rate of 66.9% (107/160) in the bi-atrial group, significant lower than that in the left atrial group (80.0%, 116/145, P < 0.05). At late follow-up, 215 of the 266 patients (80.8%) were in stable sinus rhythm. Sinus rhythm rate of the bi-atrial group was 80.0%, not significantly different from that of the left atrial group (81.9%, P > 0.05). The Kaplan-Meier survival analysis showed there was no significant difference in the AF rhythm rate between these 2 groups (P = 0.33). Logistic regression analysis showed that the left atrial diameter of >/= 80 mm was an independent predictor of AF recurrence. Both the left and bi-atrial procedures are successful in terms of restoring sinus rhythm. Left atrial ablation in severe cases and where the incision of right atrium is not needed is a reasonable choice.

Remote magnetic with open-irrigated catheter vs. manual navigation for ablation of atrial fibrillation: a systematic review and meta-analysis.

PubMed

Proietti, Riccardo; Pecoraro, Valentina; Di Biase, Luigi; Natale, Andrea; Santangeli, Pasquale; Viecca, Maurizio; Sagone, Antonio; Galli, Alessio; Moja, Lorenzo; Tagliabue, Ludovica

2013-09-01

The aim of this study was to determine the efficacy and safety of remote magnetic navigation (RMN) with open-irrigated catheter vs. manual catheter navigation (MCN) in performing atrial fibrillation (AF) ablation. We searched in PubMed (1948-2013) and EMBASE (1974-2013) studies comparing RMN with MCN. Outcomes considered were AF recurrence (primary outcome), pulmonary vein isolation (PVI), procedural complications, and data on procedure's performance. Odds ratios (OR) and mean difference (MD) were extracted and pooled using a random-effect model. Confidence in the estimates of the obtained effects (quality of evidence) was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. We identified seven controlled trials, six non-randomized and one randomized, including a total of 941 patients. Studies were at high risk of bias. No difference was observed between RMN and MCN on AF recurrence [OR 1.18, 95% confidence interval (CI) 0.85 to 1.65, P = 0.32] or PVI (OR 0.41, 95% CI 0.11-1.47, P = 0.17). Remote magnetic navigation was associated with less peri-procedural complications (Peto OR 0.41, 95% CI 0.19-0.88, P = 0.02). Mean fluoroscopy time was reduced in RMN group (-22.22 min; 95% CI -42.48 to -1.96, P = 0.03), although the overall duration of the procedure was longer (60.91 min; 95% CI 31.17 to 90.65, P < 0.0001). In conclusion, RMN is not superior to MCN in achieving freedom from recurrent AF at mid-term follow-up or PVI. The procedure implies less peri-procedural complications, requires a shorter fluoroscopy time but a longer total procedural time. For the low quality of the available evidence, a proper designed randomized controlled trial could turn the direction and the effect of the dimensions explored.

Renal denervation for improving outcomes of catheter ablation in patients with atrial fibrillation and hypertension: early experience.

PubMed

Pokushalov, Evgeny; Romanov, Alexander; Katritsis, Demosthenes G; Artyomenko, Sergey; Bayramova, Sevda; Losik, Denis; Baranova, Vera; Karaskov, Alexander; Steinberg, Jonathan S

2014-07-01

The potential role of renal denervation (RD) in patients with AF and less severe hypertension is unknown. The purpose of this study was to assess the potential role of RD as an adjunct to pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) and moderate resistant or severe resistant hypertension. The data for this study were obtained from 2 different prospective randomized studies, analyzed by meta-analysis. Patients with paroxysmal AF or persistent AF and moderate resistant hypertension (office blood pressure BP ≥140/90 mm Hg and <160/100 mm Hg; first study; n = 48) or severe resistant hypertension (≥160/100 mm Hg; second study; n = 38) were randomized to PVI or PVI with RD. At 12 months, 26 of the 41 PVI with RD patients (63%) were AF-free vs 16 of the 39 patients (41%) in the PVI-only group (P = .014). In patients with severe hypertension, 11 of the 18 PVI with RD patients (61%) vs 5 of the 18 PVI-only patients (28%) were AF-free (P = .03). For moderate hypertension, the differences were less dramatic: 11 of 21 (52%) vs 15 of 23 (65%) when RD added (P = .19). The superior efficacy of adding RD was most apparent in persistent AF and severe hypertension (hazard ratio 0.25, confidence interval 0.09-0.72, P = .01). Duration of the procedure and fluoroscopy were nonsignificantly longer in the RD group. RD may improve the results of PVI in patients with persistent AF and/or severe resistant hypertension. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Diagnostic Accuracy of a Novel Mobile Phone Application for the Detection and Monitoring of Atrial Fibrillation.

PubMed

Rozen, Guy; Vaid, Jeena; Hosseini, Seyed Mohammadreza; Kaadan, M Ihsan; Rafael, Allon; Roka, Attila; Poh, Yukkee C; Poh, Ming-Zher; Heist, Edwin Kevin; Ruskin, Jeremy Neil

2018-05-15

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults, associated with significant morbidity, increased mortality, and rising health-care costs. Simple and available tools for the accurate detection of arrhythmia recurrence in patients after electrical cardioversion (CV) or ablation procedures for AF can help to guide therapeutic decisions. We conducted a prospective, single-center study to evaluate the accuracy of Cardiio Rhythm Mobile Application (CRMA) for AF detection. Patients >18 years of age who were scheduled for elective CV for AF were enrolled in the study. CRMA finger pulse recordings, utilizing an iPhone camera, were obtained before (pre-CV) and after (post-CV) the CV. The findings were validated against surface electrocardiograms. Ninety-eight patients (75.5% men), mean age of 67.7 ± 10.5 years, were enrolled. No electrocardiogram for validation was available in 1 case. Pre-CV CRMA readings were analyzed in 97 of the 98 patients. Post-CV CRMA readings were analyzed for 92 of 93 patients who underwent CV. One patient left before the recording was obtained. The Cardiio Rhythm Mobile Application correctly identified 94 of 101 AF recordings (93.1%) as AF and 80 of 88 non-AF recordings (90.1%) as non-AF. The sensitivity was 93.1% (95% confidence interval [CI] = 86.9% to 97.2%) and the specificity was 90.9% (95% CI = 82.9% to 96.0%). The positive predictive value was 92.2% (95% CI = 85.8% to 95.8%) and the negative predictive value was 92.0% (95% CI = 94.8% to 95.9%). In conclusion, the CRMA demonstrates promising potential in accurate detection and discrimination of AF from normal sinus rhythm in patients with a history of AF. Copyright © 2018 Elsevier Inc. All rights reserved.

Parasympathetic, sympathetic, and sensory interactions in the iris: nerve growth factor regulates cholinergic ciliary ganglion innervation in vivo.

PubMed

Kessler, J A

1985-10-01

Interactions between peptidergic sensory nerves, noradrenergic sympathetic nerves, and cholinergic parasympathetic fibers were examined in the rat iris. The putative peptide neurotransmitter, substance P (SP), was used as an index of the trigeminal sensory innervation, tyrosine hydroxylase (TH) activity served to monitor the sympathetic fibers, and choline acetyltransferase (CAT) activity was used as an index of the parasympathetic innervation. Destruction of the sympathetic innervation by neonatal administration of 6-hydroxydopamine resulted in increased SP development and a smaller increase in CAT activity in the iris. Moreover, trigeminal ablation resulted in an increase in both TH and CAT activities. Finally, ciliary ganglionectomy resulted in increased SP and a smaller increase in TH activity in the iris. Administration of nerve growth factor (NGF) into the anterior chamber substantially increased both SP and TH activity in the iris and also increased CAT activity to a lesser extent. Moreover, administration of anti-NGF into the anterior chamber prevented both the sympathectomy-induced increases in SP and CAT, and the increases in TH and CAT activities after trigeminal ablation, suggesting that NGF mediated these increases. These observations suggest that the sympathetic, sensory, and parasympathetic innervations of the iris interact by altering availability of NGF elaborated by the iris. Regulation of iris CAT activity was examined in greater detail. Injection of the cholinergic toxin, AF64A, into the anterior chamber concurrently with ablation of the sympathetic and sensory innervations paradoxically increased CAT activity, whereas AF64A alone decreased CAT activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Using anatomical landmark to avoid phrenic nerve injury during balloon-based procedures in atrial fibrillation patients.

PubMed

Smith, Nicolina M; Segars, Larry; Kauffman, Travis; Olinger, Anthony B

2017-12-01

Atrial fibrillation (AF) is an arrhythmia which affects as many as 2.7 million Americans. AF should be treated, because it can lead to a four-to-fivefold increased risk of experiencing a stroke. The American College of Cardiology/American Heart Association guidelines for the treatment of drug refractory and symptomatic paroxysmal AF denote catheter ablation as the standard of care. The newest ablation treatment, cryoballoon, uses a cold balloon tip. The biggest risk factor associated with the cryoballoon ablation is phrenic nerve injury (PNI). The purpose of this study is to measure relevant distances from specific landmarks to the right phrenic nerve (RPN) to create a safe zone for physicians. Using 30 cadaveric specimens, we measured laterally from the right superior pulmonary vein orifice (RSPV) to the RPN at the level of the sixth thoracic vertebra and laterally from the lateral border of the sixth thoracic vertebral body (T6) to the RPN. The depth and width of the left atrium (LA) were also measured to establish a cross-sectional area of the LA. The cross-sectional area of the LA was then correlated with the averaged measurements to see if the area of the LA could be a predictor of the location of the RPN. The average distance from the RPN-RSPV was 9.6 mm (range 4.3-18.8 mm). The average RPN-T6 distance was 30.6 mm (range 13.7-49.9 mm). There was a non-significant trend that suggests as the size of the LA increases, the measured distances also increased. Using the lateral border of the sixth thoracic vertebra as a landmark, which can be viewed under fluoroscopy during the procedure, physicians can triangulate the distance to the RSPV and determine the approximate position of the RPN. Furthermore, physicians can perform a preoperative echocardiogram to determine the size of the LA to assist in determining the position of the RPN with the hopes of avoiding injury to the RPN.

Atrial fibrillation driven by micro-anatomic intramural re-entry revealed by simultaneous sub-epicardial and sub-endocardial optical mapping in explanted human hearts

PubMed Central

Hansen, Brian J.; Zhao, Jichao; Csepe, Thomas A.; Moore, Brandon T.; Li, Ning; Jayne, Laura A.; Kalyanasundaram, Anuradha; Lim, Praise; Bratasz, Anna; Powell, Kimerly A.; Simonetti, Orlando P.; Higgins, Robert S.D.; Kilic, Ahmet; Mohler, Peter J.; Janssen, Paul M.L.; Weiss, Raul; Hummel, John D.; Fedorov, Vadim V.

2015-01-01

Aims The complex architecture of the human atria may create physical substrates for sustained re-entry to drive atrial fibrillation (AF). The existence of sustained, anatomically defined AF drivers in humans has been challenged partly due to the lack of simultaneous endocardial–epicardial (Endo–Epi) mapping coupled with high-resolution 3D structural imaging. Methods and results Coronary-perfused human right atria from explanted diseased hearts (n = 8, 43–72 years old) were optically mapped simultaneously by three high-resolution CMOS cameras (two aligned Endo–Epi views (330 µm2 resolution) and one panoramic view). 3D gadolinium-enhanced magnetic resonance imaging (GE-MRI, 80 µm3 resolution) revealed the atrial wall structure varied in thickness (1.0 ± 0.7–6.8 ± 2.4 mm), transmural fiber angle differences, and interstitial fibrosis causing transmural activation delay from 23 ± 11 to 43 ± 22 ms at increased pacing rates. Sustained AF (>90 min) was induced by burst pacing during pinacidil (30–100 µM) perfusion. Dual-sided sub-Endo–sub-Epi optical mapping revealed that AF was driven by spatially and temporally stable intramural re-entry with 107 ± 50 ms cycle length and transmural activation delay of 67 ± 31 ms. Intramural re-entrant drivers were captured primarily by sub-Endo mapping, while sub-Epi mapping visualized re-entry or ‘breakthrough’ patterns. Re-entrant drivers were anchored on 3D micro-anatomic tracks (15.4 ± 2.2 × 6.0 ± 2.3 mm2, 2.9 ± 0.9 mm depth) formed by atrial musculature characterized by increased transmural fiber angle differences and interstitial fibrosis. Targeted radiofrequency ablation of the tracks verified these re-entries as drivers of AF. Conclusions Integrated 3D structural–functional mapping of diseased human right atria ex vivo revealed that the complex atrial microstructure caused significant differences between Endo vs. Epi activation during pacing and sustained AF driven by intramural re-entry anchored to fibrosis-insulated atrial bundles. PMID:26059724

Making better scar: Emerging approaches for modifying mechanical and electrical properties following infarction and ablation.

PubMed

Holmes, Jeffrey W; Laksman, Zachary; Gepstein, Lior

2016-01-01

Following myocardial infarction (MI), damaged myocytes are replaced by collagenous scar tissue, which serves an important mechanical function - maintaining integrity of the heart wall against enormous mechanical forces - but also disrupts electrical function as structural and electrical remodeling in the infarct and borderzone predispose to re-entry and ventricular tachycardia. Novel emerging regenerative approaches aim to replace this scar tissue with viable myocytes. Yet an alternative strategy of therapeutically modifying selected scar properties may also prove important, and in some cases may offer similar benefits with lower risk or regulatory complexity. Here, we review potential goals for such modifications as well as recent proof-of-concept studies employing specific modifications, including gene therapy to locally increase conduction velocity or prolong the refractory period in and around the infarct scar, and modification of scar anisotropy to improve regional mechanics and pump function. Another advantage of scar modification techniques is that they have applications well beyond MI. In particular, ablation treats electrical abnormalities of the heart by intentionally generating scar to block aberrant conduction pathways. Yet in diseases such as atrial fibrillation (AF) where ablation can be extensive, treating the electrical disorder can significantly impair mechanical function. Creating smaller, denser scars that more effectively block conduction, and choosing the location of those lesions by balancing their electrical and mechanical impacts, could significantly improve outcomes for AF patients. We review some recent advances in this area, including the use of computational models to predict the mechanical effects of specific lesion sets and gene therapy for functional ablation. Overall, emerging techniques for modifying scar properties represents a potentially important set of tools for improving patient outcomes across a range of heart diseases, whether used in place of or as an adjunct to regenerative approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mapping and isolation of the pulmonary veins using the PVAC catheter.

PubMed

Duytschaever, Mattias; Anne, Wim; Papiashvili, Giorgi; Vandekerckhove, Yves; Tavernier, Rene

2010-02-01

We aimed to investigate the feasibility, efficacy, and safety of the pulmonary vein ablation catheter (PVAC) catheter (a novel multielectrode catheter using duty-cycled bipolar and unipolar radiofrequency energy, Medtronic, Minneapolis, MN, USA) to completely isolate the pulmonary veins (PVs). Twenty-seven patients (60 +/- 8 years) with paroxysmal atrial fibrillation (AF) underwent PV isolation with the PVAC catheter. PVAC was used for both mapping and isolation of the PVs (PVAC-guided ablation). After PVAC ablation, presence/absence of PV potentials (PVP) was verified using a conventional circular mapping catheter. In case of residual PVP on the circular catheter, PVAC ablation was continued. After PVAC-guided ablation 99 of 106 PVs (93%) and 21 of 27 patients (78%) were proven to be isolated. Failure to isolate was due to a mapping failure in four right-sided PVs and a true ablation failure in three right-sided PVs. After continued PVAC ablation, 103 of 106 PVs (97%) and 25 of 27 patients (93%) were shown to be isolated. The total procedural time from femoral vein access to complete catheter withdrawal was 176 +/- 25 minutes. The actual dwelling-time of the PVAC within the left atrium was 102 +/- 37 minutes. Esophageal T degrees rise to >38.5 degrees occurred in nine of 19 monitored patients (47%). (1) PVAC-guided ablation (i.e., mapping and ablation with a single catheter) results in isolation of all PVs in 73% of the patients. (2) An additional circular mapping catheter is required to increase complete isolation rate to 93% of the patients. (3) Given the esophageal T degrees rise in almost 50% of patients, safety precautions are needed.

Does permanent atrial fibrillation modify response to cardiac resynchronization therapy in heart failure patients?

PubMed

Abreu, Ana; Oliveira, Mário; Silva Cunha, Pedro; Santa Clara, Helena; Portugal, Guilherme; Gonçalves Rodrigues, Inês; Santos, Vanessa; Morais, Luís; Selas, Mafalda; Soares, Rui; Branco, Luísa; Ferreira, Rui; Mota Carmo, Miguel

2017-10-01

The benefits of cardiac resynchronization therapy (CRT) documented in heart failure (HF) may be influenced by atrial fibrillation (AF). We aimed to compare CRT response in patients in AF and in sinus rhythm (SR). We prospectively studied 101 HF patients treated by CRT. Rates of clinical, echocardiographic and functional response, baseline NYHA class and variation, left ventricular ejection fraction, volumes and mass, atrial volumes, cardiopulmonary exercise test (CPET) duration (CPET dur), peak oxygen consumption (VO 2 max) and ventilatory efficiency (VE/VCO 2 slope) were compared between AF and SR patients, before and at three and six months after implantation of a CRT device. All patients achieved ≥95% biventricular pacing, and 5.7% underwent atrioventricular junction ablation. Patients were divided into AF (n=35) and SR (n=66) groups; AF patients were older, with larger atrial volumes and lower CPET dur and VO 2 max before CRT. The percentages of clinical and echocardiographic responders were similar in the two groups, but there were more functional responders in the AF group (71% vs. 39% in SR patients; p=0.012). In SR patients, left atrial volume and left ventricular mass were significantly reduced (p=0.015 and p=0.021, respectively), whereas in AF patients, CPET dur (p=0.003) and VO 2 max (p=0.001; 0.083 age-adjusted) showed larger increases. Clinical and echocardiographic response rates were similar in SR and AF patients, with a better functional response in AF. Improvement in left ventricular function and volumes occurred in both groups, but left ventricular mass reduction and left atrial reverse remodeling were seen exclusively in SR patients (ClinicalTrials.gov identifier: NCT02413151; FCT code: PTDC/DES/120249/2010). Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Atrial fibrillation: stroke prevention in focus.

PubMed

Ferguson, Caleb; Inglis, Sally C; Newton, Phillip J; Middleton, Sandy; Macdonald, Peter S; Davidson, Patricia M

2014-05-01

Atrial fibrillation (AF) is a common arrhythmia and a risk factor for stroke and other, adverse events. Internationally there have been recent advancements in the therapies available for, stroke prevention in AF. Nurses will care for individuals with AF across a variety of primary and acute, care settings and should be familiar with evidence based therapies. This paper provides a review of the epidemiology of AF and stroke, stroke and bleeding risk, assessment tools and evidence based treatments for the prevention of stroke in AF including the use of, novel anti-thrombin agents. A review of key databases was conducted from 2002 to 2012 using the key search terms 'atrial, fibrillation' 'anticoagulation' 'risk assessment' and 'clinical management'. The following electronic, databases were searched: CINAHL, Medline, Scopus, the Cochrane Library and Google Scholar., Reference lists were manually hand searched. Key clinical guidelines from National Institute for, Clinical Excellence (NICE, UK), American Heart Association (AHA, USA), American College of Cardiology, (ACC, USA) and the European Society of Cardiology (ESC) and key government policy documents were, also included. Articles were included in the review if they addressed nursing management with a focus, on Australia. Many treatment options exist for AF. Best practice guidelines make a variety of, recommendations which include cardioversion, ablation, pulmonary vein isolation, pharmacological, agents for rate or rhythm control approaches, and antithrombotic therapy (including anticoagulation, and antiplatelet therapy). Treatment should be patient centred and individualised based upon, persistency of the rhythm, causal nature, risk and co-morbid conditions. AF is a common and burdensome condition where treatment is complex and not without, risk. Nurses will encounter individuals with AF across a variety of primary and acute care areas, understanding the risk of AF and appropriate therapies is important across all care settings. Treatment, must be individually tailored to the needs of the patient and balanced with the best available evidence. Copyright © 2013 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

Routine versus aggressive upstream rhythm control for prevention of early atrial fibrillation in heart failure: background, aims and design of the RACE 3 study.

PubMed

Alings, M; Smit, M D; Moes, M L; Crijns, H J G M; Tijssen, J G P; Brügemann, J; Hillege, H L; Lane, D A; Lip, G Y H; Smeets, J R L M; Tieleman, R G; Tukkie, R; Willems, F F; Vermond, R A; Van Veldhuisen, D J; Van Gelder, I C

2013-07-01

Rhythm control for atrial fibrillation (AF) is cumbersome because of its progressive nature caused by structural remodelling. Upstream therapy refers to therapeutic interventions aiming to modify the atrial substrate, leading to prevention of AF. The Routine versus Aggressive upstream rhythm Control for prevention of Early AF in heart failure (RACE 3) study hypothesises that aggressive upstream rhythm control increases persistence of sinus rhythm compared with conventional rhythm control in patients with early AF and mild-to-moderate early systolic or diastolic heart failure undergoing electrical cardioversion. RACE 3 is a prospective, randomised, open, multinational, multicenter trial. Upstream rhythm control consists of angiotensin converting enzyme inhibitors and/or angiotensin receptor blockers, mineralocorticoid receptor antagonists, statins, cardiac rehabilitation therapy, and intensive counselling on dietary restrictions, exercise maintenance, and drug adherence. Conventional rhythm control consists of routine rhythm control therapy without cardiac rehabilitation therapy and intensive counselling. In both arms, every effort is made to keep patients in the rhythm control strategy, and ion channel antiarrhythmic drugs or pulmonary vein ablation may be instituted if AF relapses. Total inclusion will be 250 patients. If upstream therapy proves to be effective in improving maintenance of sinus rhythm, it could become a new approach to rhythm control supporting conventional pharmacological and non-pharmacological rhythm control.

Atrial fibrillation in cardiac resynchronization therapy with a defibrillator: a risk factor for mortality, appropriate and inappropriate shocks.

PubMed

van Boven, Nick; Theuns, Dominic; Bogaard, Kjell; Ruiter, Jaap; Kimman, Geert; Berman, Lily; VAN DER Ploeg, Tjeerd; Kardys, Isabella; Umans, Victor

2013-10-01

Knowledge about predictive factors for mortality and (in)appropriate shocks in cardiac resynchronization therapy with a defibrillator (CRT-D) should be available and updated to predict clinical outcome. We retrospectively analyzed 543 consecutive patients assigned to CRT-D in 2 tertiary medical centers. The aim of this study was to assess risk factors for all-cause mortality, appropriate and inappropriate shocks. Mean follow-up time was 3.2 (±1.8) years. A total of 110 (20%) patients died, 71 (13%) received ≥1 appropriate shocks, and 33 (6.1%) received ≥1 inappropriate shocks. No patients received a His bundle ablation and biventricular pacing percentage was not analyzed. Multivariable Cox regression analysis showed that a history of atrial fibrillation (AF) (HR 1.74 CI 1.06-2.86), higher creatinine (HR 1.12; CI 1.08-1.16), and a poorer left ventricular ejection fraction (LVEF) (HR 0.97; CI 0.94-1.01) independently predict all-cause mortality. In the entire cohort, history of AF and secondary prevention were independent predictors of appropriate shocks and variables associated with inappropriate shocks were history of AF and QRS ≥150 milliseconds. In primary prevention patients, history of AF also predicted appropriate shocks as did ischemic cardiomyopathy and poorer LVEF. History of AF, QRS ≥150 milliseconds, and lower creatinine were associated with inappropriate shocks in this subgroup. Appropriate shocks increased mortality risk, but inappropriate shocks did not. In symptomatic CHF patients treated with CRT-D, history of AF is an independent risk factor not only for mortality, but also for appropriate and inappropriate shocks. Further efforts in AF management may optimize the care in CRT-D patients. © 2013 Wiley Periodicals, Inc.

[Morphological and electrophysiological changes of the heart atria in necropsy patients with atrial fibrillation - a pilot study].

PubMed

Matějková, Adéla; Steiner, Ivo

2014-01-01

Atrial fibrillation (AF), the most common supraventricular tachycardia, has a morphological base, so called remodelation of atrial myocardium, with its abnormal conduction pattern as a consequence. The remodelation regards electrical, contractile, and structural properties. In this pilot study we attempted to find relations between the myocardial morphological (scarring, amyloidosis, left atrial enlargement) and electrophysiological (ECG characteristics of the P-wave) changes in patients with AF. We examined 40 hearts of necropsy patients - 20 with a history of AF and 20 with no history of AF. Grossly, the heart weight and the size of the left atrium (LA) were evaluated. Histologically, 7 standard sites from the atria were examined. In each specimen, the degree of myocardial scarring and of deposition of isolated atrial amyloid (IAA) were assessed. We failed to show any significant difference in the P-wave pattern between patients with and without AF. Morphologically, however, there were several differences - the patients with AF had significantly heavier hearts, larger left atria, more severely scarred myocardium of the LA and the atrial septum, and more severe deposition of IAA in both atria in comparison to the control group of patients with sinus rhythm. The left atrial distribution of both fibrosis and amyloidosis was irregular. In patients with AF the former was most pronounced in the LA ceiling while the latter in the LA anterior wall. The entire series showed more marked amyloidosis in the left than in the right atrium. An interesting finding was the universal absence of IAA in the sinoatrial node. The knowledge of distribution of atrial myocardial structural changes could be utilized by pathologists in taking specimens for histology and also by cardiologists in targeting the radiofrequency ablation therapy.

Reappraisal of the clinical implications of adenosine triphosphate in terms of the prediction of reconnection sites in cases with electrical isolation of the pulmonary veins.

PubMed

Okishige, Kaoru; Aoyagi, Hideshi; Ihara, Kensuke; Iwai, Shinsuke; Nakamura, Tomofumi; Yamashita, Mitsumi; Katoh, Nobutaka; Hasegawa, Tomoaki; Kawaguchi, Naohiko; Keida, Takehiko; Sasano, Tetsuo; Hirao, Kenzo

2015-11-01

Dormant conduction (DC) induced by intravenous adenosine triphosphate (ATP) after pulmonary vein (PV) isolation (PVI) could predict subsequent PV reconnection (RC) sites. This study aimed to investigate the relationship between the DC and RC sites during the long-term follow-up. Ninety-one consecutive patients (62 males; mean age, 62 ± 11 years) with symptomatic persistent (n = 18) or paroxysmal (n = 73) atrial fibrillation (AF) who underwent PVI were included in this study. After a successful PVI, we administered ATP to reveal the DC sites. In total, DC sites were observed in 46 (51%) patients, and all were left un-ablated after marking or tagging all of them using fluoroscopic images and a three-dimensional (3D) mapping system. After the follow-up period (14.8 ± 3.6 months), AF recurred in 29 (32%) patients, all of whom had a DC in the initial ablation session, and underwent redo sessions. We divided the DC sites into three groups; in group A, the RC sites differed from the DC sites, in group B, the RC sites were identical to the DC sites, and in group C, the RC sites involved both DC and other sites. As a result, 20 (69%), 3 (11.5%), and 6 (19.5%) patients belonged to groups A, B, and C, respectively. Statistical analyses comparing the agreement between DC and the RC sites yielded a weak relationship. DC sites implying RC sites had a weak agreement, and other options to predict RC sites will be required to improve the clinical benefit of CA of AF.

CoolLoop® First: A First In Man Study To Test A Novel Circular Cryoablation System In Paroxysmal Atrial Fibrillation.

PubMed

Stuehlinger, Markus; Hoenig, Simon; Spuller, Karin; Koman, Christian; Stoeger, Markus; Poelzl, Gerhard; Ulmer, Hanno; Pachinger, Otmar; Steinwender, Clemens

2015-01-01

Pulmonary vein (PV) isolation is the mainstay of catheter treatment of paroxysmal atrial fibrillation (AF). The CoolLoop® cryoablation catheter (AFreeze® GmbH; Innsbruck, Austria) was developed to create wide and complete circular lesions around the PVs. In this study we evaluated feasibility and safety of this novel ablation system in humans. 10 patients (6M/4F; 57.6±7.6y) with paroxysmal AF were included in 2 referral centers. The CoolLoop® catheter was positioned at each PV antrum using a steerable transseptal sheath. Subsequently, 2-6 double-freezes over 5min were performed at each vein and PV-isolation was assessed thereafter using a circular mapping catheter. During cryoablation of the right PVs, pacing was used to monitor phrenic nerve function. The CoolLoop® catheter could be successfully positioned at each PV. A mean of 5.6±1.8 cryoablations were performed in the LSPV, 5.2±1.6 in the LIPV, 6.3±2.5 in the RSPV and 5.4±1.6 in the RIPV, respectively. Mean procedure time was 251±60min and mean fluoroscopy time was 44.0±13.2min. 6 / 10 LSPV, 6 / 10 LIPV, 5 / 10 RSPV and 6 / 10 RIPV could be isolated exclusively using the novel cryoablation system. One patient developed groin hematoma and a brief episode of ST-elevation due to air embolism was observed in another subject. No other clinical complications occurred during 3 months of follow up. PV-isolation for paroxysmal atrial fibrillation using the CoolLoop® catheter is feasible and appears safe. Clinical long term efficacy still needs to be evaluated and will be compared with established catheters used for AF ablation.

Clinical impact of quantitative left atrial vortex flow analysis in patients with atrial fibrillation: a comparison with invasive left atrial voltage mapping.

PubMed

Lee, Jung Myung; Hong, Geu-Ru; Pak, Hui-Nam; Shim, Chi Young; Houle, Helene; Vannan, Mani A; Kim, Minji; Chung, Namsik

2015-08-01

Recently, left atrial (LA) vortex flow analysis using contrast transesophageal echocardiography (TEE) has been shown to be feasible and has demonstrated significant differences in vortex flow morphology and pulsatility between normal subjects and patients with atrial fibrillation (AF). However, the relationship between LA vortex flow and electrophysiological properties and the clinical significance of LA vortex flow are unknown. The aims of this study were (1) to compare LA vortex flow parameters with LA voltage and (2) to assess the predictive value of LA vortex flow parameters for the recurrence of AF after radiofrequency catheter ablation (RFCA). Thirty-nine patients with symptomatic non-valvular AF underwent contrast TEE before undergoing RFCA for AF. Quantitative LA vortex flow parameters were analyzed by Omega flow (Siemens Medical Solution, Mountain View, CA, USA). The morphology and pulsatility of LA vortex flow were compared with electrophysiologic parameters that were measured invasively. Hemodynamic, electrophysiological, and vortex flow parameters were compared between patients with and without early recurrence of AF after RFCA. Morphologic parameters, including LA vortex depth, length, width, and sphericity index were not associated with LA voltage or hemodynamic parameters. The relative strength (RS), which represents the pulsatility power of LA, was positively correlated with LA voltage (R = 0.53, p = 0.01) and LA appendage flow velocity (R = 0.73, p < 0.001) and negatively correlated with LA volume index (R = -0.56, p < 0.001). Patients with recurrent AF after RFCA showed significantly lower RS (1.7 ± 0.2 vs 1.9 ± 0.4, p = 0.048) and LA voltage (0.9 ± 0.7 vs 1.7 ± 0.8, p = 0.004) than patients without AF recurrence. In the relatively small LA dimension group (LA volume index ≤ 33 ml/m(2)), RS was significantly lower (2.1 ± 0.3 vs 1.7 ± 0.1, p = 0.029) in patients with the recurrent AF. Quantitative LA vortex flow analysis, especially RS, correlated well with LA voltage. Decreased pulsatility strength in the LA was associated with recurrent AF. LA vortex may have incremental value in predicting the recurrence of AF.

Dabigatran exhibits low intensity of left atrial spontaneous echo contrast in patients with nonvalvular atrial fibrillation as compared with warfarin.

PubMed

Watanabe, Tetsuya; Shinoda, Yukinori; Ikeoka, Kuniyasu; Inui, Hirooki; Fukuoka, Hidetada; Sunaga, Akihiro; Kanda, Takashi; Uematsu, Masaaki; Hoshida, Shiro

2017-03-01

The presence of spontaneous echo contrast (SEC) in the left atrium has been reported to be an independent predictor of thromboembolic risk in patients with atrial fibrillation (AF). Dabigatran was associated with lower rates of stroke and systemic embolism as compared with warfarin when administered at a higher dose. Between July 2011 and October 2015, nonvalvular AF patients treated with warfarin or dabigatran who had transesophageal echocardiography prior to ablation therapy for AF were enrolled. The intensity of SEC was classified into four grades, from 0 to 3. Univariate and multivariate analysis was performed to analyze factors associated with SEC. Sixty-five patients were on dabigatran and 65 were on warfarin, with the prothrombin time in therapeutic range. There were no significant differences in the age, CHADS2 score, left atrial dimension, and left atrial appendage flow between the two groups. However, there were more grade 2 or higher patients with left atrial SEC in the warfarin group (n = 20) than in the dabigatran group (n = 2) (p < 0.001). When multivariate regression analysis was performed, grade 2 or higher left atrial SEC was independently associated with no dabigatran usage in addition to high brain natriuretic peptide level and high incidence of diabetes mellitus or persistent AF. Thus, dabigatran exhibited low intensity of left atrial SEC in nonvalvular AF patients as compared with warfarin.

The AFFORD clinical decision aid to identify emergency department patients with atrial fibrillation at low risk for 30-day adverse events.

PubMed

Barrett, Tyler W; Storrow, Alan B; Jenkins, Cathy A; Abraham, Robert L; Liu, Dandan; Miller, Karen F; Moser, Kelly M; Russ, Stephan; Roden, Dan M; Harrell, Frank E; Darbar, Dawood

2015-03-15

There is wide variation in the management of patients with atrial fibrillation (AF) in the emergency department (ED). We aimed to derive and internally validate the first prospective, ED-based clinical decision aid to identify patients with AF at low risk for 30-day adverse events. We performed a prospective cohort study at a university-affiliated tertiary-care ED. Patients were enrolled from June 9, 2010, to February 28, 2013, and followed for 30 days. We enrolled a convenience sample of patients in ED presenting with symptomatic AF. Candidate predictors were based on ED data available in the first 2 hours. The decision aid was derived using model approximation (preconditioning) followed by strong bootstrap internal validation. We used an ordinal outcome hierarchy defined as the incidence of the most severe adverse event within 30 days of the ED evaluation. Of 497 patients enrolled, stroke and AF-related death occurred in 13 (3%) and 4 (<1%) patients, respectively. The decision aid included the following: age, triage vitals (systolic blood pressure, temperature, respiratory rate, oxygen saturation, supplemental oxygen requirement), medical history (heart failure, home sotalol use, previous percutaneous coronary intervention, electrical cardioversion, cardiac ablation, frequency of AF symptoms), and ED data (2 hours heart rate, chest radiograph results, hemoglobin, creatinine, and brain natriuretic peptide). The decision aid's c-statistic in predicting any 30-day adverse event was 0.7 (95% confidence interval 0.65, 0.76). In conclusion, in patients with AF in the ED, Atrial Fibrillation and Flutter Outcome Risk Determination provides the first evidence-based decision aid for identifying patients who are at low risk for 30-day adverse events and candidates for safe discharge. Copyright © 2015 Elsevier Inc. All rights reserved.

Biatrial Electrical and Structural Atrial Changes in Heart Failure: Electroanatomic Mapping in Persistent Atrial Fibrillation in Humans.

PubMed

Prabhu, Sandeep; Voskoboinik, Aleksandr; McLellan, Alex J A; Peck, Kah Y; Pathik, Bhupesh; Nalliah, Chrishan J; Wong, Geoff R; Azzopardi, Sonia M; Lee, Geoffrey; Mariani, Justin; Ling, Liang-Han; Taylor, Andrew J; Kalman, Jonathan M; Kistler, Peter M

2018-01-01

This study sought to characterize the biatrial substrate in heart failure (HF) and persistent atrial fibrillation (PeAF). Atrial fibrillation (AF) and HF frequently coexist; however, the contribution of HF to the biatrial substrate in PeAF is unclear. Consecutive patients with PeAF and normal left ventricular (NLV) systolic function (left ventricular ejection fraction [LVEF] >55%) or idiopathic cardiomyopathy (LVEF ≤45%) undergoing AF ablation were enrolled. In AF, pulmonary vein (PV) cycle length (PVCL) was recorded via a multipolar catheter in each PV and in the left atrial appendage for 100 consecutive cycles. After electrical cardioversion, biatrial electroanatomic mapping was performed. Complex electrograms, voltage, scarring, and conduction velocity were assessed. Forty patients, 20 patients with HF (mean age: 62 ± 8.9 years; AF duration: 15 ± 11 months; LVEF: 33 ± 8.4%) and 20 with NLV (mean age: 59 ± 6.7 years; AF duration: 14 ± 9.1 months; p = 0.69; mean LVEF: 61 ± 3.6%; p < 0.001), were enrolled. HF reduced biatrial tissue voltage (p < 0.001) with greater voltage heterogeneity (p < 0.001). HF was associated with significantly more biatrial fractionation (left atrium [LA]: 30% vs. 9%; p < 0.001; right atrium [RA]: 28% vs. 11%; p < 0.001), low voltage (<0.5 mV) (LA: 23% vs. 6%; p = 0.002; RA: 20% vs 11%; p = 0.006), and scarring (<0.05 mV) in the LA (p = 0.005). HF was associated with a slower average PVCL (185 vs. 164 ms; p = 0.016), which correlated significantly with PV antral bipolar voltage (R = -0.62; p < 0.001) and fractionation (R = 0.46; p = 0.001). HF is associated with significantly reduced biatrial tissue voltage, fractionation, and prolongation of PVCL. Advanced biatrial remodeling may have implications for invasive and noninvasive rhythm control strategies in patients with AF and HF. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Comparison of Left Atrial Bipolar Voltage and Scar Using Multielectrode Fast Automated Mapping versus Point-by-Point Contact Electroanatomic Mapping in Patients With Atrial Fibrillation Undergoing Repeat Ablation.

PubMed

Liang, Jackson J; Elafros, Melissa A; Muser, Daniele; Pathak, Rajeev K; Santangeli, Pasquale; Supple, Gregory E; Schaller, Robert D; Frankel, David S; Dixit, Sanjay

2017-03-01

Bipolar voltage criteria to delineate left atrial (LA) scar have been derived using point-by-point (PBP) contact electroanatomical mapping. It remains unclear how PBP-derived LA scar correlates with multielectrode fast automated mapping (ME-FAM) derived scar. We aimed to correlate scar and bipolar voltages from LA maps created using PBP versus ME-FAM. In consecutive patients undergoing repeat AF ablation, 2 separate LA maps were created using PBP and ME-FAM during sinus rhythm before ablation. Contiguous areas in the LA with a bipolar voltage cutoff of ≤0.2 mV represented dense scar; LA scar percentage was calculated for each map. Each LA shell was divided into 9 regions and each region further subdivided into 4 quadrants for additional analysis; mean voltages of all points obtained using PBP versus ME-FAM in each region were compared. Forty maps (20 PBP: mean 228.5 ± 95.6 points; 20 ME-FAM: 923.0 ± 382.6 points) were created in 20 patients. Mapping time with ME-FAM was shorter compared with PBP (13.3 ± 5.3 vs. 34.4 ± 13.1 minutes; P < 0.001). Mean LA scar percentage was higher with PBP compared with ME-FAM (15.5 ± 17.1% vs. 12.8 ± 17.6%; P = 0.04). Mean PBP voltage distribution was lower (compared with ME-FAM) in the septum (0.95 ± 0.73 vs. 1.46 ± 0.99 mV; P = 0.009), posterior wall (0.84 ± 0.42 vs. 1.40 ± 0.83 mV; P = 0.0008), roof (0.78 ± 0.80 vs. 1.39 ± 1.09 mV; P = 0.0003), and right PV-LA junction (0.34 ± 0.25 vs. 0.59 ± 0.50 mV; P = 0.01) regions, while voltages were similar in all other LA regions (all P > 0.05). In AF patients undergoing repeat ablation, bipolar voltage is greater in certain LA segments with ME-FAM compared with PBP mapping. © 2016 Wiley Periodicals, Inc.

Interatrial septal motion as a novel index to predict left atrial pressure.

PubMed

Masai, Kumiko; Kishima, Hideyuki; Takahashi, Satoshi; Ashida, Kenki; Goda, Akiko; Mine, Takanao; Asakura, Masanori; Ishihara, Masaharu; Masuyama, Tohru

2018-01-22

We investigated whether the interatrial septal (IAS) motion of each heartbeat which is observed by transesophageal echocardiography reflects left atrial pressure (LAP) in patients with atrial fibrillation (AF). We studied 100 patients (70 males, age 67 ± 9 years) who underwent catheter ablation for AF. The amplitude of IAS motion was measured using M-mode and averaged for five cardiac cycles. Left and right atrial pressures, the left to right atrial pressure gradient were directly measured during the catheter ablation. In patients with sinus rhythm during measurement, elevated mean LAP, larger maximum left to right atrial pressure gradient, and greater left atrial emptying fraction were associated with IAS motion. The optimal cut-off value of the IAS motion for predicting high LAP (mean LAP > 15 mmHg) was 8.5 mm (sensitivity 100%, specificity 70.1%) in patients with sinus rhythm during pressure measurement. In addition, all patients were divided into 6 groups based on rhythm during measurement and cutoff value of IAS motion. In patients with sinus rhythm during measurement, low IAS motion group had a highest prevalence of elevated LAP compared with high IAS motion group (64 vs. 0%, P < 0.0001). The amplitude of interatrial septal motion during sinus rhythm reflects left atrial pressure in patients with atrial fibrillation. Interatrial septal motion could be a new index to predict elevated left atrial pressure.

Management of atrial fibrillation in seven European countries after the publication of the 2010 ESC Guidelines on atrial fibrillation: primary results of the PREvention oF thromboemolic events--European Registry in Atrial Fibrillation (PREFER in AF).

PubMed

Kirchhof, Paulus; Ammentorp, Bettina; Darius, Harald; De Caterina, Raffaele; Le Heuzey, Jean-Yves; Schilling, Richard John; Schmitt, Josef; Zamorano, Jose Luis

2014-01-01

We sought to describe the management of patients with atrial fibrillation (AF) in Europe after the release of the 2010 AF Guidelines of the European Society of Cardiology. The PREFER in AF registry enrolled consecutive patients with AF from January 2012 to January 2013 in 461 centres in seven European countries. Seven thousand two hundred and forty-three evaluable patients were enrolled, aged 71.5 ± 11 years, 60.1% male, CHA2DS2VASc score 3.4 ± 1.8 (mean ± standard deviation). Thirty per cent patients had paroxysmal, 24.0% had persistent, 7.2% had long-standing persistent, and 38.8% had permanent AF. Oral anticoagulation was used in the majority of patients: 4799 patients (66.3%) received a vitamin K antagonist (VKA) as mono-therapy, 720 patients a combination of VKA and antiplatelet agents (9.9%), 442 patients (6.1%) a new oral anticoagulant drugs (NOAC). Antiplatelet agents alone were given to 808 patients (11.2%), no antithrombotic therapy to 474 patients (6.5%). Of 7034 evaluable patients, 5530 (78.6%) patients were adequately rate controlled (mean heart rate 60-100 bpm). Half of the patients (50.7%) received rhythm control therapy by electrical cardioversion (18.1%), pharmacological cardioversion (19.5%), antiarrhythmic drugs (amiodarone 24.1%, flecainide or propafenone 13.5%, sotalol 5.5%, dronedarone 4.0%), and catheter ablation (5.0%). The management of AF patients in 2012 has adapted to recent evidence and guideline recommendations. Oral anticoagulant therapy with VKA (majority) or NOACs is given to over 80% of eligible patients, including those at risk for bleeding. Rate is often adequately controlled, and rhythm control therapy is widely used.

Reduction in radiation dose for atrial fibrillation ablation over time: A 12-year single-center experience of 2344 patients.

PubMed

Voskoboinik, Aleksandr; Kalman, Elana S; Savicky, Yonatan; Sparks, Paul B; Morton, Joseph B; Lee, Geoffrey; Kistler, Peter M; Kalman, Jonathan M

2017-06-01

Pulmonary vein isolation (PVI) is a well-established treatment of atrial fibrillation (AF), with contact force (CF)-sensing catheters joining 3-dimensional mapping systems and image integration as technological advancements over the last decade. The purpose of this study was to analyze trends in radiation exposure for AF ablation over the last 12 years at our center. We reviewed prospectively collected data of 2344 consecutive PVI procedures for either paroxysmal or persistent AF between January 2004 and December 2015. During this period, all cases used 3-dimensional mapping systems, with 8 software and 2 hardware upgrades. Primary endpoints were fluoroscopy time, absorbed dose (Air Kerma in mGy), and effective dose (mSv). In total, 1914 patients underwent initial PVI, and 430 patients underwent redo PVI using radiofrequency energy. Fluoroscopy time, and absorbed and effective doses significantly and progressively decreased over the 12-year period for initial PVI as follows: 2004-2006: 61 ± 27 minutes; 2007-2009: 46 ± 14 minutes, 1365 ± 1369 mGy, 11.3 ± 12.5 mSv; 2010-2012: 31 ± 11, 464 ± 339 mGy, 9.0 ± 10.4 mSv; and 2013-2015: 17 ± 9 minutes, 304 ± 758 mGy, 5.5 ± 6.7 mSv. CF-sensing catheters were used for 357/508 PVI only cases between 2014 and 2015. Fluoroscopy times (11 ± 5 vs 21 ± 8 minutes; P <.001) and absorbed dose (200 ± 524 vs 470 ± 1326 mGy; P = .004) were significantly shorter with this catheter. Radiation exposure has dramatically decreased over the last decade for PVI and is related to operator experience, annual case volume, technology evolution, and more recently CF-sensing catheters. This has significant implications for both patient and operator long-term risk. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Importance of rate control or rate regulation for improving exercise capacity and quality of life in patients with permanent atrial fibrillation and normal left ventricular function: a randomised controlled study

PubMed Central

Levy, T; Walker, S; Mason, M; Spurrell, P; Rex, S; Brant, S; Paul, V

2001-01-01

OBJECTIVE—To determine the importance of rhythm regulation or rate control in patients with permanent atrial fibrillation (AF) and normal left ventricular function.
PATIENTS AND INTERVENTIONS—Thirty six patients with a mixed fast and slow ventricular response rate to their AF were randomised to either His bundle ablation (HBA) and VVIR pacemaker (HBA group) or VVI pacemaker and atrioventricular modifying drugs (Med group). Outcomes assessed at one, three, six, and 12 months included exercise duration and quality of life.
RESULTS—Exercise duration significantly improved from baseline in both groups. There was no difference in outcome between the groups (Med +40% v HBA +20%, p = NS). The heart rate profile on exercise was similarly slowed in both groups compared to baseline. Quality of life significantly improved in both treatment arms for the modified Karolinska questionnaire (KQ) (Med +50% v HBA +50%, p = NS) and the Nottingham health profile (NHP) (Med +40% v HBA +20%, p = NS). However, for the individual symptom scores of each questionnaire more were improved in the Med group (KQ-Med 6 improved v HBA 4, NHP-Med 3 v HBA 1). Left ventricular function was equally preserved by both treatments during follow up.
CONCLUSION—In these patients control of ventricular response rate with either HBA + VVIR pacemaker or atrioventricular modifying drugs + VVI pacemaker will lead to a significant improvement in exercise duration and quality of life. Rhythm regulation by HBA did not confer additional benefit, suggesting rate control alone is necessary for the successful symptomatic treatment of these patients in permanent AF.


Keywords: ablation; atrial fibrillation; pacemaker; atrioventricular modifying drugs PMID:11156667

High-voltage zones within the pulmonary vein antra: Major determinants of acute pulmonary vein reconnections after atrial fibrillation ablation.

PubMed

Nagashima, Koichi; Watanabe, Ichiro; Okumura, Yasuo; Iso, Kazuki; Takahashi, Keiko; Watanabe, Ryuta; Arai, Masaru; Kurokawa, Sayaka; Nakai, Toshiko; Ohkubo, Kimie; Yoda, Shunichi; Hirayama, Atsushi

2017-08-01

Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is mainly due to PV reconnections. Patient-specific tissue characteristics that may contribute remain unidentified. This study aimed to assess the relationship between the bipolar electrogram voltage amplitudes recorded from the PV-left atrial (LA) junction and acute PV reconnection sites. Three-dimensional LA voltage maps created before an extensive encircling PVI in 47 AF patients (31 men; mean age 62 ± 11 years) were examined for an association between the EGM voltage amplitude recorded from the PV-LA junction and acute post-PVI PV reconnections (spontaneous PV reconnections and/or ATP-provoked dormant PV conduction). Acute PV reconnections were observed in 17 patients (36%) and in 24 (3%) of the 748 PV segments (16 segments per patient) and were associated with relatively high bipolar voltage amplitudes (3.26 ± 0.85 vs. 1.79 ± 1.15 mV, p < 0.0001) and a relatively low mean force-time integral (FTI) (428 ± 56 vs. 473 ± 76 gs, p = 0.0039) as well as FTI/PV-LA bipolar voltage (137 [106, 166] vs. 295 [193, 498] gs/mV, p < 0.0001). An analysis of the receiver operating characteristic curves revealed a high prognostic performance of the LA bipolar voltage and FTI/PV-LA bipolar voltage for acute PV reconnections (areas under the curve: 0.86 and 0.89, respectively); the best cutoff values were >2.12 mV and ≤183 gs/mV, respectively. The PV-LA voltage on the PV-encircling ablation line and FTI/PV-LA voltage were related to the acute post-PVI PV reconnections. A more durable ablation strategy is warranted for high-voltage zones.

Effect of pre-procedural interrupted apixaban on heparin anticoagulation during catheter ablation for atrial fibrillation: a prospective observational study.

PubMed

Bin Abdulhak, Aref A; Kennedy, Kevin F; Gupta, Sanjaya; Giocondo, Michael; Ramza, Brian; Wimmer, Alan P

2015-11-01

Effective intraprocedural anticoagulation is considered essential to minimize the risk of thromboembolism in catheter ablation (CA) of atrial fibrillation (AF). The effect of interrupted apixaban on intraprocedural heparin dosing requirements and levels of achieved anticoagulation with heparin has not been well studied. The purpose of the present study was to compare heparin administration and activated clotted times (ACTs) for patients undergoing CA for AF treated with interrupted apixaban before the procedure with patients on uninterrupted warfarin. Consecutive patients undergoing CA for AF treated with interrupted apixaban or uninterrupted warfarin were prospectively enrolled. Heparin administration determined by a standard protocol and normalized to patient weight and procedure duration, as well as rapidity, and degree of anticoagulation with heparin (as measured by mean ACT, peak ACT, time to ACT ≥300 s, and time to ACT ≥350 s) were compared between the groups. Forty-eight patients were enrolled (25 apixaban and 23 warfarin). Heparin administered by bolus (51.3 ± 21.5 vs 27.8 ± 9.6 units/kg/h; p < 0.001) and mean heparin drip rate (25.3 ± 3.6 vs 20.7 ± 2.4 units/kg/h; p < 0.001) were significantly higher in the apixaban group compared to the warfarin group. Despite greater heparin administration, apixaban patients achieved a significantly lower mean ACT (332.3 ± 17.0 vs 384.5 ± 53.9; p < 0.001) and peak ACT (369.5 ± 22.6 vs 432.3 ± 75.8, p < 0.001) compared to the warfarin group. The time to ACT ≥350 s (66.7 ± 35.8 vs 26.9 ± 34.0; p < 0.001) was significantly longer for apixaban-treated patients. Outcome differences persisted after analysis using linear models and Cox proportional hazard regression with adjustment for propensity scores. A standard intraprocedural heparin protocol results in delayed and lower levels of anticoagulation as measured by the ACT for interrupted apixaban-treated patients in comparison to those on uninterrupted warfarin during CA of AF.

Stroke risks and patterns of warfarin therapy among atrial fibrillation patients post radiofrequency ablation: A real-world experience.

PubMed

Zhang, Juan; Liu, Xingpeng; Liu, Xiaoqing; Yin, Xiandong; Wang, Yanjiang; Lu, Xiaoying; Yang, Xinchun

2017-11-01

We assessed the thromboembolic risks of atrial fibrillation (AF) patients who had undergone radiofrequency ablation (RFA) using the CHADS2-VASc risk scoring system and further investigated the patterns of warfarin use for thromboprophylaxis according to patient thromboembolic risk scores.In this study, we analyzed the stroke risks of patients who had undergone RFA for AF at our hospital between March 2014 and June 2016 using the CHADS2, CHADS2-VASc, and Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly (> 65 years) (HAS-BLED) scoring systems. We retrieved medications, co-morbidities, and initial warfarin dosage data. The primary outcome was the percentage of patients initiated with warfarin therapy for stroke prophylaxis in AF who had a CHADS2-VASc score of 0.Totally, 309 patients were initiated with warfarin therapy for stroke prophylaxis in AF post-RFA. The baseline warfarin dosage was 2.76 ± 0.61 mg. The baseline CHADS2-VASC score was 2.93 ± 1.96 and 40 (12.95%) had a CHADS2-VASC score of 0, 42 (13.6%) had a CHADS2-VASCscore of 1, and 227 (73.5%) had a CHADS2-VASC score ≥2. The baseline CHADS2 score was 2.17 ± 1.55 and 48 (15.5%) had a CHADS2 score of 0, 68 (22.0%) had a CHADS2 score of 1, and 193 (62.5%) had a CHADS2 score ≥2. The baseline HAS-BLED score was 1.25 ± 0.91 and 69 (22.3%) had a HAS-BLED score of 0, 121 (39.2%) had a HAS-BLED score of 1, and 119 (38.5%) had a HAS-BLED score ≥2. Patients aged <65 years or 65 years, male and female patients, patients with or without hypertension, coronary heart disease, or diabetes mellitus, and patients with or without previous stroke/transient ischemic attack differed significantly in stroke risks by CHADS2-VASC, CHADS2, and HAS-BLED scores for stroke risks. Patients with different baseline international normalized ratio differed significantly in CHADS2-VASC scores. Furthermore, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and statins were of statistical significance for stroke risks.The majority of AF patients post-RFAs was of high stroke risk and received warfarin thromboprophylaxis in accordance with national guidelines. Our findings suggest that low and intermediate stroke risk patients should be evaluated for stroke risks and risk factors so that tailored warfarin thromboprophylaxis therapy can be given and inappropriate use of warfarin in AF patients can be avoided. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Oesophageal Injury During AF Ablation: Techniques for Prevention

PubMed Central

Romero, Jorge; Avendano, Ricardo; Grushko, Michael; Diaz, Juan Carlos; Du, Xianfeng; Gianni, Carola; Natale, Andrea

2018-01-01

Atrial fibrillation remains the most common arrhythmia worldwide, with pulmonary vein isolation (PVI) being an essential component in the treatment of this arrhythmia. In view of the close proximity of the oesophagus with the posterior wall of the left atrium, oesophageal injury prevention has become a major concern during PVI procedures. Oesophageal changes varying from erythema to fistulas have been reported, with atrio-oesophageal fistulas being the most feared as they are associated with major morbidity and mortality. This review article provides a detailed description of the risk factors associated with oesophageal injury during ablation, along with an overview of the currently available techniques to prevent oesophageal injury. We expect that this state of the art review will deliver the tools to help electrophysiologists prevent potential oesophageal injuries, as well as increase the focus on research areas in which evidence is lacking. PMID:29636969

Rhythm-based heartbeat duration normalization for atrial fibrillation detection.

PubMed

Islam, Md Saiful; Ammour, Nassim; Alajlan, Naif; Aboalsamh, Hatim

2016-05-01

Screening of atrial fibrillation (AF) for high-risk patients including all patients aged 65 years and older is important for prevention of risk of stroke. Different technologies such as modified blood pressure monitor, single lead ECG-based finger-probe, and smart phone using plethysmogram signal have been emerging for this purpose. All these technologies use irregularity of heartbeat duration as a feature for AF detection. We have investigated a normalization method of heartbeat duration for improved AF detection. AF is an arrhythmia in which heartbeat duration generally becomes irregularly irregular. From a window of heartbeat duration, we estimate the possible rhythm of the majority of heartbeats and normalize duration of all heartbeats in the window based on the rhythm so that we can measure the irregularity of heartbeats for both AF and non-AF rhythms in the same scale. Irregularity is measured by the entropy of distribution of the normalized duration. Then we classify a window of heartbeats as AF or non-AF by thresholding the measured irregularity. The effect of this normalization is evaluated by comparing AF detection performances using duration with the normalization, without normalization, and with other existing normalizations. Sensitivity and specificity of AF detection using normalized heartbeat duration were tested on two landmark databases available online and compared with results of other methods (with/without normalization) by receiver operating characteristic (ROC) curves. ROC analysis showed that the normalization was able to improve the performance of AF detection and it was consistent for a wide range of sensitivity and specificity for use of different thresholds. Detection accuracy was also computed for equal rates of sensitivity and specificity for different methods. Using normalized heartbeat duration, we obtained 96.38% accuracy which is more than 4% improvement compared to AF detection without normalization. The proposed normalization method was found useful for improving performance and robustness of AF detection. Incorporation of this method in a screening device could be crucial to reduce the risk of AF-related stroke. In general, the incorporation of the rhythm-based normalization in an AF detection method seems important for developing a robust AF screening device. Copyright © 2016 Elsevier Ltd. All rights reserved.

Current strategy for treatment of patients with Wolff-Parkinson-White syndrome and asymptomatic preexcitation in Europe: European Heart Rhythm Association survey.

PubMed

Svendsen, Jesper Hastrup; Dagres, Nikolaos; Dobreanu, Dan; Bongiorni, Maria Grazia; Marinskis, Germanas; Blomström-Lundqvist, Carina

2013-05-01

The aims of this survey was to provide insight into treatment activity, the strategy of treatment, and risk stratification of patients with asymptomatic and symptomatic ventricular pre-excitation across Europe. Fifty-eight centres, members of the European Heart Rhythm Association EP research network, covering 20 countries answered the survey questions. All centres were high-volume ablation centres. A younger person with asymptomatic Wolff-Parkinson-White (WPW) pattern has a higher likelihood of being risk-stratified or receiving ablation therapy compared with an older subject. Two-thirds of centres report that they have observed a decline in the number of patients ablated for an accessory pathway during the last 10 years. Pre-excited atrial fibrillation is rarely seen. Discontinuation of a scheduled WPW ablation due to close vicinity of the accessory pathway to the AV node happens very rarely. Patients with a first episode of pre-excited atrial fibrillation would immediately be referred for catheter ablation to be performed within weeks by 80.4% of the centres. A significant proportion of responders (50.9%) would use electrical cardioversion to restore sinus rhythm in a patient with pre-excited atrial fibrillation. With respect to the choice of antiarrhythmic medication for a patient with pre-excited AF, the majority (80.0%) would choose class 1C antiarrhytmic drugs while waiting for a catheter ablation. A patient seen in the emergency room with a second episode of orthodromic atrioventricular reentry tachycardia would be referred for immediate ablation by 79.2-90.6% of centres depending on the presence of pre-excitation. The volume of paediatric ablations performed on children younger than 12 years was low (46.4%: 0 patients per year; 46.4%: 1-9 patients per year). The majority of responding centres (61-69%) report that their country lack national guidelines dealing with clinical strategies related to WPW. There is a need for national guidelines dealing with clinical strategy in patients with WPW syndrome. Older individuals with asymptomatic WPW pattern have a higher risk of not receiving risk stratification or curative therapy with ablation compared with younger patients, despite the higher risk of developing atrial fibrillation.

Cardioversion and subsequent quality of life and natural history of atrial fibrillation.

PubMed

Pokorney, Sean D; Kim, Sunghee; Thomas, Laine; Fonarow, Gregg C; Kowey, Peter R; Gersh, Bernard J; Mahaffey, Kenneth W; Peterson, Eric D; Piccini, Jonathan P

2017-03-01

Cardioversion is a class I procedure for patients with symptomatic atrial fibrillation (AF) pursuing rhythm control. There are few contemporary reports on quality of life and outcomes after cardioversion. Using the nationwide prospective ORBIT-AF registry, cardioversion patients were propensity matched 3:1 to noncardioverted patients and Cox proportional hazards modeling evaluated hospitalization at 1 year in those with and without cardioversion. Cardiovascular outcomes, AF progression, and quality of life were evaluated for the matched cohorts with and without cardioversion. Among 9,642 patients, 817 patients (8%) underwent 906 cardioversions during a median follow-up of 12 (interquartile range 6-18) months. Among matched cardioverted and noncardioverted patients, 1-year cardiovascular hospitalization rates were 43% vs 21% (adjusted hazard ratio 2.2, 95% CI 1.8-2.8, P<.001), and sinus rhythm at both first and second follow-ups was 36% vs 27% (P=.042), respectively. Findings were similar among first-time cardioversion patients. Matched cardioversion patients did not exhibit greater symptom improvement (34% vs 42%) or less symptomatic progression (15% vs 4%) by European Heart Rhythm Association scores. Cardioversion was associated with AF progression with an odds ratio of 1.6 (95% CI 1.2-2.2, P=.001) after cardioversion and 2.7 (P<.001) after first cardioversion vs matched noncardioversion patients. After cardioversion, only 18% of patients not previously on an antiarrhythmic started one, less than 5% underwent ablation, and 22% stopped their antiarrhythmic. Cardioversion was not associated with improved AF-related quality of life or less progression. Many patients who undergo cardioversion do not receive adjunctive rhythm control therapies. These findings may help to better inform therapeutic decision making. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Oral anticoagulant use in cardiovascular disorders: a perspective on present and potential indications for rivaroxaban.

PubMed

Camm, A John; Fox, Keith A A

2018-05-21

Four non-vitamin-K-antagonist oral anticoagulants (NOACs) have been approved for use in various cardiovascular indications. The direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors apixaban, edoxaban and rivaroxaban are now increasingly used in clinical practice. For some of these agents, available data from real-world studies support the efficacy and safety data in phase III clinical trials. This review aims to summarize the current status of trials and observational studies of oral anticoagulant use over the spectrum of cardiovascular disorders (excluding venous thrombosis), provide a reference source beyond stroke prevention for atrial fibrillation (AF) and examine the potential for novel applications in the cardiovascular field. We searched the recent literature for data on completed and upcoming trials of oral anticoagulants with a particular focus on rivaroxaban. Recent data in specific patient subgroups, such as patients with AF undergoing catheter ablation or cardioversion, have led to an extended approval for rivaroxaban, whereas the other NOACs have ongoing or recently completed trials in this setting. However, there are unmet medical needs for several arterial thromboembolic-related conditions, including patients with: AF and acute coronary syndrome, AF and coronary artery disease undergoing elective percutaneous coronary intervention, coronary artery disease and peripheral artery disease, implanted cardiac devices, and embolic stroke of unknown source. NOACs may provide alternative treatment options in areas of unmet need, and numerous studies are underway to assess their benefit-risk profiles in these settings.

Left atrial appendage dimensions predict the risk of stroke/TIA in patients with atrial fibrillation.

PubMed

Beinart, Roy; Heist, E Kevin; Newell, John B; Holmvang, Godtfred; Ruskin, Jeremy N; Mansour, Moussa

2011-01-01

Risk of Stroke/TIA in Patients With Atrial Fibrillation. Most strokes in patients with atrial fibrillation (AF) arise from thrombus formation in left atrial appendage (LAA). Our aim was to identify LAA features associated with a higher stroke risk in patients with AF using magnetic resonance imaging and angiography (MRI/MRA). The study included 144 patients with nonvalvular AF who were not receiving warfarin and who underwent MRI/MRA prior to catheter ablation for AF. LAA volume, LAA depth, short and long axes of LAA neck, and numbers of lobes were measured. Of the 144 patients, 18 had a prior stroke or transient ischemic attack (TIA) (13 and 5, respectively). Compared with patients who had no history of stroke/TIA, these patients were older, had higher prevalence of hypertension and hyperlipidemia and had higher LAA volume (22.9 ± 9.6 cm(3) vs. 14.5 ± 7.1 cm(3) , P < 0.001). Their LAA depth (3.76 ± 0.9 cm vs. 3.21 ± 0.8 cm, P = 0.006) and the long and short axes of the LAA neck (3.12 ± 0.7 cm vs. 2.08 ± 0.7 cm, P < 0.001; 2.06 ± 0.5 cm vs. 1.37 ± 0.4 cm, P < 0.001, respectively) were larger. Using stepwise logistic regression model, the only statistically significant multivariable predictors of events were age (OR = 1.21 per year, 95% CI 1.06-1.38, P = 0.004), aspirin use (OR = 0.039, 95% CI 0.005-0.28, P = 0.001), and LAA neck dimensions (short axis × long axis) (OR = 3.59 per cm(2) , 95% CI 1.93-6.69, P < 0.001). LAA dimensions predict strokes/TIAs in patients with AF. LAA assessment by MRI/MRA can potentially be used as an adjunctive tool for risk stratification for embolic events in AF patients. © 2010 Wiley Periodicals, Inc.

Clinical and electrophysiological evaluation of pediatric Wolff-Parkinson-White patients

PubMed Central

Yıldırım, Işıl; Özer, Sema; Karagöz, Tevfik; Şahin, Murat; Özkutlu, Süheyla; Alehan, Dursun; Çeliker, Alpay

2015-01-01

Objective: Wolff-Parkinson-White (WPW) syndrome presents with paroxysmal supraventricular tachycardia and is characterized by electrocardiographic (ECG) findings of a short PR interval and a delta wave. The objective of this study was to evaluate the electrophysiological properties of children with WPW syndrome and to develop an algorithm for the management of these patients with limited access to electrophysiological study. Methods: A retrospective review of all pediatric patients who underwent electrophysiological evaluation for WPW syndrome was performed. Results: One hundred nine patients underwent electrophysiological evaluation at a single tertiary center between 1997 and 2011. The median age of the patients was 11 years (0.1-18). Of the 109 patients, 82 presented with tachycardia (median age 11 (0.1-18) years), and 14 presented with syncope (median age 12 (6-16) years); 13 were asymptomatic (median age 10 (2-13) years). Induced AF degenerated to ventricular fibrillation (VF) in 2 patients. Of the 2 patients with VF, 1 was asymptomatic and the other had syncope; the accessory pathway effective refractory period was ≤180 ms in both. An intracardiac electrophysiological study was performed in 92 patients, and ablation was not attempted for risk of atrioventricular block in 8 (8.6%). The success and recurrence rate of ablation were 90.5% and 23.8% respectively. Conclusion: The induction of VF in 2 of 109 patients in our study suggests that the prognosis of WPW in children is not as benign as once thought. All patients with a WPW pattern on the ECG should be assessed electrophysiologically and risk-stratified. Ablation of patients with risk factors can prevent sudden death in this population. PMID:26006136

Alignment-free microbial phylogenomics under scenarios of sequence divergence, genome rearrangement and lateral genetic transfer.

PubMed

Bernard, Guillaume; Chan, Cheong Xin; Ragan, Mark A

2016-07-01

Alignment-free (AF) approaches have recently been highlighted as alternatives to methods based on multiple sequence alignment in phylogenetic inference. However, the sensitivity of AF methods to genome-scale evolutionary scenarios is little known. Here, using simulated microbial genome data we systematically assess the sensitivity of nine AF methods to three important evolutionary scenarios: sequence divergence, lateral genetic transfer (LGT) and genome rearrangement. Among these, AF methods are most sensitive to the extent of sequence divergence, less sensitive to low and moderate frequencies of LGT, and most robust against genome rearrangement. We describe the application of AF methods to three well-studied empirical genome datasets, and introduce a new application of the jackknife to assess node support. Our results demonstrate that AF phylogenomics is computationally scalable to multi-genome data and can generate biologically meaningful phylogenies and insights into microbial evolution.

[ESC guidelines on atrial fibrillation 2016 : Summary of the most relevant recommendations and modifications].

PubMed

Eckardt, L; Häusler, K G; Ravens, U; Borggrefe, M; Kirchhof, P

2016-12-01

The first European Society of Cardiology (ESC) guidelines on atrial fibrillation (AF) developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS) were published in August 2016. These guidelines replace the revised guidelines from 2012 and contain some interesting new aspects. The topics range from the pathophysiology through diagnostics, therapy and stroke prevention up to special clinical situations, such as atrial fibrillation in cardiopathy, sport and pregnancy. Early screening, patient informed consent, individualized therapy and the modification of factors promoting atrial fibrillation are of particular importance. The guidelines recommend the establishment of AF heart teams, containing specialists from various disciplines. The guidelines also underline the importance of non-vitamin K‑dependent oral anticoagulants (NOAC) for stroke prevention compared to standard anticoagulants with vitamin K antagonists. For symptomatic and especially paroxysmal atrial fibrillation, the guidelines emphasize the importance of an antiarrhythmic treatment with catheter ablation and/or pharmaceutical antiarrhythmic therapy in addition to a frequency regulating therapy.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1

PubMed Central

Diener, Hans-Christoph; Aisenberg, James; Ansell, Jack; Atar, Dan; Breithardt, Günter; Eikelboom, John; Ezekowitz, Michael D.; Granger, Christopher B.; Halperin, Jonathan L.; Hohnloser, Stefan H.; Hylek, Elaine M.; Kirchhof, Paulus; Lane, Deirdre A.; Verheugt, Freek W.A.; Veltkamp, Roland; Lip, Gregory Y.H.

2017-01-01

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation. PMID:26848149

Predictability of lesion durability for AF ablation using phased radiofrequency: Power, temperature, and duration impact creation of transmural lesions.

PubMed

Hocini, Mélèze; Condie, Cathy; Stewart, Mark T; Kirchhof, Nicole; Foell, Jason D

2016-07-01

Long-term clinical outcomes for atrial fibrillation ablation depend on the creation of durable transmural lesions during pulmonary vein isolation and on substrate modification. Focal conventional radiofrequency (RF) ablation studies have demonstrated that tissue temperature and power are important factors for lesion formation. However, the impact and predictability of temperature and power on contiguous, transmural lesion formation with a phased RF system has not been described. The purpose of this study was to determine the sensitivity, specificity, and predictability of power and temperature to create contiguous, transmural lesions with the temperature-controlled, multielectrode phased RF PVAC GOLD catheter. Single ablations with the PVAC GOLD catheter were performed in the superior vena cava of 22 pigs. Ablations from 198 PVAC GOLD electrodes were evaluated by gross examination and histopathology for lesion transmurality and contiguity. Lesions were compared to temperature and power data from the phased RF GENius generator. Effective contact was defined as electrodes with a temperature of ≥50°C and a power of ≥3 W. Eighty-five percent (168 of 198) of the lesions were transmural and 79% (106 of 134) were contiguous. Electrode analysis showed that >30 seconds of effective contact identified transmural lesions with 85% sensitivity (95% confidence interval [CI] 78%-89%), 93% specificity (95% CI 76%-99%), and 99% positive predictive value (95% CI 94%-100%). Sensitivity for lesion contiguity was 95% (95% CI 89%-98%), with 62% specificity (95% CI 42%-78%) and 90% positive predictive value (95% CI 83%-95%). No char or coagulum was observed on the catheter or tissue. PVAC GOLD safely, effectively, and predictably creates transmural and contiguous lesions. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Utility of esophageal temperature monitoring during pulmonary vein isolation for atrial fibrillation using duty-cycled phased radiofrequency ablation.

PubMed

Deneke, Thomas; Bünz, Kathrin; Bastian, Annely; Päsler, Marcus; Anders, Helge; Lehmann, Rainer; Meuser, Wolfgang; de Groot, Joris R; Horlitz, Marc; Haberkorn, Ron; Mügge, Andreas; Shin, Dong-In

2011-03-01

A novel ablation system has been introduced for rapid treatment of atrial fibrillation (AF). This system delivers duty-cycled phased radiofrequency (RF) energy via an over-the-wire catheter (PVAC® , Medtronic) to achieve pulmonary vein (PV) isolation. Lower power and depth control suggests that collateral damage might be minimized. However, no studies have investigated the potential for thermal effect and damage to the esophagus. Ninety consecutive patients undergoing PV-isolation were evaluated. Group A (48 patients) had continuous luminal esophageal temperature (LET) monitoring using a temperature probe with 3 metal electrodes located in the vicinity of the targeted PV ostia. Ablation ceased when LET exceeded 40 °C. Only patients with LET ≥ 39 °C underwent endoscopic evaluation to assess esophageal damage. Group B (42 patients) excluded LET monitoring but all patients underwent endoscopy. In Group A, 27 (56%) patients showed LET ≥ 39 °C (mean LET 40.5 °C). Endoscopy revealed esophageal alterations in 5 (8%) (3 erythema and 2 intramural bleeding). One hundred eighty-nine out of 190 (99.5%) targeted PVs were successfully isolated, with 1 PV unsuccessful due to high LET. In Group B all 165 targeted PVs (100%) were successfully isolated. Endoscopy in Group 2 revealed no esophageal alterations. Using a duty-cycled, phased RF ablation system is safe and effective to isolate PVs. No Eso alteration was documented after ablation when LET was not monitored. This suggests that the LET probe may contribute to the thermal effect. Whether the documented increments in LET are due to direct tissue heating or possible interaction between the LET probe requires further investigation. © 2010 Wiley Periodicals, Inc.

Surgical ablation of atrial fibrillation in patients with a giant left atrium undergoing mitral valve surgery.

PubMed

Kim, Ho Jin; Kim, Joon Bum; Jung, Sung-Ho; Choo, Suk Jung; Chung, Cheol Hyun; Lee, Jae Won

2016-08-01

As the efficacy of surgical ablation for atrial fibrillation (AF) is reported to be suboptimal for patients with a giant left atrium (LA), its routine use on this population has remained controversial. We sought to evaluate the clinical outcomes of patients with a giant LA undergoing mitral valve (MV) surgery with/without the maze procedure. We identified 759 patients with a giant LA (>60 mm) and AF undergoing MV surgery from 1999 through 2012. Of these, 400 underwent MV surgery with the maze procedure (maze group), and the remainder (n=359) underwent MV surgery only (no-maze group). To reduce the impact of selection bias, propensity score analyses were performed based on 25 baseline covariates. Early death occurred in five (1.3%) and nine (2.5%) patients in the maze and the no-maze group, respectively (p=0.28). Freedom from AF at 5 years was 68.9% in the maze group and 9.6% in the no-maze group (p<0.001). After adjustment, the maze group showed a significantly lower risk of death (HR, 0.65; 95% CI 0.44 to 0.98; p=0.038), thromboembolic events (HR, 0.23; 95% CI 0.09 to 0.58; p=0.002) and composite adverse outcomes (death, congestive heart failure and valve-related complications; HR, 0.55; 95% CI 0.42 to 0.71; p<0.001) than the no-maze group. In subgroup analyses, MV surgery with the maze procedure resulted in higher survival and event-free survival in most risk subgroups than without the maze procedure. The concomitant maze procedure improved postoperative rhythm status, clinical outcomes and cardiac functions in patients with a giant LA undergoing MV surgery. This study indicates that the patients with a giant LA undergoing MV surgery may benefit from an addition of the maze procedure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Analysis of Ablative Performance of C/C Composite Throat Containing Defects Based on X-ray 3D Reconstruction in a Solid Rocket Motor

NASA Astrophysics Data System (ADS)

Hui, Wei-Hua; Bao, Fu-Ting; Wei, Xiang-Geng; Liu, Yang

2015-12-01

In this paper, a new measuring method of ablation rate was proposed based on X-ray three-dimensional (3D) reconstruction. The ablation of 4-direction carbon/carbon composite nozzles was investigated in the combustion environment of a solid rocket motor, and the macroscopic ablation and linear recession rate were studied through the X-ray 3D reconstruction method. The results showed that the maximum relative error of the X-ray 3D reconstruction was 0.0576%, which met the minimum accuracy of the ablation analysis; along the nozzle axial direction, from convergence segment, throat to expansion segment, the ablation gradually weakened; in terms of defect ablation, the middle ablation was weak, while the ablation in both sides was more serious. In a word, the proposed reconstruction method based on X-ray about C/C nozzle ablation can construct a clear model of ablative nozzle which characterizes the details about micro-cracks, deposition, pores and surface to analyze ablation, so that this method can create the ablation curve in any surface clearly.

Mutations in GPR143/OA1 and ABCA4 Inform Interpretations of Short-Wavelength and Near-Infrared Fundus Autofluorescence

PubMed Central

Paavo, Maarjaliis; Zhao, Jin; Kim, Hye Jin; Lee, Winston; Zernant, Jana; Cai, Carolyn; Allikmets, Rando; Tsang, Stephen H.; Sparrow, Janet R.

2018-01-01

Purpose We sought to advance interpretations and quantification of short-wavelength fundus autofluorescence (SW-AF) emitted from bisretinoid lipofuscin and near-infrared autofluoresence (NIR-AF) originating from melanin. Methods Carriers of mutations in X-linked GPR143/OA1, a common form of ocular albinism; patients with confirmed mutations in ABCA4 conferring increased SW-AF; and subjects with healthy eyes were studied. SW-AF (488 nm excitation, 500–680 nm emission) and NIR-AF (excitation 787 nm, emission >830 nm) images were acquired with a confocal scanning laser ophthalmoscope. SW-AF images were analyzed for quantitative autofluoresence (qAF). Analogous methods of image acquisition and analysis were performed in albino and pigmented Abca4−/− mice and wild-type mice. Results Quantitation of SW-AF (qAF), construction of qAF color-coded maps, and examination of NIR-AF images from GPR143/OA1 carriers revealed mosaics in which patches of fundus exhibiting NIR-AF signal had qAF levels within normal limits whereas the hypopigmented areas in the NIR-AF image corresponded to foci of elevated qAF. qAF also was increased in albino versus pigmented mice. Although melanin contributes to fundus infrared reflectance, the latter appeared to be uniform in en face reflectance images of GPR143/OA1-carriers. In patients diagnosed with ABCA4-associated disease, NIR-AF increased in tandem with increased qAF originating in bisretinoid lipofuscin. Similarly in Abca4−/− mice having increased SW-AF, NIR-AF was more pronounced than in wild-type mice. Conclusions These studies corroborate RPE melanin as the major source of NIR-AF but also indicate that bisretinoid lipofuscin, when present at sufficient concentrations, contributes to the NIR-AF signal. Ocular melanin attenuates the SW-AF signal.

A Novel Application for the Detection of an Irregular Pulse using an iPhone 4S in Patients with Atrial Fibrillation

PubMed Central

McManus, David D.; Lee, Jinseok; Maitas, Oscar; Esa, Nada; Pidikiti, Rahul; Carlucci, Alex; Harrington, Josephine; Mick, Eric; Chon, Ki H.

2012-01-01

Background Atrial fibrillation (AF) is common and associated with adverse health outcomes. Timely detection of AF can be challenging using traditional diagnostic tools. Smartphone use is increasing and may provide an inexpensive and user-friendly means to diagnose AF. Objective To test the hypothesis that a smartphone-based application could detect an irregular pulse from AF. Methods 76 adults with persistent AF were consented for participation in our study. We obtained pulsatile time series recordings before and after cardioversion using an iPhone 4S camera. A novel smartphone application conducted real-time pulse analysis using 2 statistical methods [Root Mean Square of Successive RR Differences (RMSSD/mean); Shannon Entropy (ShE)]. We examined the sensitivity, specificity, and predictive accuracy of both algorithms using the 12-lead electrocardiogram as the gold standard. Results RMSDD/mean and ShE were higher in participants in AF compared with sinus rhythm. The 2 methods were inversely related to AF in regression models adjusting for key factors including heart rate and blood pressure (β coefficients per SD-increment in RMSDD/mean and ShE were −0.20 and −0.35; p<0.001). An algorithm combining the 2 statistical methods demonstrated excellent sensitivity (0.962), specificity (0.975), and accuracy (0.968) for beat-to-beat discrimination of an irregular pulse during AF from sinus rhythm. Conclusions In a prospectively recruited cohort of 76 participants undergoing cardioversion for AF, we found that a novel algorithm analyzing signals recorded using an iPhone 4S accurately distinguished pulse recordings during AF from sinus rhythm. Data are needed to explore the performance and acceptability of smartphone-based applications for AF detection. PMID:23220686

Pulmonary vein isolation with real-time pulmonary vein potential recording using second-generation cryoballoon: Procedural and biophysical predictors of acute pulmonary vein reconnection.

PubMed

Wei, Hui-Qiang; Guo, Xiao-Gang; Zhou, Gong-Bu; Sun, Qi; Liu, Xu; Yang, Jian-Du; Luo, Bin; Ma, Jian

2018-01-01

The study sought to evaluate the procedural and biophysical factors related to acute pulmonary vein isolation (PVI) guided by real-time pulmonary vein (PV) potential recordings. A total of 180 consecutive patients with drug-resistant atrial fibrillation (AF) undergoing CB2 (second-generation version of cryoballoon) ablation were enrolled. Real-time monitoring of PV potentials was obtained using an inner lumen spiral mapping catheter. Acute isolation was achieved in all PVs without touch-up ablation. Real-time assessment of PV disconnection was possible in 611 of 711 (85.9%) PVs. A total of 617 (86.8%) PVs were isolated during the initial freeze. Longer time cycle integration (TCI) (TTI * freeze cycle, TCI) (254.6 ± 112.8 seconds vs 74.1 ± 59.7 seconds, P < 0.001), time to isolation (TTI) (94.3 ± 34.0 seconds vs 46.3 ± 26.2 seconds, P < 0.001), higher nadir temperature (-45.5 ± 5.3°C vs -50.4 ± 5.5°C, P < 0.001), longer time to -40°C (77.3 ± 22.7 seconds vs 55.7 ± 23.2 seconds, P < 0.001), faster interval rewarming time at 0°C (9.4 ± 4.3 seconds vs 12.4 ± 4.9 seconds, P = 0.008), and total balloon rewarming time (38.1 ± 11.6 seconds vs 47.7 ± 14.0 seconds, P = 0.003) were observed in PVs with acute reconduction. TTI ≤ 65 seconds predicted absence of acute reconnection with 84.2% sensitivity and 75.7% specificity, whereas TCI ≤ 119 seconds presented 94.7% sensitivity and 80.2% specificity. At a mean follow-up of 4.7 ± 1.4 months, 82.2% of patients were free of AF. None of those with PV reconnections suffered from AF recurrences. The ablation using CB2 is effective in achieving acute PVI. Real-time assessment of PVI could be achieved during CB application in 86% of PVs. The incidence of spontaneous PV reconnection is very low, observed in just 3% of isolated PVs. TTI ≤ 65 seconds and TCI ≤ 119 seconds predicted absence of acute PV reconnection. Although they may identify effective cryoapplications in the acute phase, their performance still needs to be verified in the long term. © 2017 Wiley Periodicals, Inc.

Atrial fibrillation driven by micro-anatomic intramural re-entry revealed by simultaneous sub-epicardial and sub-endocardial optical mapping in explanted human hearts.

PubMed

Hansen, Brian J; Zhao, Jichao; Csepe, Thomas A; Moore, Brandon T; Li, Ning; Jayne, Laura A; Kalyanasundaram, Anuradha; Lim, Praise; Bratasz, Anna; Powell, Kimerly A; Simonetti, Orlando P; Higgins, Robert S D; Kilic, Ahmet; Mohler, Peter J; Janssen, Paul M L; Weiss, Raul; Hummel, John D; Fedorov, Vadim V

2015-09-14

The complex architecture of the human atria may create physical substrates for sustained re-entry to drive atrial fibrillation (AF). The existence of sustained, anatomically defined AF drivers in humans has been challenged partly due to the lack of simultaneous endocardial-epicardial (Endo-Epi) mapping coupled with high-resolution 3D structural imaging. Coronary-perfused human right atria from explanted diseased hearts (n = 8, 43-72 years old) were optically mapped simultaneously by three high-resolution CMOS cameras (two aligned Endo-Epi views (330 µm2 resolution) and one panoramic view). 3D gadolinium-enhanced magnetic resonance imaging (GE-MRI, 80 µm3 resolution) revealed the atrial wall structure varied in thickness (1.0 ± 0.7-6.8 ± 2.4 mm), transmural fiber angle differences, and interstitial fibrosis causing transmural activation delay from 23 ± 11 to 43 ± 22 ms at increased pacing rates. Sustained AF (>90 min) was induced by burst pacing during pinacidil (30-100 µM) perfusion. Dual-sided sub-Endo-sub-Epi optical mapping revealed that AF was driven by spatially and temporally stable intramural re-entry with 107 ± 50 ms cycle length and transmural activation delay of 67 ± 31 ms. Intramural re-entrant drivers were captured primarily by sub-Endo mapping, while sub-Epi mapping visualized re-entry or 'breakthrough' patterns. Re-entrant drivers were anchored on 3D micro-anatomic tracks (15.4 ± 2.2 × 6.0 ± 2.3 mm2, 2.9 ± 0.9 mm depth) formed by atrial musculature characterized by increased transmural fiber angle differences and interstitial fibrosis. Targeted radiofrequency ablation of the tracks verified these re-entries as drivers of AF. Integrated 3D structural-functional mapping of diseased human right atria ex vivo revealed that the complex atrial microstructure caused significant differences between Endo vs. Epi activation during pacing and sustained AF driven by intramural re-entry anchored to fibrosis-insulated atrial bundles. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

How are patients with atrial fibrillation approached and informed about their risk profile and available therapies in Europe? Results of the European Heart Rhythm Association Survey.

PubMed

Potpara, Tatjana S; Pison, Laurent; Larsen, Torben B; Estner, Heidi; Madrid, Antonio; Blomström-Lundqvist, Carina

2015-03-01

This European Heart Rhythm (EHRA) Scientific Initiatives Committee EP Wire Survey aimed at exploring the common practices in approaching patients with atrial fibrillation (AF) and informing them about their risk profiles and available therapies in Europe. In the majority of 53 responding centres, patients were seen by cardiologists (86.8%) or arrhythmologists (64.2%). First- and follow-up visits most commonly lasted 21-30 and 11-20 min (41.5 and 69.8% of centres, respectively). In most centres (80.2%) stroke and bleeding risk had the highest priority for discussion with AF patients; 50.9% of centres had a structured patient education programme for stroke prevention. Individual patient stroke risk was assessed at every visit in 69.2% of the centres; 46.1% of centres had a hospital-based anticoagulation clinic. Information about non-vitamin K oral anticoagulants (NOACs) was communicated to all AF patients eligible for oral anticoagulation (38.5% of centres) or to warfarin-naive/unstable patients (42.3%). Only two centres (3.8%) had a structured NOAC adherence follow-up programme; in eight centres (15.4%) patients were requested to sign the statement they have been informed about the risks of non-adherence to NOAC therapy, and three centres (5.8%) had a patient education programme. Patient preferences were of the highest relevance regarding oral anticoagulation and AF ablation (64.7 and 49.0% of centres, respectively). This EP Wire Survey shows that in Europe considerable amount of time and resources are used in daily clinical practice to inform AF patients about their risk profile and available therapies. However, a diversity of strategies used across the European hospitals was noted, and further research is needed to better define optimal strategies for informing AF patients about their risk profile and treatment options. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

The European Heart Rhythm Association symptom classification for atrial fibrillation: validation and improvement through a simple modification.

PubMed

Wynn, Gareth J; Todd, Derick M; Webber, Matthew; Bonnett, Laura; McShane, James; Kirchhof, Paulus; Gupta, Dhiraj

2014-07-01

To validate the European Heart Rhythm Association (EHRA) symptom classification in atrial fibrillation (AF) and test whether its discriminative ability could be improved by a simple modification. We compared the EHRA classification with three quality of life (QoL) measures: the AF-specific Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) questionnaire; two components of the EQ-5D instrument, a health-related utility which can be used to calculate cost-effectiveness, and the visual analogue scale (VAS) which demonstrates patients' own assessment of health status. We then proposed a simple modification [modified EHRA (mEHRA)] to improve discrimination at the point where major treatment decisions are made. quality of life data and clinician-allocated EHRA class were prospectively collected on 362 patients with AF. A step-wise, negative association was seen between the EHRA class and both the AFEQT and the VAS scores. Health-related utility was only significantly different between Classes 2 and 3 (P < 0.001). We developed and validated the mEHRA score separating Class 2 (symptomatic AF not limiting daily activities), based on whether the patients were 'troubled by their AF' (Class 2b) or not (Class 2a). This produced two distinct groups with lower AFEQT and VAS scores and, importantly, both clinically and statistically significant lower health utility (Δutility 0.9, P = 0.01) in Class 2b than Class 2a. Based on patients' own assessment of their health status and the disease-specific AFEQT, the EHRA score can be considered a useful semi-quantitative classification. The mEHRA score has a clearer separation in health utility to assess the cost efficacy of interventions such as ablation, where Class 2b symptoms appear to be the appropriate treatment threshold. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.

Graphene oxide-coated stir bar sorptive extraction of trace aflatoxins from soy milk followed by high performance liquid chromatography-laser-induced fluorescence detection.

PubMed

Ma, Haiyan; Ran, Congcong; Li, Mengjiao; Gao, Jinglin; Wang, Xinyu; Zhang, Lina; Bian, Jing; Li, Junmei; Jiang, Ye

2018-04-01

Mycotoxins are potential food pollutants produced by fungi. Among them, aflatoxins (AFs) are the most toxic. Therefore, AFs were selected as models, and a sensitive, simple and green graphene oxide (GO)-based stir bar sorptive extraction (SBSE) method was developed for extraction and determination of AFs with high performance liquid chromatography-laser-induced fluorescence detector (HPLC-LIF). This method improved the sensitivity of AFs detection and solved the deposition difficulty of the direct use of GO as adsorbent. Several parameters including a spiked amount of NaCl, stirring rate, extraction time and desorption time were investigated. Under optimal conditions, the quantitative method had low limits of detection of 2.4-8.0 pg/mL, which were better than some reported AFs analytical methods. The developed method has been applied to soy milk samples with good recoveries ranging from 80.5 to 102.3%. The prepared GO-based SBSE can be used as a sensitive screening technique for detecting AFs in soy milk.

The Indian consensus guidance on stroke prevention in atrial fibrillation: An emphasis on practical use of nonvitamin K oral anticoagulants.

PubMed

Dalal, Jamshed; Bhave, Abhay; Oomman, Abraham; Vora, Amit; Saxena, Anil; Kahali, Dhiman; Poncha, Fali; Gambhir, D S; Chaudhuri, Jaydip Ray; Sinha, Nakul; Ray, Saumitra; Iyengar, S S; Banerjee, Suvro; Kaul, Upendra

2015-12-01

The last ten years have seen rapid strides in the evolution of nonvitamin K oral anticoagulants (NOACs) for stroke prevention in patients with atrial fibrillation (AF). For the preparation of this consensus, a comprehensive literature search was performed and data on available trials, subpopulation analyses, and case reports were analyzed. This Indian consensus document intends to provide guidance on selecting the right NOAC for the right patients by formulating expert opinions based on the available trials and Asian/Indian subpopulation analyses of these trials. A section has been dedicated to the current evidence of NOACs in the Asian population. Practical suggestions have been formulated in the following clinical situations: (i) Dose recommendations of the NOACs in different clinical scenarios; (ii) NOACs in patients with rheumatic heart disease (RHD); (iii) Monitoring anticoagulant effect of the NOACs; (iv) Overdose of NOACs; (v) Antidotes to NOACs; (vi) Treatment of hypertrophic cardiomyopathy (HCM) with AF using NOACs; (vii) NOACs dose in elderly, (viii) Switching between NOACs and vitamin K antagonists (VKA); (ix) Cardioversion or ablation in NOAC-treated patients; (x) Planned/emergency surgical interventions in patients currently on NOACs; (xi) Management of bleeding complications of NOACs; (xii) Management of acute coronary syndrome (ACS) in AF with NOACs; (xiii) Management of acute ischemic stroke while on NOACs. Copyright © 2015. Published by Elsevier B.V.

Three-dimensional dominant frequency mapping using autoregressive spectral analysis of atrial electrograms of patients in persistent atrial fibrillation.

PubMed

Salinet, João L; Masca, Nicholas; Stafford, Peter J; Ng, G André; Schlindwein, Fernando S

2016-03-08

Areas with high frequency activity within the atrium are thought to be 'drivers' of the rhythm in patients with atrial fibrillation (AF) and ablation of these areas seems to be an effective therapy in eliminating DF gradient and restoring sinus rhythm. Clinical groups have applied the traditional FFT-based approach to generate the three-dimensional dominant frequency (3D DF) maps during electrophysiology (EP) procedures but literature is restricted on using alternative spectral estimation techniques that can have a better frequency resolution that FFT-based spectral estimation. Autoregressive (AR) model-based spectral estimation techniques, with emphasis on selection of appropriate sampling rate and AR model order, were implemented to generate high-density 3D DF maps of atrial electrograms (AEGs) in persistent atrial fibrillation (persAF). For each patient, 2048 simultaneous AEGs were recorded for 20.478 s-long segments in the left atrium (LA) and exported for analysis, together with their anatomical locations. After the DFs were identified using AR-based spectral estimation, they were colour coded to produce sequential 3D DF maps. These maps were systematically compared with maps found using the Fourier-based approach. 3D DF maps can be obtained using AR-based spectral estimation after AEGs downsampling (DS) and the resulting maps are very similar to those obtained using FFT-based spectral estimation (mean 90.23 %). There were no significant differences between AR techniques (p = 0.62). The processing time for AR-based approach was considerably shorter (from 5.44 to 5.05 s) when lower sampling frequencies and model order values were used. Higher levels of DS presented higher rates of DF agreement (sampling frequency of 37.5 Hz). We have demonstrated the feasibility of using AR spectral estimation methods for producing 3D DF maps and characterised their differences to the maps produced using the FFT technique, offering an alternative approach for 3D DF computation in human persAF studies.

A new transform for the analysis of complex fractionated atrial electrograms

PubMed Central

2011-01-01

Background Representation of independent biophysical sources using Fourier analysis can be inefficient because the basis is sinusoidal and general. When complex fractionated atrial electrograms (CFAE) are acquired during atrial fibrillation (AF), the electrogram morphology depends on the mix of distinct nonsinusoidal generators. Identification of these generators using efficient methods of representation and comparison would be useful for targeting catheter ablation sites to prevent arrhythmia reinduction. Method A data-driven basis and transform is described which utilizes the ensemble average of signal segments to identify and distinguish CFAE morphologic components and frequencies. Calculation of the dominant frequency (DF) of actual CFAE, and identification of simulated independent generator frequencies and morphologies embedded in CFAE, is done using a total of 216 recordings from 10 paroxysmal and 10 persistent AF patients. The transform is tested versus Fourier analysis to detect spectral components in the presence of phase noise and interference. Correspondence is shown between ensemble basis vectors of highest power and corresponding synthetic drivers embedded in CFAE. Results The ensemble basis is orthogonal, and efficient for representation of CFAE components as compared with Fourier analysis (p ≤ 0.002). When three synthetic drivers with additive phase noise and interference were decomposed, the top three peaks in the ensemble power spectrum corresponded to the driver frequencies more closely as compared with top Fourier power spectrum peaks (p ≤ 0.005). The synthesized drivers with phase noise and interference were extractable from their corresponding ensemble basis with a mean error of less than 10%. Conclusions The new transform is able to efficiently identify CFAE features using DF calculation and by discerning morphologic differences. Unlike the Fourier transform method, it does not distort CFAE signals prior to analysis, and is relatively robust to jitter in periodic events. Thus the ensemble method can provide a useful alternative for quantitative characterization of CFAE during clinical study. PMID:21569421

Development of the dichlorvos-ammonia (DV-AM) method for the visual detection of aflatoxigenic fungi.

PubMed

Yabe, Kimiko; Hatabayashi, Hidemi; Ikehata, Akifumi; Zheng, Yazhi; Kushiro, Masayo

2015-12-01

Aflatoxins (AFs) are carcinogenic and toxic secondary metabolites produced mainly by Aspergillus flavus and Aspergillus parasiticus. To monitor and regulate the AF contamination of crops, a sensitive and precise detection method for these toxigenic fungi in environments is necessary. We herein developed a novel visual detection method, the dichlorvos-ammonia (DV-AM) method, for identifying AF-producing fungi using DV and AM vapor on agar culture plates, in which DV inhibits the esterase in AF biosynthesis, causing the accumulation of anthraquinone precursors (versiconal hemiacetal acetate and versiconol acetate) of AFs in mycelia on the agar plate, followed by a change in the color of the colonies from light yellow to brilliant purple-red by the AM vapor treatment. We also investigated the appropriate culture conditions to increase the color intensity. It should be noted that other species producing the same precursors of AFs such as Aspergillus nidulans and Aspergillus versicolor could be discriminated from the Aspergillus section Flavi based on the differences of their phenotypes. The DV-AM method was also useful for the isolation of nonaflatoxigenic fungi showing no color change, for screening microorganisms that inhibit the AF production by fungi, and for the characterization of the fungi infecting corn kernels. Thus, the DV-AM method can provide a highly sensitive and visible indicator for the detection of aflatoxigenic fungi.

Laser micro-etching of metal prostheses for personal identification

PubMed Central

Ganapathy, Dhanraj; Sivaswamy, Vinay; Sekhar, Prathap

2017-01-01

Denture marking techniques play a vital role in establishing personal identification in suitable clinical and forensic situations. The denture marking techniques are categorized broadly into additive and ablative methods. Additive methods involve embedding or impregnation of markers for establishing personal identity. Ablative methods involve partial removal of the denture surface thereby providing a marking for identification. Engraving and etching methods are the commonly used ablative methods. Ablative methods can be of contact and noncontact subtypes. Laser micro-etching is a precise noncontact ablative denture marking technique that could be used for prostheses-guided personal identification. PMID:28584473

Laser micro-etching of metal prostheses for personal identification.

PubMed

Ganapathy, Dhanraj; Sivaswamy, Vinay; Sekhar, Prathap

2017-01-01

Denture marking techniques play a vital role in establishing personal identification in suitable clinical and forensic situations. The denture marking techniques are categorized broadly into additive and ablative methods. Additive methods involve embedding or impregnation of markers for establishing personal identity. Ablative methods involve partial removal of the denture surface thereby providing a marking for identification. Engraving and etching methods are the commonly used ablative methods. Ablative methods can be of contact and noncontact subtypes. Laser micro-etching is a precise noncontact ablative denture marking technique that could be used for prostheses-guided personal identification.

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

PubMed Central

Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2013-01-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts. PMID:24236224

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

NASA Astrophysics Data System (ADS)

Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2012-03-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

Sequence specific peptidomimetic molecules inhibitors of a protein-protein interaction at the helix 1 level of c-Myc.

PubMed

Nieddu, Erika; Melchiori, A; Pescarolo, M P; Bagnasco, L; Biasotti, B; Licheri, B; Malacarne, D; Tortolina, L; Castagnino, N; Pasa, S; Cimoli, G; Avignolo, C; Ponassi, R; Balbi, C; Patrone, E; D'arrigo, C; Barboro, P; Vasile, F; Orecchia, P; Carnemolla, B; Damonte, G; Millo, E; Palomba, D; Fassina, G; Mazzei, M; Parodi, S

2005-04-01

Our work is focused in the broad area of strategies and efforts to inhibit protein-protein interactions. The possible strategies in this field are definitely much more varied than in the case of ATP-pocket inhibitors. In our previous work (10), we reported that a retro-inverso (RI) form of Helix1 (H1) of c-Myc, linked to an RI-internalization sequence arising from the third alpha-helix of Antennapedia (Int) was endowed with an antiproliferative and proapoptotic activity toward the cancer cell lines MCF-7 and HCT-116. The activity apparently was dependent upon the presence of the Myc motif. In this work, by ala-scan mapping of the H1 portion of our molecules with D-aa, we found two amino acids necessary for antiproliferative activity: D-Lys in 4 and D-Arg in 5 (numbers refer to L-forms). In the natural hetero-dimer, these two side chains project to the outside of the four alpha-helix bundle. Moreover, we were able to obtain three peptides more active than the original lead. They strongly reduced cell proliferation and survival (RI-Int-VV-H1-E2A,S6A,F8A; RI-Int-VV-H1-S6A,F8A,R11A; RI-Int-VV-H1-S6A,F8A,Q13A): after 8 days at 10 muM total cell number was approximately 1% of the number of cells initially seeded. In these more potent molecules, the ablated side chains project to the inside in the corresponding natural four alpha-helix bundle. In the present work, we also investigated the behavior of our molecules at the biochemical level. Using both a circular dichroism (CD) and a fluorescence anisotropy approach, we noted that side chains projecting at the interior of the four alpha-helix bundle are needed for inducing the partial unfolding of Myc-H2, without an opening of the leucine zipper. Side chains projecting at the outside are not required for this biochemical effect. However, antiproliferative activity had the opposite requirements: side chains projecting at the outside of the bundle were essential, and, on the contrary, ablation of one side chain at a time projecting at the inside increased rather than decreased biological activity. We conclude that our active molecules probably interfere at the level of a protein-protein interaction between Myc-Max and a third protein of the transcription complex. Finally, CD and nuclear magnetic resonance (NMR) data, plus dynamic simulations, suggest a prevalent random coil conformation of the H1 portion of our molecules, at least in diluted solutions. The introduction of a kink (substitution with proline in positions 5 or 7) led to an important reduction of biological activity. We have also synthesized a longer peptido-mimetic molecule (RI-Int-H1-S6A,F8A-loop-H2) with the intent of obtaining a wider zone of interaction and a stronger interference at the level of the higher-order structure (enhanceosome). RI-Int-H1-S6A,F8A-loop-H2 was less active rather than more active in respect to RI-Int-VV-H1-S6A,F8A, apparently because it has a clear bent to form a beta-sheet (CD and NMR data).

Chemistry of 1,1,2,2,9,9,10,10-octafluoro-[2,2]-paracyclophane: Its synthesis and reactions

NASA Astrophysics Data System (ADS)

Duan, Jian-Xin

This dissertation describes the first example of the synthesis of 1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophane (AF4) under non-high-dilution conditions. Under very mild reaction conditions, bis-p-(chlorodifluoromethyl)benzene (TFPX dichloride) and its derivatives reacted with Zn dust in N,N-dimethyl acetamide (DMA) (Zinc method) affording the corresponding AF4 and its derivatives in moderate to good yields. Purification of products was also studied and an efficient purification process was developed. A new and very cheap method for preparation of TFPX dichloride is also disclosed. Using the very cheap fluorinating reagent, anhydrous hydrogen fluoride (AHF), 1,4-bis(trichloromethyl)benezene or its derivatives were converted to TFPX and its derivatives in high yields (F/Cl exchange reaction). With the success of the Zinc method and F/Cl exchange reaction, highly pure AF4 thus can be provided to the semiconductor industry and academy research scientists in large quantity and at a very low price. Starting from AF4, numerous AF4 derivatives were synthesized using convenient reaction conditions. Reaction of AF4 with fuming nitric acid at room temperature gave mono-nitroAF4 in almost quantitative yield. Reduction of the mono-nitroAF4 with iron powder in the presence of HCl in alcoholic solvent gave the aminoAF4 in 90% yield. Via the diazonium salt intermediate, iodoAF4 was also obtained in good yield. Under similar reaction conditions, disubstituted AF4 derivatives were also prepared in good yields. Heating a mixture of AF4, trifluoroacetyl peroxide and dichloromethane gave the trifluoromethylated dimeric AF4 as a mixture of diastereomers. When these products were heated to 170--180°C in the presence of I 2, 4-trifluoromethyl-AF4 was obtained in almost 87% yield. X-ray structural analysis showed that the C-C bond connecting the two cyclophane moieties to be longer than the normal C-C bond. Kinetic studies, conducted in the presence of excess amount of hydrogen donor, showed this bond to be quite weak. Oxidation of AF4 with HIO3 in the presence of catalytic amount of H2SO4 in trifluoroacetic acid gave AF4 quinone in one step. AF4 quinone can be easily reduced to the hydroquinone by Na 2S2O4 aqueous solution.

A novel method for determination of aflatoxin B1 mediated by FCLA + BSA

NASA Astrophysics Data System (ADS)

Chen, WenLi; Xing, Da

2005-02-01

As a chemiluminescence (CL) probe, 3,7-dihydro-6-{4-{2-(N"-(5-fluoresceinyl) thioureido)ethoxy}phenyl}-2-met -hylimi-dazo{1,2-a}pyrazin-3-one dosium salt (FCLA) can sensitively and specifically react with singlet oxygen (1O2 ) and superoxide(O2""). BSA (Bovine Serum Albumin) can enlarge the CL intensity of FCLA to 860%. This report presents a novel method for determination of Aflatoxin B1 (AfB1) mediated by FCLA+BSA. The concentration of AFB1 showed an obvious positive correlation with the CL intensity mediated by FCLA+BSA. This method could measure accurately ng/ml of AfB1 concentration. At the same time, the fluorescence spectrum of FCLA+BSA and FCLA+BSA+AfB1 were measured respectively, which showed that the fluorescence intensity of FCLA+BSA+AfB1 was higher than FCLA+BSA. Comparing the peak value of FCLA, FCLA+BSA and FCLA+BSA+AfB1 had a 6nm Einstein shift (red shift). The study suggested that CL method mediated by FCLA+BSA might be applicable to the determination of AfB1 concentration.

Measurement of intrahepatic pressure during radiofrequency ablation in porcine liver.

PubMed

Kawamoto, Chiaki; Yamauchi, Atsushi; Baba, Yoko; Kaneko, Keiko; Yakabi, Koji

2010-04-01

To identify the most effective procedures to avoid increased intrahepatic pressure during radiofrequency ablation, we evaluated different ablation methods. Laparotomy was performed in 19 pigs. Intrahepatic pressure was monitored using an invasive blood pressure monitor. Radiofrequency ablation was performed as follows: single-step standard ablation; single-step at 30 W; single-step at 70 W; 4-step at 30 W; 8-step at 30 W; 8-step at 70 W; and cooled-tip. The array was fully deployed in single-step methods. In the multi-step methods, the array was gradually deployed in four or eight steps. With the cooled-tip, ablation was performed by increasing output by 10 W/min, starting at 40 W. Intrahepatic pressure was as follows: single-step standard ablation, 154.5 +/- 30.9 mmHg; single-step at 30 W, 34.2 +/- 20.0 mmHg; single-step at 70 W, 46.7 +/- 24.3 mmHg; 4-step at 30 W, 42.3 +/- 17.9 mmHg; 8-step at 30 W, 24.1 +/- 18.2 mmHg; 8-step at 70 W, 47.5 +/- 31.5 mmHg; and cooled-tip, 114.5 +/- 16.6 mmHg. The radiofrequency ablation-induced area was spherical with single-step standard ablation, 4-step at 30 W, and 8-step at 30 W. Conversely, the ablated area was irregular with single-step at 30 W, single-step at 70 W, and 8-step at 70 W. The ablation time was significantly shorter for the multi-step method than for the single-step method. Increased intrahepatic pressure could be controlled using multi-step methods. From the shapes of the ablation area, 30-W 8-step expansions appear to be most suitable for radiofrequency ablation.

A novel application for the detection of an irregular pulse using an iPhone 4S in patients with atrial fibrillation.

PubMed

McManus, David D; Lee, Jinseok; Maitas, Oscar; Esa, Nada; Pidikiti, Rahul; Carlucci, Alex; Harrington, Josephine; Mick, Eric; Chon, Ki H

2013-03-01

Atrial fibrillation (AF) is common and associated with adverse health outcomes. Timely detection of AF can be challenging using traditional diagnostic tools. Smartphone use is increasing and may provide an inexpensive and user-friendly means to diagnoseAF. To test the hypothesis that a smartphone-based application could detect an irregular pulse fromAF. Seventy-six adults with persistent AF were consented for participation in our study. We obtained pulsatile time series recordings before and after cardioversion using an iPhone 4S camera. A novel smartphone application conducted real-time pulse analysis using 2 statistical methods: root mean square of successive RR difference (RMSSD/mean) and Shannon entropy (ShE). We examined the sensitivity, specificity, and predictive accuracy of both algorithms using the 12-lead electrocardiogram as the gold standard. RMSDD/mean and ShE were higher in participants in AF than in those with sinus rhythm. The 2 methods were inversely related to AF in regression models adjusting for key factors including heart rate and blood pressure (beta coefficients per SD increment in RMSDD/mean and ShE were-0.20 and-0.35; P<.001). An algorithm combining the 2 statistical methods demonstrated excellent sensitivity (0.962), specificity (0.975), and accuracy (0.968) for beat-to-beat discrimination of an irregular pulse during AF from sinus rhythm. In a prospectively recruited cohort of 76 participants undergoing cardioversion for AF, we found that a novel algorithm analyzing signals recorded using an iPhone 4S accurately distinguished pulse recordings during AF from sinus rhythm. Data are needed to explore the performance and acceptability of smartphone-based applications for AF detection. Copyright © 2013 Heart Rhythm Society. All rights reserved.

Reference gene selection for molecular studies of dormancy in wild oat (Avena fatua L.) caryopses by RT-qPCR method.

PubMed

Ruduś, Izabela; Kępczyński, Jan

2018-01-01

Molecular studies of primary and secondary dormancy in Avena fatua L., a serious weed of cereal and other crops, are intended to reveal the species-specific details of underlying molecular mechanisms which in turn may be useable in weed management. Among others, quantitative real-time PCR (RT-qPCR) data of comparative gene expression analysis may give some insight into the involvement of particular wild oat genes in dormancy release, maintenance or induction by unfavorable conditions. To assure obtaining biologically significant results using this method, the expression stability of selected candidate reference genes in different data subsets was evaluated using four statistical algorithms i.e. geNorm, NormFinder, Best Keeper and ΔCt method. Although some discrepancies in their ranking outputs were noticed, evidently two ubiquitin-conjugating enzyme homologs, AfUBC1 and AfUBC2, as well as one homolog of glyceraldehyde 3-phosphate dehydrogenase AfGAPDH1 and TATA-binding protein AfTBP2 appeared as more stably expressed than AfEF1a (translation elongation factor 1α), AfGAPDH2 or the least stable α-tubulin homolog AfTUA1 in caryopses and seedlings of A. fatua. Gene expression analysis of a dormancy-related wild oat transcription factor VIVIPAROUS1 (AfVP1) allowed for a validation of candidate reference genes performance. Based on the obtained results it can be recommended that the normalization factor calculated as a geometric mean of Cq values of AfUBC1, AfUBC2 and AfGAPDH1 would be optimal for RT-qPCR results normalization in the experiments comprising A. fatua caryopses of different dormancy status.

Setup for functional cell ablation with lasers: coupling of a laser to a microscope.

PubMed

Sweeney, Sean T; Hidalgo, Alicia; de Belle, J Steven; Keshishian, Haig

2012-06-01

The selective removal of cells by ablation is a powerful tool in the study of eukaryotic developmental biology, providing much information about their origin, fate, or function in the developing organism. In Drosophila, three main methods have been used to ablate cells: chemical, genetic, and laser ablation. Each method has its own applicability with regard to developmental stage and the cells to be ablated, and its own limitations. The primary advantage of laser-based ablation is the flexibility provided by the method: The operations can be performed in any cell pattern and at any time in development. Laser-based techniques permit manipulation of structures within cells, even to the molecular level. They can also be used for gene activation. However, laser ablation can be expensive, labor-intensive, and time-consuming. Although live cells can be difficult to image in Drosophila embryos, the use of vital fluorescent imaging methods has made laser-mediated cell manipulation methods more appealing; the methods are relatively straightforward. This article provides the information necessary for setting up and using a laser microscope for lasesr ablation studies.

A structured reading algorithm improves telemetric detection of atrial fibrillation after acute ischemic stroke.

PubMed

Kallmünzer, Bernd; Breuer, Lorenz; Hering, Christiane; Raaz-Schrauder, Dorette; Kollmar, Rainer; Huttner, Hagen B; Schwab, Stefan; Köhrmann, Martin

2012-04-01

Anticoagulation is a highly effective secondary prevention in patients with cardioembolic stroke and atrial fibrillation/flutter (AF). However, the condition remains underdiagnosed, because paroxysmal AF may be missed by diagnostic tests in the acute phase. In this study, the sensitivity of AF detection was assessed for serial electrocardiographic recordings and continuous stroke unit telemetric monitoring with or without a structured algorithm to analyze telemetric data (SEA-AF). Three hundred forty-six consecutive patients with acute ischemic stroke were prospectively included and subjected to standard telemetric monitoring. In addition, telemetric data were separately analyzed following SEA-AF, consisting of a structured evaluation of episodes with high risk for AF and a chronological beat-to-beat screening of the full registration. Serial electrocardiograms were conducted in 24-hour intervals. Median effective telemetry monitoring time was 75.5 hours (interquartile range 64-86 hours). Overall, AF was diagnosed in 119 of 346 patients (34.4%). The structured reading algorithm was the most sensitive method to detected AF. Conventional telemetry and serial electrocardiographic assessments were less effective. However, only 35% of patients with previously documented paroxysmal AF and negative baseline electrocardiogram demonstrated AF episodes during monitoring. Continuous stroke unit telemetry using SEA-AF shows a significantly higher detection rate for AF compared with daily electrocardiographic assessments and standard telemetry without structured reading. The low overall probability to detect paroxysmal AF with either method during the first days after stroke demonstrates the urgent need for complementary diagnostic strategies such as long-term monitoring and frequent follow-up assessments. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT01177748.

Ethnic Distribution of ECG Predictors of Atrial Fibrillation and Its Impact on Understanding the Ethnic Distribution of Ischemic Stroke in the Atherosclerosis Risk in Communities (ARIC) Study

PubMed Central

Soliman, Elsayed Z.; Prineas, Ronald J.; Case, L. Douglas; Zhang, Zhu-ming; Goff, David C.

2009-01-01

Background and Purpose The paradox of the reported low prevalence of atrial fibrillation (AF) in blacks compared with whites despite higher stroke rates in the former could be related to limitations in the current methods used to diagnose AF in population-based studies. Hence, this study aimed to use the ethnic distribution of ECG predictors of AF as measures of AF propensity in different ethnic groups. Methods The distribution of baseline measures of P-wave terminal force, P-wave duration, P-wave area, and PR duration (referred to as AF predictors) were compared by ethnicity in 15 429 participants (27% black) from the Atherosclerosis Risk in Communities (ARIC) study by unpaired t test, χ2, and logistic-regression analysis, as appropriate. Cox proportional-hazards analysis was used to separately examine the association of AF predictors with incident AF and ischemic stroke. Results Whereas AF was significantly less common in blacks compared with whites (0.24% vs 0.95%, P<0.0001), similar to what has been reported in previous studies, blacks had significantly higher and more abnormal values of AF predictors (P<0.0001 for all comparisons). Black ethnicity was significantly associated with abnormal AF predictors compared with whites; odds ratios for different AF predictors ranged from 2.1 to 3.1. AF predictors were significantly and independently associated with AF and ischemic stroke with no significant interaction between ethnicity and AF predictors, findings that further justify using AF predictors as an earlier indicator of future risk of AF and stroke. Conclusions There is a disconnect between the ethnic distribution of AF predictors and the ethnic distribution of AF, probably because the former, unlike the latter, do not suffer from low sensitivity. These results raise the possibility that blacks might actually have a higher prevalence of AF that might have been missed by previous studies owing to limited methodology, a difference that could partially explain the greater stroke risk in blacks. PMID:19213946

Detection of atrial fibrillation after ischemic stroke or transient ischemic attack: a systematic review and meta-analysis.

PubMed

Kishore, Amit; Vail, Andy; Majid, Arshad; Dawson, Jesse; Lees, Kennedy R; Tyrrell, Pippa J; Smith, Craig J

2014-02-01

Atrial fibrillation (AF) confers a high risk of recurrent stroke, although detection methods and definitions of paroxysmal AF during screening vary. We therefore undertook a systematic review and meta-analysis to determine the frequency of newly detected AF using noninvasive or invasive cardiac monitoring after ischemic stroke or transient ischemic attack. Prospective observational studies or randomized controlled trials of patients with ischemic stroke, transient ischemic attack, or both, who underwent any cardiac monitoring for a minimum of 12 hours, were included after electronic searches of multiple databases. The primary outcome was detection of any new AF during the monitoring period. We prespecified subgroup analysis of selected (prescreened or cryptogenic) versus unselected patients and according to duration of monitoring. A total of 32 studies were analyzed. The overall detection rate of any AF was 11.5% (95% confidence interval, 8.9%-14.3%), although the timing, duration, method of monitoring, and reporting of diagnostic criteria used for paroxysmal AF varied. Detection rates were higher in selected (13.4%; 95% confidence interval, 9.0%-18.4%) than in unselected patients (6.2%; 95% confidence interval, 4.4%-8.3%). There was substantial heterogeneity even within specified subgroups. Detection of AF was highly variable, and the review was limited by small sample sizes and marked heterogeneity. Further studies are required to inform patient selection, optimal timing, methods, and duration of monitoring for detection of AF/paroxysmal AF.

Distinct contractile and molecular differences between two goat models of atrial dysfunction: AV block-induced atrial dilatation and atrial fibrillation.

PubMed

Greiser, Maura; Neuberger, Hans-Ruprecht; Harks, Erik; El-Armouche, Ali; Boknik, Peter; de Haan, Sunniva; Verheyen, Fons; Verheule, Sander; Schmitz, Wilhelm; Ravens, Ursula; Nattel, Stanley; Allessie, Maurits A; Dobrev, Dobromir; Schotten, Ulrich

2009-03-01

Atrial dilatation is an independent risk factor for thromboembolism in patients with and without atrial fibrillation (AF). In many patients, atrial dilatation goes along with depressed contractile function of the dilated atria. While some mechanisms causing atrial contractile dysfunction in fibrillating atria have been addressed previously, the cellular and molecular mechanisms of atrial contractile remodeling in dilated atria are unknown. This study characterized in vivo atrial contractile function in a goat model of atrial dilatation and compared it to a goat model of AF. Differences in the underlying mechanisms were elucidated by studying contractile function, electrophysiology and sarcoplasmic reticulum (SR) Ca2+ load in atrial muscle bundles and by analyzing expression and phosphorylation levels of key Ca2+-handling proteins, myofilaments and the expression and activity of their upstream regulators. In 7 chronically instrumented, awake goats atrial contractile dysfunction was monitored during 3 weeks of progressive atrial dilatation after AV-node ablation (AV block goats (AVB)). In open chest experiments atrial work index (AWI) and refractoriness were measured (10 goats with AVB, 5 goats with ten days of AF induced by repetitive atrial burst pacing (AF), 10 controls). Isometric force of contraction (FC), transmembrane action potentials (APs) and rapid cooling contractures (RCC, a measure of SR Ca2+ load) were studied in right atrial muscle bundles. Total and phosphorylated Ca2+-handling and myofilament protein levels were quantified by Western blot. In AVB goats, atrial size increased by 18% (from 26.6+/-4.4 to 31.6+/-5.5 mm, n=7 p<0.01) while atrial fractional shortening (AFS) decreased (from 18.4+/-1.7 to 12.8+/-4.0% at 400 ms, n=7, p<0.01). In open chest experiments, AWI was reduced in AVB and in AF goats compared to controls (at 400 ms: 8.4+/-0.9, n=7, and 3.2+/-1.8, n=5, vs 18.9+/-5.3 mmxmmHg, n=7, respectively, p<0.05 vs control). FC of isolated right atrial muscle bundles was reduced in AVB (n=8) and in AF (n=5) goats compared to controls (n=9) (at 2 Hz: 2.3+/-0.5 and 0.7+/-0.2 vs 5.5+/-1.0 mN/mm2, respectively, p<0.05). APs were shorter in AF, but unchanged in AVB goats. RCCs were reduced in AVB and AF versus control (AVB, 3.4+/-0.5 and AF, 4.1+/-1.4 vs 12.2+/-3.2 mN/mm2, p<0.05). Protein levels of protein kinase A (PKA) phosphorylated phospholamban (PLB) were reduced in AVB (n=8) and AF (n=8) vs control (n=7) by 37.9+/-12.4% and 29.7+/-10.1%, respectively (p<0.01), whereas calmodulin-dependent protein kinase II (CaMKII) phosphorylated ryanodine channels (RyR2) were increased by 166+/-55% in AVB (n=8) and by 146+/-56% in AF (n=8) goats (p<0.01). PKA-phosphorylated myosin-binding protein-C and troponin-I were reduced exclusively in AVB goat atria (by 75+/-10% and 55+/-15%, respectively, n=8, p<0.05). Atrial dilatation developing during slow ventricular rhythm after complete AV block as well as AF-induced remodeling are associated with atrial contractile dysfunction. Both AVB and AF goat atria show decreased SR Ca2+ load, likely caused by PLB dephosphorylation and RYR2 hyperphosphorylation. While shorter APs further compromise contractility in AF goat atria, reduced myofilament phosphorylation may impair contractility in AVB goat atria. Thus, atrial hypocontractility appears to have distinct molecular contributors in different types of atrial remodeling.

Detection of atrial fibrillation with seismocardiography.

PubMed

Pankaala, Mikko; Koivisto, Tero; Lahdenoja, Olli; Kiviniemi, Tuomas; Saraste, Antti; Vasankari, Tuija; Airaksinen, Juhani

2016-08-01

In this paper we study the feasibility of seismocardiography (SCG) for the detection of Atrial Fibrillation (AF). In this preclinical study, data acquired from one patient having paroxysmal AF (no other heart diseases) is used to introduce specific changes in SCG signal due to AF. Observed changes and phenomena create a foundation for the development of SCG-based AF detection algorithms. SCG data was recorded from the sternum of an AF patient in dorso-ventral direction while at rest in a supine position using a three-axis high precision MEMS accelerometer simultaneously with a one-lead ECG. In contrast to ECG, the magnitude of beats registered with SCG varies considerably from beat to beat during AF. We show that the magnitude of the beats is not random but is in relation to beat intervals. It is shown that extra indicators for detecting AF become available when SCG data is combined with electrocardiographical (ECG) data; there is a certain behavior in the electromechanical delay characteristic of the AF. It is discussed how all this information can be taken advantage of in the detection of AF. Today electrocardiography (ECG) is the primary method for diagnosing arrhythmias, but there is a growing need for simpler and more convenient method for detecting asymptomatic AF. Given the very small dimensions of modern MEMS accelerometers (2mm×2mm), a reliable MEMS based measurement may provide totally new venues for arrhythmia detection.

Improvement in quality of life after catheter ablation for paroxysmal versus long-standing persistent atrial fibrillation: a prospective study with 3-year follow-up.

PubMed

Bulková, Veronika; Fiala, Martin; Havránek, Stěpán; Simek, Jan; Skňouřil, Libor; Januška, Jaroslav; Spinar, Jindřich; Wichterle, Dan

2014-07-18

Changes in quality of life (QoL) after catheter ablation for long-standing persistent atrial fibrillation (LSPAF) are not well described. We sought to compare QoL improvement after catheter ablation of paroxysmal atrial fibrillation (PAF) versus that after LSPAF. A total of 261 PAF and 126 LSPAF ablation recipients were prospectively followed for arrhythmia recurrence, QoL, hospital stay, and sick leave. In PAF versus LSPAF groups, 1.3±0.6 versus 1.6±0.7 procedures were performed per patient (P<0.00001) during a 3-year follow-up. Good arrhythmia control was achieved in 86% versus 87% of patients (P=0.69) and in 69% versus 69% of patients not receiving antiarrhythmic drugs (P=0.99). The baseline QoL was better in the PAF than in the LSPAF group (European Quality of Life Group instrument self-report questionnaire visual analog scale: 66.4±14.2 versus 61.0±14.2, P=0.0005; European Quality of Life Group 3-level, 5-dimensional descriptive system: 71.4±9.2 versus 67.7±13.8, P=0.002). Postablation 3-year increase in QoL was significant in both groups (all P<0.00001) and significantly lower in PAF versus LSPAF patients (visual analog scale: +5.0±14.5 versus +10.2±12.8, P=0.001; descriptive system: +5.9±14.3 versus +9.3±13.9, P=0.03). In multivariate analysis, LSPAF, less advanced age, shorter history of AF and good arrhythmia control were consistently associated with postablation 3-year improvement in QoL. Days of hospital stay for cardiovascular reasons and days on sick leave per patient/year were significantly reduced in both groups. Patients with LSPAF had worse baseline QoL. The magnitude of QoL improvement after ablation of LSPAF was significantly greater compared with after ablation of PAF, particularly when good arrhythmia control was achieved without the use of antiarrhythmic drugs. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Increased left atrial pressure in non-heart failure patients with subclinical hypothyroidism and atrial fibrillation.

PubMed

Sairaku, Akinori; Nakano, Yukiko; Uchimura, Yuko; Tokuyama, Takehito; Kawazoe, Hiroshi; Watanabe, Yoshikazu; Matsumura, Hiroya; Kihara, Yasuki

2016-05-01

The impact of subclinical hypothyroidism on the cardiovascular risk is still debated. We aimed to measure the relationship between subclinical hypothyroidism and the left atrial (LA) pressure. The LA pressures and thyroid function were measured in consecutive patients undergoing atrial fibrillation (AF) ablation, who did not have any known heart failure, structural heart disease, or overt thyroid disease. Subclinical hypothyroidism (4.5≤ thyroid-stimulating hormone <19.9 mIU/L) was present in 61 (13.0%) of the 471 patients included. More subclinical hypothyroidism patients than euthyroid patients (55.7% vs 40.2%; P=0.04).'euthyroid patients had persistent or long-standing persistent AF (55.7% vs 40.2%; P = 0.04). The mean LA pressure (10.9 ± 4.7 vs 9.1 ± 4.3 mmHg; P = 0.002) and LA V-wave pressure (17.4 ± 6.5 vs 14.3 ± 5.9 mmHg; P < 0.001) were, respectively, higher in the patients with subclinical hypothyroidism than in the euthyroid patients. After an adjustment for potential confounders, the LA pressures remained significantly higher in the subclinical hypothyroidism patients. A multiple logistic regression model showed that subclinical hypothyroidism was independently associated with a mean LA pressure of >18 mmHg (odds ratio 3.94, 95% CI 1.28 11.2; P = 0.02). Subclinical hypothyroidism may increase the LA pressure in AF patients. © 2016 The authors.

Numerical method of carbon-based material ablation effects on aero-heating for half-sphere

NASA Astrophysics Data System (ADS)

Wang, Jiang-Feng; Li, Jia-Wei; Zhao, Fa-Ming; Fan, Xiao-Feng

2018-05-01

A numerical method of aerodynamic heating with material thermal ablation effects for hypersonic half-sphere is presented. A surface material ablation model is provided to analyze the ablation effects on aero-thermal properties and structural heat conduction for thermal protection system (TPS) of hypersonic vehicles. To demonstrate its capability, applications for thermal analysis of hypersonic vehicles using carbonaceous ceramic ablators are performed and discussed. The numerical results show the high efficiency and validation of the method developed in thermal characteristics analysis of hypersonic aerodynamic heating.

Internal defibrillation: where we have been and where we should be going?

PubMed

Lévy, Samuel

2005-08-01

Internal cardioversion has been developed as an alternative technique for patients who are resistant to external DC cardioversion of atrial fibrillation (AF) and was found to be associated with higher success rates. It used initially high energies (200-300 J) delivered between an intracardiac catheter and a backplate. Subsequent studies have shown that it is possible to terminate with energies of 1 to 6 Joules, paroxysmal or induced AF in 90 percent of patients and persistent AF in 75 percent of patients, using biphasic shocks delivered between a right atrium-coronary sinus vectors. Consequently, internal atrial defibrillation can be performed under sedation only without the need for general anesthesia. Recently developed external defibrillators, capable of delivering biphasic shocks, have increased the success rates of external cardioversion and reduced the need for internal cardioversion. However, internal defibrillation is still useful in overweight or obese patients, in patients with chronic obstructive pulmonary disease or asthma who are more difficult to defibrillate, and in patients with implanted devices which may be injured by high energy shocks. Low energy internal defibrillation has also proven to be safe and this has prompted the development of implantable devices for terminating AF. The first device used was the Metrix system, a stand-alone atrial defibrillator (without ventricular defibrillation) which was found to be safe and effective in selected groups of patients. Unfortunately, this device is no longer being marketed. Only double chamber defibrillators with pacing capabilities are presently available: the Medtronic GEM III AT, an updated version of the Jewel AF and the Guidant PRIZM AVT. These devices can be patient-activated or programmed to deliver automatically ounce atrial tachyarrhythmias are detected, therapies including pacing or/and shocks. Attempts to define the group of patients who might benefit from these devices are described but the respective role of atrial defibrillators versus other non-pharmacologic therapies for AF, such as surgery and radiofrequency catheter ablation, remains to be determined. Advantages and limitations or atrial defibrillators and approaches to reduce shock related discomfort which may be a concern in some patients, are reviewed. Studies have shown that despite shock discomfort, quality of life was improved in patients with atrial defibrillators and the need for repeated hospitalizations was reduced. The cost of these devices remains a concern for the treatment of a non-lethal arrhythmia. Attention that atrial defibrillators will receive from cardiologists and from the industry in the future, will depend of the long-term results of other non-pharmacological options and of the identification of the group of AF patients which will require restoration and maintenance of sinus rhythm. But there is no doubt that selected subsets of patients with AF could benefit from atrial defibrillation.

Passive auto-focus for digital still cameras and camera phones: Filter-switching and low-light techniques

NASA Astrophysics Data System (ADS)

Gamadia, Mark Noel

In order to gain valuable market share in the growing consumer digital still camera and camera phone market, camera manufacturers have to continually add and improve existing features to their latest product offerings. Auto-focus (AF) is one such feature, whose aim is to enable consumers to quickly take sharply focused pictures with little or no manual intervention in adjusting the camera's focus lens. While AF has been a standard feature in digital still and cell-phone cameras, consumers often complain about their cameras' slow AF performance, which may lead to missed photographic opportunities, rendering valuable moments and events with undesired out-of-focus pictures. This dissertation addresses this critical issue to advance the state-of-the-art in the digital band-pass filter, passive AF method. This method is widely used to realize AF in the camera industry, where a focus actuator is adjusted via a search algorithm to locate the in-focus position by maximizing a sharpness measure extracted from a particular frequency band of the incoming image of the scene. There are no known systematic methods for automatically deriving the parameters such as the digital pass-bands or the search step-size increments used in existing passive AF schemes. Conventional methods require time consuming experimentation and tuning in order to arrive at a set of parameters which balance AF performance in terms of speed and accuracy ultimately causing a delay in product time-to-market. This dissertation presents a new framework for determining an optimal set of passive AF parameters, named Filter- Switching AF, providing an automatic approach to achieve superior AF performance, both in good and low lighting conditions based on the following performance measures (metrics): speed (total number of iterations), accuracy (offset from truth), power consumption (total distance moved), and user experience (in-focus position overrun). Performance results using three different prototype cameras are presented to further illustrate the real-world AF performance gains achieved by the developed approach. The major contribution of this dissertation is that the developed auto focusing approach can be successfully used by camera manufacturers in the development of the AF feature in future generations of digital still cameras and camera phones.

Study protocol for Smartphone Monitoring for Atrial fibrillation in Real-Time in India (SMART-India): a community-based screening and referral programme

PubMed Central

Karna, Sunil; Patel, Harshil; Fahey, Nisha; Raithatha, Shyamsundar; Handorf, Anna; Bostrom, John; Bashar, Syed; Talati, Kandarp; Shah, Ravi; Goldberg, Robert J; Thanvi, Sunil; Allison, Jeroan J; Chon, Ki; Nimbalkar, Somashekhar Marutirao; McManus, David D

2017-01-01

Introduction Atrial fibrillation (AF), the world’s most common arrhythmia, often goes undetected and untreated in low-resource communities, including India, where AF epidemiology is undefined. AF is an important risk factor for stroke, which plagues an estimated 1.6 million Indians annually. As such, early detection of AF and management of high-risk patients is critically important to decrease stroke burden in individuals with AF. This study aims to describe the epidemiology of AF in Anand District, Gujarat, India, characterise the clinical profile of individuals who are diagnosed with AF and determine the performance of two mobile technologies for community-based AF screening. Methods This observational study builds on findings from a previous feasibility study and leverages two novel technologies as well as an existing community health programme to perform door-to-door AF screening for 2000 people from 60 villages of Anand District, Gujarat, India using local health workers. A single-lead ECG and a pulse-based application is used to screen each individual for AF three times over a period of 5 days. Participants with suspected arrhythmias are followed up by study cardiologist who makes final diagnoses. Participants diagnosed with AF are initiated on treatment based on current anticoagulation guidelines and clinical reasoning. Analytical plan Age-stratified and sex-stratified prevalence of AF in the Anand District will be calculated for sample and estimated for Anand distribution using survey design weights. Sociodemographic and clinical factors associated with AF will be evaluated using multivariable regression methods. Performance of each mobile technology in detecting AF will be evaluated using a 12-lead ECG interpretation as the gold standard. Ethics and dissemination This protocol was approved separately by the Institutional Review Board of University of Massachusetts Medical School and the Human Research Ethics Committee at Charutar Arogya Mandal. The findings of this study will be disseminated through peer-reviewed journals and scientific conferences. PMID:29247089

Low-cost humic acid-bonded silica as an effective solid-phase extraction sorbent for convenient determination of aflatoxins in edible oils.

PubMed

Zhou, Neng-Zhi; Liu, Ping; Su, Xiao-Chuan; Liao, Yan-Hua; Lei, Ning-Sheng; Liang, Yong-Hong; Zhou, Shao-Huan; Lin, Wen-Si; Chen, Jie; Feng, Yu-Qi; Tang, Yang

2017-06-01

Aflatoxins (AFs) are highly toxic, mutagenic, carcinogenic, and teratogenic secondary metabolites produced by the toxigenic fungi Aspergillus flavus and Aspergillus parasiticus. AFs tend to contaminate a wide range of foods which is a serious and recurring food safety problem worldwide. Currently, immunoaffinity chromatography (IAC) has become the most conventional sample clean-up method for determining AFs in foodstuffs. However, IAC method is limited in the large-scale food analysis because it requires the use of expensive disposable cartridges and the IA procedure is time-consuming. Herein, to achieve the cost-effective determination of AFs in edible oils, we developed a promising solid-phase extraction (SPE) method based on commercially available humic acid-bonded silica (HAS) sorbent, followed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) analysis. In HAS-SPE, AFs can be captured by the HAS sorbent with both hydrophobic and hydrophilic interactions, whereas the oil matrix was captured only with the hydrophobic interactions. The oil matrix can be sufficiently washed off with isopropanol, while the AFs were still retained on the SPE packing, thus achieving selective extraction of AFs and clean-up of oil matrices. Under the optimal conditions of HAS-SPE, satisfactory recoveries ranging from 82% to 106% for four AFs (B 1 , B 2 , G 1 , and G 2 ) were achieved in various oil matrices, containing blended oil, tea oil, rapeseed oil, peanut oil, sunflower seed oil, corn oil, blended olive oil, rice oil, soybean oil, and sesame oil. Only minor matrix effects ranging from 99% to 105% for four AFs were observed. Moreover, the LODs of AFs between 0.012 and 0.035 μg/kg completely meet the regulatory levels fixed by the EU, China or other countries. The methodology was further validated for assaying the naturally contaminated peanut oils, and consistent results between the HAS-SPE and the referenced IAC were obtained. In addition, HAS-SPE can directly treat diluted oil sample without liquid-liquid extraction and is automatable, thus making it simple and convenient for the large-scale determination of AFs in edible oils. Using this method, we successfully detected four AFs in the naturally contaminated peanut oils, which is, to the best of our knowledge, the first report about the determination of AFs in edible oils using HA-based SPE. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace elements and antibacterial activity in amniotic fluid.

PubMed

Honkonen, E; Näntö, V; Hyörä, H; Vuorinen, K; Erkkola, R

1986-01-01

Antibacterial activity and trace element concentrations in amniotic fluid (AF) were determined in a population of 39 pregnant women in the second half of gestation. Antibacterial activity in each AF was measured by a spectrophotometric micromethod after 18 h incubation at 37 degrees C using Escherichia coli K 12 as a reference bacterium. Concentrations of zinc, iron, copper, calcium, potassium and bromine were measured by particle-induced X-ray emission method and the zinc concentration was also measured by atomic absorption spectrophotometry. Phosphate concentration was determined by direct albumin adding method. In AFs with good antibacterial activity significantly lower concentrations of potassium and bromine were found when compared to AFs with lower antibacterial activity. Concentrations of zinc, iron, copper, calcium or phosphate did not correlate with antibacterial activity in AF.

A simple web-based tool to compare freshwater fish data collected using AFS standard methods

USGS Publications Warehouse

Bonar, Scott A.; Mercado-Silva, Norman; Rahr, Matt; Torrey, Yuta T.; Cate, Averill

2016-01-01

The American Fisheries Society (AFS) recently published Standard Methods for Sampling North American Freshwater Fishes. Enlisting the expertise of 284 scientists from 107 organizations throughout Canada, Mexico, and the United States, this text was developed to facilitate comparisons of fish data across regions or time. Here we describe a user-friendly web tool that automates among-sample comparisons in individual fish condition, population length-frequency distributions, and catch per unit effort (CPUE) data collected using AFS standard methods. Currently, the web tool (1) provides instantaneous summaries of almost 4,000 data sets of condition, length frequency, and CPUE of common freshwater fishes collected using standard gears in 43 states and provinces; (2) is easily appended with new standardized field data to update subsequent queries and summaries; (3) compares fish data from a particular water body with continent, ecoregion, and state data summaries; and (4) provides additional information about AFS standard fish sampling including benefits, ongoing validation studies, and opportunities to comment on specific methods. The web tool—programmed in a PHP-based Drupal framework—was supported by several AFS Sections, agencies, and universities and is freely available from the AFS website and fisheriesstandardsampling.org. With widespread use, the online tool could become an important resource for fisheries biologists.

Ablation article and method

NASA Technical Reports Server (NTRS)

Erickson, W. D.; Sullivan, E. M. (Inventor)

1973-01-01

An ablation article, such as a conical heat shield, having an ablating surface is provided with at least one discrete area of at least one seed material, such as aluminum. When subjected to ablation conditions, the seed material is ablated. Radiation emanating from the ablated seed material is detected to analyze ablation effects without disturbing the ablation surface. By providing different seed materials having different radiation characteristics, the ablating effects on various areas of the ablating surface can be analyzed under any prevailing ablation conditions. The ablating article can be provided with means for detecting the radiation characteristics of the ablated seed material to provide a self-contained analysis unit.

Porous silicon photoluminescence biosensor for rapid and sensitive detection of toxins

NASA Astrophysics Data System (ADS)

Melnyk, Yulia; Pavlova, Karyna; Myndrul, Valerii; Viter, Roman; Smyntyna, Valentyn; Iatsunskyi, Igor

2017-08-01

A rapid and low cost photoluminescence (PL) immunosensor for the determination of low concentrations of Ochratoxin A(OTA) and Aflatoxine B1 (AfB1) has been developed. This biosensor was based on porous silicon (PSi) fabricated by metal-assisted chemical etching (MACE) and modified by antibodies against OTA/AfB1 (anti-OTA/anti-AfB1). Biofunctionalization method of the PSi surface by anti-OTA/ anti-AfB1 was developed. The changes of the PL intensity after interaction of the immobilized anti-OTA/anti-AfB1with OTA/AfB1 antigens were used as biosensor signal, allowing sensitive and selective detection of OTA/AfB1 antigens in BSA solution. The sensitivity of the reported optical biosensor towards OTA/AfB1 antigens is in the range from 10-3 to 102 ng/ml.

Method and apparatus for guiding ablative therapy of abnormal biological electrical excitation

NASA Technical Reports Server (NTRS)

Armoundas, Antonis A. (Inventor); Feldman, Andrew B. (Inventor); Sherman, Derin A. (Inventor); Cohen, Richard J. (Inventor)

2001-01-01

This invention involves method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. In particular, it is designed for treatment of cardiac arrhythmias. In the method of this invention electrical signals are acquired from passive electrodes, and an inverse dipole method is used to identify the site of origin of an arrhytmia. The location of the tip of the ablation catheter is similarly localized from signals acquired from the passive electrodes while electrical energy is delivered to the tip of the catheter. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

Correlations Among Near-Infrared and Short-Wavelength Autofluorescence and Spectral-Domain Optical Coherence Tomography in Recessive Stargardt Disease

PubMed Central

Duncker, Tobias; Marsiglia, Marcela; Lee, Winston; Zernant, Jana; Tsang, Stephen H.; Allikmets, Rando; Greenstein, Vivienne C.; Sparrow, Janet R.

2014-01-01

Purpose. Short-wavelength (SW) fundus autofluorescence (AF) is considered to originate from lipofuscin in retinal pigment epithelium (RPE) and near-infrared (NIR) AF from melanin. In patients with recessive Stargardt disease (STGD1), we correlated SW-AF and NIR-AF with structural information obtained by spectral-domain optical coherence tomography (SD-OCT). Methods. Twenty-four STGD1 patients (45 eyes; age 8 to 61 years) carrying confirmed disease-associated ABCA4 mutations were studied prospectively. Short-wavelength AF, NIR-AF, and SD-OCT images were acquired. Results. Five phenotypes were identified according to features of the central lesion and extent of fundus change. Central zones of reduced NIR-AF were typically larger than areas of diminished SW-AF and reduced NIR-AF usually approximated areas of ellipsoid zone (EZ) loss identified by SD-OCT (group 1; r, 0.93, P < 0.0001). In patients having a central lesion with overlapping parafoveal rings of increased NIR-AF and SW-AF (group 3), the extent of EZ loss was strongly correlated with the inner diameter of the NIR-AF ring (r, 0.89, P < 0.0001) and the eccentricity of the outer border of the NIR-AF ring was greater than that of the SW-AF ring. Conclusions. Lesion areas were more completely delineated in NIR-AF images than with SW-AF. In most cases, EZ loss was observed only at locations where NIR-AF was reduced or absent, indicating that RPE cell atrophy occurs in advance of photoreceptor cell degeneration. Because SW-AF was often increased within the central area of EZ disruption, degenerating photoreceptor cells may produce lipofuscin at accelerated levels. Consideration is given to mechanisms underlying hyper–NIR-AF in conjunction with increased SW-AF. PMID:25342616

Automated measurement of office, home and ambulatory blood pressure in atrial fibrillation.

PubMed

Kollias, Anastasios; Stergiou, George S

2014-01-01

1. Hypertension and atrial fibrillation (AF) often coexist and are strong risk factors for stroke. Current guidelines for blood pressure (BP) measurement in AF recommend repeated measurements using the auscultatory method, whereas the accuracy of the automated devices is regarded as questionable. This review presents the current evidence on the feasibility and accuracy of automated BP measurement in the presence of AF and the potential for automated detection of undiagnosed AF during such measurements. 2. Studies evaluating the use of automated BP monitors in AF are limited and have significant heterogeneity in methodology and protocols. Overall, the oscillometric method is feasible for static (office or home) and ambulatory use and appears to be more accurate for systolic than diastolic BP measurement. 3. Given that systolic hypertension is particularly common and important in the elderly, the automated BP measurement method may be acceptable for self-home and ambulatory monitoring, but not for professional office or clinic measurement. 4. An embedded algorithm for the detection of asymptomatic AF during routine automated BP measurement with high diagnostic accuracy has been developed and appears to be a useful screening tool for elderly hypertensives. © 2013 Wiley Publishing Asia Pty Ltd.

Influence of the Liquid on Femtosecond Laser Ablation of Iron

NASA Astrophysics Data System (ADS)

Kanitz, A.; Hoppius, J. S.; Gurevich, E. L.; Ostendorf, A.

Ultrashort pulse laser ablation has become a very important industrial method for highly precise material removal ranging from sensitive thin film processing to drilling and cutting of metals. Over the last decade, a new method to produce pure nanoparticles emerged from this technique: Pulsed Laser Ablation in Liquids (PLAL). By this method, the ablation of material by a laser beam is used to generate a metal vapor within the liquid in order to obtain nanoparticles from its recondensation process. It is well known that the liquid significantly alters the ablation properties of the substrate, in our case iron. For example, the ablation rate and crater morphology differ depending on the used liquid. We present our studies on the efficiency and quality of ablated grooves in water, methanol, acetone, ethanol and toluene. The produced grooves are investigated by means of white-light interferometry, EDX and SEM.

Research and Development of Energetic Ionic Liquids

DTIC Science & Technology

2012-03-01

Navy/ AF ) – USAF AF - M315E • Propellant uses ionic liquids to yield low vapor toxicity 22 – Sweden/ECAPS LMP-103S • Propellant uses ADN-based formulation...hydrazine replacement monopropellant objectives, relevant monopropellant properties, AF -M1028A monopropellant composition and physical properties...thruster tests of AF -M1028A, ionic liquids as explosives, predictive toxicology, predictive methods expected payoff. AFRL continues efforts in energetic

Trowelable ablative coating composition and method of use

NASA Technical Reports Server (NTRS)

Headrick, Stephen E. (Inventor); Hill, Roger L. (Inventor)

1989-01-01

A trowelable ablative coating composition is disclosed. The composition comprises an epoxy resin, an amide curing agent, glass microspheres and ground cork. A method for protecting a substrate is also disclosed. The method comprises applying the trowelable ablative coating discussed above to a substrate and curing the coating composition.

Trowelable ablative coating composition and method of use

NASA Technical Reports Server (NTRS)

Headrick, Stephen E. (Inventor); Hill, Roger L. (Inventor)

1988-01-01

A trowelable ablative coating composition is disclosed. The composition comprises an epoxy resin, an amide curing agent, glass microspheres and ground cork. A method for protecting a substrate is also disclosed. The method comprises applying the trowelable ablative coating discussed above to a substrate and curing the coating composition.

Crypto-Giardia antigen rapid test versus conventional modified Ziehl-Neelsen acid fast staining method for diagnosis of cryptosporidiosis.

PubMed

Zaglool, Dina Abdulla Muhammad; Mohamed, Amr; Khodari, Yousif Abdul Wahid; Farooq, Mian Usman

2013-03-01

To evaluate the validity of Crypto-Giardia antigen rapid test (CA-RT) in comparison with the conventional modified Ziehl-Neelsen acid fast (MZN-AF) staining method for the diagnosis of cryptosporidiosis. Fifteen preserved stool samples from previously confirmed infections were used as positive controls and 40 stool samples from healthy people were used as negative control. A total of 85 stool samples were collected from suspected patients with cryptosporidiosis over 6 months during the period from January till June, 2011. The study was conducted in the department of parasitology, central laboratory, Alnoor Specialist Hospital, Makkah, Saudi Arabia. All samples were subjected to CA-RT and conventional MZN-AF staining method. Validation parameters including sensitivity (SN), specificity (SP), accuracy index (AI), positive predictive value (PPV), and negative predictive value (NPV) were evaluated for both tests. Out of 15 positive controls, CA-RT detected 13 (86.7%) while MZN-AF detected 11(73.3%) positive cases. However, CA-RT detected no positive case in 40 normal controls but MZN-AF detected 2(5%) as positive cases. Based on the results, the SN, SP, AI, PPV and NPV were high in CA-RT than MZN-AF staining method, ie., 86.7%vs. 73.3%, 100%vs. 95%, 96.4%vs. 89.1%, 100%vs. 84.6% and 95.2%vs. 90.5%, respectively. Out of a total of 85 suspected specimens, CA-RT detected 7(8.2%) but MZN-AF detected 6(7.1%) cases as positive. CA-RT immunoassay is more valid and reliable than MZN-AF staining method. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Discordance between Blue-Light Autofluorescence and Near-Infrared Autofluorescence in Age-Related Macular Degeneration

PubMed Central

Heiferman, Michael J.; Fawzi, Amani A.

2016-01-01

Purpose To identify the origin and significance of discordance between blue-light autofluorescence (BL-AF; 488nm) and near-infrared autofluorescence (NI-AF; 787nm) in patients with age-related macular degeneration (AMD). Methods A total of 86 eyes of 59 patients with a diagnosis of AMD were included in this cross-sectional study conducted between March 9, 2015 and May 1, 2015. A masked observer examined the BL-AF, NI-AF, and spectral-domain optical coherence tomography (OCT) images. Areas with discordance of autofluorescence patterns between NI-AF and BL-AF images were correlated with structural findings at the corresponding location in OCT scans. Results 79 eyes had discordance between BL-AF and NI-AF. The most common OCT finding accounting for these discrepancies was pigment migration accounting for 35 lesions in 21 eyes. The most clinically relevant finding was geographic atrophy missed on BL-AF in seven eyes. Conclusions Our findings indicate that variations in the distribution of lipofuscin, melanin and melanolipofuscin account for the majority of discordance between BL-AF and NI-AF. Given our finding of missed geographic atrophy lesions on BL-AF in 24% of eyes with geographic atrophy (7/29 eyes), clinicians should consider multimodal imaging, including NI-AF and OCT, especially in clinical trials of geographic atrophy. PMID:28005672

PULSESMART: Pulse-based Arrhythmia Discrimination Using a Novel Smartphone Application

PubMed Central

McManus, David D.; Chong, Jo Woon; Soni, Apurv; Saczynski, Jane S.; Esa, Nada; Napolitano, Craig; Darling, Chad E.; Boyer, Edward; Rosen, Rochelle K.; Floyd, Kevin C.; Chon, Ki H.

2015-01-01

Background Atrial fibrillation (AF) is a common and dangerous paroxysmal rhythm abnormality. Smartphones are increasingly used for mobile health applications by older patients at risk for AF and may be useful for AF screening. Objectives To test whether an enhanced smartphone app for AF detection can discriminate between sinus rhythm (SR), AF, premature atrial contractions (PACs) and premature ventricular contractions (PVCs). Methods We analyzed 219 2-minute pulse recordings from 121 participants with AF (n=98), PACs (n=15), or PVCs (n=15) using an iPhone 4S. We obtained pulsatile time series recordings in 91 participants after successful cardioversion to sinus rhythm from pre-existing AF. The PULSESMART app conducted pulse analysis using 3 methods [Root Mean Square of Successive RR Differences; Shannon Entropy; Poincare plot]. We examined the sensitivity, specificity, and predictive accuracy of the app for AF, PAC, and PVC discrimination from sinus rhythm using the 12-lead EKG or 3-lead telemetry as the gold standard. We also administered a brief usability questionnaire to a subgroup (n=65) of app users. Results The smartphone-based app demonstrated excellent sensitivity (0.970), specificity (0.935), and accuracy (0.951) for real-time identification of an irregular pulse during AF. The app also showed good accuracy for PAC (0.955) and PVC discrimination (0.960). The vast majority of surveyed app users (83%) reported that it was “useful” and “not complex” to use. Conclusions A smartphone app can accurately discriminate pulse recordings during AF from sinus rhythm, PACs, and PVCs. PMID:26391728

Meta-Analysis of Effectiveness and Safety of Oral Anticoagulants in Atrial Fibrillation With Focus on Apixaban.

PubMed

Bai, Ying; Shi, Xu-Bo; Ma, Chang-Sheng; Lip, Gregory Y H

2017-11-01

We performed a meta-analysis of data on the effectiveness and safety of apixaban compared with other oral anticoagulants (warfarin or rivaroxaban or dabigatran or edoxaban) for stroke prevention in atrial fibrillation (AF) in different settings of randomized controlled trials, real-world studies, and radiofrequency ablation (RFA). Thirty studies were searched in PubMed, the Cochrane Library, and Clinicaltrials.gov databases reporting comparative effectiveness and safety of apixaban with warfarin (n = 23), rivaroxaban (n = 12), dabigatran (n = 13), or edoxaban (n = 2) for stroke prevention in AF. In real-world estimates, apixaban was similar to warfarin for the prevention of stroke or systematic thromboembolism (hazard ratio 0.93, 95% CI 0.71 to 1.14, I 2  = 82.9%, N = 7), and safer than warfarin in the risks of major bleeding (hazard ratio 0.62, 95% CI 0.54 to 0.70, I 2  = 18.7%, N = 9) in patients with AF. The risk of stroke or thromboembolism with apixaban was similar to rivaroxaban, dabigatran, and edoxaban in the settings of real-world studies and RFA. Major bleeding with apixaban was generally lower than rivaroxaban (relative risks 0.45, 95% CI 0.38 to 0.53, I 2  = 0%, N = 5) and similar to dabigatran in real-world studies (relative risks 1.44, 95% CI 0.33 to 6.30, I 2  = 97.7%, N = 5), but similar to rivaroxaban, dabigatran, and edoxaban in RFA. In conclusion, our meta-analysis provides a comprehensive estimate of the effectiveness and safety of apixaban compared with other oral anticoagulants (warfarin, rivaroxaban, dabigatran, and edoxaban) in patients with AF in different settings of randomized controlled trial, real-world studies, and RFA. Copyright © 2017 Elsevier Inc. All rights reserved.

Adding left atrial appendage closure to open heart surgery provides protection from ischemic brain injury six years after surgery independently of atrial fibrillation history: the LAACS randomized study.

PubMed

Park-Hansen, Jesper; Holme, Susanne J V; Irmukhamedov, Akhmadjon; Carranza, Christian L; Greve, Anders M; Al-Farra, Gina; Riis, Robert G C; Nilsson, Brian; Clausen, Johan S R; Nørskov, Anne S; Kruuse, Christina R; Rostrup, Egill; Dominguez, Helena

2018-05-23

Open heart surgery is associated with high occurrence of atrial fibrillation (AF), subsequently increasing the risk of post-operative ischemic stroke. Concomitant with open heart surgery, a cardiac ablation procedure is commonly performed in patients with known AF, often followed by left atrial appendage closure with surgery (LAACS). However, the protective effect of LAACS on the risk of cerebral ischemia following cardiac surgery remains controversial. We have studied whether LAACS in addition to open heart surgery protects against post-operative ischemic brain injury regardless of a previous AF diagnosis. One hundred eighty-seven patients scheduled for open heart surgery were enrolled in a prospective, open-label clinical trial and randomized to concomitant LAACS vs. standard care. Randomization was stratified by usage of oral anticoagulation (OAC) planned to last at least 3 months after surgery. The primary endpoint was a composite of post-operative symptomatic ischemic stroke, transient ischemic attack or imaging findings of silent cerebral ischemic (SCI) lesions. During a mean follow-up of 3.7 years, 14 (16%) primary events occurred among patients receiving standard surgery vs. 5 (5%) in the group randomized to additional LAACS (hazard ratio 0.3; 95% CI: 0.1-0.8, p = 0.02). In per protocol analysis (n = 141), 14 (18%) primary events occurred in the control group vs. 4 (6%) in the LAACS group (hazard ratio 0.3; 95% CI: 0.1-1.0, p = 0.05). In a real-world setting, LAACS in addition to elective open-heart surgery was associated with lower risk of post-operative ischemic brain injury. The protective effect was not conditional on AF/OAC status at baseline. LAACS study, clinicaltrials.gov NCT02378116 , March 4th 2015, retrospectively registered.

Atrial Fibrillation Burden: Moving Beyond Atrial Fibrillation as a Binary Entity: A Scientific Statement From the American Heart Association.

PubMed

Chen, Lin Y; Chung, Mina K; Allen, Larry A; Ezekowitz, Michael; Furie, Karen L; McCabe, Pamela; Noseworthy, Peter A; Perez, Marco V; Turakhia, Mintu P

2018-05-15

Our understanding of the risk factors and complications of atrial fibrillation (AF) is based mostly on studies that have evaluated AF in a binary fashion (present or absent) and have not investigated AF burden. This scientific statement discusses the published literature and knowledge gaps related to methods of defining and measuring AF burden, the relationship of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. Many studies examine outcomes by AF burden classified by AF type (paroxysmal versus nonparoxysmal); however, quantitatively, AF burden can be defined by longest duration, number of AF episodes during a monitoring period, and the proportion of time an individual is in AF during a monitoring period (expressed as a percentage). Current guidelines make identical recommendations for anticoagulation regardless of AF pattern or burden; however, a review of recent evidence suggests that higher AF burden is associated with higher risk of stroke. It is unclear whether the risk increases continuously or whether a threshold exists; if a threshold exists, it has not been defined. Higher burden of AF is also associated with higher prevalence and incidence of heart failure and higher risk of mortality, but not necessarily lower quality of life. A structured and comprehensive risk factor management program targeting risk factors, weight loss, and maintenance of a healthy weight appears to be effective in reducing AF burden. Despite this growing understanding of AF burden, research is needed into validation of definitions and measures of AF burden, determination of the threshold of AF burden that results in an increased risk of stroke that warrants anticoagulation, and discovery of the mechanisms underlying the weak temporal correlations of AF and stroke. Moreover, developments in monitoring technologies will likely change the landscape of long-term AF monitoring and could allow better definition of the significance of changes in AF burden over time. © 2018 American Heart Association, Inc.

Voxelwise distribution of acute ischemic stroke lesions in patients with newly diagnosed atrial fibrillation: Trigger of arrhythmia or only target of embolism?

PubMed Central

Johnson, Timothy D.; Dittgen, Felix; Nichols, Thomas E.; Malzahn, Uwe; Veltkamp, Roland

2017-01-01

Objective Atrial fibrillation (AF) is frequently detected after ischemic stroke for the first time, and brain regions involved in autonomic control have been suspected to trigger AF. We examined whether specific brain regions are associated with newly detected AF after ischemic stroke. Methods Patients with acute cerebral infarctions on diffusion-weighted magnetic resonance imaging were included in this lesion mapping study. Lesions were mapped and modeled voxelwise using Bayesian Spatial Generalised Linear Mixed Modeling to determine differences in infarct locations between stroke patients with new AF, without AF and with AF already known before the stroke. Results 582 patients were included (median age 68 years; 63.2% male). AF was present in 109/582 patients [(18.7%); new AF: 39/109 (35.8%), known AF: 70/109 (64.2%)]. AF patients had larger infarct volumes than patients without AF (mean: 29.7 ± 45.8 ml vs. 15.2 ± 35.1 ml; p<0.001). Lesions in AF patients accumulated in the right central middle cerebral artery territory. Increasing stroke size predicted progressive cortical but not pontine and thalamic involvement. Patients with new AF had more frequently lesions in the right insula compared to patients without AF when stroke size was not accounted for, but no specific brain region was more frequently involved after adjustment for infarct volume. Controlled for stroke size, left parietal involvement was less likely for patients with new AF than for those without AF or with known AF. Conclusions In the search for brain areas potentially triggering cardiac arrhythmias infarct size should be accounted for. After controlling for infarct size, there is currently no evidence that ischemic stroke lesions of specific brain areas are associated with new AF compared to patients without AF. This challenges the neurogenic hypothesis of AF according to which a relevant proportion of new AF is triggered by ischemic brain lesions of particular locations. PMID:28542605

Asbestos Free Insulation Development for the Space Shuttle Solid Propellant Rocket Motor (RSRM)

NASA Technical Reports Server (NTRS)

Allred, Larry D.; Eddy, Norman F.; McCool, A. A. (Technical Monitor)

2000-01-01

Asbestos has been used for many years as an ablation inhibitor in insulating materials. It has been a constituent of the AS/NBR insulation used to protect the steel case of the RSRM (Reusable Solid Rocket Motor) since its inception. This paper discusses the development of a potential replacement RSRM insulation design, several of the numerous design issues that were worked and processing problems that were resolved. The earlier design demonstration on FSM-5 (Flight Support Motor) of the selected 7% and 11% Kevlar(registered) filled EPDM (KF/EPDM) candidate materials was expanded. Full-scale process simulation articles were built and FSM-8 was manufactured using multiple Asbestos Free (AF) components and materials. Two major problems had to be overcome in developing the AF design. First, bondline corrosion, which occurred in the double-cured region of the aft dome, had to be eliminated. Second, KF/EPDM creates high levels of electrostatic energy (ESE), which does not readily dissipate from the insulation surface. An uncontrolled electrostatic discharge (ESD) of this surface energy during many phases of production could create serious safety hazards. Numerous processing changes were implemented and a conductive paint was developed to prevent exposed external insulation surfaces from generating ESE/ESD. Additionally, special internal instrumentation was incorporated into FSM-8 to record real-time internal motor environment data. These data included inhibitor insulation erosion rates and internal thermal environments. The FSM-8 static test was successfully conducted in February 2000 and much valuable data were obtained to characterize the AF insulation design.

Nonthermal ablation in the rat brain using focused ultrasound and an ultrasound contrast agent: long-term effects

PubMed Central

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2016-01-01

OBJECTIVE Thermal ablation with transcranial MRI-guided focused ultrasound (FUS) is currently under investigation as a less invasive alternative to radiosurgery and resection. A major limitation of the method is that its use is currently restricted to centrally located brain targets. The combination of FUS and a microbubble-based ultrasound contrast agent greatly reduces the ultrasound exposure level needed to ablate brain tissue and could be an effective means to increase the “treatment envelope” for FUS in the brain. This method, however, ablates tissue through a different mechanism: destruction of the microvasculature. It is not known whether nonthermal FUS ablation in substantial volumes of tissue can safely be performed without unexpected effects. The authors investigated this question by ablating volumes in the brains of normal rats. METHODS Overlapping sonications were performed in rats (n = 15) to ablate a volume in 1 hemisphere per animal. The sonications (10-msec bursts at 1 Hz for 60 seconds; peak negative pressure 0.8 MPa) were combined with the ultrasound contrast agent Optison (100 μl/kg). The rats were followed with MRI for 4–9 weeks after FUS, and the brains were examined with histological methods. RESULTS Two weeks after sonication and later, the lesions appeared as cyst-like areas in T2-weighted MR images that were stable over time. Histological examination demonstrated well-defined lesions consisting of a cyst-like cavity that remained lined by astrocytic tissue. Some white matter structures within the sonicated area were partially intact. CONCLUSIONS The results of this study indicate that nonthermal FUS ablation can be used to safely ablate tissue volumes in the brain without unexpected delayed effects. The findings are encouraging for the use of this ablation method in the brain. PMID:26848919

Adverse effects of permanent atrial fibrillation on heart failure in patients with preserved left ventricular function and chronic right apical pacing for complete heart block.

PubMed

Lampe, Brigitte; Hammerstingl, Christoph; Schwab, Jörg Otto; Mellert, Fritz; Stoffel-Wagner, Birgit; Grigull, Andreas; Fimmers, Rolf; Maisch, Bernhard; Nickenig, Georg; Lewalter, Thorsten; Yang, Alexander

2012-10-01

The impact of atrial fibrillation (AF) on heart failure (HF) was evaluated in patients with preserved left ventricular (LV) function and long-term right ventricular (RV) pacing for complete heart block. Clinical, echocardiographic, and laboratory parameters of HF were assessed in 35 patients with established AF who had undergone ablation of the atrioventricular node and pacemaker implantation (Group A) and 31 patients who received dual-chamber pacing for spontaneous complete heart block (Group B). During a follow-up period of 12.7 ± 7.5 years, New York Heart Association (NYHA) functional class increased from 1.3 ± 0.5 to 2.1 ± 0.6 (p < 0.0001) in Group A, and from 1.3 ± 0.4 to 1.6 ± 0.7 (p < 0.01) in Group B. Left ventricular ejection fraction (LVEF) decreased from 59.7 ± 5.1 to 53.0 ± 8.2 (p < 0.0001) in Group A, but remained stable (58.6 ± 4.2 vs. 56.9 ± 7.0 %, p = 0,21) in Group B. At the end of follow-up, markers of LV function were moderately depressed in Group A compared with those in Group B: NYHA class 2.1 ± 0.6 versus 1.6 ± 0.7, p = 0.001; LVEF 53.0 ± 8.2 versus 56.9 ± 7.0 %, p < 0.05; LV diastolic diameter 53.6 ± 5.8 mm versus 50.7 ± 4.9 mm, p < 0.05; N-terminal pro-brain natriuretic peptide (NT-proBNP) 1116.8 ± 883.9 versus 622.9 ± 1059.4 pg/ml, p < 0.05. Progression of paroxysmal AF to permanent AF during follow-up was common, while new onset of AF was rare. Permanent AF was an independent predictor of declining LVEF >10 %, increasing NYHA class ≥1, and NT-proBNP levels >1,000 pg/ml. Permanent AF was associated with adverse effects on LV function and symptoms of HF in patients with long-term RV pacing for complete heart block, and appears to play an important role in the development of HF in this specific patient cohort.

Dynamics and diversity of the bacterial community during the spontaneous decay of açai (Euterpe oleracea) fruits.

PubMed

Moura, Fábio Gomes; Graças, Diego Assis das; Santos, Agenor Valadares; Silva, Artur Luiz da Costa da; Rogez, Hervé

2018-04-30

The biodiversity and evolution of the microbial community in açai fruits (AF) between three geographical origins and two spontaneous decay conditions were examined by applying culture-independent methods. Culture-independent methods based on 16S rRNA from fifteen samples revealed that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria were the most abundant phyla. At the genus level, Massilia (taxon with more than 50% of the sequences remaining constant during the 30h of decay), Pantoea, Naxibacter, Enterobacter, Raoultella and Klebsiella were identified, forming the carposphere bacterial microbiota of AF. AF is fibre-rich and Massilia bacteria could find a large quantity of substrate for its growth through cellulase production. Beta diversity showed that the quality parameters of AF (pH, soluble solids, titratable acidity and lipids) and elemental analysis (C, N, H and C/N ratio) were unable to drive microbial patterns in AF. This research offers new insight into the indigenous bacterial community composition on AF as a function of spontaneous postharvest decay. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Exact Calculation of the Joint Allele Frequency Spectrum for Isolation with Migration Models.

PubMed

Kern, Andrew D; Hey, Jody

2017-09-01

Population genomic datasets collected over the past decade have spurred interest in developing methods that can utilize massive numbers of loci for inference of demographic and selective histories of populations. The allele frequency spectrum (AFS) provides a convenient statistic for such analysis, and, accordingly, much attention has been paid to predicting theoretical expectations of the AFS under a number of different models. However, to date, exact solutions for the joint AFS of two or more populations under models of migration and divergence have not been found. Here, we present a novel Markov chain representation of the coalescent on the state space of the joint AFS that allows for rapid, exact calculation of the joint AFS under isolation with migration (IM) models. In turn, we show how our Markov chain method, in the context of composite likelihood estimation, can be used for accurate inference of parameters of the IM model using SNP data. Lastly, we apply our method to recent whole genome datasets from African Drosophila melanogaster . Copyright © 2017 Kern and Hey.

Nonlinear Analysis of Two-phase Circumferential Motion in the Ablation Circumstance

NASA Astrophysics Data System (ADS)

Xiao-liang, Xu; Hai-ming, Huang; Zi-mao, Zhang

2010-05-01

In aerospace craft reentry and solid rocket propellant nozzle, thermal chemistry ablation is a complex process coupling with convection, heat transfer, mass transfer and chemical reaction. Based on discrete vortex method (DVM), thermal chemical ablation model and particle kinetic model, a computational module dealing with the two-phase circumferential motion in ablation circumstance is designed, the ablation velocity and circumferential field can be thus calculated. The calculated nonlinear time series are analyzed in chaotic identification method: relative chaotic characters such as correlation dimension and the maximum Lyapunov exponent are calculated, fractal dimension of vortex bulbs and particles distributions are also obtained, thus the nonlinear ablation process can be judged as a spatiotemporal chaotic process.

Machining of glass and quartz using nanosecond and picosecond laser pulses

NASA Astrophysics Data System (ADS)

Ashkenasi, David; Kaszemeikat, Tristan; Mueller, Norbert; Lemke, Andreas; Eichler, Hans Joachim

2012-03-01

New laser processing strategies in micro processing of glass, quartz and other optically transparent materials are being developed with increasing effort. Utilizing diode-pumped solid-state laser generating nanosecond pulsed green (532 nm) laser light in conjunction with either scanners or special trepanning systems can provide for reliable glass machining at excellent efficiency. Micro ablation can be induced either from the front or rear side of the glass sample. Ablation rates of over 100 μm per pulse can be achieved in rear side processing. In comparison, picosecond laser processing of glass and quartz (at a wavelength of 1064 or 532 nm) yield smaller feed rates at however much better surface and bore wall quality. This is of great importance for small sized features, e.g. through-hole diameters smaller 50 μm in thin glass. Critical for applications with minimum micro cracks and maximum performance is an appropriate distribution of laser pulses over the work piece along with optimum laser parameters. Laser machining tasks are long aspect micro drilling, slanted through holes, internal contour cuts, micro pockets and more complex geometries in e.g. soda-lime glass, B33, B270, D236T, AF45 and BK7 glass, quartz, and Zerodur.

Generalized internal model robust control for active front steering intervention

NASA Astrophysics Data System (ADS)

Wu, Jian; Zhao, Youqun; Ji, Xuewu; Liu, Yahui; Zhang, Lipeng

2015-03-01

Because of the tire nonlinearity and vehicle's parameters' uncertainties, robust control methods based on the worst cases, such as H ∞, µ synthesis, have been widely used in active front steering control, however, in order to guarantee the stability of active front steering system (AFS) controller, the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control. In this paper, a generalized internal model robust control (GIMC) that can overcome the contradiction between performance and stability is used in the AFS control. In GIMC, the Youla parameterization is used in an improved way. And GIMC controller includes two sections: a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters' uncertainties and some external disturbances. Simulations of double lane change (DLC) maneuver and that of braking on split- µ road are conducted to compare the performance and stability of the GIMC control, the nominal performance PID controller and the H ∞ controller. Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations, H ∞ controller is conservative so that the performance is a little low, and only the GIMC controller overcomes the contradiction between performance and robustness, which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller. Therefore, the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system, that is, can solve the instability of PID or LQP control methods and the low performance of the standard H ∞ controller.

Aspergillus fumigatus (Af) Hydroxamate Siderophores Protect Formation of Af Biofilms from the Pseudomonas aeruginosa (Pa) Product Pyoverdine

PubMed Central

Sass, Gabriele; Stevens, David A

2017-01-01

Abstract Background Pa and Af are pathogens frequently found together in airways of immunocompromised patients and patients with cystic fibrosis (CF). Hence, interactions of Pa and Af require understanding. Both Pa and Af are crucially dependent on the availability of iron, and therefore are competitors in their microenvironment. We have shown, using deletion mutants of Pa, that the Pa siderophore pyoverdine, the dominant Pa inhibitor of Af, interferes with Af biofilms by iron chelation, and denial of iron to the fungus. Methods Protective compounds in Af supernatants were evaluated using assays for the quantification of Af biofilm metabolism by XTT measurement, spectrometric pyoverdine measurement, as well as Chrome Azorole S (CAS) assay for the determination of siderophore production. Results Here we provide evidence that whereas iron usage by Af promotes pyoverdine production by Pa, Af has developed a defense mechanism against anti-fungal pyoverdine effects. The ability of Af to produce hydroxamate siderophores, and shed these into the surrounding medium, where they sequester and transport iron, is a key factor for Af self-defense against Pa. Under low iron conditions, such as in the presence of high amounts of the Pa siderophore pyoverdine, siderophore-bound iron is then fed to Af, protecting the fungus from iron starvation. Af with a deletion mutation in sidA, a gene essential for the production of hydroxamate siderophores, was significantly more sensitive to Pa supernatants, as well as pure pyoverdine, than wild-type Af. Af supernatants, produced in the presence of celastrol, an inhibitor of SidA-generated biosynthesis of siderophores, or produced by the sidA mutant, were not able to protect Af from iron starvation. Conclusion Interference with the iron-dependent Af self-defense mechanism might represent a new approach for therapy against aspergillosis. Disclosures All authors: No reported disclosures.

Ethnic distribution of ECG predictors of atrial fibrillation and its impact on understanding the ethnic distribution of ischemic stroke in the Atherosclerosis Risk in Communities (ARIC) study.

PubMed

Soliman, Elsayed Z; Prineas, Ronald J; Case, L Douglas; Zhang, Zhu-ming; Goff, David C

2009-04-01

The paradox of the reported low prevalence of atrial fibrillation (AF) in blacks compared with whites despite higher stroke rates in the former could be related to limitations in the current methods used to diagnose AF in population-based studies. Hence, this study aimed to use the ethnic distribution of ECG predictors of AF as measures of AF propensity in different ethnic groups. The distribution of baseline measures of P-wave terminal force, P-wave duration, P-wave area, and PR duration (referred to as AF predictors) were compared by ethnicity in 15 429 participants (27% black) from the Atherosclerosis Risk in Communities (ARIC) study by unpaired t test, chi(2), and logistic-regression analysis, as appropriate. Cox proportional-hazards analysis was used to separately examine the association of AF predictors with incident AF and ischemic stroke. Whereas AF was significantly less common in blacks compared with whites (0.24% vs 0.95%, P<0.0001), similar to what has been reported in previous studies, blacks had significantly higher and more abnormal values of AF predictors (P<0.0001 for all comparisons). Black ethnicity was significantly associated with abnormal AF predictors compared with whites; odds ratios for different AF predictors ranged from 2.1 to 3.1. AF predictors were significantly and independently associated with AF and ischemic stroke with no significant interaction between ethnicity and AF predictors, findings that further justify using AF predictors as an earlier indicator of future risk of AF and stroke. There is a disconnect between the ethnic distribution of AF predictors and the ethnic distribution of AF, probably because the former, unlike the latter, do not suffer from low sensitivity. These results raise the possibility that blacks might actually have a higher prevalence of AF that might have been missed by previous studies owing to limited methodology, a difference that could partially explain the greater stroke risk in blacks.

Presence and transcriptional activity of anaerobic fungi in agricultural biogas plants.

PubMed

Dollhofer, Veronika; Callaghan, Tony M; Griffith, Gareth W; Lebuhn, Michael; Bauer, Johann

2017-07-01

Bioaugmentation with anaerobic fungi (AF) is promising for improved biogas generation from lignocelluloses-rich substrates. However, before implementing AF into biogas processes it is necessary to investigate their natural occurrence, community structure and transcriptional activity in agricultural biogas plants. Thus, AF were detected with three specific PCR based methods: (i) Copies of their 18S genes were found in 7 of 10 biogas plants. (ii) Transcripts of a GH5 endoglucanase gene were present at low level in two digesters, indicating transcriptional cellulolytic activity of AF. (iii) Phylogeny of the AF-community was inferred with the 28S gene. A new Piromyces species was isolated from a PCR-positive digester. Evidence for AF was only found in biogas plants operated with high proportions of animal feces. Thus, AF were most likely transferred into digesters with animal derived substrates. Additionally, high process temperatures in combination with long retention times seemed to impede AF survival and activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

PubMed Central

Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

2010-01-01

Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

Imaging Lenticular Autofluorescence in Older Subjects

PubMed Central

Charng, Jason; Tan, Rose; Luu, Chi D.; Sadigh, Sam; Stambolian, Dwight; Guymer, Robyn H.; Jacobson, Samuel G.; Cideciyan, Artur V.

2017-01-01

Purpose To evaluate whether a practical method of imaging lenticular autofluorescence (AF) can provide an individualized measure correlated with age-related lens yellowing in older subjects undergoing tests involving shorter wavelength lights. Methods Lenticular AF was imaged with 488-nm excitation using a confocal scanning laser ophthalmoscope (cSLO) routinely used for retinal AF imaging. There were 75 older subjects (ages 47–87) at two sites; a small cohort of younger subjects served as controls. At one site, the cSLO was equipped with an internal reference to allow quantitative AF measurements; at the other site, reduced-illuminance AF imaging (RAFI) was used. In a subset of subjects, lens density index was independently estimated from dark-adapted spectral sensitivities performed psychophysically. Results Lenticular AF intensity was significantly higher in the older eyes than the younger cohort when measured with the internal reference (59.2 ± 15.4 vs. 134.4 ± 31.7 gray levels; P < 0.05) as well as when recorded with RAFI without the internal reference (10.9 ± 1.5 vs. 26.1 ± 5.7 gray levels; P < 0.05). Lenticular AF was positively correlated with age; however, there could also be large differences between individuals of similar age. Lenticular AF intensity correlated well with lens density indices estimated from psychophysical measures. Conclusions Lenticular AF measured with a retinal cSLO can provide a practical and individualized measure of lens yellowing, and may be a good candidate to distinguish between preretinal and retinal deficits involving short-wavelength lights in older eyes. PMID:28973367

Ablative Thermal Response Analysis Using the Finite Element Method

NASA Technical Reports Server (NTRS)

Dec John A.; Braun, Robert D.

2009-01-01

A review of the classic techniques used to solve ablative thermal response problems is presented. The advantages and disadvantages of both the finite element and finite difference methods are described. As a first step in developing a three dimensional finite element based ablative thermal response capability, a one dimensional computer tool has been developed. The finite element method is used to discretize the governing differential equations and Galerkin's method of weighted residuals is used to derive the element equations. A code to code comparison between the current 1-D tool and the 1-D Fully Implicit Ablation and Thermal Response Program (FIAT) has been performed.

Incidence, type of atrial fibrillation and risk factors for stroke: a population-based cohort study

PubMed Central

Johansson, Cecilia; Dahlqvist, Erik; Andersson, Jonas; Jansson, Jan-Håkan; Johansson, Lars

2017-01-01

Purpose The aims of this study were to estimate the incidence of atrial fibrillation and atrial flutter (AF), to assess the presence of provoking factors and risk factors for stroke and systemic embolism, and to determine the type of AF in patients with first-diagnosed AF. Patients and methods This cohort study was performed in northern Sweden between January 1, 2011 and December 31, 2012. Diagnosis registries were searched for the International Classification of Diseases-10 code for AF (I48) to identify cases of incident AF. All AF diagnoses were electrocardiogram-verified. Data pertaining to provoking factors, type of AF and presence of risk factors for stroke and systemic embolism according to the CHA2DS2-VASc score were obtained from medical records. Results The incidence of AF in the entire population was 4.0 per 1,000 person-years. The incidence was 27.5 per 1,000 person-years in patients aged ≥80 years. A total of 21% of all patients had a provoking factor in association with the first-diagnosed episode of AF. The CHA2DS2-VASc score was 2 or higher in 81% of the patients. Permanent AF was the most common type of AF (29%). Conclusion There was a considerable increase in the incidence of AF with age, and a provoking factor was found in one-fifth. The most common type of AF was permanent AF. Four in five patients had a CHA2DS2-VASc score of 2 or more. PMID:28182159

Method for evaluation of predictive models of microwave ablation via post-procedural clinical imaging

NASA Astrophysics Data System (ADS)

Collins, Jarrod A.; Brown, Daniel; Kingham, T. Peter; Jarnagin, William R.; Miga, Michael I.; Clements, Logan W.

2015-03-01

Development of a clinically accurate predictive model of microwave ablation (MWA) procedures would represent a significant advancement and facilitate an implementation of patient-specific treatment planning to achieve optimal probe placement and ablation outcomes. While studies have been performed to evaluate predictive models of MWA, the ability to quantify the performance of predictive models via clinical data has been limited to comparing geometric measurements of the predicted and actual ablation zones. The accuracy of placement, as determined by the degree of spatial overlap between ablation zones, has not been achieved. In order to overcome this limitation, a method of evaluation is proposed where the actual location of the MWA antenna is tracked and recorded during the procedure via a surgical navigation system. Predictive models of the MWA are then computed using the known position of the antenna within the preoperative image space. Two different predictive MWA models were used for the preliminary evaluation of the proposed method: (1) a geometric model based on the labeling associated with the ablation antenna and (2) a 3-D finite element method based computational model of MWA using COMSOL. Given the follow-up tomographic images that are acquired at approximately 30 days after the procedure, a 3-D surface model of the necrotic zone was generated to represent the true ablation zone. A quantification of the overlap between the predicted ablation zones and the true ablation zone was performed after a rigid registration was computed between the pre- and post-procedural tomograms. While both model show significant overlap with the true ablation zone, these preliminary results suggest a slightly higher degree of overlap with the geometric model.

Parallel imaging of knee cartilage at 3 Tesla.

PubMed

Zuo, Jin; Li, Xiaojuan; Banerjee, Suchandrima; Han, Eric; Majumdar, Sharmila

2007-10-01

To evaluate the feasibility and reproducibility of quantitative cartilage imaging with parallel imaging at 3T and to determine the impact of the acceleration factor (AF) on morphological and relaxation measurements. An eight-channel phased-array knee coil was employed for conventional and parallel imaging on a 3T scanner. The imaging protocol consisted of a T2-weighted fast spin echo (FSE), a 3D-spoiled gradient echo (SPGR), a custom 3D-SPGR T1rho, and a 3D-SPGR T2 sequence. Parallel imaging was performed with an array spatial sensitivity technique (ASSET). The left knees of six healthy volunteers were scanned with both conventional and parallel imaging (AF = 2). Morphological parameters and relaxation maps from parallel imaging methods (AF = 2) showed comparable results with conventional method. The intraclass correlation coefficient (ICC) of the two methods for cartilage volume, mean cartilage thickness, T1rho, and T2 were 0.999, 0.977, 0.964, and 0.969, respectively, while demonstrating excellent reproducibility. No significant measurement differences were found when AF reached 3 despite the low signal-to-noise ratio (SNR). The study demonstrated that parallel imaging can be applied to current knee cartilage quantification at AF = 2 without degrading measurement accuracy with good reproducibility while effectively reducing scan time. Shorter imaging times can be achieved with higher AF at the cost of SNR. (c) 2007 Wiley-Liss, Inc.

Method and apparatus for the guided ablative therapy of fast ventricular arrhythmia

NASA Technical Reports Server (NTRS)

Cohen, Richard J. (Inventor); Barley, Maya (Inventor)

2010-01-01

Method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. The excitation from the previous excitatory wave is significant at the beginning of the next excitation. In particular, it is designed for treatment of fast cardiac arrhythmias. Electrical signals are acquired from recording electrodes, and an inverse dipole method is used to identify the site of origin of an arrhythmia. The location of the tip of an ablation catheter is similarly localized from signals acquired from the recording electrodes while electrical pacing energy is delivered to the tip of the catheter close to or in contact with the cardiac tissue. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

NASA Technical Reports Server (NTRS)

Devismes, D.; Cohen, Barbara A.

2014-01-01

In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K-Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some µg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example, variable vacuum pressure), and c) the ablation is made with hundreds of successive laser pulses. In this work, we aim to understand the effects that occur on LIBS spectra when a homogeneous rock or a mineral is ablated under high vacuum. Understanding these effects is important to define best practices for LIBS measurements and may lead to improved measurement (or possibly prediction) of the ablated volume. We will describe our laboratory approach and first results, and discuss its utility for situ absolute geochronology campaigns.

Multimodal Imaging of Disease-Associated Pigmentary Changes in Retinitis Pigmentosa

PubMed Central

Schuerch, Kaspar; Marsiglia, Marcela; Lee, Winston; Tsang, Stephen H.; Sparrow, Janet R.

2016-01-01

Purpose Using multiple imaging modalities we evaluated the changes in photoreceptor cells and RPE that are associated with bone spicule-shaped melanin pigmentation in retinitis pigmentosa (RP). Methods In a cohort of 60 RP patients, short-wavelength autofluorescence (SW-AF), near-infrared (NIR)-AF, NIR-reflectance (NIR-R), spectral domain optical coherence tomography (SD-OCT) and color fundus images were studied. Results Central AF rings were visible in both SW-AF and NIR-AF images. Bone spicule pigmentation was non-reflective in NIR-R, hypoautofluorescent with SW-AF and NIR-AF imaging and presented as intraretinal hyperreflective foci in SD-OCT images. In areas beyond the AF ring outer border, the photoreceptor ellipsoid zone (EZ) band was absent in SD-OCT scans and the visibility of choroidal vessels in SW-AF, NIR-AF and NIR-R images was indicative of reduced RPE pigmentation. Choroidal visibility was most pronounced in the zone approaching peripheral areas of bone spicule pigmentation; here RPE/Bruch’s membrane thinning became apparent in SD-OCT scans. Conclusions These findings are consistent with a process by which RPE cells vacate their monolayer and migrate into inner retina in response to photoreceptor cell degeneration. The remaining RPE spread, undergo thinning and consequently become less pigmented. An explanation for the absence of NIR-AF melanin signal in relation to bone spicule pigmentation is not forthcoming. PMID:28005673

Wenxin Keli for atrial fibrillation

PubMed Central

He, Zhuogen; Zheng, Minan; Xie, Pingchang; Wang, Yuanping; Yan, Xia; Deng, Dingwei

2018-01-01

Abstract Background: Atrial fibrillation (AF) is a most common cardiac arrhythmia in clinical practice. In China, Wenxin Keli (WXKL) therapy is a common treatment for AF, but its effects and safety remain uncertain. This protocol is to provide the methods used to assess the effectiveness and safety of WXKL for the treatment of patients with AF. Methods: We will search comprehensively the 4 English databases EMBASE, the Cochrane Central Register of Controlled Trials (Cochrane Library), PubMed, and Medline and 3 Chinese databases China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), and Chinese Science and Technology Periodical database (VIP) on computer on March 2018 for the randomized controlled trials (RCTs) regarding WXKL for AF. The therapeutic effects according to the sinus rhythm and p-wave dispersion (Pwd) will be accepted as the primary outcomes. We will use RevMan V.5.3 software as well to compute the data synthesis carefully when a meta-analysis is allowed. Results: This study will provide a high-quality synthesis of current evidence of WXKL for AF. Conclusion: The conclusion of our systematic review will provide evidence to judge whether WXKL is an effective intervention for patient with AF. PROSPERO registration number: PROSPERO CRD 42018082045. PMID:29702984

Left atrial structure and function in atrial fibrillation: ENGAGE AF-TIMI 48

PubMed Central

Gupta, Deepak K.; Shah, Amil M.; Giugliano, Robert P.; Ruff, Christian T.; Antman, Elliott M.; Grip, Laura T.; Deenadayalu, Naveen; Hoffman, Elaine; Patel, Indravadan; Shi, Minggao; Mercuri, Michele; Mitrovic, Veselin; Braunwald, Eugene; Solomon, Scott D.

2014-01-01

Aims The complex relationship between left atrial (LA) structure and function, electrical burden of atrial fibrillation (AF) and stroke risk is not well understood. We aimed to describe LA structure and function in AF. Methods and results Left atrial structure and function was assessed in 971 subjects enrolled in the echocardiographic substudy of ENGAGE AF-TIMI 48. Left atrial size, emptying fraction (LAEF), and contractile function were compared across AF types (paroxysmal, persistent, or permanent) and CHADS2 scores as an estimate of stroke risk. The majority of AF patients (55%) had both LA enlargement and reduced LAEF, with an inverse relationship between LA size and LAEF (R = −0.57, P < 0.001). With an increasing electrical burden of AF and higher CHADS2 scores, LA size increased and LAEF declined. Moreover, 19% of AF subjects had impaired LAEF despite normal LA size, and LA contractile dysfunction was present even among the subset of AF subjects in sinus rhythm at the time of echocardiography. Conclusions In a contemporary AF population, LA structure and function were increasingly abnormal with a greater electrical burden of AF and higher stroke risk estimated by the CHADS2 score. Moreover, LA dysfunction was present despite normal LA size and sinus rhythm, suggesting that the assessment of LA function may add important incremental information in the evaluation of AF patients. Clinical Trial Registration: http://www.clinicaltrials.gov; ID = NCT00781391. PMID:24302269