Pulmonary Hypertension due to Radiofrequency Catheter Ablation (RFCA) for Atrial Fibrillation: The Lungs, the Atrium or the Ventricle?

PubMed

Verma, Isha; Tripathi, Hemantkumar; Sikachi, Rutuja Rajanikant; Agrawal, Abhinav

2016-12-01

Atrial fibrillation is the most common heart rhythm disorder in United States, characterised by rapid and irregular beating of both the atria resulting in the similar ventricular response. While rate and rhythm control using pharmacological regimens remain the primary management strategies in these patients, radiofrequency catheter ablation (RFCA) is rapidly rising as an alternative modality of treatment. Increase in the incidence of RFCA has shed light on complications associated with this procedure. Pulmonary hypertension (PH) is one of the long-term complications that has been observed postcatheter ablation. There have been multiple mechanisms which have been proposed to explain these elevated pulmonary pressures. These include the involvement of the lungs due to pulmonary vein stenosis, pulmonary vein occlusion and, rarely, pulmonary embolism. Radiofrequency catheter ablation can also lead to scarring of the atrium which can cause left atrial diastolic dysfunction leading to elevated pulmonary pressures. Recently, it was also proposed that elevated pulmonary pressure was related to the unmasking of left ventricular diastolic dysfunction occurring after this procedure. In this article, we review all the mechanisms that are associated with the development of pulmonary hypertension in patients undergoing RCFA for atrial fibrillation and the approach to diagnosis and management of such patients. 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.

Computational Modeling of Open-Irrigated Electrodes for Radiofrequency Cardiac Ablation Including Blood Motion-Saline Flow Interaction

PubMed Central

González-Suárez, Ana; Berjano, Enrique; Guerra, Jose M.; Gerardo-Giorda, Luca

2016-01-01

Radiofrequency catheter ablation (RFCA) is a routine treatment for cardiac arrhythmias. During RFCA, the electrode-tissue interface temperature should be kept below 80°C to avoid thrombus formation. Open-irrigated electrodes facilitate power delivery while keeping low temperatures around the catheter. No computational model of an open-irrigated electrode in endocardial RFCA accounting for both the saline irrigation flow and the blood motion in the cardiac chamber has been proposed yet. We present the first computational model including both effects at once. The model has been validated against existing experimental results. Computational results showed that the surface lesion width and blood temperature are affected by both the electrode design and the irrigation flow rate. Smaller surface lesion widths and blood temperatures are obtained with higher irrigation flow rate, while the lesion depth is not affected by changing the irrigation flow rate. Larger lesions are obtained with increasing power and the electrode-tissue contact. Also, larger lesions are obtained when electrode is placed horizontally. Overall, the computational findings are in close agreement with previous experimental results providing an excellent tool for future catheter research. PMID:26938638

Intrapericardial echocardiography: a novel catheter-based approach to cardiac imaging.

PubMed

Rodrigues, Ana Clara Tude; d'Avila, Andre; Houghtaling, Christopher; Ruskin, Jeremy N; Picard, Michael; Reddy, Vivek Y

2004-03-01

Transvascular catheter-based intracardiac echocardiography has been successfully used to help guide catheter ablation and electrophysiologic procedures. It has recently been demonstrated that catheters can be safely placed into the pericardial space to allow for epicardial cardiac mapping and ablation. We evaluated the feasibility of catheter-based intrapericardial echocardiography (IPE) during such procedures to identify cardiac structures and visualize intracardiac catheters. IPE was performed in 7 goats by placing a phased-array ultrasound transducer contained within a 10F steerable catheter into the pericardial space using the same transthoracic subxyphoid approach as used to map and ablate epicardial ventricular tachycardia. Images were obtained of cardiac structures and of intracardiac ablation catheters. After the procedure, the hearts were harvested to assess for possible IPE-related lesions. The IPE catheter could be easily placed inside the pericardial space in all animals. In 7 of 7 cases, longitudinal and short-axis views of right- and left-sided chambers and valves were obtained, similar in orientation to transesophageal echocardiography. Visualization of atrial appendages (6/7), pulmonary veins (6/7), coronary arteries (6/7), and coronary sinus (3/6) was also feasible. Assessment of intracardiac transvalvar and venous blood flow was achieved by spectral and color Doppler. The ablation catheter could be clearly visualized inside cardiac chambers. No arrhythmias were induced with IPE catheter manipulation. After harvesting the hearts, no lesions resulting from the procedure were observed. In this experimental setting, IPE was able to provide detailed images of cardiac structures and establish the relative position of the ablation catheter.

Optimal contact forces to minimize cardiac perforations before, during, and/or after radiofrequency or cryothermal ablations.

PubMed

Quallich, Stephen G; Van Heel, Michael; Iaizzo, Paul A

2015-02-01

Catheter perforations remain a major clinical concern during ablation procedures for treatment of atrial arrhythmias and may lead to life-threatening cardiac tamponade. Radiofrequency (RF) ablation alters the biomechanical properties of cardiac tissue, ultimately allowing for perforation to occur more readily. Studies on the effects of cryoablation on perforation force as well as studies defining the perforation force of human tissue are limited. The purpose of this study was to investigate the required force to elicit perforation of cardiac atrial tissue after or during ablation procedures. Effects of RF or cryothermal ablations on catheter perforation forces for both swine (n = 83 animals, 530 treatments) and human (n = 8 specimens, 136 treatments) cardiac tissue were investigated. Overall average forces resulting in perforation of healthy unablated tissue were 406g ± 170g for swine and 591g ± 240g for humans. Post-RF ablation applications considerably reduced these forces to 246g ± 118g for swine and 362 ± 185g for humans (P <.001). Treatments with cryoablation did not significantly alter forces required to induce perforations. Decreasing catheter sizes resulted in a reduction in forces required to perforate the atrial wall (P <.001). Catheter perforations occurred over an array of contact forces with a minimum of 38g being observed. The swine model likely underestimates the required perforation forces relative to those of human tissues. We provide novel insights related to the comparative effects of RF and cryothermal ablations on the potential for inducing undesired punctures, with RF ablation reducing perforation force significantly. These data are insightful for physicians performing ablation procedures as well as for medical device designers. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy

NASA Astrophysics Data System (ADS)

Kim, Dae-Hyeong; Lu, Nanshu; Ghaffari, Roozbeh; Kim, Yun-Soung; Lee, Stephen P.; Xu, Lizhi; Wu, Jian; Kim, Rak-Hwan; Song, Jizhou; Liu, Zhuangjian; Viventi, Jonathan; de Graff, Bassel; Elolampi, Brian; Mansour, Moussa; Slepian, Marvin J.; Hwang, Sukwon; Moss, Joshua D.; Won, Sang-Min; Huang, Younggang; Litt, Brian; Rogers, John A.

2011-04-01

Developing advanced surgical tools for minimally invasive procedures represents an activity of central importance to improving human health. A key challenge is in establishing biocompatible interfaces between the classes of semiconductor device and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on materials that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide diverse, multimodal functionality suitable for clinical use. As examples, we present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radiofrequency electrodes for controlled, local ablation of tissue. Use of such ‘instrumented’ balloon catheters in live animal models illustrates their operation, as well as their specific utility in cardiac ablation therapy. The same concepts can be applied to other substrates of interest, such as surgical gloves.

Stiff Left Atrial Syndrome: A Complication Undergoing Radiofrequency Catheter Ablation for Atrial Fibrillation.

PubMed

Yang, Yufan; Liu, Qiming; Wu, Zhihong; Li, Xuping; Xiao, Yichao; Tu, Tao; Zhou, Shenghua

2016-07-01

Radiofrequency catheter ablation for atrial fibrillation is an effective approach for treating atrial fibrillation. Its complications have attracted much attention, of which the stiff left atrial syndrome is a recently discovered complication that has not been completely understood. This study aims to investigate the concept, pathologic basis, clinical characteristics, predictors, and treatment protocols of the stiff left atrial syndrome after radiofrequency ablation for atrial fibrillation. © 2016 Wiley Periodicals, Inc.

Toward guidance of epicardial cardiac radiofrequency ablation therapy using optical coherence tomography

NASA Astrophysics Data System (ADS)

Fleming, Christine P.; Quan, Kara J.; Rollins, Andrew M.

2010-07-01

Radiofrequency ablation (RFA) is the standard of care to cure many cardiac arrhythmias. Epicardial ablation for the treatment of ventricular tachycardia has limited success rates due in part to the presence of epicardial fat, which prevents proper rf energy delivery, inadequate contact of ablation catheter with tissue, and increased likelihood of complications with energy delivery in close proximity to coronary vessels. A method to directly visualize the epicardial surface during RFA could potentially provide feedback to reduce complications and titrate rf energy dose by detecting critical structures, assessing probe contact, and confirming energy delivery by visualizing lesion formation. Currently, there is no technology available for direct visualization of the heart surface during epicardial RFA therapy. We demonstrate that optical coherence tomography (OCT) imaging has the potential to fill this unmet need. Spectral domain OCT at 1310 nm is employed to image the epicardial surface of freshly excised swine hearts using a microscope integrated bench-top scanner and a forward imaging catheter probe. OCT image features are observed that clearly distinguish untreated myocardium, ablation lesions, epicardial fat, and coronary vessels, and assess tissue contact with catheter-based imaging. These results support the potential for real-time guidance of epicardial RFA therapy using OCT imaging.

Results of Cryoenergy and Radiofrequency-Based Catheter Ablation for Treating Ventricular Arrhythmias Arising From the Papillary Muscles of the Left Ventricle, Guided by Intracardiac Echocardiography and Image Integration.

PubMed

Rivera, Santiago; Ricapito, Maria de la Paz; Tomas, Leandro; Parodi, Josefina; Bardera Molina, Guillermo; Banega, Rodrigo; Bueti, Pablo; Orosco, Agustin; Reinoso, Marcelo; Caro, Milagros; Belardi, Diego; Albina, Gaston; Giniger, Alberto; Scazzuso, Fernando

2016-04-01

Catheter radiofrequency ablation of ventricular arrhythmias (VAs) arising from the left ventricle's papillary muscles has been associated with inconsistent results. The use of cryoenergy versus radiofrequency has not been compared yet. This study compares outcomes and complications of catheter ablation of VA from the papillary muscles of the left ventricle with either cryoenergy or radiofrequency. Twenty-one patients (40±12 years old; 47% males; median ejection fraction 59±7.3%) with drug refractory premature ventricular contractions or ventricular tachycardia underwent catheter cryoablation or radiofrequency ablation. VAs were localized using 3-dimensional mapping, multidetector computed tomography, and intracardiac echocardiography, with arrhythmia foci being mapped at either the anterolateral papillary muscle or posteromedial papillary muscles of the left ventricle. Focal ablation was performed using an 8-mm cryoablation catheter or a 4-mm open-irrigated radiofrequency catheter, via transmitral approach. Acute success rate was 100% for cryoenergy (n=12) and 78% for radiofrequency (n=9; P=0.08). Catheter stability was achieved in all patients (100%) treated with cryoenergy, and only in 2 (25%) patients treated with radiofrequency (P=0.001). Incidence of multiple VA morphologies was observed in 7 patients treated with radiofrequency (77.7%), whereas none was observed in those treated with cryoenergy (P=0.001). VA recurrence at 6 months follow-up was 0% for cryoablation and 44% for radiofrequency (P=0.03). Cryoablation was associated with higher success rates and lower recurrence rates than radiofrequency catheter ablation, better catheter stability, and lesser incidence of polymorphic arrhythmias. © 2016 American Heart Association, Inc.

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

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.

Radiofrequency catheter ablation in patients with symptomatic atrial flutter/tachycardia after orthotopic heart transplantation.

PubMed

Li, Yi-gang; Grönefeld, Gerian; Israel, Carsten; Lu, Shang-biao; Wang, Qun-shan; Hohnloser, Stefan H

2006-12-20

Atrial tachycardia or flutter is common in patients after orthotopic heart transplantation. Radiofrequency catheter ablation to treat this arrhythmia has not been well defined in this setting. This study was conducted to assess the incidence of various symptomatic atrial arrhythmias and the efficacy and safety of radiofrequency catheter ablation in these patients. Electrophysiological study and catheter ablation were performed in patients with symptomatic tachyarrhythmia. One Halo catheter with 20 poles was positioned around the tricuspid annulus of the donor right atrium, or positioned around the surgical anastomosis when it is necessary. Three quadripolar electrode catheters were inserted via the right or left femoral vein and positioned in the recipient atrium, the bundle of His position, the coronary sinus. Programmed atrial stimulation and burst pacing were performed to prove electrical conduction between the recipient and the donor atria and to induce atrial arrhythmias. Out of 55 consecutive heart transplantation patients, 6 males [(58 +/- 12) years] developed symptomatic tachycardias at a mean of (5 +/- 4) years after heart transplantation. Electrical propagation through the suture line between the recipient and the donor atrium was demonstrated during atrial flutter or during recipient atrium and donor atrium pacing in 2 patients. By mapping around the suture line, the earliest fragmented electrogram of donor atrium was assessed. This electrical connection was successfully ablated in the anterior lateral atrium in both patients. There was no electrical propagation through the suture line in the other 4 patients. Two had typical atrial flutter in the donor atrium which was successfully ablated by completing a linear ablation between the tricuspid annulus and the inferior vena cava. Two patients had atrial tachycardia which was ablated in the anterior septal and lateral donor atrium. There were no procedure-related complications. Patients were free of

Outcome of Radiofrequency Catheter Ablation as a non-pharmacological therapy for idiopathic Ventricular Tachycardia.

PubMed

Samore, Naseer Ahmed; Imran Majeed, Syed Muhammad; Kayani, Azhar Mahmud; Bhalli, Muhammad Asif; Shabbir, Muhammad

2009-09-01

To determine the outcome of Radiofrequency Catheter Ablation (RFCA) as a non-pharmacological curative therapy for idiopathic Ventricular Tachycardia (VT) and to identify procedure-related complications. Descriptive study. The Armed Forces Institute of Cardiology and National Institute of Heart Diseases, Rawalpindi, from February 2001 to October 2008. Ninety eight consecutive patients with idiopathic VT, resistant to drug therapy, who underwent Electrophysiology Studies (EPS) radiofrequency catheter ablation were enrolled. Clinical and electrophysiological variables were recorded and a descriptive analysis was done. Out of the 98 patients, 79 were males (80.6%). The mean age was 33.29+11.93 years. Modes of presentation were sustained VT, Repetitive Monomorphic VT (RMVT), Non-sustained VT (NSVT) and Ventricular Premature Beats (VPBs). Right Ventricular Outflow Tract (RVOT) VT was found in 37 patients, 37 had Idiopathic Left Ventricular Tachycardia (ILVT), 20 had Left Ventricular Outflow Tract (LVOT) VT, and Inflow Right Ventricular Tachycardia (IRVT) was found in 7 patients. Other sites of origin of VT were infrequent. Eight patients had dual morphologies of VT. Atrioventricular Nodal Re-entry Tachycardia (AVNRT) was found in 8 patients. RFCA was successful in abolishing inducible VT in 88 patients. One patient developed complete AV block requiring a permanent pacemaker. Results of this study confirm a high degree of success and safety of radiofrequency catheter ablation as curative therapy for idiopathic ventricular tachycardia.

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.

Biophysics and pathology of catheter energy delivery systems.

PubMed

Nath, S; Haines, D E

1995-01-01

Catheter ablation has rapidly emerged as the treatment of choice for many symptomatic cardiac arrhythmias. The initial experience with catheter ablation used high-energy DC as the energy source. However, over the last several years radiofrequency (RF) catheter ablation has become the dominant mode of energy delivery. Currently, a major limitation of RF ablation is the small lesion size created by this technique that has reduced its success rate in ablation of larger arrhythmogenic substrates such as coronary artery disease-related ventricular tachycardia. Alternate energy sources such as microwave or ultrasound catheter ablation are being developed that have the potential for producing larger lesions than RF ablation. This review will discuss the biophysics and pathophysiology of the various energy modalities used in catheter ablation.

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.

Large-deflection statics analysis of active cardiac catheters through co-rotational modelling.

PubMed

Peng Qi; Chen Qiu; Mehndiratta, Aadarsh; I-Ming Chen; Haoyong Yu

2016-08-01

This paper presents a co-rotational concept for large-deflection formulation of cardiac catheters. Using this approach, the catheter is first discretized with a number of equal length beam elements and nodes, and the rigid body motions of an individual beam element are separated from its deformations. Therefore, it is adequate for modelling arbitrarily large deflections of a catheter with linear elastic analysis at the local element level. A novel design of active cardiac catheter of 9 Fr in diameter at the beginning of the paper is proposed, which is based on the contra-rotating double helix patterns and is improved from the previous prototypes. The modelling section is followed by MATLAB simulations of various deflections when the catheter is exerted different types of loads. This proves the feasibility of the presented modelling approach. To the best knowledge of the authors, it is the first to utilize this methodology for large-deflection static analysis of the catheter, which will enable more accurate control of robot-assisted cardiac catheterization procedures. Future work would include further experimental validations.

Development of a force-reflecting robotic platform for cardiac catheter navigation.

PubMed

Park, Jun Woo; Choi, Jaesoon; Pak, Hui-Nam; Song, Seung Joon; Lee, Jung Chan; Park, Yongdoo; Shin, Seung Min; Sun, Kyung

2010-11-01

Electrophysiological catheters are used for both diagnostics and clinical intervention. To facilitate more accurate and precise catheter navigation, robotic cardiac catheter navigation systems have been developed and commercialized. The authors have developed a novel force-reflecting robotic catheter navigation system. The system is a network-based master-slave configuration having a 3-degree of freedom robotic manipulator for operation with a conventional cardiac ablation catheter. The master manipulator implements a haptic user interface device with force feedback using a force or torque signal either measured with a sensor or estimated from the motor current signal in the slave manipulator. The slave manipulator is a robotic motion control platform on which the cardiac ablation catheter is mounted. The catheter motions-forward and backward movements, rolling, and catheter tip bending-are controlled by electromechanical actuators located in the slave manipulator. The control software runs on a real-time operating system-based workstation and implements the master/slave motion synchronization control of the robot system. The master/slave motion synchronization response was assessed with step, sinusoidal, and arbitrarily varying motion commands, and showed satisfactory performance with insignificant steady-state motion error. The current system successfully implemented the motion control function and will undergo safety and performance evaluation by means of animal experiments. Further studies on the force feedback control algorithm and on an active motion catheter with an embedded actuation mechanism are underway. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, 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.

Prediction of radiofrequency ablation lesion formation using a novel temperature sensing technology incorporated in a force sensing catheter.

PubMed

Rozen, Guy; Ptaszek, Leon; Zilberman, Israel; Cordaro, Kevin; Heist, E Kevin; Beeckler, Christopher; Altmann, Andres; Ying, Zhang; Liu, Zhenjiang; Ruskin, Jeremy N; Govari, Assaf; Mansour, Moussa

2017-02-01

Real-time radiofrequency (RF) ablation lesion assessment is a major unmet need in cardiac electrophysiology. The purpose of this study was to assess whether improved temperature measurement using a novel thermocoupling (TC) technology combined with information derived from impedance change, contact force (CF) sensing, and catheter orientation allows accurate real-time prediction of ablation lesion formation. RF ablation lesions were delivered in the ventricles of 15 swine using a novel externally irrigated-tip catheter containing 6 miniature TC sensors in addition to force sensing technology. Ablation duration, power, irrigation rate, impedance drop, CF, and temperature from each sensor were recorded. The catheter "orientation factor" was calculated using measurements from the different TC sensors. Information derived from all the sources was included in a mathematical model developed to predict lesion depth and validated against histologic measurements. A total of 143 ablation lesions were delivered to the left ventricle (n = 74) and right ventricle (n = 69). Mean CF applied during the ablations was 14.34 ± 3.55g, and mean impedance drop achieved during the ablations was 17.5 ± 6.41 Ω. Mean difference between predicted and measured ablation lesion depth was 0.72 ± 0.56 mm. In the majority of lesions (91.6%), the difference between estimated and measured depth was ≤1.5 mm. Accurate real-time prediction of RF lesion depth is feasible using a novel ablation catheter-based system in conjunction with a mathematical prediction model, combining elaborate temperature measurements with information derived from catheter orientation, CF sensing, impedance change, and additional ablation parameters. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Radiofrequency catheter ablation versus balloon cryoablation of atrial fibrillation: markers of myocardial damage, inflammation, and thrombogenesis.

PubMed

Antolič, Bor; Pernat, Andrej; Cvijić, Marta; Žižek, David; Jan, Matevž; Šinkovec, Matjaž

2016-07-01

Evidence from animal and human studies suggests that cryoablation might be associated with a lesser inflammatory response and activation of coagulation compared with radiofrequency ablation. The study was aimed at comparing the effect of cryoballoon and radiofrequency catheter ablation of paroxysmal atrial fibrillation on markers of myocardial damage, inflammation, and activation of coagulation. Forty-one patients received either cryoballoon (n = 23) or radiofrequency (n = 18) ablation of atrial fibrillation. We measured troponin I, high-sensitivity CRP, and interleukin 6 at baseline from the cubital vein, and from the right and left atrium before and after ablation, and from the cubital vein the following day. Prothrombin fragments 1 + 2, soluble P‑selectin, and D‑dimer were measured before and after ablation from both atria. We observed higher troponin I release in the cryoballoon than in the radiofrequency group (7.01 mcg/l (interquartile range [IQR]: 5.30-9.09) vs 2.32 mcg/l (IQR: 1.45-2.98), p < 0.001). The levels of inflammatory markers (high-sensitivity CRP and interleukin 6) in the two groups were comparable, as were the levels of markers of coagulation activation. Procedure duration, fluoroscopy times, and mid-term success (23 months, IQR 7-32) of the two groups were also comparable. Cryoballoon ablation of atrial fibrillation causes more significant myocardial damage, that is, more extensive ablation lesions, compared with radiofrequency catheter ablation. However, no major differences between these two ablation techniques with regard to the inflammatory response and activation of the coagulation system were observed.

Radiofrequency catheter ablation of idiopathic ventricular arrhythmias originating from intramural foci in the left ventricular outflow tract: efficacy of sequential versus simultaneous unipolar catheter ablation.

PubMed

Yamada, Takumi; Maddox, William R; McElderry, H Thomas; Doppalapudi, Harish; Plumb, Vance J; Kay, G Neal

2015-04-01

Idiopathic ventricular arrhythmias (VAs) originating from the left ventricular outflow tract (LVOT) sometimes require catheter ablation from the endocardial and epicardial sides for their elimination, suggesting the presence of intramural VA foci. This study investigated the efficacy of sequential and simultaneous unipolar radiofrequency catheter ablation from the endocardial and epicardial sides in treating intramural LVOT VAs. Fourteen consecutive LVOT VAs, which required sequential or simultaneous irrigated unipolar radiofrequency ablation from the endocardial and epicardial sides for their elimination, were studied. The first ablation was performed at the site with the earliest local ventricular activation and best pace map on the endocardial or epicardial side. When the first ablation was unsuccessful, the second ablation was delivered on the other surface. If this sequential unipolar ablation failed, simultaneous unipolar ablation from both sides was performed. The first ablation was performed on the epicardial side in 9 VAs and endocardial side in 5 VAs. The intramural LVOT VAs were successfully eliminated by the sequential (n=9) or simultaneous (n=5) unipolar catheter ablation. Simultaneous ablation was most likely to be required for the elimination of the VAs when the distance between the endocardial and epicardial ablation sites was >8 mm and the earliest local ventricular activation time relative to the QRS onset during the VAs of <-30 ms was recorded at those ablation sites. LVOT VAs originating from intramural foci could usually be eliminated by sequential unipolar radiofrequency ablation and sometimes required simultaneous ablation from both the endocardial and epicardial sides. © 2015 American Heart Association, Inc.

Anatomical Basis for the Cardiac Interventional Electrophysiologist

PubMed Central

Sánchez-Quintana, Damián; Doblado-Calatrava, Manuel; Cabrera, José Angel; Macías, Yolanda; Saremi, Farhood

2015-01-01

The establishment of radiofrequency catheter ablation techniques as the mainstay in the treatment of tachycardia has renewed new interest in cardiac anatomy. The interventional arrhythmologist has drawn attention not only to the gross anatomic details of the heart but also to architectural and histological characteristics of various cardiac regions that are relevant to the development or recurrence of tachyarrhythmias and procedural related complications of catheter ablation. In this review, therefore, we discuss some anatomic landmarks commonly used in catheter ablations including the terminal crest, sinus node region, Koch's triangle, cavotricuspid isthmus, Eustachian ridge and valve, pulmonary venous orifices, venoatrial junctions, and ventricular outflow tracts. We also discuss the anatomical features of important structures in the vicinity of the atria and pulmonary veins, such as the esophagus and phrenic nerves. This paper provides basic anatomic information to improve understanding of the mapping and ablative procedures for cardiac interventional electrophysiologists. PMID:26665006

Black-box modeling to estimate tissue temperature during radiofrequency catheter cardiac ablation: Feasibility study on an agar phantom model.

PubMed

Blasco-Gimenez, Ramón; Lequerica, Juan L; Herrero, Maria; Hornero, Fernando; Berjano, Enrique J

2010-04-01

The aim of this work was to study linear deterministic models to predict tissue temperature during radiofrequency cardiac ablation (RFCA) by measuring magnitudes such as electrode temperature, power and impedance between active and dispersive electrodes. The concept involves autoregressive models with exogenous input (ARX), which is a particular case of the autoregressive moving average model with exogenous input (ARMAX). The values of the mode parameters were determined from a least-squares fit of experimental data. The data were obtained from radiofrequency ablations conducted on agar models with different contact pressure conditions between electrode and agar (0 and 20 g) and different flow rates around the electrode (1, 1.5 and 2 L min(-1)). Half of all the ablations were chosen randomly to be used for identification (i.e. determination of model parameters) and the other half were used for model validation. The results suggest that (1) a linear model can be developed to predict tissue temperature at a depth of 4.5 mm during RF cardiac ablation by using the variables applied power, impedance and electrode temperature; (2) the best model provides a reasonably accurate estimate of tissue temperature with a 60% probability of achieving average errors better than 5 degrees C; (3) substantial errors (larger than 15 degrees C) were found only in 6.6% of cases and were associated with abnormal experiments (e.g. those involving the displacement of the ablation electrode) and (4) the impact of measuring impedance on the overall estimate is negligible (around 1 degrees C).

Determination of lesion size by ultrasound during radiofrequency catheter ablation.

PubMed

Awad, S; Eick, O

2003-01-01

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

Role of Contact Force Sensing in Catheter Ablation of Cardiac Arrhythmias: Evolution or History Repeating Itself?

PubMed

Ariyarathna, Nilshan; Kumar, Saurabh; Thomas, Stuart P; Stevenson, William G; Michaud, Gregory F

2018-06-01

Adequate catheter-tissue contact facilitates efficient heat energy transfer to target tissue. Tissue contact is thus critical to achieving lesion transmurality and success of radiofrequency (RF) ablation procedures, a fact recognized more than 2 decades ago. The availability of real-time contact force (CF)-sensing catheters has reinvigorated the field of ablation biophysics and optimized lesion formation. The ability to measure and display CF came with the promise of dramatic improvement in safety and efficacy; however, CF quality was noted to have just as important an influence on lesion formation as absolute CF quantity. Multiple other factors have emerged as key elements influencing effective lesion formation, including catheter stability, lesion contiguity and continuity, lesion density, contact homogeneity across a line of ablation, spatiotemporal dynamics of contact governed by cardiac and respiratory motion, contact directionality, and anatomic wall thickness, in addition to traditional ablation indices of power and RF duration. There is greater appreciation of surrogate markers as a guide to lesion formation, such as impedance fall, loss of pace capture, and change in unipolar electrogram morphology. In contrast, other surrogates such as tactile feedback, catheter motion, and electrogram amplitude are notably poor predictors of actual contact and lesion formation. This review aims to contextualize the role of CF sensing in lesion formation with respect of the fundamental principles of biophysics of RF ablation and summarize the state-of-the-art evidence behind the role of CF in optimizing lesion formation. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Selective Angiography Using the Radiofrequency Catheter: An Alternative Technique for Mapping and Ablation in the Aortic Cusps.

PubMed

Roca-Luque, Ivo; Rivas, Nuria; Francisco, Jaume; Perez, Jordi; Acosta, Gabriel; Oristrell, Gerard; Terricabres, Maria; Garcia-Dorado, David; Moya, Angel

2017-01-01

Ablation in aortic cusps could be necessary in up to 15% of the patients, especially in para-Hisian atrial tachycardia and ventricular arrhythmias arising from outflow tracts. Risk of coronary damage has led to recommendation of systematic coronary angiography (CA) during the procedure. Other image tests as intravascular (ICE) or transesophageal echocardiography (TEE) have been proposed. Both methods have limitations: additional vascular access for ICE and need for additional CA in some patients in case of TEE. We describe an alternative method to assess relation of catheter tip and coronary ostia during ablation in aortic cusps without additional vascular accesses by performing selective angiography with the ablation catheter. We prospectively evaluated 12 consecutive patients (69.3 ± 8.5, 6 female) who underwent ablation in right (1), left (5), and noncoronary cusps (6). We performed angiography through the ablation cooled tip radiofrequency catheter at the ablation site. Ablation was effective in 91.6% of the patients (3 patients needed additional ablation out of coronary cusps: pulmonary cusp, right ventricular outflow tract (RVOT), and coronary sinus and 1 patient underwent a second procedure because recurrence). No complications occurred neither during procedure nor follow-up (6.2 ± 3.8 months). No technical problems occurred with the ablation catheter after contrast injection. Selective angiography through a cooled-tip radiofrequency ablation catheter is feasible to assess relation of coronary ostia and ablation site when ablation in aortic cusps. It allows continuous real-time assessment of this relation, avoids the need for additional vascular accesses and no complications occurred in our series. © 2016 Wiley Periodicals, Inc.

Efficacy and safety of catheter-based radiofrequency renal denervation in stented renal arteries.

PubMed

Mahfoud, Felix; Tunev, Stefan; Ruwart, Jennifer; Schulz-Jander, Daniel; Cremers, Bodo; Linz, Dominik; Zeller, Thomas; Bhatt, Deepak L; Rocha-Singh, Krishna; Böhm, Michael; Melder, Robert J

2014-12-01

In selected patients with hypertension, renal artery (RA) stenting is used to treat significant atherosclerotic stenoses. However, blood pressure often remains uncontrolled after the procedure. Although catheter-based renal denervation (RDN) can reduce blood pressure in certain patients with resistant hypertension, there are no data on the feasibility and safety of RDN in stented RA. We report marked blood pressure reduction after RDN in a patient with resistant hypertension who underwent previous stenting. Subsequently, radiofrequency ablation was investigated within the stented segment of porcine RA, distal to the stented segment, and in nonstented RA and compared with stent only and untreated controls. There were neither observations of thrombus nor gross or histological changes in the kidneys. After radiofrequency ablation of the nonstented RA, sympathetic nerves innervating the kidney were significantly reduced, as indicated by significant decreases in sympathetic terminal axons and reduction of norepinephrine in renal tissue. Similar denervation efficacy was found when RDN was performed distal to a renal stent. In contrast, when radiofrequency ablation was performed within the stented segment of the RA, significant sympathetic nerve ablation was not seen. Histological observation showed favorable healing in all arteries. Radiofrequency ablation of previously stented RA demonstrated that RDN provides equally safe experimental procedural outcomes in a porcine model whether the radiofrequency treatment is delivered within, adjacent, or without the stent struts being present in the RA. However, efficacious RDN is only achieved when radiofrequency ablation is delivered to the nonstented RA segment distal to the stent. © 2014 American Heart Association, Inc.

Cardiac magnetic resonance radiofrequency tissue tagging for diagnosis of constrictive pericarditis: A proof of concept study.

PubMed

Power, John A; Thompson, Diane V; Rayarao, Geetha; Doyle, Mark; Biederman, Robert W W

2016-05-01

Invasive cardiac catheterization is the venerable "gold standard" for diagnosing constrictive pericarditis. However, its sensitivity and specificity vary dramatically from center to center. Given the ability to unequivocally define segments of the pericardium with the heart via radiofrequency tissue tagging, we hypothesize that cardiac magnetic resonance has the capability to be the new gold standard. All patients who were referred for cardiac magnetic resonance evaluation of constrictive pericarditis underwent cardiac magnetic resonance radiofrequency tissue tagging to define visceral-parietal pericardial adherence to determine constriction. This was then compared with intraoperative surgical findings. Likewise, all preoperative cardiac catheterization testing was reviewed in a blinded manner. A total of 120 patients were referred for clinical suspicion of constrictive pericarditis. Thirty-nine patients were defined as constrictive pericarditis positive solely via radiofrequency tissue-tagging cardiac magnetic resonance, of whom 21 were positive, 4 were negative, and 1 was equivocal for constrictive pericarditis, as defined by cardiac catheterization. Of these patients, 16 underwent pericardiectomy and were surgically confirmed. There was 100% agreement between cardiac magnetic resonance-defined constrictive pericarditis positivity and postsurgical findings. No patients were misclassified by cardiac magnetic resonance. In regard to the remaining constrictive pericarditis-positive patients defined by cardiac magnetic resonance, 10 were treated medically, declined, were ineligible for surgery, or were lost to follow-up. Long-term follow-up of those who were constrictive pericarditis negative by cardiac magnetic resonance showed no early or late crossover to the surgery arm. Cardiac magnetic resonance via radiofrequency tissue tagging offers a unique, efficient, and effective manner of defining clinically and surgically relevant constrictive pericarditis

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.

Robust classification of contact orientation between tissue and an integrated spectroscopy and radiofrequency ablation catheter

NASA Astrophysics Data System (ADS)

Zaryab, Mohammad; Singh-Moon, Rajinder P.; Hendon, Christine P.

2017-02-01

Using light-based catheters for radiofrequency ablation (RFA) therapies grants the ability to accurately derive tissue properties such as lesion depth and overtreatment from spectroscopic information. However, this information is heavily reliant on contact quality with the treatment area and the orientation of the catheter. Thus to improve assessments of tissue properties, this work utilizes Bayesian modelling to classify whether the catheter is indeed in proper contact with the tissue. Initially in-laboratory experiments were conducted with ten fresh swine hearts submerged in blood. A total of 1555 unique near infrared spectra were collected from a spectrometer using a light-based catheter and manually tagged as "full perpendicular contact," "angled contact," and "no contact," between the catheter and heart tissue. Three features were prominent in all spectra for distinguishing purposes: area underneath the spectra, an intensity "valley" between 730 nm and 800 nm, along with the slope between 850 nm and 1150 nm. A classifier featuring bootstrapping, adaboost, and k-means techniques was thus created and achieved a 96.05% accuracy in classifying full contact, 98.33% accuracy in classifying angled contact, and 100% accuracy in classifying no contact.

Extending the use of the pacing pulmonary artery catheter for safe minimally invasive cardiac surgery.

PubMed

Levin, Ricardo; Leacche, Marzia; Petracek, Michael R; Deegan, Robert J; Eagle, Susan S; Thompson, Annemarie; Pretorius, Mias; Solenkova, Nataliya V; Umakanthan, Ramanan; Brewer, Zachary E; Byrne, John G

2010-08-01

In this study, the therapeutic use of pacing pulmonary artery catheters in association with minimally invasive cardiac surgery was evaluated. A retrospective study. A single institutional university hospital. Two hundred twenty-four consecutive patients undergoing minimally invasive cardiac surgery through a small (5-cm) right anterolateral thoracotomy using fibrillatory arrest without aortic cross-clamping. Two hundred eighteen patients underwent mitral valve surgery (97%) alone or in combination with other procedures. Six patients underwent other cardiac operations. In all patients, the pacing pulmonary artery catheter was used intraoperatively to induce ventricular fibrillation during the cooling period, and in the postoperative period it also was used in 37 (17%) patients who needed to be paced, mainly for bradyarrhythmias (51%). There were no complications related to the insertion of the catheters. Six (3%) patients experienced a loss of pacing capture, and 2 (1%) experienced another complication requiring the surgical removal of the catheter. Seven (3%) patients needed postoperative implantation of a permanent pacemaker. In combination with minimally invasive cardiac surgery, pacing pulmonary artery catheters were therapeutically useful to induce ventricular fibrillatory arrest intraoperatively and for obtaining pacing capability in the postoperative period. Their use was associated with a low number of complications. Copyright 2010 Elsevier Inc. All rights reserved.

Use of bipolar radiofrequency catheter ablation in treatment of cardiac arrhythmias.

PubMed

Soucek, Filip; Starek, Zdenek

2018-05-23

Background Arrhythmia management is a complex process involving both pharmacological and non-pharmacological approaches. Radiofrequency ablation is the pillar of non-pharmacological arrhythmia treatment. Unipolar ablation is considered to be the gold standard in the treatment of the majority of arrhythmias; however, its efficacy is limited to specific cases. In particular, the creation of deep or transmural lesions to eliminate intramurally originating arrhythmias remains inadequate. Bipolar ablation is proposed as an alternative to overcome unipolar ablation boundaries. Results Despite promising results gained from in vitro and animal studies showing that bipolar ablation is superior in creating transmural lesions, the use of bipolar ablation in daily clinical practice is limited. Several studies have been published showing that bipolar ablation is effective in the treatment of clinical arrhythmias after failed unipolar ablation, however there is inconsistency regarding safety of bipolar ablation within the available research papers. According to research evidence the most common indications for bipolar ablation use are ventricular originating rhythmic disorders in patients with structural heart disease resistant to standard radiofrequency ablation. Conclusions To allow wider clinical application the efficiency and safety of bipolar ablation need to be verified in future studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Successful Radiofrequency Catheter Ablation for Wolff-Parkinson-White Syndrome Within the Neck of a Coronary Sinus Diverticulum

PubMed Central

Jang, Sung-Won; Kim, Dong-Bin; Kwon, Bum-Jun; Cho, Eun-Joo; Shin, Woo-Seung; Kim, Ji-Hoon; Jin, Seung-Won; Oh, Yong-Seog; Lee, Man-Young; Kim, Jae-Hyung

2009-01-01

Posteroseptal accessory pathways are often associated with coronary sinus diverticula. These diverticula contain myocardial coats which serve as a bypass tract. We report a 54-year-old woman who underwent radiofrequency (RF) catheter ablation for Wolff-Parkinson-White (WPW) syndrome. The surface electrocardiography (ECG) demonstrated pre-excitation, indicating a posteroseptal accessory pathway. A catheter ablation via a transaortic approach failed to ablate the accessory pathway. Coronary sinus venography revealed the presence of a diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the coronary sinus myocardial extension potential, which was successfully ablated by delivery of RF energy. PMID:19949625

Catheter-Malposition-Induced Cardiac Tamponade via Contrast Media Leakage During Computed Tomography Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, C.-D.; Ko, S.-F.; Huang, C.-F.

We present a rare case of a central venous catheter-malposition-induced life-threatening cardiac tamponade as a result of computed tomography (CT) with contrast enhancement in an infant with a ventricular septal defect and pulmonary atresia after a modified Blalock-Taussig shunt. The diagnosis was confirmed by chest radiographs and CT study with catheter perforation through the right atrial wall and extravasation of the contrast medium into the pericardium, leading to cardiac tamponade and subsequent circulatory collapse. Two hours after successful cardiopulmonary resuscitation, the patient gradually resumed normal hemodynamic status.

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.

Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles.

PubMed

Nguyen, Duy T; Tzou, Wendy S; Zheng, Lijun; Barham, Waseem; Schuller, Joseph L; Shillinglaw, Benjamin; Quaife, Robert A; Sauer, William H

2016-05-01

Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy. Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops. Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias. © 2016 American Heart Association, Inc.

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.

An Endovascular Approach to the Entrapped Central Venous Catheter After Cardiac Surgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desai, Shamit S., E-mail: shamit.desai@northwestern.edu; Konanur, Meghana; Foltz, Gretchen

PurposeEntrapment of central venous catheters (CVC) at the superior vena cava (SVC) cardiopulmonary bypass cannulation site by closing purse-string sutures is a rare complication of cardiac surgery. Historically, resternotomy has been required for suture release. An endovascular catheter release approach was developed.Materials and MethodsFour cases of CVC tethering against the SVC wall and associated resistance to removal, suggestive of entrapment, were encountered. In each case, catheter removal was achieved using a reverse catheter fluoroscopically guided over the suture fixation point between catheter and SVC wall, followed by the placement of a guidewire through the catheter. The guidewire was snared andmore » externalized to create a through-and-through access with the apex of the loop around the suture. A snare placed from the femoral venous access provided concurrent downward traction on the distal CVC during suture release maneuvers.ResultsIn the initial attempt, gentle traction freed the CVC, which fractured and was removed in two sections. In the subsequent three cases, traction alone did not release the CVC. Therefore, a cutting balloon was introduced over the guidewire and inflated. Gentle back-and-forth motion of the cutting balloon atherotomes successfully incised the suture in all three attempts. No significant postprocedural complications were encountered. During all cases, a cardiovascular surgeon was present in the interventional suite and prepared for emergent resternotomy, if necessary.ConclusionAn endovascular algorithm to the “entrapped CVC” is proposed, which likely reduces risks posed by resternotomy to cardiac surgery patients in the post-operative period.« less

Direct measurement of the lethal isotherm for radiofrequency ablation of myocardial tissue.

PubMed

Wood, Mark; Goldberg, Scott; Lau, Melissa; Goel, Aneesh; Alexander, Daniel; Han, Frederick; Feinstein, Shawn

2011-06-01

The lethal isotherm for radiofrequency catheter ablation of cardiac myocardium is widely accepted to be 50°C, but this has not been directly measured. The purpose of this study was to directly measure the tissue temperature at the edge of radiofrequency lesions in real time using infrared thermal imaging. Fifteen radiofrequency lesions of 6 to 240 seconds in duration were applied to the left ventricular surface of isolated perfused pig hearts. At the end of radiofrequency delivery, a thermal image of the tissue surface was acquired with an infrared camera. The lesion was then stained and an optical image of the lesion was obtained. The thermal and optical images were electronically merged to allow determination of the tissue temperature at the edge of the lesion at the end of radiofrequency delivery. By adjusting the temperature overlay display to conform with the edge of the radiofrequency lesion, the lethal isotherm was measured to be 60.6°C (interquartile ranges, 59.7° to 62.4°C; range, 58.1° to 64.2°C). The areas encompassed by the lesion border in the optical image and the lethal isotherm in the thermal image were statistically similar and highly correlated (Spearman ρ=0.99, P<0.001). The lethal isotherm temperature was not related to the duration of radiofrequency delivery or to lesion size (both P>0.64). The areas circumscribed by 50°C isotherms were significantly larger than the areas of the lesions on optical imaging (P=0.002). By direct measurement, the lethal isotherm for cardiac myocardium is near 61°C for radiofrequency energy deliveries <240 seconds in duration. A 50°C isotherm overestimates lesion size. Accurate knowledge of the lethal isotherm for radiofrequency ablation is important to clinical practice as well as mathematical modeling of radiofrequency lesions.

Incessant ventricular tachycardia early after acute myocardial infarction: efficacy of radiofrequency catheter ablation but not of optimal coronary revascularization.

PubMed

Bonanno, C; Ometto, R; Finocchi, G; Rulfo, F; La Vecchia, L; Vincenzi, M

1999-12-01

Incessant ventricular tachycardia is an arrhythmia refractory to conventional antiarrhythmic treatment. We describe the case of 55-year-old man who presented incessant ventricular tachycardia in the early post-acute phase of myocardial infarction. Optimal coronary revascularization was not effective, but radiofrequency catheter ablation was able to eliminate the anatomic substrate and clinical arrhythmic recurrence.

Feasibility of blind aortic catheter placement in the prehospital environment to guide resuscitation in cardiac arrest.

PubMed

Manning, James E

2013-08-01

Aortic catheter-based resuscitation therapies are emerging with laboratory investigations showing benefit in models of trauma-related noncompressible torso hemorrhage and nontraumatic cardiac arrest. For these investigational aortic catheter-based therapies to reach their greatest potential clinical benefit, the ability to initiate them in the prehospital setting will be important. Feasibility of prehospital aortic catheterization without imaging capability supports this potential and is described in this report. A physician prehospital response system was created in cooperation with the local emergency medical services system to provide invasive hemodynamic monitoring during cardiac arrest. Physicians were dispatched to all known or suspected prehospital cardiac arrests covered by the emergency medical services system. Physicians responded with a specialized vascular catheterization pack and a monitor with invasive pressure monitoring capability. The physicians performed blind thoracic aortic and central venous catheterizations in cardiac arrest patients in the prehospital setting to measure coronary perfusion pressure, to optimize closed-chest cardiopulmonary resuscitation technique, and to administer intra-aortic epinephrine. During a 2-year period, 22 medical cardiac arrest patients underwent prehospital invasive hemodynamic monitoring to guide resuscitation. Most patients had both aortic and central venous catheters inserted. The combination of intra-aortic epinephrine and adjustments in closed-chest cardiopulmonary resuscitation technique resulted in improved coronary perfusion pressure. Return of spontaneous circulation with survival to hospital admission was achieved in 50% (11 of 22) of these patients. This report demonstrates the feasibility of successful blind aortic and central venous catheterizations in the prehospital environment and supports the potential feasibility of other emerging aortic catheter-based resuscitation therapies.

Real-time x-ray fluoroscopy-based catheter detection and tracking for cardiac electrophysiology interventions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma Yingliang; Housden, R. James; Razavi, Reza

2013-07-15

Purpose: X-ray fluoroscopically guided cardiac electrophysiology (EP) procedures are commonly carried out to treat patients with arrhythmias. X-ray images have poor soft tissue contrast and, for this reason, overlay of a three-dimensional (3D) roadmap derived from preprocedural volumetric images can be used to add anatomical information. It is useful to know the position of the catheter electrodes relative to the cardiac anatomy, for example, to record ablation therapy locations during atrial fibrillation therapy. Also, the electrode positions of the coronary sinus (CS) catheter or lasso catheter can be used for road map motion correction.Methods: In this paper, the authors presentmore » a novel unified computational framework for image-based catheter detection and tracking without any user interaction. The proposed framework includes fast blob detection, shape-constrained searching and model-based detection. In addition, catheter tracking methods were designed based on the customized catheter models input from the detection method. Three real-time detection and tracking methods are derived from the computational framework to detect or track the three most common types of catheters in EP procedures: the ablation catheter, the CS catheter, and the lasso catheter. Since the proposed methods use the same blob detection method to extract key information from x-ray images, the ablation, CS, and lasso catheters can be detected and tracked simultaneously in real-time.Results: The catheter detection methods were tested on 105 different clinical fluoroscopy sequences taken from 31 clinical procedures. Two-dimensional (2D) detection errors of 0.50 {+-} 0.29, 0.92 {+-} 0.61, and 0.63 {+-} 0.45 mm as well as success rates of 99.4%, 97.2%, and 88.9% were achieved for the CS catheter, ablation catheter, and lasso catheter, respectively. With the tracking method, accuracies were increased to 0.45 {+-} 0.28, 0.64 {+-} 0.37, and 0.53 {+-} 0.38 mm and success rates increased to

Surface evaluation of cardiac angiographic catheters after simulated use and reprocessing

NASA Astrophysics Data System (ADS)

Lucas, Thabata Coaglio; Oréfice, Rodrigo Lambert; Pinotti, Marcos; Huebner, Rudolf

2009-12-01

Reprocessing of single-use intravascular catheters is a common practice in public health services and hospitals. The determination of safe number of reprocessing cycles before the catheter integrity becomes compromised has been a priority issue. The present paper addresses the evaluating molecular and micro-structural integrity of reprocessed cardiac angiographic catheters. The Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy were carried out to elucidate morphological changes. The tensile test was performed on catheters to examine changes in bulk characteristics. In this work, samples of catheters were reprocessed until nine times and sterilized by hydrogen peroxide plasma. It was observed that the number of hydrogen-bonded carbonyls groups increased in 0.05 u.a. ( p < 0.001) after each reprocessing cycle. The spectra indicated degradation products included acids, esters, alcohols, and small amounts of other products containing a carbonyl functional group. The micrographs revealed that only after the fourth reprocessing cycle the effect increased in the surface roughness was more pronounced. On the other hand, after each reprocessing cycle and as consequence of extensive aging of polyamide/polyurethane blends of the catheters surface, it was observed that the micro-fissures, micro-scratches and micro-pores increased in quantity and length. The mechanical test proved that the Young modulus increased in average 3.26 MPa ( p = 0.0003) at increasing number of reprocessing cycles, also suggestive of crosslinking in this material.

Contrast-enhanced cardiac C-arm CT evaluation of radiofrequency ablation lesions in the left ventricle

PubMed Central

Girard, Erin E; Al-Ahmad, Amin A; Rosenberg, Jarrett; Luong, Richard; Moore, Teri; Lauritsch, Günter; Boese, Jan; Fahrig, Rebecca

2011-01-01

Objectives The purpose of this study was to evaluate use of cardiac C-arm computed tomography (CT) in the assessment of the dimensions and temporal characteristics of radiofrequency ablation (RFA) lesions. This imaging modality uses a standard C-arm fluoroscopy system rotating around the patient, providing CT-like images during the RFA procedure. Background Both magnetic resonance imaging (MRI) and CT can be used to assess myocardial necrotic tissue. Several studies have reported visualizing cardiac RF ablation lesions with MRI, however obtaining MR images during interventional procedures is not common practice. Direct visualization of RFA lesions using C-arm CT during the procedure may improve outcomes and circumvent complications associated with cardiac ablation procedures. Methods RFA lesions were created on the endocardial surface of the left ventricle of 9 swine using a 7-F RF ablation catheter. An ECG-gated C-arm CT imaging protocol was used to acquire projection images during iodine contrast injection and following the injection every 5 min for up to 30 min, with no additional contrast. Reconstructed images were analyzed offline. The mean and standard deviation of the signal intensity of the lesion and normal myocardium were measured in all images in each time series. Lesion dimensions and area were measured and compared in pathologic specimens and C-arm CT images. Results All ablation lesions (n=29) were visualized and lesion dimensions, as measured on C-arm CT, correlated well with postmortem tissue measurements (1D dimensions : concordance correlation = 0.87; area : concordance correlation = 0.90). Lesions were visualized as a perfusion defect on first-pass C-arm CT images with a signal intensity 95 HU lower than normal myocardium (95% confidence interval: -111 to -79 HU). Images acquired at 1 and 5 minutes exhibited an enhancing ring surrounding the perfusion defect in 24 (83%) lesions. Conclusions RFA lesion size, including transmurality, can be

Formation of thermal coagulum on multielectrode catheters during phased radiofrequency energy ablation of persistent atrial fibrillation.

PubMed

Debruyne, Philippe; Rossenbacker, Tom; Vankelecom, Bart; Charlier, Filip; Roosen, John; Ector, Bavo; Janssens, Luc

2014-02-01

Radiofrequency ablation (RFA) can unfavorably cause coagulum on the ablation electrode. The aim of this study was to assess this phenomenon on three different multielectrode catheters used to treat persistent atrial fibrillation with duty-cycled RFA. Twenty-six consecutive patients have been treated with the pulmonary vein ablation catheter (PVAC) and the multiarray ablation catheter (MAAC). In 13 patients, additional ablation with the multiarray septal catheter (MASC) has been performed. The multichannel RF generator GENius™ (Medtronic Inc., Minneapolis, MN, USA) independently delivered energy in a bipolar and unipolar mode (ratio of 4/1, 2/1, or 1/1) to any of the electrodes. Versions 14.2, 14.3, and 14.4 of the generator were used. Coagulum presence was determined postablation by careful visual inspection of the catheter electrodes. No coagulum formation was visualized on the PVACs. Coagulum formation was visualized in 59% of the electrodes of the MAACs using a 2/1 mode and the 14.2 software version versus 69% using the 14.4 version and a 2/1 mode (P = 0.7) versus 14% of the electrodes applying a 1/1 ratio and the 14.4 software version (P < 0.001). Duty-cycled RFA in 2/1 bipolar/unipolar ratio generates a substantial frequency of coagulum formation on the multielectrode catheters MAAC and MASC. The use of the 14.4 version of the software to drive the RF generator and the use of energy in the default 1/1 bipolar/unipolar ratio could significantly reduce the frequency of coagulum formation, but so far, could not completely overcome it. The PVAC did not form coagulum, regardless of generator version or energy ratio used. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

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.

Use of asymmetric bidirectional catheters with different curvature radius for catheter ablation of cardiac arrhythmias.

PubMed

Mantziari, Lilian; Suman-Horduna, Irina; Gujic, Marko; Jones, David G; Wong, Tom; Markides, Vias; Foran, John P; Ernst, Sabine

2013-06-01

The impact of recently introduced asymmetric bidirectional ablation catheters on procedural parameters and acute success rates of ablation procedures is unknown. We retrospectively analyzed data regarding ablations using a novel bidirectional catheter in a tertiary cardiac center and compared these in 1:5 ratio with a control group of procedures matched for age, gender, operator, and ablation type. A total of 50 cases and 250 controls of median age 60 (50-68) years were studied. Structural heart disease was equally prevalent in both groups (39%) while history of previous ablations was more common in the study arm (54% vs 30%, P = 0.001). Most of the ablation cases were for atrial fibrillation (46%), followed by atrial tachycardia (28%), supraventricular tachycardia (12%), and ventricular tachycardia (14%). Median procedure duration was 128 (52-147) minutes with the bidirectional, versus 143 (105-200) minutes with the conventional catheter (P = 0.232), and median fluoroscopy time was 17 (10-34) minutes versus 23 (12-39) minutes, respectively (P = 0.988). There was a trend toward a lower procedure duration for the atrial tachycardia ablations, 89 (52-147) minutes versus 130 (100-210) minutes, P = 0.064. The procedure was successfully completed in 96% of the bidirectional versus 84% of the control cases (P = 0.151). A negative correlation was observed between the relative fluoroscopy duration and the case number (r = -0.312, P = 0.028), reflecting the learning curve for the bidirectional catheter. The introduction of the bidirectional catheter resulted in no prolongation of procedure parameters and similar success rates, while there was a trend toward a lower procedure duration for atrial tachycardia ablations. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Safety profile of multielectrode-phased radiofrequency pulmonary vein ablation catheter and irrigated radiofrequency catheter.

PubMed

Wasmer, K; Foraita, P; Leitz, P; Güner, F; Pott, C; Lange, P S; Eckardt, L; Mönnig, G

2016-01-01

Silent cerebral lesions with the multielectrode-phased radiofrequency (RF) pulmonary vein ablation catheter (PVAC(®)) have recently been investigated. However, comparative data on safety in relation to irrigated RF ablation are missing. One hundred and fifty consecutive patients (58 ± 12 years, 56 female) underwent first pulmonary vein isolation (PVI) for atrial fibrillation (61% paroxysmal) using PVAC(®) (PVAC). Procedure data as well as in-hospital complications were compared with 300 matched patients who underwent PVI using irrigated RF (iRF). Procedure duration (148 ± 63 vs. 208 ± 70 min; P < 0.001), RF duration (24 ± 10 vs. 49 ± 25 min; P < 0.001), and fluoroscopy time (21 ± 10 vs. 35 ± 13 min; P < 0.001) were significantly shorter using PVAC. Major complication rates [major bleeding, transitoric ischaemic attack (TIA), and pericardial tamponade] were not significantly different between groups (PVAC, n = 3; 2% vs. iRF n = 17; 6%). Overall complication rate, including minor events, was similar in both groups [n = 21 (14%) vs. n = 48 (16%)]. Most of these were bleeding complications due to vascular access [n = 8 (5.3%) vs. n = 22 (7.3%)], which required surgical intervention in five patients [n = 1 (0.7%) vs. n = 4 (1.3%)]. Pericardial effusion [n = 4 (2.7%) vs. n = 19 (6.3%); pericardial tamponade requiring drainage n = 0 vs. n = 6] occurred more frequently using iRF. Two patients in each group developed a TIA (1.3% vs. 0.6%). Of note, four of five thromboembolic events in the PVAC group (two TIAs and three transient ST elevations during ablation) occurred when all 10 electrodes were used for ablation. Pulmonary vein isolation using PVAC as a 'one-shot-system' has a comparable complication rate but a different risk profile. Pericardial effusion and tamponade occurred more frequently using iRF, whereas thromboembolic events were more prevalent using PVAC. Occurrence of clinically relevant thromboembolic events might be reduced by avoidance of electrode

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

Renal sympathetic denervation using an externally irrigated radiofrequency ablation catheter for treatment of resistant hypertension - Acute safety and short term efficacy.

PubMed

Yalagudri, Sachin; Raju, Narayana; Das, Bharati; Daware, Ashwin; Maiya, Shreesha; Jothiraj, Kannan; Ravikishore, A G

2015-01-01

This study was conducted to assess the acute safety and short term efficacy of renal sympathetic denervation (RSDN) using solid tip radiofrequency ablation (RFA) catheter and saline irrigation through the renal guiding catheter to achieve effective denervation. RSDN using a specialized solid-tip RFA catheter has recently been demonstrated to safely reduce systemic blood pressure in patients with refractory hypertension, the limitation being inadequate power delivery in renal arteries. So, we used solid-tip RFA catheter along with saline irrigation for RSDN. Nine patients with resistant hypertension underwent CT and conventional renal angiography, followed by bilateral or unilateral RSDN using 5F RFA catheter with saline irrigation through renal guiding catheter. Repeat renal angiography was performed at the end of the procedure. In all patients, pre- and post-procedure serum creatinine was measured. Over 1-month period: 1) the systolic/diastolic blood pressure decreased by -57 ± 20/-25 ± 7.5 mm Hg; 2) all patients experienced a decrease in systolic blood pressure of at least -36 mm Hg (range 36-98 mm Hg); 3) there was no evidence of renal artery injury immediate post-procedure. There was no significant change in serum creatinine level. This data shows the acute procedural safety and short term efficacy of RSDN using modified externally irrigated solid tip RFA catheter. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Validation of cardiac output studies from the Mostcare compared to a pulmonary artery catheter in septic patients.

PubMed

Gopal, S; Do, T; Pooni, J S; Martinelli, G

2014-03-01

The Mostcare monitor is a non-invasive cardiac output monitor. It has been well validated in cardiac surgical patients but there is limited evidence on its use in patients with severe sepsis and septic shock. The study included the first 22 consecutive patients with severe sepsis and septic shock in whom the floatation of a pulmonary artery catheter was deemed necessary to guide clinical management. Cardiac output measurements including cardiac output, cardiac index and stroke volume were simultaneously calculated and recorded from a thermodilution pulmonary artery catheter and from the Mostcare monitor respectively. The two methods of measuring cardiac output were compared by Bland-Altman statistics and linear regression analysis. A percentage error of less than 30% was defined as acceptable for this study. Bland-Altman analysis for cardiac output showed a Bias of 0.31 L.min-1, precision (=SD) of 1.97 L.min-1 and a percentage error of 62.54%. For Cardiac Index the bias was 0.21 L.min-1.m-2, precision of 1.10 L.min-1.m-2 and a percentage error of 64%. For stroke volume the bias was 5 mL, precision of 24.46 mL and percentage error of 70.21%. Linear regression produced a correlation coefficient r2 for cardiac output, cardiac index, and stroke volume, of 0.403, 0.306, and 0.3 respectively. Compared to thermodilution cardiac output, cardiac output studies obtained from the Mostcare monitor have an unacceptably high error rate. The Mostcare monitor demonstrated to be an unreliable monitoring device to measure cardiac output in patients with severe sepsis and septic shock on an intensive care unit.

Lesion size estimator of cardiac radiofrequency ablation at different common locations with different tip temperatures.

PubMed

Lai, Yu-Chi; Choy, Young Bin; Haemmerich, Dieter; Vorperian, Vicken R; Webster, John G

2004-10-01

Finite element method (FEM) analysis has become a common method to analyze the lesion formation during temperature-controlled radiofrequency (RF) cardiac ablation. We present a process of FEM modeling a system including blood, myocardium, and an ablation catheter with a thermistor embedded at the tip. The simulation used a simple proportional-integral (PI) controller to control the entire process operated in temperature-controlled mode. Several factors affect the lesion size such as target temperature, blood flow rate, and application time. We simulated the time response of RF ablation at different locations by using different target temperatures. The applied sites were divided into two groups each with a different convective heat transfer coefficient. The first group was high-flow such as the atrioventricular (AV) node and the atrial aspect of the AV annulus, and the other was low-flow such as beneath the valve or inside the coronary sinus. Results showed the change of lesion depth and lesion width with time, under different conditions. We collected data for all conditions and used it to create a database. We implemented a user-interface, the lesion size estimator, where the user enters set temperature and location. Based on the database, the software estimated lesion dimensions during different applied durations. This software could be used as a first-step predictor to help the electrophysiologist choose treatment parameters.

Asymptomatic Ventricular Pre-excitation: Between Sudden Cardiac Death and Catheter Ablation.

PubMed

Brugada, Josep; Keegan, Roberto

2018-03-01

Debate about the best clinical approach to the management of asymptomatic patients with ventricular pre-excitation and advice on whether or not to invasively stratify and ablate is on-going. Weak evidence about the real risk of sudden cardiac death and the potential benefit of catheter ablation has probably prevented the clarification of action in this not infrequent and sometimes conflicting clinical situation. After analysing all available data, real evidence-based medicine could be the alternative strategy for managing this group of patients. According to recent surveys, most electrophysiologists invasively stratify. Based on all accepted risk factors - younger age, male, associated structural heart disease, posteroseptal localisation, ability of the accessory pathway to conduct anterogradely at short intervals of ≤250 milliseconds and inducibility of sustained atrioventricular re-entrant tachycardia and/or atrial fibrillation - a shared decisionmaking process on catheter ablation is proposed.

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.

Asymptomatic Ventricular Pre-excitation: Between Sudden Cardiac Death and Catheter Ablation

PubMed Central

Brugada, Josep

2018-01-01

Debate about the best clinical approach to the management of asymptomatic patients with ventricular pre-excitation and advice on whether or not to invasively stratify and ablate is on-going. Weak evidence about the real risk of sudden cardiac death and the potential benefit of catheter ablation has probably prevented the clarification of action in this not infrequent and sometimes conflicting clinical situation. After analysing all available data, real evidence-based medicine could be the alternative strategy for managing this group of patients. According to recent surveys, most electrophysiologists invasively stratify. Based on all accepted risk factors – younger age, male, associated structural heart disease, posteroseptal localisation, ability of the accessory pathway to conduct anterogradely at short intervals of ≤250 milliseconds and inducibility of sustained atrioventricular re-entrant tachycardia and/or atrial fibrillation – a shared decisionmaking process on catheter ablation is proposed. PMID:29636970

Pulmonary vein reconnection following catheter ablation of atrial fibrillation using the second-generation cryoballoon versus open-irrigated radiofrequency: results of a multicenter analysis.

PubMed

Aryana, Arash; Singh, Sheldon M; Mugnai, Giacomo; de Asmundis, Carlo; Kowalski, Marcin; Pujara, Deep K; Cohen, Andrew I; Singh, Steve K; Fuenzalida, Charles E; Prager, Nelson; Bowers, Mark R; O'Neill, Padraig Gearoid; Brugada, Pedro; d'Avila, André; Chierchia, Gian-Battista

2016-12-01

Catheter ablation of atrial fibrillation (CAAF) using the cryoballoon has emerged as an alternate strategy to point-by-point radiofrequency. However, there is little comparative data on long-term durability of pulmonary vein (PV) isolation comparing these two modalities. In this multicenter, retrospective analysis, the incidences/patterns of late PV reconnection following an index CAAF using the second-generation cryoballoon versus open-irrigated, non-force-sensing radiofrequency were examined. Of the 2002 patients who underwent a first-time CAAF, 186/1126 patients (16.5 %) ablated using cryoballoon and 174/876 patients (19.9 %) with non-contact force-guided radiofrequency required a repeat procedure at 11 ± 5 months. During follow-up, the incidence of atrial flutters/tachycardias was lower (19.9 vs. 32.8 %; p = 0.005) and fewer patients exhibited PV reconnection (47.3 vs. 60.9 %; p = 0.007) with cryoballoon versus radiofrequency. Additionally, fewer PVs had reconnected with cryoballoon versus radiofrequency (18.8 vs. 34.6 %; p < 0.001). With cryoballoon, the right inferior (p < 0.001) and left common (p = 0.039) PVs were more likely to exhibit late reconnection, versus the left superior PV with radiofrequency (p = 0.012). However, when comparing the two strategies, the left common PV was more likely to exhibit reconnection with cryoballoon, whereas all other PVs with the exception of the right inferior PV demonstrated a lower reconnection rate with cryoballoon versus radiofrequency. Lastly, in a logistic regression multivariate analysis, cryoballoon ablation and PV ablation time emerged as significant predictors of durable PV isolation at repeat procedure. In this large multicenter, retrospective analysis, CAAF using the second-generation cryoballoon was associated with improved durability of PV isolation compared to open-irrigated, non-force-sensing radiofrequency.

Concurrent application of charge using a novel circuit prevents heat-related coagulum formation during radiofrequency ablation.

PubMed

Lim, Bernard; Venkatachalam, Kalpathi L; Jahangir, Arshad; Johnson, Susan B; Asirvatham, Samuel J

2008-08-01

Thromboembolism resulting from coagulum formation on the catheter and electrode surfaces is a serious complication with radiofrequency ablation procedures for heart rhythm disorders. Why coagulum occurs despite therapeutic heparinization is unclear. In this report, we demonstrate a novel approach to minimize coagulum formation based on the electromolecular characteristics of fibrinogen. Atomic force microscopy was used to establish that fibrinogen deposited on surfaces underwent conformational changes that resulted in spontaneous clot formation. We then immersed ablation catheters that were uncharged, negatively, or positively charged in heparinized blood for 30 minutes and noted the extent of clot formation. In separate experiments, ablation catheters were sutured to the ventricle of an excised porcine heart immersed in whole, heparinized blood and radiofrequency ablation performed for 5 minutes with and without charge delivered to the catheter tips. Electron microscopy of the catheter tips showed surface coverage of fibrin clot of the catheter to be 33.8% for negatively charged catheters, compared with 84.7% (P = 0.01) in noncharged catheters. There was no significant difference in surface coverage of fibrin clot between positively charged catheters (93.8%) and noncharged catheters (84.7%, P = ns). In contrast, the thickness of surface clot coverage for positively charged catheters was 87.5%, compared with 28.45% (P= 0.03) for noncharged catheters and 11.25% (P = 0.03) for negatively charged catheters, compared with noncharged catheters. We describe a novel method of placing negative charge on electrodes during ablation that reduced coagulum formation. This may decrease thromboembolism-related complications with radiofrequency ablation procedures.

Alternate energy sources for catheter ablation.

PubMed

Wang, P J; Homoud, M K; Link, M S; Estes III, N A

1999-07-01

Because of the limitations of conventional radiofrequency ablation in creating large or linear lesions, alternative energy sources have been used as possible methods of catheter ablation. Modified radiofrequency energy, cryoablation, and microwave, laser, and ultrasound technologies may be able to create longer, deeper, and more controlled lesions and may be particularly suited for the treatment of ventricular tachycardias and for linear atrial ablation. Future studies will establish the efficacy of these new and promising technologies.

Reinnervation following catheter-based radio-frequency renal denervation.

PubMed

Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

What is the topic of this review? Does catheter-based renal denervation effectively denervate the afferent and efferent renal nerves and does reinnervation occur? What advances does it highlight? Following catheter-based renal denervation, the afferent and efferent responses to electrical stimulation were abolished, renal sympathetic nerve activity was absent, and levels of renal noradrenaline and immunohistochemistry for tyrosine hydroxylase and calcitonin gene-related peptide were significantly reduced. By 11 months after renal denervation, both the functional responses and anatomical markers of afferent and efferent renal nerves had returned to normal, indicating reinnervation. Renal denervation reduces blood pressure in animals with experimental hypertension and, recently, catheter-based renal denervation was shown to cause a prolonged decrease in blood pressure in patients with resistant hypertension. The randomized, sham-controlled Symplicity HTN-3 trial failed to meet its primary efficacy end-point, but there is evidence that renal denervation was incomplete in many patients. Currently, there is little information regarding the effectiveness of catheter-based renal denervation and the extent of reinnervation. We assessed the effectiveness of renal nerve denervation with the Symplicity Flex catheter and the functional and anatomical reinnervation at 5.5 and 11 months postdenervation. In anaesthetized, non-denervated sheep, there was a high level of renal sympathetic nerve activity, and electrical stimulation of the renal nerve increased blood pressure and reduced heart rate (afferent response) and caused renal vasoconstriction and reduced renal blood flow (efferent response). Immediately after renal denervation, renal sympathetic nerve activity and the responses to electrical stimulation were absent, indicating effective denervation. By 11 months after denervation, renal sympathetic nerve activity was present and the responses to electrical stimulation

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.

Does age at the time of elective cardiac surgery or catheter intervention in children influence the longitudinal development of psychological distress and styles of coping of parents?

PubMed

Utens, Elisabeth M; Versluis-Den Bieman, Herma J; Witsenburg, Maarten; Bogers, Ad J J C; Hess, John; Verhulst, Frank C

2002-12-01

To assess the influence of age at a cardiac procedure of children, who underwent elective cardiac surgery or interventional cardiac catheterisation for treatment of congenital cardiac defects between 3 months and 7 years of age, on the longitudinal development of psychological distress and styles of coping of their parents. We used the General Health Questionnaire to measure psychological distress, and the Utrecht Coping List to measure styles of coping. Parents completed questionnaires on average respectively 5 weeks prior to, and 18.7 months after, cardiac surgery or catheter intervention for their child. Apart from one exception, no significant influence was found of the age at which children underwent elective cardiac surgery or catheter intervention on the pre- to postprocedural course of psychological distress and the styles of coping of their parents. Across time, parents of children undergoing surgery reported, on average, significantly higher levels of psychological distress than parents of children who underwent catheter intervention. After the procedure, parents of children who underwent either procedure reported significantly lower levels of psychological distress, and showed a weaker tendency to use several styles of coping, than did their reference groups. Age of the children at the time of elective cardiac surgery or catheter intervention did not influence the course of psychological distress of their parents, nor the styles of coping used by the parents. Future research should investigate in what way the age at which these cardiac procedures are performed influences the emotional and cognitive development of the children.

Atrial fibrillation and sudden cardiac death: catheter-based sensor and mapping system of the heart

NASA Astrophysics Data System (ADS)

Ramasamy, Mouli; Kumar, Prashanth S.; Varadan, Vijay K.

2017-04-01

Ventricular arrhythmias in the heart and the rapid heartbeat of ventricular tachycardia can lead to sudden cardiac death. This is a major health issue worldwide. What is needed is to develop a catheter based sensor and mapping approach which will provide the mechanisms of ventricular arrhythmia, and effectively prevent and treat the same, potentially save life.

Detection of electrophysiology catheters in noisy fluoroscopy images.

PubMed

Franken, Erik; Rongen, Peter; van Almsick, Markus; ter Haar Romeny, Bart

2006-01-01

Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust image analysis method that can detect the catheters in X-ray fluoroscopy images. Our method uses steerable tensor voting in combination with a catheter-specific multi-step extraction algorithm. The evaluation on clinical fluoroscopy images shows that especially the extraction of the catheter tip is successful and that the use of tensor voting accounts for a large increase in performance.

Rationale and design of the NO-PARTY trial: near-zero fluoroscopic exposure during catheter ablation of supraventricular arrhythmias in young patients.

PubMed

Casella, Michela; Dello Russo, Antonio; Pelargonio, Gemma; Bongiorni, Maria Grazia; Del Greco, Maurizio; Piacenti, Marcello; Andreassi, Maria Grazia; Santangeli, Pasquale; Bartoletti, Stefano; Moltrasio, Massimo; Fassini, Gaetano; Marini, Massimiliano; Di Cori, Andrea; Di Biase, Luigi; Fiorentini, Cesare; Zecchi, Paolo; Natale, Andrea; Picano, Eugenio; Tondo, Claudio

2012-10-01

Radiofrequency catheter ablation is the mainstay of therapy for supraventricular tachyarrhythmias. Conventional radiofrequency catheter ablation requires the use of fluoroscopy, thus exposing patients to ionising radiation. The feasibility and safety of non-fluoroscopic radiofrequency catheter ablation has been recently reported in a wide range of supraventricular tachyarrhythmias using the EnSite NavX™ mapping system. The NO-PARTY is a multi-centre, randomised controlled trial designed to test the hypothesis that catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system results in a clinically significant reduction in exposure to ionising radiation compared with conventional catheter ablation. The study will randomise 210 patients undergoing catheter ablation of supraventricular tachyarrhythmias to either a conventional ablation technique or one guided by the EnSite NavX™ mapping system. The primary end-point is the reduction of the radiation dose to the patient. Secondary end-points include procedural success, reduction of the radiation dose to the operator, and a cost-effectiveness analysis. In a subgroup of patients, we will also evaluate the radiobiological effectiveness of dose reduction by assessing acute chromosomal DNA damage in peripheral blood lymphocytes. NO-PARTY will determine whether radiofrequency catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system is a suitable and cost-effective approach to achieve a clinically significant reduction in ionising radiation exposure for both patient and operator.

Remote magnetic navigation for accurate, real-time catheter positioning and ablation in cardiac electrophysiology procedures.

PubMed

Filgueiras-Rama, David; Estrada, Alejandro; Shachar, Josh; Castrejón, Sergio; Doiny, David; Ortega, Marta; Gang, Eli; Merino, José L

2013-04-21

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate.

Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures

PubMed Central

Filgueiras-Rama, David; Estrada, Alejandro; Shachar, Josh; Castrejón, Sergio; Doiny, David; Ortega, Marta; Gang, Eli; Merino, José L.

2013-01-01

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate. PMID:23628883

Catheter radiofrequency ablation for arrhythmias under the guidance of the Carto 3 three-dimensional mapping system in an operating room without digital subtraction angiography.

PubMed

Huang, Xingfu; Chen, Yanjia; Huang, Zheng; He, Liwei; Liu, Shenrong; Deng, Xiaojiang; Wang, Yongsheng; Li, Rucheng; Xu, Dingli; Peng, Jian

2018-06-01

Several studies have reported the efficacy of a zero-fluoroscopy approach for catheter radiofrequency ablation of arrhythmias in a digital subtraction angiography (DSA) room. However, no reports are available on the ablation of arrhythmias in the absence of DSA in the operating room. To investigate the efficacy and safety of catheter radiofrequency ablation for arrhythmias under the guidance of a Carto 3 three-dimensional (3D) mapping system in an operating room without DSA. Patients were enrolled according to the type of arrhythmia. The Carto 3 mapping system was used to reconstruct heart models and guide the electrophysiologic examination, mapping, and ablation. The total procedure, reconstruction, electrophysiologic examination, and mapping times were recorded. Furthermore, immediate success rates and complications were also recorded. A total of 20 patients were enrolled, including 12 males. The average age was 51.3 ± 17.2 (19-76) years. Nine cases of atrioventricular nodal re-entrant tachycardia, 7 cases of frequent ventricular premature contractions, 3 cases of Wolff-Parkinson-White syndrome, and 1 case of typical atrial flutter were included. All arrhythmias were successfully ablated. The procedure time was 127.0 ± 21.0 (99-177) minutes, the reconstruction time was 6.5 ± 2.9 (3-14) minutes, the electrophysiologic study time was 10.4 ± 3.4 (6-20) minutes, and the mapping time was 11.7 ± 8.3 (3-36) minutes. No complications occurred. Radiofrequency ablation of arrhythmias without DSA is effective and feasible under the guidance of the Carto 3 mapping system. However, the electrophysiology physician must have sufficient experience, and related emergency measures must be present to ensure safety.

Real-time circumferential mapping catheter tracking for motion compensation in atrial fibrillation ablation procedures

NASA Astrophysics Data System (ADS)

Brost, Alexander; Bourier, Felix; Wimmer, Andreas; Koch, Martin; Kiraly, Atilla; Liao, Rui; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2012-02-01

Atrial fibrillation (AFib) has been identified as a major cause of stroke. Radiofrequency catheter ablation has become an increasingly important treatment option, especially when drug therapy fails. Navigation under X-ray can be enhanced by using augmented fluoroscopy. It renders overlay images from pre-operative 3-D data sets which are then fused with X-ray images to provide more details about the underlying soft-tissue anatomy. Unfortunately, these fluoroscopic overlay images are compromised by respiratory and cardiac motion. Various methods to deal with motion have been proposed. To meet clinical demands, they have to be fast. Methods providing a processing frame rate of 3 frames-per-second (fps) are considered suitable for interventional electrophysiology catheter procedures if an acquisition frame rate of 2 fps is used. Unfortunately, when working at a processing rate of 3 fps, the delay until the actual motion compensated image can be displayed is about 300 ms. More recent algorithms can achieve frame rates of up to 20 fps, which reduces the lag to 50 ms. By using a novel approach involving a 3-D catheter model, catheter segmentation and a distance transform, we can speed up motion compensation to 25 fps which results in a display delay of only 40 ms on a standard workstation for medical applications. Our method uses a constrained 2-D/3-D registration to perform catheter tracking, and it obtained a 2-D tracking error of 0.61 mm.

Arrhythmogenic substrate at the interventricular septum as a target site for radiofrequency catheter ablation of recurrent ventricular tachycardia in left dominant arrhythmogenic cardiomyopathy.

PubMed

Havranek, Stepan; Palecek, Tomas; Kovarnik, Tomas; Vitkova, Ivana; Psenicka, Miroslav; Linhart, Ales; Wichterle, Dan

2015-03-10

Left dominant arrhythmogenic cardiomyopathy (LDAC) is a rare condition characterised by progressive fibrofatty replacement of the myocardium of the left ventricle (LV) in combination with ventricular arrhythmias of LV origin. A thirty-five-year-old male was referred for evaluation of recurrent sustained monomorphic ventricular tachycardia (VT) of 200 bpm and right bundle branch block (RBBB) morphology. Cardiac magnetic resonance imaging showed late gadolinium enhancement distributed circumferentially in the epicardial layer of the LV free wall myocardium including the rightward portion of the interventricular septum (IVS). The clinical RBBB VT was reproduced during the EP study. Ablation at an LV septum site with absence of abnormal electrograms and a suboptimum pacemap rendered the VT of clinical morphology noninducible. Three other VTs, all of left bundle branch block (LBBB) pattern, were induced by programmed electrical stimulation. The regions corresponding to abnormal electrograms were identified and ablated at the mid-to-apical RV septum and the anteroseptal portion of the right ventricular outflow tract. No abnormalities were found at the RV free wall including the inferolateral peritricuspid annulus region. Histological examination confirmed the presence of abnormal fibrous and adipose tissue with myocyte reduction in endomyocardial samples taken from both the left and right aspects of the IVS. LDAC rarely manifests with sustained monomorphic ventricular tachycardia. In this case, several VTs of both RBBB and LBBB morphology were amenable to endocardial radiofrequency catheter ablation.

Nerve conduction studies are safe in patients with central venous catheters.

PubMed

London, Zachary N; Mundwiler, Andrew; Oral, Hakan; Gallagher, Gary W

2017-08-01

It is unknown if central venous catheters bypass the skin's electrical resistance and engender a risk of nerve conduction study-induced cardiac arrhythmia. The objective of this study is to determine if nerve conduction studies affect cardiac conduction and rhythm in patients with central venous catheters. Under continuous 12-lead electrocardiogram monitoring, subjects with and without central venous catheters underwent a series of upper extremity nerve conduction studies. A cardiologist reviewed the electrocardiogram tracings for evidence of cardiac conduction abnormality or arrhythmia. Ten control subjects and 10 subjects with central venous catheters underwent the nerve conduction study protocol. No malignant arrhythmias or conduction abnormalities were noted in either group. Nerve conduction studies of the upper extremities, including both proximal stimulation and repetitive stimulation, do not appear to confer increased risk of cardiac conduction abnormality in those patients with central venous catheters who are not critically ill or have a prior history of arrhythmia. Muscle Nerve 56: 321-323, 2017. © 2016 Wiley Periodicals, Inc.

Towards modeling of cardiac micro-structure with catheter-based confocal microscopy: a novel approach for dye delivery and tissue characterization.

PubMed

Lasher, Richard A; Hitchcock, Robert W; Sachse, Frank B

2009-08-01

This work presents a methodology for modeling of cardiac tissue micro-structure. The approach is based on catheter-based confocal imaging systems, which are emerging as tools for diagnosis in various clinical disciplines. A limitation of these systems is that a fluorescent marker must be available in sufficient concentration in the imaged region. We introduce a novel method for the local delivery of fluorescent markers to cardiac tissue based on a hydro-gel carrier brought into contact with the tissue surface. The method was tested with living rabbit cardiac tissue and applied to acquire three-dimensional image stacks with a standard inverted confocal microscope and two-dimensional images with a catheter-based confocal microscope. We processed these image stacks to obtain spatial models and quantitative data on tissue microstructure. Volumes of atrial and ventricular myocytes were 4901 +/- 1713 and 10 299 +/-3598 mum (3) (mean+/-sd), respectively. Atrial and ventricular myocyte volume fractions were 72.4 +/-4.7% and 79.7 +/- 2.9% (mean +/-sd), respectively. Atrial and ventricular myocyte density was 165 571 +/- 55 836 and 86 957 +/- 32 280 cells/mm (3) (mean+/-sd), respectively. These statistical data and spatial descriptions of tissue microstructure provide important input for modeling studies of cardiac tissue function. We propose that the described methodology can also be used to characterize diseased tissue and allows for personalized modeling of cardiac tissue.

Radiofrequency ablation of fast ventricular tachycardia causing an ICD storm in an infant with hypertrophic cardiomyopathy.

PubMed

Ergul, Yakup; Ozyilmaz, Isa; Bilici, Meki; Ozturk, Erkut; Haydin, Sertaç; Guzeltas, Alper

2018-04-01

An implantable cardioverter defibrillator (ICD) storm involves very frequent arrhythmia episodes and ICD shocks, and it is associated with poor short-term and long-term prognosis. Radiofrequency catheter ablation can be used as an effective rescue treatment for patients with an ICD storm. To our knowledge, this is the first report of an infant with hypertrophic cardiomyopathy presenting with an ICD storm and undergoing successful radiofrequency catheter ablation salvage treatment for the fast left posterior fascicular ventricular tachycardia. © 2017 Wiley Periodicals, Inc.

Towards optical spectroscopic anatomical mapping (OSAM) for lesion validation in cardiac tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singh-Moon, Rajinder P.; Zaryab, Mohammad; Hendon, Christine P.

2017-02-01

Electroanatomical mapping (EAM) is an invaluable tool for guiding cardiac radiofrequency ablation (RFA) therapy. The principle roles of EAM is the identification of candidate ablation sites by detecting regions of abnormal electrogram activity and lesion validation subsequent to RF energy delivery. However, incomplete lesions may present interim electrical inactivity similar to effective treatment in the acute setting, despite efforts to reveal them with pacing or drugs, such as adenosine. Studies report that the misidentification and recovery of such lesions is a leading cause of arrhythmia recurrence and repeat procedures. In previous work, we demonstrated spectroscopic characterization of cardiac tissues using a fiber optic-integrated RF ablation catheter. In this work, we introduce OSAM (optical spectroscopic anatomical mapping), the application of this spectroscopic technique to obtain 2-dimensional biodistribution maps. We demonstrate its diagnostic potential as an auxiliary method for lesion validation in treated swine preparations. Endocardial lesion sets were created on fresh swine cardiac samples using a commercial RFA system. An optically-integrated catheter console fabricated in-house was used for measurement of tissue optical spectra between 600-1000nm. Three dimensional, Spatio-spectral datasets were generated by raster scanning of the optical catheter across the treated sample surface in the presence of whole blood. Tissue optical parameters were recovered at each spatial position using an inverse Monte Carlo method. OSAM biodistribution maps showed stark correspondence with gross examination of tetrazolium chloride stained tissue specimens. Specifically, we demonstrate the ability of OSAM to readily distinguish between shallow and deeper lesions, a limitation faced by current EAM techniques. These results showcase the OSAMs potential for lesion validation strategies for the treatment of cardiac arrhythmias.

Comparing Methods for Cardiac Output: Intraoperatively Doppler-Derived Cardiac Output Measured With 3-Dimensional Echocardiography Is Not Interchangeable With Cardiac Output by Pulmonary Catheter Thermodilution.

PubMed

Graeser, Karin; Zemtsovski, Mikhail; Kofoed, Klaus F; Winther-Jensen, Matilde; Nilsson, Jens C; Kjaergaard, Jesper; Møller-Sørensen, Hasse

2018-01-09

Estimation of cardiac output (CO) is essential in the treatment of circulatory unstable patients. CO measured by pulmonary artery catheter thermodilution is considered the gold standard but carries a small risk of severe complications. Stroke volume and CO can be measured by transesophageal echocardiography (TEE), which is widely used during cardiac surgery. We hypothesized that Doppler-derived CO by 3-dimensional (3D) TEE would agree well with CO measured with pulmonary artery catheter thermodilution as a reference method based on accurate measurements of the cross-sectional area of the left ventricular outflow tract. The primary aim was a systematic comparison of CO with Doppler-derived 3D TEE and CO by thermodilution in a broad population of patients undergoing cardiac surgery. A subanalysis was performed comparing cross-sectional area by TEE with cardiac computed tomography (CT) angiography. Sixty-two patients, scheduled for elective heart surgery, were included; 1 was subsequently excluded for logistic reasons. Inclusion criteria were coronary artery bypass surgery (N = 42) and aortic valve replacement (N = 19). Exclusion criteria were chronic atrial fibrillation, left ventricular ejection fraction below 0.40 and intracardiac shunts. Nineteen randomly selected patients had a cardiac CT the day before surgery. All images were stored for blinded post hoc analyses, and Bland-Altman plots were used to assess agreement between measurement methods, defined as the bias (mean difference between methods), limits of agreement (equal to bias ± 2 standard deviations of the bias), and percentage error (limits of agreement divided by the mean of the 2 methods). Precision was determined for the individual methods (equal to 2 standard deviations of the bias between replicate measurements) to determine the acceptable limits of agreement. We found a good precision for Doppler-derived CO measured by 3D TEE, but although the bias for Doppler-derived CO by 3D compared to

Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures

PubMed Central

2012-01-01

Background One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating. Methods A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip. Results A maximum temperature rise of 22.4°C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2°C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8°C. Conclusion Up to a maximum of 22.4°C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip

Value of local electrogram characteristics predicting successful catheter ablation of left-versus right-sided accessory atrioventricular pathways by radiofrequency current.

PubMed

Lin, J L; Schie, J T; Tseng, C D; Chen, W J; Cheng, T F; Tsou, S S; Chen, J J; Tseng, Y Z; Lien, W P

1995-01-01

Despite similar guidance by local electrogram criteria, catheter ablation of right-sided accessory atrioventricular (AV) pathways by radiofrequency current has been less effective than that of left-sided ones. In order to elucidate the possible diversities in local electrosignal criteria, we systematically analyzed the morphological and timing characteristics of 215 bipolar local electrograms from catheter ablation sites of 65 left-sided accessory AV pathways and of 356 from those of 37 right-sided ones in 92 consecutive patients with Wolff-Parkinson-White syndrome or AV reentrant tachycardia incorporating concealed accessory AV pathways. After stepwise multivariate analysis, we selected the presence of a possible accessory pathway potential, local ventricular activation preceding QRS complex for 20 ms or more during ventricular insertion mapping, and the local retrograde ventriculoatrial (VA) continuity, local retrograde VA interval < or = 50 ms, electrogram stability (left-sided targets only), retrograde accessory pathway potential (right-sided targets only) during atrial insertion mapping, as independent local electrogram predictors for successful ablation of left- and right-sided accessory AV pathways. Combination of all local electrogram predictors could have moderate chance of success (80 and 51%) for the ventricular and atrial insertion ablation of left-sided accessory AV pathways, but only low probability of success (40% in ventricular insertion ablation) or very low sensitivity (12.5% in atrial insertion ablation) for right-sided ones. In conclusion, with the present approach, successful catheter ablation of right-sided accessory AV pathways, compared to left-sided ones, still necessitate a breakthrough in the precision mapping and the efficiency of energy delivery.

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus.more » There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.« less

Cryo-balloon catheter localization in fluoroscopic images

NASA Astrophysics Data System (ADS)

Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2013-03-01

Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

[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

Insights into energy delivery to myocardial tissue during radiofrequency ablation through application of the first law of thermodynamics.

PubMed

Bunch, T Jared; Day, John D; Packer, Douglas L

2009-04-01

The approach to catheter-based radiofrequency ablation of atrial fibrillation has evolved, and as a consequence, more energy is delivered in the posterior left atrium, exposing neighboring tissue to untoward thermal injury. Simultaneously, catheter technology has advanced to allow more efficient energy delivery into the myocardium, which compounds the likelihood of collateral injury. This review focuses on the basic principles of thermodynamics as they apply to energy delivery during radiofrequency ablation. These principles can be used to titrate energy delivery and plan ablative approaches in an effort to minimize complications during the procedure.

Ex vivo human bile duct radiofrequency ablation with a bipolar catheter.

PubMed

Atar, Mustafa; Kadayifci, Abdurrahman; Daglilar, Ebubekir; Hagen, Catherine; Fernandez-Del Castillo, Carlos; Brugge, William R

2018-06-01

Management of the primary and secondary tumors of the bile ducts still remains as a major clinical challenge. Radiofrequency (RF) ablation (RFA) of these tumors is feasible but the effect of RF energy on the human common bile duct (CBD) and surrounding tissues has not been investigated. This pilot study aimed to determine the relationship between RF energy and the depth of ablation in the normal human CBD. The study was performed on fresh ex vivo human biliary-pancreatic tissue which had been resected for a pancreatic cyst or mass. The study was conducted within 15 min after resection. A bipolar Habib RFA catheter was placed into the middle of the intact CBD, and three different (5, 7, 10 W) power settings were applied over a 90-s period by an RF generator. Gross and histological examinations were performed. The depth of coagulation necrosis in CBD and the effect of RFA on CBD wall and surrounding pancreas tissue were determined by microscopic examination. The study included eight tissue samples. 5 W power was applied to three sites and RFA caused only focal epithelial necrosis limited to the CBD mucosa. 7 and 10 W were applied to five sites and coagulation necrosis occurred in all cases. Microscopically, necrosis was transmural, involved accessory bile duct glands, and extended to the surrounding pancreatic tissue in four of these cases. Macroscopically, RFA resulted in circumferential white-yellowish color change extending approximately 2 cm of the CBD. Bipolar RF energy application with 5 W resulted in limited ablation on CBD wall. However, 7 and 10 W generated tissue necrosis which extended through the CBD wall and into surrounding pancreas tissue. Endoscopic biliary RFA is an effective technique for local biliary tissue ablation but the use of high energy may injure surrounding tissue.

Successful catheter ablation of ventricular premature complexes from the right atrial side of the atrioventricular septum with good contact force.

PubMed

Arai, Marina; Fukamizu, Seiji; Kawamura, Iwanari; Miyazawa, Satoshi; Hojo, Rintaro; Sakurada, Harumizu; Hiraoka, Masayasu

2018-04-01

The acquisition of good contact force for radiofrequency catheter ablation of ventricular premature complexes (VPCs) originating from the basal septum of the left ventricle (LV) is often difficult. We describe a case of VPCs originating from the basal septum of the LV, which were successfully eliminated by applying radiofrequency at the right atrium (RA) side of the atrioventricular septum (AVS) without causing any significant impairment of atrioventricular conduction because the ablation catheter could obtain better contact force through the RA approach. Moreover, intracardiac echocardiography (ICE) and RA angiography effectively demonstrated the AVS.

A statistical model of catheter motion from interventional x-ray images: application to image-based gating

NASA Astrophysics Data System (ADS)

Panayiotou, M.; King, A. P.; Ma, Y.; Housden, R. J.; Rinaldi, C. A.; Gill, J.; Cooklin, M.; O'Neill, M.; Rhode, K. S.

2013-11-01

The motion and deformation of catheters that lie inside cardiac structures can provide valuable information about the motion of the heart. In this paper we describe the formation of a novel statistical model of the motion of a coronary sinus (CS) catheter based on principal component analysis of tracked electrode locations from standard mono-plane x-ray fluoroscopy images. We demonstrate the application of our model for the purposes of retrospective cardiac and respiratory gating of x-ray fluoroscopy images in normal dose x-ray fluoroscopy images, and demonstrate how a modification of the technique allows application to very low dose scenarios. We validated our method on ten mono-plane imaging sequences comprising a total of 610 frames from ten different patients undergoing radiofrequency ablation for the treatment of atrial fibrillation. For normal dose images we established systole, end-inspiration and end-expiration gating with success rates of 100%, 92.1% and 86.9%, respectively. For very low dose applications, the method was tested on the same ten mono-plane x-ray fluoroscopy sequences without noise and with added noise at signal to noise ratio (SNR) values of √50, √10, √8, √6, √5, √2 and √1 to simulate the image quality of increasingly lower dose x-ray images. The method was able to detect the CS catheter even in the lowest SNR images with median errors not exceeding 2.6 mm per electrode. Furthermore, gating success rates of 100%, 71.4% and 85.7% were achieved at the low SNR value of √2, representing a dose reduction of more than 25 times. Thus, the technique has the potential to extract useful information whilst substantially reducing the radiation exposure.

Epidemiological profile of Wolff-Parkinson-White syndrome in a general population younger than 50 years of age in an era of radiofrequency catheter ablation.

PubMed

Lu, Chun-Wei; Wu, Mei-Hwan; Chen, Hui-Chi; Kao, Feng-Yu; Huang, San-Kuei

2014-07-01

The prevalence of Wolff-Parkinson-White (WPW) syndrome varies between 0.68 and 1.7/1000. The epidemiological profile may be modified after the introduction of transcatheter interventions. The aim of this study is to investigate the epidemiological trends of the WPW syndrome in a general population during a period with available and reimbursed transcatheter ablation. Data of WPW patients <50 years old were retrieved from our national database (2000-2010). We identified 6086 (61% male) patients, accounting for an overall prevalence of 0.36/1000 with a peak of 0.61/1000 in ages 20-24 years. The risk of death and sudden death was 0.071% and 0.02% per patient-year, respectively. The 42 deaths occurred at a median age of 29 years. Associated congenial heart disease was noted in 158 (2.6%) patients, including 42 with Ebstein's anomaly that increased the mortality risk (P=0.001, OR=8.5). In those without congenital heart disease, myocardial dysfunction occurred in 115 (1.9%) patients and increased the risk of death (P<0.001, OR=10.6) and sudden death. Radiofrequency catheter ablation was performed in 2527 patients at a median age of 25.7 years (4.54% per patient-year, discharge mortality 0.16%); 11 (0.4%) before the age of 5, and 2231 (88%) after the age of 15. Whereas repeated ablation procedures accounted for 6.0% of the procedures, those in Ebstein's patients were 25%. Radiofrequency catheter ablation is already a common treatment for WPW patients, particularly during young adulthood, which accounts for a lower prevalence. Myocardial dysfunction and associated congenital heart disease remain as risks of mortality. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Robotic positioning of standard electrophysiology catheters: a novel approach to catheter robotics.

PubMed

Knight, Bradley; Ayers, Gregory M; Cohen, Todd J

2008-05-01

Robotic systems have been developed to manipulate and position electrophysiology (EP) catheters remotely. One limitation of existing systems is their requirement for specialized catheters or sheaths. We evaluated a system (Catheter Robotics Remote Catheter Manipulation System [RCMS], Catheter Robotics, Inc., Budd Lake, New Jersey) that manipulates conventional EP catheters placed through standard introducer sheaths. The remote controller functions much like the EP catheter handle, and the system permits repeated catheter disengagement for manual manipulation without requiring removal of the catheter from the body. This study tested the hypothesis that the RCMS would be able to safely and effectively position catheters at various intracardiac sites and obtain thresholds and electrograms similar to those obtained with manual catheter manipulation. Two identical 7 Fr catheters (Blazer II; Boston Scientific Corp., Natick, Massachusetts) were inserted into the right femoral veins of 6 mongrel dogs through separate, standard 7 Fr sheaths. The first catheter was manually placed at a right ventricular endocardial site. The second catheter handle was placed in the mating holder of the RCMS and moved to approximately the same site as the first catheter using the Catheter Robotics RCMS. The pacing threshold was determined for each catheter. This sequence was performed at 2 right atrial and 2 right ventricular sites. The distance between the manually and robotically placed catheters tips was measured, and pacing thresholds and His-bundle recordings were compared. The heart was inspected at necropsy for signs of cardiac perforation or injury. Compared to manual positioning, remote catheter placement produced the same pacing threshold at 7/24 sites, a lower threshold at 11/24 sites, and a higher threshold at only 6/24 sites (p > 0.05). The average distance between catheter tips was 0.46 +/- 0.32 cm (median 0.32, range 0.13-1.16 cm). There was no difference between right atrial

The left atrial catheter: its uses and complications.

PubMed

Leitman, B S; Naidich, D P; McGuinness, G; McCauley, D I

1992-11-01

The authors describe the radiographic appearance of the left atrial catheter, a widely used postsurgical intracardiac device. Recognition of the characteristic appearance of this catheter should be of value in detection of potential complications, including line fracture with resultant retention and/or embolization, infection, prosthetic valve dysfunction, and even cardiac tamponade.

Incidence of silent cerebral thromboembolic lesions after atrial fibrillation ablation may change according to technology used: comparison of irrigated radiofrequency, multipolar nonirrigated catheter and cryoballoon.

PubMed

Gaita, Fiorenzo; Leclercq, Jean François; Schumacher, Burghard; Scaglione, Marco; Toso, Elisabetta; Halimi, Franck; Schade, Anja; Froehner, Steffen; Ziegler, Volker; Sergi, Domenico; Cesarani, Federico; Blandino, Alessandro

2011-09-01

Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies. One hundred and eight patients (67% men; age 56 ± 9 years) with PAF were enrolled in a consecutive manner to undergo PVI performed with irrigated radiofrequency (RF) catheter (Group 1, 36 patients), multielectrode catheter (PVAC) associated with duty-cycled RF generator (Group 2, 36 patients) and cryoballoon (Group 3, 36 patients). The protocol included a cerebral magnetic resonance imaging before and after the procedure. After PVI, the following patients showed new silent cerebral ischemic lesions at postprocedural cerebral MRI: 3 patients in Group 1 (8.3%), 14 patients in Group 2 (38.9%), 2 patients in Group 3 (5.6%). PVAC related to higher incidence of silent cerebral ischemic events compared to irrigated RF (P = 0.002) and cryoballoon (P = 0.001), whereas no statistical differences were found between irrigated RF catheter and cryoballoon groups (8.3% vs 5.6%, P = 0.5). At the multivariate analysis, the only independent predictor of new ischemic asymptomatic cerebral lesions after PVI was ablation performed with PVAC (OR 1.48 95% CI 1.19-1.62, P < 0.001). The incidence of silent cerebral lesions after PVI is different depending on technologies used: PVAC increases the risk of 1.48 times compared to irrigated RF and cryoballoon ablation.  © 2011 Wiley Periodicals, Inc.

Renal denervation with standard radiofrequency ablation catheter is effective in 24-hour ambulatory blood pressure reduction - follow-up at 1/3/6/12 months.

PubMed

Prochnau, D; Otto, S; Figulla, H-R; Surber, R

2016-07-01

To examine the effect of renal denervation (RDN) on 24‑h ambulatory blood pressure (ABP) with a standard radiofrequency ablation catheter (RF catheter). Seventy-five patients with resistant hypertension received bilateral RDN with an RF catheter (6 RF applications, 1 minute each, 8-12 watts). Seventy patients fulfilled inclusion criteria with mean systolic ABP ≥140 mmHg (mean 165/89) despite treatment with ≥3 antihypertensive drugs (mean 5.9) including a diuretic, and were further analysed for ABP changes. Follow-up at 1/3/6/12 months comprised biochemical evaluations and ABP measurement. At 6/12 months, duplex sonography of the renal arteries was additionally performed. At 1/3/6/12 months we observed a significant reduction in systolic ABP of -15/-17/-18/-15 mmHg (n = 55/53/57/50; non-parametric Friedman test, p < 0.001) and diastolic ABP of -6/-9/-10/-7 mmHg (p < 0.001). Of the patients, 70 %/64 % showed a systolic ABP reduction of ≥10 mmHg, and 77 %/70 % of ≥5 mmHg at 6/12-month follow-up. Two patients (2.7 %) developed renal artery stenosis (>70 %) with subsequent stenting without complications. Logistic regression analysis with systolic ABP reduction ≥10 mmHg at 12 months follow-up as criterion revealed that only the mean baseline systolic ABP was significant, OR = 2.174. RDN with a standard RF catheter can be used safely to reduce mean ABP in resistant hypertension as shown in long-term follow-up.

Ultrasound Current Source Density Imaging in live rabbit hearts using clinical intracardiac catheter

NASA Astrophysics Data System (ADS)

Li, Qian

Ultrasound Current Source Density Imaging (UCSDI) is a noninvasive modality for mapping electrical activities in the body (brain and heart) in 4-dimensions (space + time). Conventional cardiac mapping technologies for guiding the radiofrequency ablation procedure for treatment of cardiac arrhythmias have certain limitations. UCSDI can potentially overcome these limitations and enhance the electrophysiology mapping of the heart. UCSDI exploits the acoustoelectric (AE) effect, an interaction between ultrasound pressure and electrical resistivity. When an ultrasound beam intersects a current path in a material, the local resistivity of the material is modulated by the ultrasonic pressure, and a change in voltage signal can be detected based on Ohm's Law. The degree of modulation is determined by the AE interaction constant K. K is a fundamental property of any type of material, and directly affects the amplitude of the AE signal detected in UCSDI. UCSDI requires detecting a small AE signal associated with electrocardiogram. So sensitivity becomes a major challenge for transferring UCSDI to the clinic. This dissertation will determine the limits of sensitivity and resolution for UCSDI, balancing the tradeoff between them by finding the optimal parameters for electrical cardiac mapping, and finally test the optimized system in a realistic setting. This work begins by describing a technique for measuring K, the AE interaction constant, in ionic solution and biological tissue, and reporting the value of K in excised rabbit cardiac tissue for the first time. K was found to be strongly dependent on concentration for the divalent salt CuSO4, but not for the monovalent salt NaCl, consistent with their different chemical properties. In the rabbit heart tissue, K was determined to be 0.041 +/- 0.012 %/MPa, similar to the measurement of K in physiologic saline: 0.034 +/- 0.003 %/MPa. Next, this dissertation investigates the sensitivity limit of UCSDI by quantifying the relation

Catheter-based Intramyocardial Injection of FGF1 or NRG1-loaded MPs Improves Cardiac Function in a Preclinical Model of Ischemia-Reperfusion

PubMed Central

Garbayo, Elisa; Gavira, Juan José; de Yebenes, Manuel Garcia; Pelacho, Beatriz; Abizanda, Gloria; Lana, Hugo; Blanco-Prieto, María José; Prosper, Felipe

2016-01-01

Cardiovascular protein therapeutics such as neuregulin (NRG1) and acidic-fibroblast growth factor (FGF1) requires new formulation strategies that allow for sustained bioavailability of the drug in the infarcted myocardium. However, there is no FDA-approved injectable protein delivery platform due to translational concerns about biomaterial administration through cardiac catheters. We therefore sought to evaluate the efficacy of percutaneous intramyocardial injection of poly(lactic-co-glycolic acid) microparticles (MPs) loaded with NRG1 and FGF1 using the NOGA MYOSTAR injection catheter in a porcine model of ischemia-reperfusion. NRG1- and FGF1-loaded MPs were prepared using a multiple emulsion solvent-evaporation technique. Infarcted pigs were treated one week after ischemia-reperfusion with MPs containing NRG1, FGF1 or non-loaded MPs delivered via clinically-translatable percutaneous transendocardial-injection. Three months post-treatment, echocardiography indicated a significant improvement in systolic and diastolic cardiac function. Moreover, improvement in bipolar voltage and decrease in transmural infarct progression was demonstrated by electromechanical NOGA-mapping. Functional benefit was associated with an increase in myocardial vascularization and remodeling. These findings in a large animal model of ischemia-reperfusion demonstrate the feasibility and efficacy of using MPs as a delivery system for growth factors and provide strong evidence to move forward with clinical studies using therapeutic proteins combined with catheter-compatible biomaterials. PMID:27184924

Catheter-based Intramyocardial Injection of FGF1 or NRG1-loaded MPs Improves Cardiac Function in a Preclinical Model of Ischemia-Reperfusion

NASA Astrophysics Data System (ADS)

Garbayo, Elisa; Gavira, Juan José; de Yebenes, Manuel Garcia; Pelacho, Beatriz; Abizanda, Gloria; Lana, Hugo; Blanco-Prieto, María José; Prosper, Felipe

2016-05-01

Cardiovascular protein therapeutics such as neuregulin (NRG1) and acidic-fibroblast growth factor (FGF1) requires new formulation strategies that allow for sustained bioavailability of the drug in the infarcted myocardium. However, there is no FDA-approved injectable protein delivery platform due to translational concerns about biomaterial administration through cardiac catheters. We therefore sought to evaluate the efficacy of percutaneous intramyocardial injection of poly(lactic-co-glycolic acid) microparticles (MPs) loaded with NRG1 and FGF1 using the NOGA MYOSTAR injection catheter in a porcine model of ischemia-reperfusion. NRG1- and FGF1-loaded MPs were prepared using a multiple emulsion solvent-evaporation technique. Infarcted pigs were treated one week after ischemia-reperfusion with MPs containing NRG1, FGF1 or non-loaded MPs delivered via clinically-translatable percutaneous transendocardial-injection. Three months post-treatment, echocardiography indicated a significant improvement in systolic and diastolic cardiac function. Moreover, improvement in bipolar voltage and decrease in transmural infarct progression was demonstrated by electromechanical NOGA-mapping. Functional benefit was associated with an increase in myocardial vascularization and remodeling. These findings in a large animal model of ischemia-reperfusion demonstrate the feasibility and efficacy of using MPs as a delivery system for growth factors and provide strong evidence to move forward with clinical studies using therapeutic proteins combined with catheter-compatible biomaterials.

[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.

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.

Long-Term Outcomes of Catheter Ablation of Ventricular Tachycardia in Patients With Cardiac Sarcoidosis.

PubMed

Muser, Daniele; Santangeli, Pasquale; Pathak, Rajeev K; Castro, Simon A; Liang, Jackson J; Magnani, Silvia; Hayashi, Tatsuya; Garcia, Fermin C; Hutchinson, Mathew D; Supple, Gregory E; Frankel, David S; Riley, Michael P; Lin, David; Schaller, Robert D; Desjardins, Benoit; Dixit, Sanjay; Callans, David J; Zado, Erica S; Marchlinski, Francis E

2016-08-01

Catheter ablation (CA) of ventricular tachycardia (VT) in patients with cardiac sarcoidosis can be challenging because of the complex underlying substrate. We sought to determine the long-term outcome of CA of VT in patients with cardiac sarcoidosis. We enrolled 31 patients (age, 55±10 years) with diagnosis of cardiac sarcoidosis based on Heart Rhythm Society criteria and VT who underwent CA. In 23 (74%) patients, preprocedure cardiac magnetic resonance imaging and positron emission tomographic (PET) evaluation were performed. Preprocedure magnetic resonance imaging was positive for late gadolinium enhancement in 21 of 23 (91%) patients, whereas abnormal 18-fluorodeoxyglucose uptake was found in 15 of 23 (65%) cases. In 14 of 15 patients with positive PET at baseline, PET was repeated after 6.1±3.7-month follow-up. After a median follow-up of 2.5 (range, 0-10.5) years, 1 (3%) patient died and 4 (13%) underwent heart transplant. Overall VT-free survival was 55% at 2-year follow-up. Among the 16 (52%) patients with VT recurrences, CA resulted in a significant reduction of VT burden, with 8 (50%) having only isolated (1-3) VT episodes and only 1 patient with recurrent VT storm. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET at baseline, and lack of PET improvement over follow-up were associated with increased risk of recurrent VT. In patients with cardiac sarcoidosis and VT, CA is effective in achieving long-term freedom from VT or improvement in VT burden in the majority of patients. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET scan at baseline, or lack of improvement at repeat PET over follow-up predict worse arrhythmia-free survival. © 2016 American Heart Association, Inc.

[Recording of ventricular pressure by conventional catheter manometer systems. Efficiency of several combinations of conventional catheters, modern transducers and catheter-flush systems (author's transl)].

PubMed

Hellige, G

1976-01-01

The experimentally in vitro determined dynamic response characteristics of 38 catheter manometer systems were uniform in the worst case to 5 c.p.s. and optimally to 26 c.p.s. Accordingly, some systems are only satisfactory for ordinary pressure recording in cardiac rest, while better systems record dp/dt correct up to moderate inotropic stimulation of the heart. In the frequency range of uniform response (amplitude error less +/- 5%) the phase distortion is also negligible. In clinical application the investigator is often restricted to special type of cardiac catheter. In this case a low compliant transducer yields superior results. In all examined systems the combination with MSD 10 transducers is best, whereas the combination with P 23 Db transducers leads to minimal results. An inadequate system for recording ventricular pressure pulses leads in most cases to overestimations of dp/dtmax. The use of low frequency pass filters to attenuate higher frequency artefacts is, under clinical conditions, not suitable for extending the range of uniform frequency response. The dynamic response of 14 catheter manometer systems with two types of continuous self flush units was determined. The use of the P 37 flush unit in combination with small internal diameter catheters leads to serious error in ordinary pressure recording, due to amplitude distortion of the lower harmonics. The frequency response characteristics of the combination of an Intraflow flush system and MSD 10 transducer was similar to the non-flushing P 23 Db transducer feature.

[Catheter ablation for paroxysmal atrial fibrillation: new generation cryoballoon or contact force sensing radiofrequency ablation?].

PubMed

Nagy, Zsófia; Kis, Zsuzsanna; Som, Zoltán; Földesi, Csaba; Kardos, Attila

2016-05-29

Contact force sensing radiofrequency ablation and the new generation cryoballoon ablation are prevalent techniques for the treatment of paroxysmal atrial fibrillation. The authors aimed to compare the procedural and 1-year outcome of patients after radiofrequency and cryoballoon ablation. 96 patients with paroxysmal atrial fibrillation (radiofrequency ablation: 58, cryoballoon: 38 patients; 65 men and 31 women aged 28-70 years) were enrolled. At postprocedural 1, 3, 6 and 12 months ECG, Holter monitoring and telephone interviews were performed. Procedure and fluorosocopy time were: radiofrequency ablation, 118.5 ± 15 min and 15.8 ± 6 min; cryoballoon, 73.5 ± 16 min (p<0.05) and 13.8 ± 4.,1 min (p = 0.09), respectively. One year later freedom from atrial fibrillation was achieved in 76.5% of patients who underwent radiofrequency ablation and in 81% of patients treated with cryoballoon. Temporary phrenic nerve palsy occurred in two patients and pericardial tamponade developed in one patient. In this single center study freedom from paroxysmal atrial fibrillation was similar in the two groups with significant shorter procedure time in the cryoballoon group.

Loss of pace capture after radiofrequency application predicts the formation of uniform transmural lesions.

PubMed

Kosmidou, Ioanna; Houde-Walter, Haley; Foley, Lori; Michaud, Gregory

2013-04-01

Lesion transmurality is critical to procedural success in radiofrequency catheter ablation. We sought to determine whether loss of pace capture (PC) with high-output unipolar and/or bipolar pacing predicts the formation of uniform transmural lesions. Ten juvenile swine were anaesthetized and prepped under sterile conditions. Seventy-seven isolated radiofrequency applications (RFAs) using a 3.5 mm tip-irrigated catheter were available for analysis. Pace capture was assessed before and after RFA at 10 mA/2 ms and catheter stability verified with a three-dimensional mapping system. Pace capture was defined as 1 : 1 or intermittent local capture per paced beat. Myocardial contact and catheter orientation were assessed using intracardiac echo. Endocardial and epicardial lesion areas were measured after sacrifice using 2,3,5-triphenyltetrazolium chloride staining. A uniform transmural lesion was defined as an epicardial-to-endocardial surface ratio (epi/endo) ≥ 76%. Seventy-four per cent of lesions were transmural and 55.8% of lesions had an epi/endo ratio ≥ 76%. In all, 79.2% of lesions associated with loss of bipolar PC were uniform whereas 20.8% of lesions with loss of bipolar PC were non-uniform (P = 0.006). Loss of bipolar PC was associated with higher mean epicardial/endocardial ratio compared with lesions with persistent PC (P = 0.019). Echocardiographic evidence of optimal catheter contact during RFA improved the predictive accuracy of uniform lesion formation when loss of bipolar PC was noted after RFA. Loss of bipolar PC after RFA is associated with the formation of uniform lesions in atrial tissue. Optimal catheter contact further improves the predictive accuracy associated with loss of PC.

Magnetic guidance versus manual control: comparison of radiofrequency lesion dimensions and evaluation of the effect of heart wall motion in a myocardial phantom.

PubMed

Bhaskaran, Abhishek; Barry, M A Tony; Al Raisi, Sara I; Chik, William; Nguyen, Doan Trang; Pouliopoulos, Jim; Nalliah, Chrishan; Hendricks, Roger; Thomas, Stuart; McEwan, Alistair L; Kovoor, Pramesh; Thiagalingam, Aravinda

2015-10-01

Magnetic navigation system (MNS) ablation was suspected to be less effective and unstable in highly mobile cardiac regions compared to radiofrequency (RF) ablations with manual control (MC). The aim of the study was to compare the (1) lesion size and (2) stability of MNS versus MC during irrigated RF ablation with and without simulated mechanical heart wall motion. In a previously validated myocardial phantom, the performance of Navistar RMT Thermocool catheter (Biosense Webster, CA, USA) guided with MNS was compared to manually controlled Navistar irrigated Thermocool catheter (Biosense Webster, CA, USA). The lesion dimensions were compared with the catheter in inferior and superior orientation, with and without 6-mm simulated wall motion. All ablations were performed with 40 W power and 30 ml/ min irrigation for 60 s. A total of 60 ablations were performed. The mean lesion volumes with MNS and MC were 57.5 ± 7.1 and 58.1 ± 7.1 mm(3), respectively, in the inferior catheter orientation (n = 23, p = 0.6), 62.8 ± 9.9 and 64.6 ± 7.6 mm(3), respectively, in the superior catheter orientation (n = 16, p = 0.9). With 6-mm simulated wall motion, the mean lesion volumes with MNS and MC were 60.2 ± 2.7 and 42.8 ± 8.4 mm(3), respectively, in the inferior catheter orientation (n = 11, p = <0.01*), 74.1 ± 5.8 and 54.2 ± 3.7 mm(3), respectively, in the superior catheter orientation (n = 10, p = <0.01*). During 6-mm simulated wall motion, the MC catheter and MNS catheter moved 5.2 ± 0.1 and 0 mm, respectively, in inferior orientation and 5.5 ± 0.1 and 0 mm, respectively, in the superior orientation on the ablation surface. The lesion dimensions were larger with MNS compared to MC in the presence of simulated wall motion, consistent with greater catheter stability. However, similar lesion dimensions were observed in the stationary model.

Design of parallel transmission radiofrequency pulses robust against respiration in cardiac MRI at 7 Tesla.

PubMed

Schmitter, Sebastian; Wu, Xiaoping; Uğurbil, Kâmil; Van de Moortele, Pierre-François

2015-11-01

Two-spoke parallel transmission (pTX) radiofrequency (RF) pulses have been demonstrated in cardiac MRI at 7T. However, current pulse designs rely on a single set of B1(+)/B0 maps that may not be valid for subsequent scans acquired at another phase of the respiration cycle because of organ displacement. Such mismatches may yield severe excitation profile degradation. B1(+)/B0 maps were obtained, using 16 transmit channels at 7T, at three breath-hold positions: exhale, half-inhale, and inhale. Standard and robust RF pulses were designed using maps obtained at exhale only, and at multiple respiratory positions, respectively. Excitation patterns were analyzed for all positions using Bloch simulations. Flip-angle homogeneity was compared in vivo in cardiac CINE acquisitions. Standard one- and two-spoke pTX RF pulses are sensitive to breath-hold position, primarily due to B1(+) alterations, with high dependency on excitation trajectory for two spokes. In vivo excitation inhomogeneity varied from nRMSE = 8.2% (exhale) up to 32.5% (inhale) with the standard design; much more stable results were obtained with the robust design with nRMSE = 9.1% (exhale) and 10.6% (inhale). A new pTX RF pulse design robust against respiration induced variations of B1(+)/B0 maps is demonstrated and is expected to have a positive impact on cardiac MRI in breath-hold, free-breathing, and real-time acquisitions. © 2014 Wiley Periodicals, Inc.

Real-time optical monitoring of permanent lesion progression in radiofrequency ablated cardiac tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singh-Moon, Rajinder P.; Hendon, Christine P.

2016-02-01

Despite considerable advances in guidance of radiofrequency ablation (RFA) therapies for atrial fibrillation, success rates have been hampered by an inability to intraoperatively characterize the extent of permanent injury. Insufficient lesions can elusively create transient conduction blockages that eventually reconduct. Prior studies suggest significantly greater met-myoglobin (Mmb) concentrations in the lesion core than those in the healthy myocardium and may serve as a marker for irreversible tissue damage. In this work, we present real-time monitoring of permanent injury through spectroscopic assessment of Mmb concentrations at the catheter tip. Atrial wedges (n=6) were excised from four fresh swine hearts and submerged under pulsatile flow of warm (37oC) phosphate buffered saline. A commercial RFA catheter inserted into a fiber optic sheath allowed for simultaneous measurement of tissue diffuse reflectance (DR) spectra (500-650nm) during application of RF energy. Optical measurements were continuously acquired before, during, and post-ablation, in addition to healthy neighboring tissue. Met-myoglobin, oxy-myoglobin, and deoxy-myoglobin concentrations were extracted from each spectrum using an inverse Monte Carlo method. Tissue injury was validated with Masson's trichrome and hematoxylin and eosin staining. Time courses revealed a rapid increase in tissue Mmb concentrations at the onset of RFA treatment and a gradual plateauing thereafter. Extracted Mmb concentrations were significantly greater post-ablation (p<0.0001) as compared to healthy tissue and correlated well with histological assessment of severe thermal tissue destruction. On going studies are aimed at integrating these findings with prior work on near infrared spectroscopic lesion depth assessment. These results support the use of spectroscopy-facilitated guidance of RFA therapies for real-time permanent injury estimation.

Results of Lumbar Endoscopic Adhesiolysis Using a Radiofrequency Catheter in Patients with Postoperative Fibrosis and Persistent or Recurrent Symptoms After Discectomy.

PubMed

Pereira, Paulo; Severo, Milton; Monteiro, Pedro; Silva, Pedro Alberto; Rebelo, Virgínia; Castro-Lopes, José Manuel; Vaz, Rui

2016-01-01

To evaluate the results of lumbar epiduroscopic adhesiolysis using mechanical methods and a radiofrequency catheter followed by epidural steroid and local anesthetic administration in patients with postoperative fibrosis and persistent or recurrent symptoms. Prospective study. Patients with persistent or recurrent low back and/or lower limb pain after lumbar spine surgery, in whom no relevant findings were present on MR images besides epidural scar tissue, were submitted to epiduroscopic adhesiolysis. Patient-reported outcomes including pain and disability were assessed in predefined time intervals and compared to baseline. Twenty-four patients were enrolled. It was possible to elicit the patient's usual pain by probing the epidural scar tissue in all patients. Statistically significant improvement in low back and lower limb pain was observed in all assessment periods up to 12 months. A pain relief over 50% was achieved in 71% of the patients at 1 month, 63% at 3 and 6 months, and 38% at 12 months. Disability scores significantly improved for around 6 months. Mean patient satisfaction rates were 80% at 1 month, 75% at 3 months, 70% at 6 months, and 67% 1 year after intervention. Only 1 transient postprocedural complication was detected. Endoscopic adhesiolysis is a potentially useful treatment for the relief of chronic intractable low back and lower limb pain in patients with previous lumbar spine surgery and epidural fibrosis. The use of larger volumes of saline during endoscopy and the employment of radiofrequency for the lysis of epidural adhesions are safe procedures, which may provide an additional benefit to the intervention. © 2014 World Institute of Pain.

Complications of intra-cardial placement of silastic central venous catheter in pediatric patients.

PubMed

Soong, W J; Jeng, M J; Hwang, B

1996-01-01

A three-year prospective study was undertaken to determine the incidence and early complications from intra-cardiac placement of percutaneous central venous catheter (CVC). CVC was inserted by using "Catheter-through-needle" technique, and the insertion length was measured by body surface landmark. CVC course and tip location were routinely checked by roentgenography. Echocardiography was performed in case of arrhythmia. After analysis of 784 CVCs, 104 (13.3%) were proved to be intra-cardial, as located by either roentgenography or echocardiography. However, catheters passed via the upper trunk (14.5%) were significantly (p < 0.05) more intra-cardially located than those via the lower trunk (4.8%). Catheters which passed via the right upper trunk veins (basilic, cephalic, or external jugular veins) were also more intra-cardially located than those via their left veins counterparts, but the finding was not statistically significant (p > 0.05). The mean body weight (3.1 +/- 2.4 kg) in the intra-cardial placement group was significantly (p < 0.05) less than that in the non-intracardial placement group (7.9 +/- 4.5 kg). In intra-cardial placement patients, 32 cases (30.8%) had episode(s) of cardiac arrhythmia including 31 premature ventricular depolarization and 1 supra-ventricular tachycardia. All cases showed the presence of intra-ventricular catheter. All arrhythmias ceased abruptly after the catheters were pulled from the hearts. No other early complications were observed. the incidence of the intracardiac placement of CVC is high, especially in small infants or when the insertion via the upper trunk. Short term intra-cardiac catheter placement has a benign clinical course except that the intraventricular catheter may cause arrhythmia. However, this kind of arrhythmia can be resolved spontaneously by withdrawing the catheter.

Steerable catheter microcoils for interventional MRI reducing resistive heating.

PubMed

Bernhardt, Anthony; Wilson, Mark W; Settecase, Fabio; Evans, Leland; Malba, Vincent; Martin, Alastair J; Saeed, Maythem; Roberts, Timothy P L; Arenson, Ronald L; Hetts, Steven W

2011-03-01

The aims of this study were to assess resistive heating of microwires used for remote catheter steering in interventional magnetic resonance imaging and to investigate the use of alumina to facilitate heat transfer to saline flowing in the catheter lumen. A microcoil was fabricated using a laser lathe onto polyimide-tipped or alumina-tipped endovascular catheters. In vitro testing was performed on a 1.5-T magnetic resonance system using a vessel phantom, body radiofrequency coil, and steady-state pulse sequence. Resistive heating was measured with water flowing over a polyimide-tip catheter or saline flowing through the lumen of an alumina-tip catheter. Preliminary in vivo testing in porcine common carotid arteries was conducted with normal blood flow or after arterial ligation when current was applied to an alumina-tip catheter for up to 5 minutes. After application of up to 1 W of direct current power, clinically significant temperature increases were noted with the polyimide-tip catheter: 23°C/W at zero flow, 13°C/W at 0.28 cm(3)/s, and 7.9°C/W at 1 cm(3)/s. Using the alumina-tip catheter, the effluent temperature rise using the lowest flow rate (0.12 cm(3)/s) was 2.3°C/W. In vivo testing demonstrated no thermal injury to vessel walls at normal and zero arterial flow. Resistive heating in current carrying wire pairs can be dissipated by saline coolant flowing within the lumen of a catheter tip composed of material that facilitates heat transfer. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

PubMed

Whitbourn, Robert; Harding, Scott A; Walton, Antony

2015-05-01

The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, p<0.001, and -7.6±20.0 mmHg, p=0.020, respectively. There were three patients with access-site complications, none of which was related to energy delivery; all were treated successfully. No new renal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

Anatomical and procedural determinants of ambulatory blood pressure lowering following catheter-based renal denervation using radiofrequency.

PubMed

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham R; Edelman, Elazer R; Cremers, Bodo; Kulenthiran, Saarraaken; Ukena, Christian; Linz, Dominik; Kindermann, Ingrid; Tsioufis, Costas; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-03-02

Catheter-based renal sympathetic denervation (RDN) has been introduced to lower blood pressure (BP) and sympathetic activity in patients with uncontrolled hypertension with at best equivocal results. It has been postulated that anatomic and procedural elements introduce unaccounted variability and yet little is known of the impact of renal anatomy and procedural parameters on BP response to RDN. Anatomical parameters such as length and diameter were analyzed by quantitative vascular analysis and the prevalence of accessory renal arteries and renal artery disease were documented in 150 patients with resistant hypertension undergoing bilateral RDN using a mono-electrode radiofrequency catheter (Symplicity Flex, Medtronic). Accessory renal arteries and renal artery disease were present in 56 (37%) and 14 patients (9%), respectively. At 6-months, 24 h-ambulatory BP was reduced by 11/6 mm Hg (p < 0.001 for both). Change of systolic blood pressure (SBP) was not related to the presence of accessory renal arteries (p = 0.543) or renal artery disease (p = 0.598). Patients with at least one main renal artery diameter ≤ 4 mm had a more pronounced reduction of 24 h-ambulatory SBP compared to patients where both arteries were >4 mm (-19 vs. -10 mmHg; p = 0.038). Neither the length of the renal artery nor the number of RF ablations influenced 24 h-ambulatory BP reduction at 6 months. 24 h-ambulatory BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, accessory arteries or renal artery disease. Further, there was no dose-response relationship observed with increasing number of ablations. Because little is known of the impact of renal anatomy and procedural parameters on blood pressure (BP) response to renal denervation (RDN), anatomical and procedural data were analyzed in 150 patients undergoing bilateral RDN. BP lowering was most pronounced in patients with smaller renal

Magnetic resonance imaging-compatible circular mapping catheter: an in vivo feasibility and safety study.

PubMed

Elbes, Delphine; Magat, Julie; Govari, Assaf; Ephrath, Yaron; Vieillot, Delphine; Beeckler, Christopher; Weerasooriya, Rukshen; Jais, Pierre; Quesson, Bruno

2017-03-01

Interventional cardiac catheter mapping is routinely guided by X-ray fluoroscopy, although radiation exposure remains a significant concern. Feasibility of catheter ablation for common flutter has recently been demonstrated under magnetic resonance imaging (MRI) guidance. The benefit of catheter ablation under MRI could be significant for complex arrhythmias such as atrial fibrillation (AF), but MRI-compatible multi-electrode catheters such as Lasso have not yet been developed. This study aimed at demonstrating the feasibility and safety of using a multi-electrode catheter [magnetic resonance (MR)-compatible Lasso] during MRI for cardiac mapping. We also aimed at measuring the level of interference between MR and electrophysiological (EP) systems. Experiments were performed in vivo in sheep (N = 5) using a multi-electrode, circular, steerable, MR-compatible diagnostic catheter. The most common MRI sequences (1.5T) relevant for cardiac examination were run with the catheter positioned in the right atrium. High-quality electrograms were recorded while imaging with a maximal signal-to-noise ratio (peak-to-peak signal amplitude/peak-to-peak noise amplitude) ranging from 5.8 to 165. Importantly, MRI image quality was unchanged. Artefacts induced by MRI sequences during mapping were demonstrated to be compatible with clinical use. Phantom data demonstrated that this 10-pole circular catheter can be used safely with a maximum of 4°C increase in temperature. This new MR-compatible 10-pole catheter appears to be safe and effective. Combining MR and multipolar EP in a single session offers the possibility to correlate substrate information (scar, fibrosis) and EP mapping as well as online monitoring of lesion formation and electrical endpoint. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Relationship between catheter contact force and radiofrequency lesion size and incidence of steam pop in the beating canine heart: electrogram amplitude, impedance, and electrode temperature are poor predictors of electrode-tissue contact force and lesion size.

PubMed

Ikeda, Atsushi; Nakagawa, Hiroshi; Lambert, Hendrik; Shah, Dipen C; Fonck, Edouard; Yulzari, Aude; Sharma, Tushar; Pitha, Jan V; Lazzara, Ralph; Jackman, Warren M

2014-12-01

Electrode-tissue contact force (CF) is believed to be a major factor in radiofrequency lesion size. The purpose of this study was to determine, in the beating canine heart, the relationship between CF and radiofrequency lesion size and the accuracy of predicting CF and lesion size by measuring electrogram amplitude, impedance, and electrode temperature. Eight dogs were studied closed chest. Using a 7F catheter with a 3.5 mm irrigated electrode and CF sensor (TactiCath, St. Jude Medical), radiofrequency applications were delivered to 3 separate sites in the right ventricle (30 W, 60 seconds, 17 mL/min irrigation) and 3 sites in the left ventricle (40 W, 60 seconds, 30 mL/min irrigation) at (1) low CF (median 8 g); (2) moderate CF (median 21 g); and (3) high CF (median 60 g). Dogs were euthanized and lesion size was measured. At constant radiofrequency and time, lesion size increased significantly with increasing CF (P<0.01). The incidence of a steam pop increased with both increasing CF and higher power. Peak electrode temperature correlated poorly with lesion size. The decrease in impedance during the radiofrequency application correlated well with lesion size for lesions in the left ventricle but less well for lesions in the right ventricle. There was a poor relationship between CF and the amplitude of the bipolar or unipolar ventricular electrogram, unipolar injury current, and impedance. Radiofrequencylesion size and the incidence of steam pop increase strikingly with increasing CF. Electrogram parameters and initial impedance are poor predictors of CF for radiofrequency ablation. © 2014 American Heart Association, Inc.

Radiofrequency power deposition near metallic wires during MR imaging: feasibility study using T1-weighted thermal imaging.

PubMed

Oulmane, F; Detti, V; Grenier, D; Perrin, E; Saint-Jalmes, H

2007-01-01

The presence of metallic conductors (implants, wires or catheters) is prohibited in MR imaging for safety purpose with respect to radiofrequency (RF) power deposition caused by RF excitation B1 field. This work describes the use of T1-weigthed MR imaging for estimating a thermal map around a metallic (copper) wire located in the center of a MR imaging unit during an imaging sequence. The experimental set up and the methodology used for capturing the elevation of temperature created by radiofrequency power deposition around the wire is presented. A proof of its efficiency to followup temperature elevation about 0,5 degrees C in a milimetric region of interest (pixel size: 1 x 1 mm2, slice thickness 5 mm) located around the wire is given, leading to further developments of MR imaging in presence of metallic implants, coils or catheters.

Complications associated with radiofrequency ablation of pulmonary veins.

PubMed

Madrid Pérez, J M; García Barquín, P M; Villanueva Marcos, A J; García Bolao, J I; Bastarrika Alemañ, G

Radiofrequency ablation is an efficacious alternative in patients with symptomatic atrial fibrillation who do not respond to or are intolerant to at least one class I or class III antiarrhythmic drug. Although radiofrequency ablation is a safe procedure, complications can occur. Depending on the location, these complications can be classified into those that affect the pulmonary veins themselves, cardiac complications, extracardiac intrathoracic complications, remote complications, and those that result from vascular access. The most common complications are hematomas, arteriovenous fistulas, and pseudoaneurysms at the puncture site. Some complications are benign and transient, such as gastroparesis or diaphragmatic elevation, whereas others are potentially fatal, such as cardiac tamponade. Radiologists must be familiar with the complications that can occur secondary to pulmonary vein ablation to ensure early diagnosis and treatment. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Amiodarone and Catheter Ablation as Cardiac Resynchronization Therapy for Children with Dilated Cardiomyopathy and Wolff-Parkinson-White Syndrome

PubMed Central

Kim, Sung Hoon; Jeong, Soo In; Kang, I-Seok; Lee, Heung Jae

2013-01-01

Preexcitation by accessory pathways (APs) is known to cause dyssynchrony of the ventricle, related to ventricular dysfunction. Correction of ventricular dyssynchrony can improve heart failure in cases of dilated cardiomyopathy (DCMP) with preexcitation. Here, we report the first case of a child with DCMP and Wolff-Parkinson-White (WPW) syndrome treated with amiodarone and radiofrequency catheter ablation (RFCA) in Korea. A 7-year-old boy, who suffered from DCMP and WPW syndrome, showed improved left ventricular function and clinical functional class after treatment with amiodarone to eliminate preexcitation. QRS duration and left ventricular ejection fraction (LVEF) were inversely correlated with amiodarone dosage. After confirming the reduction of preexcitation effects in DCMP, successful RFCA of the right anterior AP resulted in LVEF improvement, along with the disappearance of preexcitation. Our findings suggest that ventricular dyssynchrony, caused by preexcitation in DCMP with WPW syndrome, can worsen ventricular function and amiodarone, as well as RFCA, which should be considered as a treatment option, even in young children. PMID:23407697

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.

Cryo-balloon catheter position planning using AFiT

NASA Astrophysics Data System (ADS)

Kleinoeder, Andreas; Brost, Alexander; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2012-02-01

Atrial fibrillation (AFib) is the most common heart arrhythmia. In certain situations, it can result in life-threatening complications such as stroke and heart failure. For paroxsysmal AFib, pulmonary vein isolation (PVI) by catheter ablation is the recommended choice of treatment if drug therapy fails. During minimally invasive procedures, electrically active tissue around the pulmonary veins is destroyed by either applying heat or cryothermal energy to the tissue. The procedure is usually performed in electrophysiology labs under fluoroscopic guidance. Besides radio-frequency catheter ablation devices, so-called single-shot devices, e.g., the cryothermal balloon catheters, are receiving more and more interest in the electrophysiology (EP) community. Single-shot devices may be advantageous for certain cases, since they can simplify the creation of contiguous (gapless) lesion sets around the pulmonary vein which is needed to achieve PVI. In many cases, a 3-D (CT, MRI, or C-arm CT) image of a patient's left atrium is available. This data can then be used for planning purposes and for supporting catheter navigation during the procedure. Cryo-thermal balloon catheters are commercially available in two different sizes. We propose the Atrial Fibrillation Planning Tool (AFiT), which visualizes the segmented left atrium as well as multiple cryo-balloon catheters within a virtual reality, to find out how well cryo-balloons fit to the anatomy of a patient's left atrium. First evaluations have shown that AFiT helps physicians in two ways. First, they can better assess whether cryoballoon ablation or RF ablation is the treatment of choice at all. Second, they can select the proper-size cryo-balloon catheter with more confidence.

Three-Catheter Technique for Ablation of Left-Sided Accessory Pathways in Wolff-Parkinson-White is Less Expensive and Equally Successful When Compared to a Five-Catheter Technique.

PubMed

Capone, Christine A; Ceresnak, Scott R; Nappo, Lynn; Gates, Gregory J; Schechter, Clyde B; Pass, Robert H

2015-12-01

To compare the efficacy, safety, and cost-effectiveness of a three-catheter approach with a conventional five-catheter approach for the mapping and ablation of supraventricular tachycardia in pediatric patients with Wolff-Parkinson-White Syndrome (WPW) and concealed accessory pathways (APs). A retrospective review from 2008 to 2012 of patients less than 21 years with WPW who underwent a three-catheter radiofrequency (RF) ablation of a left-sided AP (ablation, right ventricular [RV] apical, and coronary sinus [CS] decapolar catheters) was performed. The three-catheter group was compared to a control group who underwent a standard five-catheter (ablation, RV apical, CS decapolar, His catheter, and right atrial catheter) ablation for the treatment of left-sided WPW or concealed AP. Demographics, ablation outcomes, and costs were compared between groups. Twenty-eight patients met inclusion criteria with 28 control patients. The groups did not differ in gender, age, weight, or body surface area. Locations of the AP on the mitral annulus were similar between the groups. All patients were ablated via transseptal approach. Note that 28 of 28 in the three-catheter group (100%) and 27 of 28 (96%) controls were acutely successfully ablated (P = 0.31). No complications were encountered. There was no difference in procedural time, time to loss of AP conduction, or number of RF applications. Use of the three-catheter technique resulted in a total savings of $2,465/case, which includes the $680 savings from using fewer catheters as well as the savings from a shortened procedure time. Ablation in patients with WPW and a left-sided AP can be performed using three catheters with similar efficacy and safety while offering significant cost savings compared to a conventional five-catheter approach. © 2015 Wiley Periodicals, Inc.

Distal Superficial Femoral Vein Cannulation for Peripherally Inserted Central Catheter Placement in Infants with Cardiac Disease.

PubMed

Richter, Robert P; Law, Mark A; Borasino, Santiago; Surd, Jessica A; Alten, Jeffrey A

2016-12-01

To describe a novel real-time ultrasound (US)-guided distal superficial femoral vein (DSFV) cannulation technique for insertion of peripherally inserted central catheters (PICC) in critically ill infants with congenital heart disease. Descriptive retrospective cohort study SETTING: Pediatric cardiac intensive care unit in a pediatric tertiary hospital PATIENTS: First 28 critically ill infants that received DSFV PICCs via this new technique. Thirty-seven US-guided DSFV PICCs were attempted on 31 infants from September 2012 to November 2014; 34 PICCs were placed in 28 patients (success rate 92%). Twenty-six of 28 patients underwent cardiac surgery. Median (IQR) age at time of PICC placement 39 days (13, 151); weight 3.4 kg (3.2, 5.3). 25/34 PICCs were placed in patients with STAT 4 or 5 category. Median PICC duration 16 days (11, 29); maximum duration 123 days. Ten infants (36%) had DSFV PICCs placed as the primary central venous access in perioperative period. Ten of 28 patients underwent cardiac catheterization while DSFV PICC was in place, four of which were performed through ipsilateral common femoral vein. Two patients had femoral arterial lines placed in the ipsilateral femoral artery while DSFV PICC was in place. There were no reported inadvertent arterial punctures. The PICC-associated infection rate was 4.6 per 1000 line days. Four of 34 DSFV PICCs (11.8%) were associated with deep venous thrombosis. DSFV is a novel venous access site for PICC placement with high success rate and sufficient longevity and flexibility for critically ill infants with cardiac disease. More experience and larger studies are needed to confirm its potential advantages. © 2016 Wiley Periodicals, Inc.

Real-time catheter localization and visualization using three-dimensional echocardiography

NASA Astrophysics Data System (ADS)

Kozlowski, Pawel; Bandaru, Raja Sekhar; D'hooge, Jan; Samset, Eigil

2017-03-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) is increasingly used during minimally invasive cardiac surgeries (MICS). In many cath labs, RT3D-TEE is already one of the requisite tools for image guidance during MICS. However, the visualization of the catheter is not always satisfactory making 3D- TEE challenging to use as the only modality for guidance. We propose a novel technique for better visualization of the catheter along with the cardiac anatomy using TEE alone - exploiting both beamforming and post processing methods. We extended our earlier method called Delay and Standard Deviation (DASD) beamforming to 3D in order to enhance specular reflections. The beam-formed image was further post-processed by the Frangi filter to segment the catheter. Multi-variate visualization techniques enabled us to render both the standard tissue and the DASD beam-formed image on a clinical ultrasound scanner simultaneously. A frame rate of 15 FPS was achieved.

Impact of Lesion Placement on Efficacy and Safety of Catheter-Based Radiofrequency Renal Denervation.

PubMed

Mahfoud, Felix; Tunev, Stefan; Ewen, Sebastian; Cremers, Bodo; Ruwart, Jennifer; Schulz-Jander, Daniel; Linz, Dominik; Davies, Justin; Kandzari, David E; Whitbourn, Robert; Böhm, Michael; Melder, Robert J

2015-10-20

Insufficient procedural efficacy has been proposed to explain nonresponse to renal denervation (RDN). The aim of this study was to examine the impact of different patterns of lesion placements on the efficacy and consistency of catheter-based radiofrequency RDN in pigs. The impact of increasing number of lesions versus location of RDN was investigated in a porcine model (Group 1; n = 51). The effect of treating the main artery, the branches, and the 2 combined was compared in Group 2 (n = 48). The durability of response and safety of combined treatment of the main artery plus branches was examined in Group 3 (n = 16). Renal norepinephrine (NE) tissue content and renal cortical axon density were assessed. Increasing the number of RF lesions (4, 8, and 12) in the main renal artery was not sufficient to yield a clear dose-response relationship on NE content and axon density. In contrast, targeted treatment of the renal artery branches or distal segment of the main renal artery resulted in markedly less variability of response and significantly greater reduction of both NE and axon density than conventional treatment of only the main renal artery. Combination treatment (main artery plus branches) produced the greatest change in renal NE and axon density with the least heterogeneity. The changes were durable through 28 days post-treatment. These data provide the rationale for investigation of an optimized approach for RDN in future clinical studies. This may have profound implications for the clinical application of RDN, as this approach may not only achieve greater reductions in sympathetic activity but also reduce treatment effect variability. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Modeling and estimation of tip contact force for steerable ablation catheters.

PubMed

Khoshnam, Mahta; Skanes, Allan C; Patel, Rajni V

2015-05-01

The efficacy of catheter-based cardiac ablation procedures can be significantly improved if real-time information is available concerning contact forces between the catheter tip and cardiac tissue. However, the widely used ablation catheters are not equipped for force sensing. This paper proposes a technique for estimating the contact forces without direct force measurements by studying the changes in the shape of the deflectable distal section of a conventional 7-Fr catheter (henceforth called the "deflectable distal shaft," the "deflectable shaft," or the "shaft" of the catheter) in different loading situations. First, the shaft curvature when the tip is moving in free space is studied and based on that, a kinematic model for the deflectable shaft in free space is proposed. In the next step, the shaft shape is analyzed in the case where the tip is in contact with the environment, and it is shown that the curvature of the deflectable shaft provides useful information about the loading status of the catheter and can be used to define an index for determining the range of contact forces exerted by the ablation tip. Experiments with two different steerable ablation catheters show that the defined index can detect the range of applied contact forces correctly in more than 80% of the cases. Based on the proposed technique, a framework for obtaining contact force information by using the shaft curvature at a limited number of points along the deflectable shaft is constructed. The proposed kinematic model and the force estimation technique can be implemented together to describe the catheter's behavior before contact, detect tip/tissue contact, and determine the range of contact forces. This study proves that the flexibility of the catheter's distal shaft provides a means of estimating the force exerted on tissue by the ablation tip.

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions.

PubMed

Perk, Gila; Lang, Roberto M; Garcia-Fernandez, Miguel Angel; Lodato, Joe; Sugeng, Lissa; Lopez, John; Knight, Brad P; Messika-Zeitoun, David; Shah, Sanjiv; Slater, James; Brochet, Eric; Varkey, Mathew; Hijazi, Ziyad; Marino, Nino; Ruiz, Carlos; Kronzon, Itzhak

2009-08-01

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery. The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered. The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and

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.

Radiofrequency Thermal Ablation Heat Energy Transfer in an Ex-Vivo Model.

PubMed

Thakur, Shivani; Lavito, Sandi; Grobner, Elizabeth; Grobner, Mark

2017-12-01

Little work has been done to consider the temperature changes and energy transfer that occur in the tissue outside the vein with ultrasound-guided vein ablation therapy. In this experiment, a Ex-Vivo model of the human calf was used to analyze heat transfer and energy degradation in tissue surrounding the vein during endovascular radiofrequency ablation (RFA). A clinical vein ablation protocol was used to determine the tissue temperature distribution in 10 per cent agar gel. Heat energy from the radiofrequency catheter was measured for 140 seconds at fixed points by four thermometer probes placed equidistant radially at 0.0025, 0.005, and 0.01 m away from the RFA catheter. The temperature rose 1.5°C at 0.0025 m, 0.6°C at 0.005 m, and 0.0°C at 0.01 m from the RFA catheter. There was a clinically insignificant heat transfer at the distances evaluated, 1.4 ± 0.2 J/s at 0.0025 m, 0.7 ± 0.3 J/s at 0.0050 m, and 0.3 ± 0.0 J/s at 0.01 m. Heat degradation occurred rapidly: 4.5 ± 0.5 J (at 0.0025 m), 4.0 ± 1.6 J (at 0.0050 m), and 3.9 ± 3.6 J (at 0.01 m). Tumescent anesthesia injected one centimeter around the vein would act as a heat sink to absorb the energy transferred outside the vein to minimize tissue and nerve damage and will help phlebologists strategize options for minimizing damage.

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

Determination of the precision error of the pulmonary artery thermodilution catheter using an in vitro continuous flow test rig.

PubMed

Yang, Xiao-Xing; Critchley, Lester A; Joynt, Gavin M

2011-01-01

Thermodilution cardiac output using a pulmonary artery catheter is the reference method against which all new methods of cardiac output measurement are judged. However, thermodilution lacks precision and has a quoted precision error of ± 20%. There is uncertainty about its true precision and this causes difficulty when validating new cardiac output technology. Our aim in this investigation was to determine the current precision error of thermodilution measurements. A test rig through which water circulated at different constant rates with ports to insert catheters into a flow chamber was assembled. Flow rate was measured by an externally placed transonic flowprobe and meter. The meter was calibrated by timed filling of a cylinder. Arrow and Edwards 7Fr thermodilution catheters, connected to a Siemens SC9000 cardiac output monitor, were tested. Thermodilution readings were made by injecting 5 mL of ice-cold water. Precision error was divided into random and systematic components, which were determined separately. Between-readings (random) variability was determined for each catheter by taking sets of 10 readings at different flow rates. Coefficient of variation (CV) was calculated for each set and averaged. Between-catheter systems (systematic) variability was derived by plotting calibration lines for sets of catheters. Slopes were used to estimate the systematic component. Performances of 3 cardiac output monitors were compared: Siemens SC9000, Siemens Sirecust 1261, and Philips MP50. Five Arrow and 5 Edwards catheters were tested using the Siemens SC9000 monitor. Flow rates between 0.7 and 7.0 L/min were studied. The CV (random error) for Arrow was 5.4% and for Edwards was 4.8%. The random precision error was ± 10.0% (95% confidence limits). CV (systematic error) was 5.8% and 6.0%, respectively. The systematic precision error was ± 11.6%. The total precision error of a single thermodilution reading was ± 15.3% and ± 13.0% for triplicate readings. Precision

Respiratory motion influence on catheter contact force during radio frequency ablation procedures

NASA Astrophysics Data System (ADS)

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

2013-03-01

Minimally invasive catheter ablation is a common treatment option for atrial fibrillation. A common treatment strategy is pulmonary vein isolation. In this case, individual ablation points need to be placed around the ostia of the pulmonary veins attached to the left atrium to generate transmural lesions and thereby block electric signals. To achieve a durable transmural lesion, the tip of the catheter has to be stable with a sufficient tissue contact during radio-frequency ablation. Besides the steerable interface operated by the physician, the movement of the catheter is also influenced by the heart and breathing motion - particularly during ablation. In this paper we investigate the influence of breathing motion on different areas of the endocardium during radio frequency ablation. To this end, we analyze the frequency spectrum of the continuous catheter contact force to identify areas with increased breathing motion using a classification method. This approach has been applied to clinical patient data acquired during three pulmonary vein isolation procedures. Initial findings show that motion due to respiration is more pronounced at the roof and around the right pulmonary veins.

Idiopathic ventricular outflow tract arrhythmias from the great cardiac vein: challenges and risks of catheter ablation.

PubMed

Steven, D; Pott, C; Bittner, A; Sultan, A; Wasmer, K; Hoffmann, B A; Köbe, J; Drewitz, I; Milberg, P; Lueker, J; Mönnig, G; Servatius, H; Willems, S; Eckardt, L

2013-11-20

Catheter ablation for idiopathic ventricular arrhythmia is well established but epicardial origin, proximity to coronary arteries, and limited accessibility may complicate ablation from the venous system in particular from the great cardiac vein (GCV). Between April 2009 and October 2010 14 patients (56 ± 15 years; 9 male) out of a total group of 117 patients with idiopathic outflow tract tachycardias were included undergoing ablation for idiopathic VT or premature ventricular contractions (PVC) originating from GCV. All patients in whom the PVC arose from the GCV were subject to the study. In these patients angiography of the left coronary system was performed with the ablation catheter at the site of earliest activation. Successful ablation was performed in 6/14 (43%) and long-term success was achieved in 5/14 (36%) patients. In 4/14 patients (28.6%) ablation was not performed. In another 4 patients (26.7%), ablation did not abolish the PVC/VT. In the majority, the anatomical proximity to the left coronary system prohibited effective RF application. In 3 patients RF application resulted in a coronary spasm with complete regression as revealed in repeat coronary angiography. A relevant proportion idiopathic VT/PVC can safely be ablated from the GCV without significant permanent coronary artery stenosis after RF application. Our data furthermore demonstrate that damage to the coronary artery system is likely to be transient. © 2013.

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.

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.

Three- and four-dimensional reconstruction of intra-cardiac anatomy from two-dimensional magnetic resonance images.

PubMed

Miquel, M E; Hill, D L G; Baker, E J; Qureshi, S A; Simon, R D B; Keevil, S F; Razavi, R S

2003-06-01

The present study was designed to evaluate the feasibility and clinical usefulness of three-dimensional (3D) reconstruction of intra-cardiac anatomy from a series of two-dimensional (2D) MR images using commercially available software. Sixteen patients (eight with structurally normal hearts but due to have catheter radio-frequency ablation of atrial tachyarrhythmias and eight with atrial septal defects (ASD) due for trans-catheter closure) and two volunteers were imaged at 1T. For each patient, a series of ECG-triggered images (5 mm thick slices, 2-3 mm apart) were acquired during breath holding. Depending on image quality, T1- or T2-weighted spin-echo images or gradient-echo cine images were used. The 3D reconstruction was performed off-line: the blood pools within cardiac chambers and great vessels were semi-automatically segmented, their outer surface was extracted using a marching cube algorithm and rendered. Intra- and inter-observer variability, effect of breath-hold position and differences between pulse sequences were assessed by imaging a volunteer. The 3D reconstructions were assessed by three cardiologists and compared with the 2D MR images and with 2D and 3D trans-esophagal and intra-cardiac echocardiography obtained during interventions. In every case, an anatomically detailed 3D volume was obtained. In the two patients where a 3 mm interval between slices was used, the resolution was not as good but it was still possible to visualize all the major anatomical structures. Spin-echo images lead to reconstructions more detailed than those obtained from gradient-echo images. However, gradient-echo images are easier to segment due to their greater contrast. Furthermore, because images were acquired at least at ten points in the cardiac cycles for every slice it was possible to reconstruct a cine loop and, for example, to visualize the evolution of the size and margins of the ASD during the cardiac cycle. 3D reconstruction proved to be an effective way to

Real-time magnetic resonance-guided ablation of typical right atrial flutter using a combination of active catheter tracking and passive catheter visualization in man: initial results from a consecutive patient series.

PubMed

Hilbert, Sebastian; Sommer, Philipp; Gutberlet, Matthias; Gaspar, Thomas; Foldyna, Borek; Piorkowski, Christopher; Weiss, Steffen; Lloyd, Thomas; Schnackenburg, Bernhard; Krueger, Sascha; Fleiter, Christian; Paetsch, Ingo; Jahnke, Cosima; Hindricks, Gerhard; Grothoff, Matthias

2016-04-01

Recently cardiac magnetic resonance (CMR) imaging has been found feasible for the visualization of the underlying substrate for cardiac arrhythmias as well as for the visualization of cardiac catheters for diagnostic and ablation procedures. Real-time CMR-guided cavotricuspid isthmus ablation was performed in a series of six patients using a combination of active catheter tracking and catheter visualization using real-time MR imaging. Cardiac magnetic resonance utilizing a 1.5 T system was performed in patients under deep propofol sedation. A three-dimensional-whole-heart sequence with navigator technique and a fast automated segmentation algorithm was used for online segmentation of all cardiac chambers, which were thereafter displayed on a dedicated image guidance platform. In three out of six patients complete isthmus block could be achieved in the MR scanner, two of these patients did not need any additional fluoroscopy. In the first patient technical issues called for a completion of the procedure in a conventional laboratory, in another two patients the isthmus was partially blocked by magnetic resonance imaging (MRI)-guided ablation. The mean procedural time for the MR procedure was 109 ± 58 min. The intubation of the CS was performed within a mean time of 2.75 ± 2.21 min. Total fluoroscopy time for completion of the isthmus block ranged from 0 to 7.5 min. The combination of active catheter tracking and passive real-time visualization in CMR-guided electrophysiologic (EP) studies using advanced interventional hardware and software was safe and enabled efficient navigation, mapping, and ablation. These cases demonstrate significant progress in the development of MR-guided EP procedures. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Initial clinical experience of remote magnetic navigation system for catheter mapping and ablation of supraventricular tachycardias.

PubMed

Xu, Dongjie; Yang, Bin; Shan, Qijun; Zou, Jiangang; Chen, Minglong; Chen, Chun; Hou, Xiaofeng; Zhang, Fengxiang; Li, Wen-Qi; Cao, Kejiang; Tse, Hung-Fat

2009-09-01

A remote magnetic navigation system (MNS) has been developed for mapping and catheter ablation of cardiac arrhythmias. The present study evaluates the safety and feasibility of this system to perform radiofrequency (RF) ablation in patients with supraventricular tachycardias (SVT). A total of 32 patients (22 female; mean age 44 +/- 16 years) with documented SVT underwent mapping and ablation using Helios II (a 4-mm-tip magnetic catheter), under the guidance of the MNS (Niobe II, Stereotaxis, Inc.). Catheter ablation procedure with MNS was successful in 30/32 (94%) patients including all patients (27/27, 100%) with atrioventricular nodal reentrant tachycardia (AVNRT) and three of five patients (60%) with atrioventricular reentrant tachycardia (AVRT) without any complication. The procedural successful rate in patients with AVNRT was significantly higher than those in patients with AVRT (P < 0.001). Overall, the medium number of RF application using the MNS was 2 (mean 2.7 +/- 1.6, range 1 to 7), and the medium numbers of RF for AVNRT and AVRT were 2 and 3, respectively. There was no significant difference in the mean procedural time between patients with AVNRT and AVRT (126.3 +/- 38.6 vs. 138.0 +/- 40.3 min, P = 0.54). However, the mean fluoroscopy time was significantly shorter in patients with AVNRT than those with AVRT (5.7 +/- 3.0 vs. 16.5 +/- 2.5 min, P < 0.001). Among those patients with AVNRT, the mean procedural time (139.3 +/- 45.0 vs. 112.3 +/- 24.9 min, P = 0.07) and fluoroscopic time (3.2 +/- 1.0 vs. 8.0 +/- 2.2 min, P < 0.001) were shorter for the later 13 patients than the first 14 patients, suggesting a learning curve in using the MNS for RF ablation. The Niobe MNS is a new technique that can allow safe and effective remote-controlled navigation and minimize the need for fluoroscopic guidance for ablation catheter of AVNRT. However, further improvement is required to achieve a higher successful rate for treatment of AVRT.

Robotic cardiac surgery: an anaesthetic challenge.

PubMed

Wang, Gang; Gao, Changqing

2014-08-01

Robotic cardiac surgery with the da Vinci robotic surgical system offers the benefits of a minimally invasive procedure, including a smaller incision and scar, reduced risk of infection, less pain and trauma, less bleeding and blood transfusion requirements, shorter hospital stay and decreased recovery time. Robotic cardiac surgery includes extracardiac and intracardiac procedures. Extracardiac procedures are often performed on a beating heart. Intracardiac procedures require the aid of peripheral cardiopulmonary bypass via a minithoracotomy. Robotic cardiac surgery, however, poses challenges to the anaesthetist, as the obligatory one-lung ventilation (OLV) and CO2 insufflation may reduce cardiac output and increase pulmonary vascular resistance, potentially resulting in hypoxaemia and haemodynamic compromise. In addition, surgery requires appropriate positioning of specialised cannulae such as an endopulmonary vent, endocoronary sinus catheter, and endoaortic clamp catheter under the guidance of transoesophageal echocardiography. Therefore, cardiac anaesthetists should have a working knowledge of these systems, OLV and haemodynamic support. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Caring for women undergoing cardiac ablation.

PubMed

Keegan, Beryl

2008-09-01

Radiofrequency cardiac ablation (RFCA) has become the treatment of choice for many cardiac arrhythmias that have not responded to medication. Complications of cardiac ablation include bleeding, thrombosis, pericardial tamponade, and stroke. Many complications are procedure specific, and several complications can be avoided with appropriate nursing care. Quality patient outcomes begin with competent nursing care. Therefore it is vital for a patient undergoing a percutaneous cardiac ablation procedure to receive supportive care and pre- and post-interventional patient education. This article discusses the nursing care of women undergoing RFCA.

Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure.

PubMed

See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi-Keong

2016-07-01

The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSiteTM NavXTM or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. Copyright © Singapore Medical Association.

Observation of the efficacy of radiofrequency catheter ablation on patients with different forms of atrial fibrillation.

PubMed

Zhao, R-C; Han, W; Han, J; Yu, J; Guo, J; Fu, J-L; Li, Z; Zhao, R-Z

2016-10-01

To study the efficacy and safety of radiofrequency catheter ablation (RFCA) in patients with different forms of atrial fibrillation. By retrospective analysis, we summarize 720 cases, where patients diagnosed with atrial fibrillation in our hospital were treated with RFCA from February 2010 to October 2014. Among the cases, 425 were diagnosed with paroxysmal atrial fibrillation and 295 with non-paroxysmal atrial fibrillation (including persistent atrial fibrillation and permanent atrial fibrillation). All patients were followed up until June 2015 to compare and analyze the differences in operation success rates, complications and recurrence rates. 395 cases (92.9%) of paroxysmal atrial fibrillation and 253 cases (85.8%) with non-paroxysmal atrial fibrillation were subject to surgery and followed up. The age of onset, disease course, underlying diseases, left atrial diameter and combined anti-arrhythmics of patients with paroxysmal atrial fibrillation were lower than those of patients with non-paroxysmal atrial fibrillation, and the differences were statistically significant (p < 0.05). The success rate of the first ablation was higher than that of non-paroxysmal atrial fibrillation. Procedure time, procedure method, complications and recurrence rate of patients with paroxysmal atrial fibrillation were lower than those of non-paroxysmal atrial fibrillation group, and the differences were statistically significant (p < 0.05). When we compared apoplexy and heart failure caused by atrial fibrillation in the two groups, the difference was not statistically significant (Apoplexy: p = 0.186; Heart failure: p = 0.170). The individual ablation success rate was higher for paroxysmal atrial fibrillation, and long-term follow-up showed that the occurrence of apoplexy and heart failure was not different from the non-paroxysmal atrial fibrillation group.

Catheter ablation as a treatment of atrioventricular block.

PubMed

Tuohy, Stephen; Saliba, Walid; Pai, Manjunath; Tchou, Patrick

2018-01-01

Symptomatic second-degree atrioventricular (AV) block is typically treated by implantation of a pacemaker. An otherwise healthy AV conduction system can nevertheless develop AV block due to interference from junctional extrasystoles. When present with a high burden, these can produce debilitating symptoms from AV block despite an underlying normal AV node and His-Purkinje system properties. The purpose of this study was to describe a catheter ablation approach for alleviating symptomatic AV block due to a ventricular nodal pathway interfering with AV conduction. Common clinical monitoring techniques such as Holter and event recorders were used. Standard electrophysiological study techniques using multipolar recording and ablation catheters were utilized during procedures. A 55-year-old woman presented with highly symptomatic, high-burden second-degree AV block due to concealed and manifest junctional premature beats. Electrophysiological characteristics indicated interference of AV conduction due to a concealed ventricular nodal pathway as the cause of the AV block. The patient's AV nodal and His-Purkinje system conduction characteristics were otherwise normal. Radiofrequency catheter ablation of the pathway was successful in restoring normal AV conduction and eliminating her clinical symptoms. Pathways inserting into the AV junction can interfere with AV conduction. When present at a high burden, this type of AV block can be highly symptomatic. Catheter ablation techniques can be used to alleviate this type of AV block and restore normal AV conduction. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Electrophysiologic and histologic observations of chronic atrioventricular block induced by closed-chest catheter desiccation with radiofrequency energy.

PubMed

Huang, S K; Bharati, S; Lev, M; Marcus, F I

1987-07-01

Direct-current or laser energy has been used to induce atrioventricular (AV) block, but certain complications associated with this type of energy have been reported. We have previously documented that radiofrequency (RF) energy can effectively and safely induce acute AV block in closed-chest dogs during the 4-7 days of follow-up. This study was undertaken to determine if the ablation was permanent and to define the chronic pathology and site of AV block. Complete AV block was successfully achieved in four dogs immediately after ablation with a bipolar "standard" RF output (750 kHz) delivered between the tip electrode of a standard 7F USCI catheter and an external patch electrode on the left lateral chest wall. During 2 months of follow-up, three dogs had persistent complete AV block with a stable escape rhythm; the other had persistent 2:1 AV block. Repeat His bundle recordings were performed at 2 months prior to sacrifice of the dogs. Supra-His AV block was noted in two dogs; His bundle potential could not be recorded in another two. Histologically, the damaged area was well delineated. In all animals, the AV node and, in some dogs, part of the His bundle were completely replaced by granulation tissue and/or cartilage. There was fatty infiltration and also chronic inflammatory cells around the lesions. Neither perforation, hemorrhage nor vacuolation was seen in the adjacent area. Thrombus was not present. It is concluded that RF energy can effectively achieve chronic AV block and produce well-circumscribed pathological lesions.

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.

Optimization of the generator settings for endobiliary radiofrequency ablation.

PubMed

Barret, Maximilien; Leblanc, Sarah; Vienne, Ariane; Rouquette, Alexandre; Beuvon, Frederic; Chaussade, Stanislas; Prat, Frederic

2015-11-10

To determine the optimal generator settings for endobiliary radiofrequency ablation. Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, "effect", and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s). The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater.

Optimization of the generator settings for endobiliary radiofrequency ablation

PubMed Central

Barret, Maximilien; Leblanc, Sarah; Vienne, Ariane; Rouquette, Alexandre; Beuvon, Frederic; Chaussade, Stanislas; Prat, Frederic

2015-01-01

AIM: To determine the optimal generator settings for endobiliary radiofrequency ablation. METHODS: Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, “effect”, and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. RESULTS: Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s). CONCLUSION: The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater. PMID:26566429

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

Percutaneous intrapericardial echocardiography during catheter ablation: a feasibility study.

PubMed

Horowitz, Barbara Natterson; Vaseghi, Marmar; Mahajan, Aman; Cesario, David A; Buch, Eric; Valderrábano, Miguel; Boyle, Noel G; Ellenbogen, Kenneth A; Shivkumar, Kalyanam

2006-11-01

Percutaneous pericardial access, epicardial mapping, and ablation have been used successfully for catheter ablation procedures. The purpose of this study was to evaluate the safety and feasibility of closed-chest direct epicardial ultrasound imaging for aiding cardiac catheter ablation procedures. An intracardiac ultrasound catheter was used for closed-chest epicardial imaging of the heart in 10 patients undergoing percutaneous epicardial access for catheter ablation. All patients underwent concomitant intracardiac echocardiography and preprocedural transesophageal echocardiography. Using a double-wire technique, two sheaths were placed in the pericardium, and a phased-array ultrasound catheter was manipulated within the pericardial sinuses for imaging. Multiple images from varying angles were obtained for catheter navigation. Notably, image stability was excellent, and structures such as the left atrial appendage were seen in great detail. No complications resulting from use of the ultrasound catheter in the pericardium occurred, and no restriction of movement due to the presence of the additional catheter in the pericardial space was observed. Wall motion was correlated to voltage maps in five patients and showed that areas of scars correlated with wall-motion abnormalities. Normal wall-motion score correlated to sensed signals of 4.2 +/- 0.3 mV (normal myocardium >1.5 mV), and scores >1 correlated to areas with signals <0.5 mV in that territory). Intrapericardial imaging using an ultrasound catheter is feasible and safe and has the potential to provide additional valuable information for complex ablation procedures.

The best of two worlds? Pulmonary vein isolation using a novel radiofrequency ablation catheter incorporating contact force sensing technology and 56-hole porous tip irrigation.

PubMed

Maurer, Tilman; Rottner, Laura; Makimoto, Hisaki; Reissmann, Bruno; Heeger, Christian-H; Lemes, Christine; Fink, Thomas; Riedl, Johannes; Santoro, Francesco; Wohlmuth, Peter; Volkmer, Marius; Mathew, Shibu; Metzner, Andreas; Ouyang, Feifan; Kuck, Karl-Heinz; Sohns, Christian

2018-05-08

This study aimed to evaluate feasibility and safety as well as 1-year clinical outcome of pulmonary vein isolation (PVI) using a unique radiofrequency ablation catheter ("Thermocool SmartTouch SurroundFlow"; STSF) incorporating both, contact force (CF) sensing technology and enhanced tip irrigation with 56 holes, in one device. A total of 110 patients suffering from drug-refractory atrial fibrillation underwent wide area circumferential PVI using either the STSF ablation catheter (75 consecutive patients, study group) or a CF catheter with conventional tip irrigation ("Thermocool SmartTouch", 35 consecutive patients, control group). For each ablation lesion, a target CF of ≥ 10-39 g and a force time integral (FTI) of > 400 g s was targeted. Acute PVI was achieved in all patients with target CF obtained in > 85% of ablation points when using either device. Mean procedure time (131.3 ± 33.7 min in the study group vs. 133.0 ± 42.0 min in the control group; p = 0.99), mean fluoroscopy time (14.0 ± 6 vs. 13.5 ± 6.6 min; p = 0.56) and total ablation time were not significantly different (1751.0 ± 394.0 vs. 1604.6 ± 287.8 s; p = 0.2). However, there was a marked reduction in total irrigation fluid delivery by 51.7% (265.52 ± 64.4 vs. 539.6 ± 118.2 ml; p < 0.01). The Kaplan-Meier estimate 12-month arrhythmia-free survival after the index procedure following a 3-month blanking period was 79.9% (95% CI 70.4%, 90.4%) for the study group and 66.7% for the control group (95% CI 50.2%, 88.5%). This finding did not reach statistical significance (p = 0.18). Major complications occurred in 2/75 patients (2.7%; one pericardial tamponade and one transient ischemic attack) in the study group and no patient in the control group (p = 18). PVI using the STSF catheter is safe and effective and results in beneficial 1-year clinical outcome. The improved tip irrigation leads to a significant reduction in

Association of physical examination with pulmonary artery catheter parameters in acute lung injury.

PubMed

Grissom, Colin K; Morris, Alan H; Lanken, Paul N; Ancukiewicz, Marek; Orme, James F; Schoenfeld, David A; Thompson, B Taylor

2009-10-01

To correlate physical examination findings, central venous pressure, fluid output, and central venous oxygen saturation with pulmonary artery catheter parameters. Retrospective study. Data from the multicenter Fluid and Catheter Treatment Trial of the National Institutes of Health Acute Respiratory Distress Syndrome Network. Five hundred thirteen patients with acute lung injury randomized to treatment with a pulmonary artery catheter. Correlation of physical examination findings (capillary refill time >2 secs, knee mottling, or cool extremities), central venous pressure, fluid output, and central venous oxygen saturation with parameters from a pulmonary artery catheter. We determined association of baseline physical examination findings and on-study parameters of central venous pressure and central venous oxygen saturation with cardiac index <2.5 L/min/m2 and mixed venous oxygen saturation <60%. We determined correlation of baseline central venous oxygen saturation and mixed venous oxygen saturation and predictive value of a low central venous oxygen saturation for a low mixed venous oxygen saturation. Prevalence of cardiac index <2.5 and mixed venous oxygen saturation <60% was 8.1% and 15.5%, respectively. Baseline presence of all three physical examination findings had low sensitivity (12% and 8%), high specificity (98% and 99%), low positive predictive value (40% and 56%), but high negative predictive value (93% and 86%) for cardiac index <2.5 and mixed venous oxygen saturation <60%, respectively. Central venous oxygen saturation <70% predicted a mixed venous oxygen saturation <60% with a sensitivity 84%,specificity 70%, positive predictive value 31%, and negative predictive value of 96%. Low cardiac index correlated with cool extremities, high central venous pressure, and low 24-hr fluid output; and low mixed venous oxygen saturation correlated with knee mottling and high central venous pressure, but these correlations were not found to be clinically useful. In

Reversion of left ventricular systolic dysfunction and abnormal stress test: by catheter ablation, in a patient with Wolff-Parkinson-White syndrome from Para-Hisian Kent bundle.

PubMed

Tu, Chung-Ming; Chu, Kai-Ming; Cheng, Cheng-Chung; Cheng, Shu-Mung; Lin, Wei-Shiang

2010-01-01

The diagnosis of Wolff-Parkinson-White syndrome is typically reserved for patients who experience ventricular pre-excitation and symptoms that are related to paroxysmal supraventricular tachycardia, such as chest pain, dyspnea, dizziness, palpitations, or syncope. Herein, we report the case of a 38-year-old woman who presented at our outpatient department because of exercise intolerance. Cardiac auscultation revealed a grade 2/6 pansystolic murmur over the left lower sternal border. Twelve-lead electrocardiography showed sinus rhythm at a rate of 76 beats/min, with a significant delta wave. Transthoracic echocardiography revealed abnormal left ventricular systolic function. The results of a thallium stress test were also abnormal. Coronary artery disease was suspected; however, coronary angiography yielded normal results. Electrophysiologic study revealed a para-Hisian Kent bundle and a dual atrioventricular nodal pathway. After radiofrequency catheter ablation was performed, the patient's left ventricular function improved and her symptoms disappeared. In Wolff-Parkinson-White syndrome, left ventricular systolic dyssynchrony can yield abnormal findings on echocardiography and thallium scanning--even in persons who have no cardiovascular risk factors. Physicians who are armed with this knowledge can avoid performing coronary angiography unnecessarily. Catheter ablation can reverse the dyssynchrony of the ventricle and improve the patient's symptoms.

Evaluation of epidural and peripheral nerve catheter heating during magnetic resonance imaging.

PubMed

Owens, Sean; Erturk, M Arcan; Ouanes, Jean-Pierre P; Murphy, Jamie D; Wu, Christopher L; Bottomley, Paul A

2014-01-01

Many epidural and peripheral nerve catheters contain conducting wire that could heat during magnetic resonance imaging (MRI), requiring removal for scanning. We tested 2 each of 6 brands of regional analgesia catheters (from Arrow International [Reading, Pennsylvania], B. Braun Medical Inc [Bethlehem, Pennsylvania], and Smiths Medical/Portex [Keene, New Hampshire]) for exposure to clinical 1.5- and 3-T MRI. Catheters testing as nonmagnetic were placed in an epidural configuration in a standard human torso-sized phantom, and an MRI pulse sequence applied at the maximum scanner-allowed radiofrequency specific absorption rate (SAR) for 15 minutes. Temperature and SAR exposure were sampled during MRI using multiple fiberoptic temperature sensors. Two catheters (the Arrow StimuCath Peripheral Nerve and B. Braun Medical Perifix FX Epidural) were found to be magnetic and not tested further. At 3 T, exposure of the remaining 3 epidural and 1 peripheral nerve catheter to the scanner's maximum RF exposure elicited anomalous heating of 4°C to 7°C in 2 Arrow Epidural (MultiPort and Flex-Tip Plus) catheters at the entry points. Temperature increases for the other catheters at 3 T, and all catheters at 1.5 T were 1.4°C or less. When normalized to the body-average US Food and Drug Administration guideline SAR of 4 W/kg, maximum projected temperature increases were 0.1°C to 2.5°C at 1.5 T and 0.7°C to 2.7°C at 3 T, except for the Arrow MultiPort Flex-Tip Plus catheter at 3 T whose increase was 14°C. Most but not all catheters can be left in place during 1.5-T MRI scans. Heating of less than 3°C during MRI for most catheters is not expected to be injurious. While heating was lower at 1.5 T versus 3 T, performance differences between products underscore the need for safety testing before performing MRI.

Effect of heparin bonding on catheter-induced fibrin formation and platelet activation.

PubMed

Nichols, A B; Owen, J; Grossman, B A; Marcella, J J; Fleisher, L N; Lee, M M

1984-11-01

Pathologic and experimental evidence indicates that platelet activation and fibrin formation contribute to the pathogenesis of angina pectoris, coronary vasospasm and myocardial infarction. Detection of localized intravascular platelet activation and fibrin formation in vivo by selective blood sampling requires catheters that do not induce coagulation ex vivo. We studied the effect of heparin bonding of catheter surfaces on activation of the coagulation system by cardiovascular catheters. Woven Dacron, polyvinylchloride, and polyurethane catheters were tested and compared with identical catheters with heparin-bonded surfaces in 47 patients undergoing percutaneous cardiac catheterization. Platelet activation was measured by radioimmunoassay of plasma platelet factor 4 (PF4), beta-thromboglobulin (BTG), and thromboxane B2 (TXB2) in blood samples withdrawn through catheters, and fibrin formation was assessed by determination of fibrinopeptide A (FPA) levels. In blood samples collected through conventional catheters, FPA, PF4, BTG, and TXB2 levels were markedly elevated; blood sampling through heparin-bonded catheters had no significant effect on FPA, PF4, BTG, or TXB2 levels. Scanning electron microscopy disclosed extensive platelet aggregates and fibrin strands adherent to the surface of conventional catheters but not to heparin-bonded catheter surfaces. This study demonstrates that (1) collection of blood samples through cardiovascular catheters causes artifactual elevation of FPA, PF4, BTG, and TXB2 levels, and (2) heparin-bonded catheter surfaces effectively prevent catheter-induced platelet alpha-granule release and fibrin formation on catheter surfaces. Heparin-bonded catheters will facilitate investigation of the role of intravascular coagulation in coronary artery disease by eliminating catheter-induced fibrin formation and platelet activation.

Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Majdalany, Bill S., E-mail: bmajdala@med.umich.edu; Elliott, Eric D., E-mail: eric.elliott@osumc.edu; Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu

Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

MEMS-Based Flexible Force Sensor for Tri-Axial Catheter Contact Force Measurement

PubMed Central

Sheng, Jun; Desai, Jaydev P.

2016-01-01

Atrial fibrillation (AFib) is a significant healthcare problem caused by the uneven and rapid discharge of electrical signals from pulmonary veins (PVs). The technique of radiofrequency (RF) ablation can block these abnormal electrical signals by ablating myocardial sleeves inside PVs. Catheter contact force measurement during RF ablation can reduce the rate of AFib recurrence, since it helps to determine effective contact of the catheter with the tissue, thereby resulting in effective power delivery for ablation. This paper presents the development of a three-dimensional (3D) force sensor to provide the real-time measurement of tri-axial catheter contact force. The 3D force sensor consists of a plastic cubic bead and five flexible force sensors. Each flexible force sensor was made of a PEDOT:PSS strain gauge and a PDMS bump on a flexible PDMS substrate. Calibration results show that the fabricated sensor has a linear response in the force range required for RF ablation. To evaluate its working performance, the fabricated sensor was pressed against gelatin tissue by a micromanipulator and also integrated on a catheter tip to test it within deionized water flow. Both experiments simulated the ventricular environment and proved the validity of applying the 3D force sensor in RF ablation. PMID:28190945

Interventional magnetic resonance angiography with no strings attached: wireless active catheter visualization.

PubMed

Quick, Harald H; Zenge, Michael O; Kuehl, Hilmar; Kaiser, Gernot; Aker, Stephanie; Massing, Sandra; Bosk, Silke; Ladd, Mark E

2005-02-01

Active instrument visualization strategies for interventional MR angiography (MRA) require vascular instruments to be equipped with some type of radiofrequency (RF) coil or dipole RF antenna for MR signal detection. Such visualization strategies traditionally necessitate a connection to the scanner with either coaxial cable or laser fibers. In order to eliminate any wire connection, RF resonators that inductively couple their signal to MR surface coils were implemented into catheters to enable wireless active instrument visualization. Instrument background to contrast-to-noise ratio was systematically investigated as a function of the excitation flip angle. Signal coupling between the catheter RF coil and surface RF coils was evaluated qualitatively and quantitatively as a function of the catheter position and orientation with regard to the static magnetic field B0 and to the surface coils. In vivo evaluation of the instruments was performed in interventional MRA procedures on five pigs under MR guidance. Cartesian and projection reconstruction TrueFISP imaging enabled simultaneous visualization of the instruments and vascular morphology in real time. The implementation of RF resonators enabled robust visualization of the catheter curvature to the very tip. Additionally, the active visualization strategy does not require any wire connection to the scanner and thus does not hamper the interventionalist during the course of an intervention.

A 10-Fr ultrasound catheter with integrated micromotor for 4-D intracardiac echocardiography.

PubMed

Lee, Warren; Griffin, Weston; Wildes, Douglas; Buckley, Donald; Topka, Terry; Chodakauskas, Thaddeus; Langer, Mark; Calisti, Serge; Bergstøl, Svein; Malacrida, Jean-Pierre; Lanteri, Frédéric; Maffre, Jennifer; McDaniel, Ben; Shivkumar, Kalyanam; Cummings, Jennifer; Callans, David; Silvestry, Frank; Packer, Douglas

2011-07-01

We developed prototype real-time 3-D intracardiac echocardiography catheters with integrated micromotors, allowing internal oscillation of a low-profile 64-element, 6.2-MHz phased-array transducer in the elevation direction. Components were designed to facilitate rotation of the array, including a low-torque flexible transducer interconnect and miniature fixtures for the transducer and micromotor. The catheter tip prototypes were integrated with two-way deflectable 10-Fr catheters and used in in vivo animal testing at multiple facilities. The 4-D ICE catheters were capable of imaging a 90° azimuth by up to 180° elevation field of view. Volume rates ranged from 1 vol/sec (180° elevation) to approximately 10 vol/sec (60° elevation). We successfully imaged electrophysiology catheters, atrial septal puncture procedures, and detailed cardiac anatomy. The elevation oscillation enabled 3-D visualization of devices and anatomy, providing new clinical information and perspective not possible with current 2-D imaging catheters.

[Catheter ablation of ectopic incessant atrial tachycardia using radiofrequency. Reversion of tachycardiomyopathy].

PubMed

de Paola, A A; Mendonça, A; Balbão, C E; Tavora, M Z; da Silva, R M; Hara, V M; Guiguer Júnior, N; Vattimo, A C; Souza, I A; Portugal, O P

1993-10-01

A 8-year-old female patient with refractory incessant atrial tachycardia, very symptomatic and with left ventricular ejection fraction of 0.25. Electrophysiological study and endocardial mapping localized the site of the origin of atrial tachycardia in the superior right atrium. In this site 2 applications of radiofrequency current (25V, 20 and 50 seconds) resulted in termination of the atrial tachycardia. She was discharged off antiarrhythmic drugs and after 2 months ejection fraction was 0.52. She was completely asymptomatic 6 months after ablation procedure.

Central Venous Catheter Insertion Site and Colonization in Pediatric Cardiac Surgery

ClinicalTrials.gov

2017-11-04

Central Line-associated Bloodstream Infection (CLABSI); Central Venous Catheter Associated Bloodstream Infection; Heart; Surgery, Heart, Functional Disturbance as Result; Congenital Heart Disease; Newborn; Infection

Radiofrequency Guide Wire Recanalization of Venous Occlusions in Patients with Malignant Superior Vena Cava Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Robert M.; David, Elizabeth; Pugash, Robyn A.

Fibrotic central venous occlusions in patients with thoracic malignancy and prior radiotherapy can be impassable with standard catheters and wires, including the trailing or stiff end of a hydrophilic wire. We report two patients with superior vena cava syndrome in whom we successfully utilized a radiofrequency guide wire (PowerWire, Baylis Medical, Montreal, Quebec, Canada) to perforate through the occlusion and recanalize the occluded segment to alleviate symptoms.

The effect of elastic modulus on ablation catheter contact area.

PubMed

Camp, Jon J; Linte, Cristian A; Rettmann, Maryam E; Sun, Deyu; Packer, Douglas L; Robb, Richard A; Holmes, David R

2015-02-21

Cardiac ablation consists of navigating a catheter into the heart and delivering RF energy to electrically isolate tissue regions that generate or propagate arrhythmia. Besides the challenges of accurate and precise targeting of the arrhythmic sites within the beating heart, limited information is currently available to the cardiologist regarding intricate electrode-tissue contact, which directly impacts the quality of produced lesions. Recent advances in ablation catheter design provide intra-procedural estimates of tissue-catheter contact force, but the most direct indicator of lesion quality for any particular energy level and duration is the tissue-catheter contact area, and that is a function of not only force, but catheter pose and material elasticity as well. In this experiment, we have employed real-time ultrasound (US) imaging to determine the complete interaction between the ablation electrode and tissue to accurately estimate contact, which will help to better understand the effect of catheter pose and position relative to the tissue. By simultaneously recording tracked position, force reading and US image of the ablation catheter, the differing material properties of polyvinyl alcohol cryogel [1] phantoms are shown to produce varying amounts of tissue depression and contact area (implying varying lesion quality) for equivalent force readings. We have shown that the elastic modulus significantly affects the surface-contact area between the catheter and tissue at any level of contact force. Thus we provide evidence that a prescribed level of catheter force may not always provide sufficient contact area to produce an effective ablation lesion in the prescribed ablation time.

Closed-chest cardiopulmonary bypass and cardioplegia: basis for less invasive cardiac surgery.

PubMed

Peters, W S; Siegel, L C; Stevens, J H; St Goar, F G; Pompili, M F; Burdon, T A

1997-06-01

We developed a method of closed-chest cardiopulmonary bypass to arrest and protect the heart with cardioplegic solution. This method was used in 54 dogs and the results were retrospectively analyzed. Bypass cannulas were placed in the right femoral vessels. A balloon occlusion catheter was passed via the left femoral artery and positioned in the ascending aorta. A pulmonary artery vent was placed via the jugular vein. In 17 of the dogs retrograde cardioplegia was provided with a percutaneous coronary sinus catheter. Cardiopulmonary bypass time was 111 +/- 27 minutes (mean +/- standard deviation) and cardiac arrest time was 66 +/- 21 minutes. Preoperative cardiac outputs were 2.9 +/- 0.70 L/min and postoperative outputs were 2.9 +/- 0.65 L/min (p = not significant). Twenty-one-French and 23F femoral arterial cannulas that allowed coaxial placement of the ascending aortic balloon catheter were tested in 3 male calves. Line pressures were higher, but not clinically limiting, with the balloon catheter placed coaxially. Adequate cardiopulmonary bypass and cardioplegia can be achieved in the dog without opening the chest, facilitating less invasive cardiac operations. A human clinical trial is in progress.

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.

Perivascular radiofrequency renal denervation lowers blood pressure and ameliorates cardiorenal fibrosis in spontaneously hypertensive rats

PubMed Central

Zhang, Yan; Su, Linan; Zhang, Yunrong; Wang, Qiang; Yang, Dachun; Li, De; Yang, Yongjian; Ma, Shuangtao

2017-01-01

Background Catheter-based renal denervation (RDN) is a promising approach to treat hypertension, but innervation patterns limit the response to endovascular RDN and the post-procedural renal artery narrowing or stenosis questions the endovascular ablation strategy. This study was performed to investigate the anti-hypertensive and target organ protective effects of perivascular RDN in spontaneously hypertensive rats (SHR). Methods SHR and normotensive Wistar-Kyoto (WKY) rats were divided into sham group (n = 10), radiofrequency ablation group (n = 20) in which rats received bilateral perivascular ablation with radiofrequency energy (2 watts), and chemical (10% phenol in 95% ethanol) ablation group (n = 12). The tail-cuff blood pressure was measured before the ablation and on day 14 and day 28 after the procedure. The plasma levels of creatinine, urea nitrogen, and catecholamines, urinary excretion of electrolytes and protein, and myocardial and glomerular fibrosis were analyzed and compared among the groups on day 28 after the procedure. Results We identified that 2-watt is the optimal radiofrequency power for perivascular RDN in rats. Perivascular radiofrequency and chemical ablation achieved roughly comparable blood pressure reduction in SHR but not in WKY on day 14 and day 28 following the procedure. Radiofrequency-mediated ablation substantially destroyed the renal nerves surrounding the renal arteries of both SHR and WKY without damaging the renal arteries and diminished the expression of tyrosine hydroxylase, the enzyme marker for postganglionic sympathetic nerves. Additionally, perivascular radiofrequency ablation also decreased the plasma catecholamines of SHR. Interestingly, both radiofrequency and chemical ablation decreased the myocardial and glomerular fibrosis of SHR, while neither increased the plasma creatinine and blood urea nitrogen nor affected the urinary excretion of electrolytes and protein when compared to sham group. Conclusions Radiofrequency

Perivascular radiofrequency renal denervation lowers blood pressure and ameliorates cardiorenal fibrosis in spontaneously hypertensive rats.

PubMed

Wei, Shujie; Li, Dan; Zhang, Yan; Su, Linan; Zhang, Yunrong; Wang, Qiang; Yang, Dachun; Li, De; Yang, Yongjian; Ma, Shuangtao

2017-01-01

Catheter-based renal denervation (RDN) is a promising approach to treat hypertension, but innervation patterns limit the response to endovascular RDN and the post-procedural renal artery narrowing or stenosis questions the endovascular ablation strategy. This study was performed to investigate the anti-hypertensive and target organ protective effects of perivascular RDN in spontaneously hypertensive rats (SHR). SHR and normotensive Wistar-Kyoto (WKY) rats were divided into sham group (n = 10), radiofrequency ablation group (n = 20) in which rats received bilateral perivascular ablation with radiofrequency energy (2 watts), and chemical (10% phenol in 95% ethanol) ablation group (n = 12). The tail-cuff blood pressure was measured before the ablation and on day 14 and day 28 after the procedure. The plasma levels of creatinine, urea nitrogen, and catecholamines, urinary excretion of electrolytes and protein, and myocardial and glomerular fibrosis were analyzed and compared among the groups on day 28 after the procedure. We identified that 2-watt is the optimal radiofrequency power for perivascular RDN in rats. Perivascular radiofrequency and chemical ablation achieved roughly comparable blood pressure reduction in SHR but not in WKY on day 14 and day 28 following the procedure. Radiofrequency-mediated ablation substantially destroyed the renal nerves surrounding the renal arteries of both SHR and WKY without damaging the renal arteries and diminished the expression of tyrosine hydroxylase, the enzyme marker for postganglionic sympathetic nerves. Additionally, perivascular radiofrequency ablation also decreased the plasma catecholamines of SHR. Interestingly, both radiofrequency and chemical ablation decreased the myocardial and glomerular fibrosis of SHR, while neither increased the plasma creatinine and blood urea nitrogen nor affected the urinary excretion of electrolytes and protein when compared to sham group. Radiofrequency-mediated perivascular RDN may become a

Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins.

PubMed

Moon, K H; Dharmarajah, B; Bootun, R; Lim, C S; Lane, Tra; Moore, H M; Sritharan, K; Davies, A H

2017-07-01

Objective Mechanochemical ablation is a novel technique for ablation of varicose veins utilising a rotating catheter and liquid sclerosant. Mechanochemical ablation and radiofrequency ablation have no reported neurological side-effect but the rotating mechanism of mechanochemical ablation may produce microbubbles. Air emboli have been implicated as a cause of cerebrovascular events during ultrasound-guided foam sclerotherapy and microbubbles in the heart during ultrasound-guided foam sclerotherapy have been demonstrated. This study investigated the presence of microbubbles in the right heart during varicose vein ablation by mechanochemical abaltion and radiofrequency abaltion. Methods Patients undergoing great saphenous vein ablation by mechanochemical abaltion or radiofrequency ablation were recruited. During the ablative procedure, the presence of microbubbles was assessed using transthoracic echocardiogram. Offline blinded image quantification was performed using International Consensus Criteria grading guidelines. Results From 32 recruited patients, 28 data sets were analysed. Eleven underwent mechanochemical abaltion and 17 underwent radiofrequency abaltion. There were no neurological complications. In total, 39% (11/28) of patients had grade 1 or 2 microbubbles detected. Thirty-six percent (4/11) of mechanochemical abaltion patients and 29% (5/17) of radiofrequency ablation patients had microbubbles with no significant difference between the groups ( p=0.8065). Conclusion A comparable prevalence of microbubbles between mechanochemical abaltion and radiofrequency ablation both of which are lower than that previously reported for ultrasound-guided foam sclerotherapy suggests that mechanochemical abaltion may not confer the same risk of neurological events as ultrasound-guided foam sclerotherapy for treatment of varicose veins.

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.

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.

Blood Cultures Drawn From Arterial Catheters Are Reliable for the Detection of Bloodstream Infection in Critically Ill Children.

PubMed

Berger, Itay; Gil Margolis, Merav; Nahum, Elhanan; Dagan, Ovdi; Levy, Itzhak; Kaplan, Eytan; Shostak, Eran; Shmuelov, Esther; Schiller, Ofer; Kadmon, Gili

2018-05-01

Arterial catheters may serve as an additional source for blood cultures in children when peripheral venipuncture is challenging. The aim of the study was to evaluate the accuracy of cultures obtained through indwelling arterial catheters for the diagnosis of bloodstream infections in critically ill pediatric patients. Observational and comparative. General and cardiac ICUs of a tertiary, university-affiliated pediatric medical center. The study group consisted of 138 patients admitted to the general or cardiac PICU in 2014-2015 who met the following criteria: presence of an indwelling arterial catheter and indication for blood culture. Blood was drawn by peripheral venipuncture and through the arterial catheter for each patient and sent for culture (total 276 culture pairs). Two specialists blinded to the blood source evaluated each positive culture to determine if the result represented true bloodstream infection or contamination. The sensitivity, specificity, and positive and negative predictive values of the arterial catheter and peripheral cultures for the diagnosis of bloodstream infection were calculated. Of the 56 positive cultures, 41 (15% of total samples) were considered diagnostic of true bloodstream infection. In the other 15 (5%), the results were attributed to contamination. The rate of false-positive results was higher for arterial catheter than for peripheral venipuncture cultures (4% vs 1.5%) but did not lead to prolonged unnecessary antibiotic treatment. On statistical analysis, arterial catheter blood cultures had high sensitivity (85%) and specificity (95%) for the diagnosis of true bloodstream infection, with comparable performance to peripheral blood cultures. Cultures of arterial catheter-drawn blood are reliable for the detection of bloodstream infection in PICUs.

Lower Hospital Charges and Societal Costs for Catheter Device Closure of Atrial Septal Defects.

PubMed

Sanchez, Jessica N; Seckeler, Michael D

2017-10-01

Atrial septal defects (ASD) are among the most common congenital heart defects. As more ASDs are corrected by interventional catheterization instead of surgery, it is critical to understand the associated clinical and societal costs. The goal of this study was to use a national U.S. database to describe hospital charges and societal costs for surgical and catheter-based (ASD) closure. Retrospective review of hospital discharge data from the Kids' Inpatient Database from January 2010 to December 2012. The database was queried for admissions for <21 years old with ICD-9 procedure codes for surgical (35.51 or 35.61) or catheter (35.52) ASD closure; those with other cardiac conditions and/or additional cardiac procedures were excluded. Age, length of stay (LOS), and hospital charges and lost parental wages (societal costs) were compared between groups using t test or Mann-Whitney U test, as appropriate. Four hundred and eighty-six surgical and 305 catheter ASD closures were identified. LOS, hospital charges, and total societal costs were higher in surgical ASD compared to catheter ASD admissions (3.6 vs. 1.3 days, p < 0.001, $87,465 vs. $64,109, p < 0.001, and $90,000 vs. $64,966, p < 0.001, respectively). In this review of a large national inpatient database, we found that hospital and societal costs for surgical ASD closure are significantly higher than catheter ASD closure in the United States in the current era. Factors that likely contribute to this include longer LOS and longer post-operative recovery. Using "real-world" data, this study demonstrates a substantial cost advantage for catheter ASD closure compared to surgical.

Is Cryoballoon Ablation Preferable to Radiofrequency Ablation for Treatment of Atrial Fibrillation by Pulmonary Vein Isolation? A Meta-Analysis

PubMed Central

Xu, Junxia; Huang, Yingqun; Cai, Hongbin; Qi, Yue; Jia, Nan; Shen, Weifeng; Lin, Jinxiu; Peng, Feng; Niu, Wenquan

2014-01-01

Objective Currently radiofrequency and cryoballoon ablations are the two standard ablation systems used for catheter ablation of atrial fibrillation; however, there is no universal consensus on which ablation is the optimal choice. We therefore sought to undertake a meta-analysis with special emphases on comparing the efficacy and safety between cryoballoon and radiofrequency ablations by synthesizing published clinical trials. Methods and Results Articles were identified by searching the MEDLINE and EMBASE databases before September 2013, by reviewing the bibliographies of eligible reports, and by consulting with experts in this field. Data were extracted independently and in duplicate. There were respectively 469 and 635 patients referred for cryoballoon and radiofrequency ablations from 14 qualified clinical trials. Overall analyses indicated that cryoballoon ablation significantly reduced fluoroscopic time and total procedure time by a weighted mean of 14.13 (95% confidence interval [95% CI]: 2.82 to 25.45; P = 0.014) minutes and 29.65 (95% CI: 8.54 to 50.77; P = 0.006) minutes compared with radiofrequency ablation, respectively, whereas ablation time in cryoballoon ablation was nonsignificantly elongated by a weighted mean of 11.66 (95% CI: −10.71 to 34.04; P = 0.307) minutes. Patients referred for cryoballoon ablation had a high yet nonsignificant success rate of catheter ablation compared with cryoballoon ablation (odds ratio; 95% CI; P: 1.34; 0.53 to 3.36; 0.538), and cryoballoon ablation was also found to be associated with the relatively low risk of having recurrent atrial fibrillation (0.75; 0.3 to 1.88; 0.538) and major complications (0.46; 0.11 to 1.83; 0.269). There was strong evidence of heterogeneity and low probability of publication bias. Conclusion Our findings demonstrate greater improvement in fluoroscopic time and total procedure duration for atrial fibrillation patients referred for cryoballoon ablation than those for

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias

PubMed Central

Yücel, Meryem A.; Steele, Sarah C.; Alexander, Mark E.; Boas, David A.; Borsook, David; Becerra, Lino

2016-01-01

The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia. PMID:27415436

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias.

PubMed

Kussman, Barry D; Aasted, Christopher M; Yücel, Meryem A; Steele, Sarah C; Alexander, Mark E; Boas, David A; Borsook, David; Becerra, Lino

2016-01-01

The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia.

Importance of catheter contact force during irrigated radiofrequency ablation: evaluation in a porcine ex vivo model using a force-sensing catheter.

PubMed

Thiagalingam, Aravinda; D'Avila, Andre; Foley, Lori; Guerrero, J Luis; Lambert, Hendrik; Leo, Giovanni; Ruskin, Jeremy N; Reddy, Vivek Y

2010-07-01

Ablation electrode-tissue contact has been shown to be an important determinant of lesion size and safety during nonirrigated ablation but little data are available during irrigated ablation. We aimed to determine the importance of contact force during irrigated-tip ablation. Freshly excised hearts from 11 male pigs were perfused and superfused using fresh, heparinized, oxygenated swine blood in an ex vivo model. One-minute ablations were placed using one of 3 different power control strategies (impedance control-15 Omega target impedance drop, and 20 W or 30 W fixed power) and 3 different contact forces (2 g, 20 g, and 60 g) to give a grid of 9 ablation groups. The force sensing catheter (Tacticath, Endosense SA) was irrigated at 17 mL/min for all of the ablations. Of a total 101 ablations, no thrombus formation was noted but popping was seen in 17 lesions. The lesion depth and incidence of pops was 5.0 +/- 1.3 mm /0%, 5.0 +/- 1.6 mm /10% and 6.7 +/- 2.5 mm /45% for the 15 Omega, 20 W, and 30 W groups (P < 0.01), respectively, and 4.4 +/- 1.8 mm /3%, 5.8 +/- 1.6 mm /17% and 6.6 +/- 2.0 mm /37% for the 2 g, 20 g, and 60 g groups, respectively (P < 0.01). The impedance drop in the first 5 seconds was significantly correlated to catheter contact force: 9.7 +/- 9.9 Omega, 22.3 +/- 11.0 Omega, and 41.7 +/- 22.1 Omega, respectively, for the 2 g, 20 g, and 60 g groups (Pearson's r = 0.65, P < 0.01). Catheter contact force has an important impact on both ablation lesion size and the incidence of pops.

Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve.

PubMed

Laranjo, Sérgio; Oliveira, Mário; Trigo, Conceição

2015-08-01

Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

Feasibility of real-time MR thermal dose mapping for predicting radiofrequency ablation outcome in the myocardium in vivo.

PubMed

Toupin, Solenn; Bour, Pierre; Lepetit-Coiffé, Matthieu; Ozenne, Valéry; Denis de Senneville, Baudouin; Schneider, Rainer; Vaussy, Alexis; Chaumeil, Arnaud; Cochet, Hubert; Sacher, Frédéric; Jaïs, Pierre; Quesson, Bruno

2017-01-25

Clinical treatment of cardiac arrhythmia by radiofrequency ablation (RFA) currently lacks quantitative and precise visualization of lesion formation in the myocardium during the procedure. This study aims at evaluating thermal dose (TD) imaging obtained from real-time magnetic resonance (MR) thermometry on the heart as a relevant indicator of the thermal lesion extent. MR temperature mapping based on the Proton Resonance Frequency Shift (PRFS) method was performed at 1.5 T on the heart, with 4 to 5 slices acquired per heartbeat. Respiratory motion was compensated using navigator-based slice tracking. Residual in-plane motion and related magnetic susceptibility artifacts were corrected online. The standard deviation of temperature was measured on healthy volunteers (N = 5) in both ventricles. On animals, the MR-compatible catheter was positioned and visualized in the left ventricle (LV) using a bSSFP pulse sequence with active catheter tracking. Twelve MR-guided RFA were performed on three sheep in vivo at various locations in left ventricle (LV). The dimensions of the thermal lesions measured on thermal dose images, on 3D T1-weighted (T1-w) images acquired immediately after the ablation and at gross pathology were correlated. MR thermometry uncertainty was 1.5 °C on average over more than 96% of the pixels covering the left and right ventricles, on each volunteer. On animals, catheter repositioning in the LV with active slice tracking was successfully performed and each ablation could be monitored in real-time by MR thermometry and thermal dosimetry. Thermal lesion dimensions on TD maps were found to be highly correlated with those observed on post-ablation T1-w images (R = 0.87) that also correlated (R = 0.89) with measurements at gross pathology. Quantitative TD mapping from real-time rapid CMR thermometry during catheter-based RFA is feasible. It provides a direct assessment of the lesion extent in the myocardium with precision in the range of one

Toward standardized mapping for left atrial analysis and cardiac ablation guidance

NASA Astrophysics Data System (ADS)

Rettmann, M. E.; Holmes, D. R.; Linte, C. A.; Packer, D. L.; Robb, R. A.

2014-03-01

In catheter-based cardiac ablation, the pulmonary vein ostia are important landmarks for guiding the ablation procedure, and for this reason, have been the focus of many studies quantifying their size, structure, and variability. Analysis of pulmonary vein structure, however, has been limited by the lack of a standardized reference space for population based studies. Standardized maps are important tools for characterizing anatomic variability across subjects with the goal of separating normal inter-subject variability from abnormal variability associated with disease. In this work, we describe a novel technique for computing flat maps of left atrial anatomy in a standardized space. A flat map of left atrial anatomy is created by casting a single ray through the volume and systematically rotating the camera viewpoint to obtain the entire field of view. The technique is validated by assessing preservation of relative surface areas and distances between the original 3D geometry and the flat map geometry. The proposed methodology is demonstrated on 10 subjects which are subsequently combined to form a probabilistic map of anatomic location for each of the pulmonary vein ostia and the boundary of the left atrial appendage. The probabilistic map demonstrates that the location of the inferior ostia have higher variability than the superior ostia and the variability of the left atrial appendage is similar to the superior pulmonary veins. This technique could also have potential application in mapping electrophysiology data, radio-frequency ablation burns, or treatment planning in cardiac ablation therapy.

Near Death Experience from Placement of an Intrathecal Catheter.

PubMed

Padalia, Devang; Jassal, Navdeep; Patel, Sagar

2016-05-01

The management of pain due to cancer is challenging and often requires invasive therapy in addition to medication management. Intrathecal drug delivery is a form of advanced therapy that delivers medication locally in the intrathecal space while reducing systemic side effects associated with high doses of opioids. Although risks associated with intrathecal drug delivery are low, some common complications include dislodgement, kinking, or fracture of the catheter, bleeding, neurological injury, infection, and cerebrospinal leaks. We present a case of a 38-year-old woman with a medical history significant for stage IV breast cancer, L2 metastatic lesion, opioid tolerance, and chronic neck and low back pain who was admitted to the hospital for intractable pain. She had failed multiple interventional procedures in the past including lumbar medial nerve radiofrequency ablation, epidural steroid injection, and trigger point injections as well as a kyphoplasty at the L2 level. Failing both oral and parenteral opioid treatments, the decision was made to place an intrathecal pump in the patient. After placement of the intrathecal catheter and prior to any bolus of medication being given, the patient became bradycardic with a heart rate in the 20s and experienced a 10 second pause. The patient had intermittent bradycardia over the following days and symptoms resolved only after removal of the intrathecal catheter itself. To our knowledge, this is the first reported case with a complication of recurrent bradycardic and asystolic episodes prior to the administration of intrathecal opioid but shortly after placement of the intrathecal catheter itself. Intrathecal drug delivery, complications, cancer pain, intrathecal analgesia, bradycardia, opioids.

Discriminating Tissue Stiffness with a Haptic Catheter: Feeling the Inside of the Beating Heart.

PubMed

Kesner, Samuel B; Howe, Robert D

2011-01-01

Catheter devices allow physicians to access the inside of the human body easily and painlessly through natural orifices and vessels. Although catheters allow for the delivery of fluids and drugs, the deployment of devices, and the acquisition of the measurements, they do not allow clinicians to assess the physical properties of tissue inside the body due to the tissue motion and transmission limitations of the catheter devices, including compliance, friction, and backlash. The goal of this research is to increase the tactile information available to physicians during catheter procedures by providing haptic feedback during palpation procedures. To accomplish this goal, we have developed the first motion compensated actuated catheter system that enables haptic perception of fast moving tissue structures. The actuated catheter is instrumented with a distal tip force sensor and a force feedback interface that allows users to adjust the position of the catheter while experiencing the forces on the catheter tip. The efficacy of this device and interface is evaluated through a psychophyisical study comparing how accurately users can differentiate various materials attached to a cardiac motion simulator using the haptic device and a conventional manual catheter. The results demonstrate that haptics improves a user's ability to differentiate material properties and decreases the total number of errors by 50% over the manual catheter system.

Discriminating Tissue Stiffness with a Haptic Catheter: Feeling the Inside of the Beating Heart

PubMed Central

Kesner, Samuel B.; Howe, Robert D.

2011-01-01

Catheter devices allow physicians to access the inside of the human body easily and painlessly through natural orifices and vessels. Although catheters allow for the delivery of fluids and drugs, the deployment of devices, and the acquisition of the measurements, they do not allow clinicians to assess the physical properties of tissue inside the body due to the tissue motion and transmission limitations of the catheter devices, including compliance, friction, and backlash. The goal of this research is to increase the tactile information available to physicians during catheter procedures by providing haptic feedback during palpation procedures. To accomplish this goal, we have developed the first motion compensated actuated catheter system that enables haptic perception of fast moving tissue structures. The actuated catheter is instrumented with a distal tip force sensor and a force feedback interface that allows users to adjust the position of the catheter while experiencing the forces on the catheter tip. The efficacy of this device and interface is evaluated through a psychophyisical study comparing how accurately users can differentiate various materials attached to a cardiac motion simulator using the haptic device and a conventional manual catheter. The results demonstrate that haptics improves a user's ability to differentiate material properties and decreases the total number of errors by 50% over the manual catheter system. PMID:25285321

[Rhythm disorders and cardiac crypto-malformations].

PubMed

Davy, J M; Raczka, F; Cung, T T; Combes, N; Bortone, A; Gaty, D

2005-12-01

Faced with a cardiac arrhythmia occuring in an apparently healthy heart, it is necessary to perform an anatomical investigation to detect any unsuspected anomalies. Congenital cardiopathy must certainly be excluded, as this is often responsible for rhythm disorders and/or cardiac conduction defects. Similarly, any acquired conditions, cardiomyopathy, or cardiac tumour must be sought. However, the possibility should always be considered of a minimal congenital malformation, which could be repsonsible for: any type of cardiac arrhythmia: rhythm disorder or conduction defect at the atrial, junctional or ventricular level, with a benign or serious prognosis. Unexpected therapeutic difficulties during radiofrequency ablation procedures or at implantation of pacemakers or defibrillators. Together with rhythm studies, the investigation of choice is high quality imaging, either the classic left or right angiography or the more modern cardiac CT or intracardiac mapping.

Dialysis catheter associated cardiac tamponade: quick diagnosis by extemporaneous echocardiography.

PubMed

Ervo, R; Angeletti, S; Turrini Dertenois, L; Cavatorta, F

2008-01-01

We report a case of pericardial tamponade associated with over the wire exchange of a central venous catheter (CVC) for hemodialysis (HD). The complication was quickly diagnosed due to an extemporaneous echocardiogram with a linear probe, before other laboratory and radiologic tests could detect it. The described approach allowed a suitable therapy with a positive result.

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.

First In Vivo Use of a Capacitive Micromachined Ultrasound Transducer Array–Based Imaging and Ablation Catheter

PubMed Central

Stephens, Douglas N.; Truong, Uyen T.; Nikoozadeh, Amin; Oralkan, Ömer; Seo, Chi Hyung; Cannata, Jonathan; Dentinger, Aaron; Thomenius, Kai; de la Rama, Alan; Nguyen, Tho; Lin, Feng; Khuri-Yakub, Pierre; Mahajan, Aman; Shivkumar, Kalyanam; O’Donnell, Matt; Sahn, David J.

2012-01-01

Objectives The primary objective was to test in vivo for the first time the general operation of a new multifunctional intracardiac echocardiography (ICE) catheter constructed with a microlinear capacitive micromachined ultrasound transducer (ML-CMUT) imaging array. Secondarily, we examined the compatibility of this catheter with electroanatomic mapping (EAM) guidance and also as a radiofrequency ablation (RFA) catheter. Preliminary thermal strain imaging (TSI)-derived temperature data were obtained from within the endocardium simultaneously during RFA to show the feasibility of direct ablation guidance procedures. Methods The new 9F forward-looking ICE catheter was constructed with 3 complementary technologies: a CMUT imaging array with a custom electronic array buffer, catheter surface electrodes for EAM guidance, and a special ablation tip, that permits simultaneous TSI and RFA. In vivo imaging studies of 5 anesthetized porcine models with 5 CMUT catheters were performed. Results The ML-CMUT ICE catheter provided high-resolution real-time wideband 2-dimensional (2D) images at greater than 8 MHz and is capable of both RFA and EAM guidance. Although the 24-element array aperture dimension is only 1.5 mm, the imaging depth of penetration is greater than 30 mm. The specially designed ultrasound-compatible metalized plastic tip allowed simultaneous imaging during ablation and direct acquisition of TSI data for tissue ablation temperatures. Postprocessing analysis showed a first-order correlation between TSI and temperature, permitting early development temperature-time relationships at specific myocardial ablation sites. Conclusions Multifunctional forward-looking ML-CMUT ICE catheters, with simultaneous intracardiac guidance, ultrasound imaging, and RFA, may offer a new means to improve interventional ablation procedures. PMID:22298868

Efficacy comparison between cryoablation and radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter: a meta-analysis

NASA Astrophysics Data System (ADS)

Chen, Yi-He; Lin, Hui; Xie, Cheng-Long; Zhang, Xiao-Ting; Li, Yi-Gang

2015-06-01

We perform this meta-analysis to compare the efficacy and safety of cryoablation versus radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter. By searching EMBASE, MEDLINE, PubMed and Cochrane electronic databases from March 1986 to September 2014, 7 randomized clinical trials were included. Acute (risk ratio[RR]: 0.93; P = 0.14) and long-term (RR: 0.94; P = 0.08) success rate were slightly lower in cryoablation group than in radiofrequency ablation group, but the difference was not statistically significant. Additionally, the fluoroscopy time was nonsignificantly reduced (weighted mean difference[WMD]: -2.83 P = 0.29), whereas procedure time was significantly longer (WMD: 25.95; P = 0.01) in cryoablation group compared with radiofrequency ablation group. Furthermore, Pain perception during the catheter ablation was substantially less in cryoabaltion group than in radiofrequency ablation group (standardized mean difference[SMD]: -2.36 P < 0.00001). Thus, our meta-analysis demonstrated that cryoablation and radiofrequency ablation produce comparable acute and long-term success rate for patients with cavotricuspid valve isthmus dependent atrial flutter. Meanwhile, cryoablation ablation tends to reduce the fluoroscopy time and significantly reduce pain perception in cost of significantly prolonged procedure time.

Efficacy comparison between cryoablation and radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter: a meta-analysis

PubMed Central

Chen, Yi-He; Lin, Hui; Xie, Cheng-Long; Zhang, Xiao-Ting; Li, Yi-Gang

2015-01-01

We perform this meta-analysis to compare the efficacy and safety of cryoablation versus radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter. By searching EMBASE, MEDLINE, PubMed and Cochrane electronic databases from March 1986 to September 2014, 7 randomized clinical trials were included. Acute (risk ratio[RR]: 0.93; P = 0.14) and long-term (RR: 0.94; P = 0.08) success rate were slightly lower in cryoablation group than in radiofrequency ablation group, but the difference was not statistically significant. Additionally, the fluoroscopy time was nonsignificantly reduced (weighted mean difference[WMD]: −2.83; P = 0.29), whereas procedure time was significantly longer (WMD: 25.95; P = 0.01) in cryoablation group compared with radiofrequency ablation group. Furthermore, Pain perception during the catheter ablation was substantially less in cryoabaltion group than in radiofrequency ablation group (standardized mean difference[SMD]: −2.36; P < 0.00001). Thus, our meta-analysis demonstrated that cryoablation and radiofrequency ablation produce comparable acute and long-term success rate for patients with cavotricuspid valve isthmus dependent atrial flutter. Meanwhile, cryoablation ablation tends to reduce the fluoroscopy time and significantly reduce pain perception in cost of significantly prolonged procedure time. PMID:26039980

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

Radiofrequency ablation for benign thyroid nodules.

PubMed

Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

2016-09-01

Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

Catheter-based renal denervation for treatment of resistant hypertension

PubMed Central

Hatipoglu, Emine; Ferro, Albert

2013-01-01

Hypertension is a common disease associated with important cardiovascular complications. Persistent blood pressure of 140/90 or higher despite combined use of a reninangiotensin system blocker, calcium channel blocker and a diuretic at highest tolerated doses constitutes resistant hypertension. Excess sympathetic activity plays an important pathogenic role in resistant hypertension in addition to contributing to the development of metabolic problems, in particular diabetes. Reduction of renal sympathetic activity by percutaneous catheter-based radiofrequency ablation via the renal arteries has been shown in several studies to decrease blood pressure in patients with resistant hypertension, and importantly is largely free of significant complications. However, longer term follow-up is required to confirm both long-term safety and efficacy. PMID:24175081

Isolated Disruption of the Right Coronary Artery Following a Steam Pop during Cavotricuspid Linear Ablation with a Contact Force Catheter.

PubMed

Brunelli, Michele; Frommhold, Markus; Back, Dieter; Mierzwa, Marco; Lauer, Bernard; Geller, J Christoph

2016-07-01

A 70-year-old woman with persistent atrial fibrillation underwent pulmonary vein isolation and linear ablation with a contact sensor catheter. During cavotricuspid isthmus ablation, a steam pop resulted in cardiac tamponade, and the patient developed severe hypotension despite successful pericardial puncture and minimal residual pericardial effusion. Right coronary artery angiography revealed extravasal contrast medium accumulation posterior of the Crux Cordis. Emergent cardiac surgery confirmed isolated disruption of the artery in the absence of additional heart perforation. Although contact sensor catheters may reduce complications, steam pops can still occur and result in dramatic complications. © 2016 Wiley Periodicals, Inc.

The biophysics of renal sympathetic denervation using radiofrequency energy.

PubMed

Patel, Hitesh C; Dhillon, Paramdeep S; Mahfoud, Felix; Lindsay, Alistair C; Hayward, Carl; Ernst, Sabine; Lyon, Alexander R; Rosen, Stuart D; di Mario, Carlo

2014-05-01

Renal sympathetic denervation is currently performed in the treatment of resistant hypertension by interventionists who otherwise do not typically use radiofrequency (RF) energy ablation in their clinical practice. Adequate RF lesion formation is dependent upon good electrode-tissue contact, power delivery, electrode-tissue interface temperature, target-tissue impedance and the size of the catheter's active electrode. There is significant interplay between these variables and hence an appreciation of the biophysical determinants of RF lesion formation is required to provide effective and safe clinical care to our patients. In this review article, we summarize the biophysics of RF ablation and explain why and how complications of renal sympathetic denervation may occur and discuss methods to minimise them.

Accuracy of chest radiography for positioning of the umbilical venous catheter.

PubMed

Guimarães, Adriana F M; Souza, Aline A C G de; Bouzada, Maria Cândida F; Meira, Zilda M A

To evaluate the accuracy of the simultaneous analysis of three radiographic anatomical landmarks - diaphragm, cardiac silhouette, and vertebral bodies - in determining the position of the umbilical venous catheter distal end using echocardiography as a reference standard. This was a cross-sectional, observational study, with the prospective inclusion of data from all neonates born in a public reference hospital, between April 2012 and September 2013, submitted to umbilical venous catheter insertion as part of their medical care. The position of the catheter distal end, determined by the simultaneous analysis of three radiographic anatomical landmarks, was compared with the anatomical position obtained by echocardiography; sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Of the 162 newborns assessed by echocardiography, only 44 (27.16%) had the catheter in optimal position, in the thoracic portion of the inferior vena cava or at the junction of the inferior vena cava with the right atrium. The catheters were located in the left atrium and interatrial septum in 54 (33.33%) newborns, in the right atrium in 26 (16.05%), intra-hepatic in 37 (22.84%), and intra-aortic in-one newborn (0.62%). The sensitivity, specificity and accuracy of the radiography to detect the catheter in the target area were 56%, 71%, and 67.28%, respectively. Anteroposterior radiography of the chest alone is not able to safely define the umbilical venous catheter position. Echocardiography allows direct visualization of the catheter tip in relation to vascular structures and, whenever possible, should be considered to identify the location of the umbilical venous catheter. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Pulmonary vein stenosis following catheter ablation of atrial fibrillation.

PubMed

Pürerfellner, Helmut; Martinek, Martin

2005-11-01

This review provides an update on the mechanisms, incidence, and current management of significant pulmonary vein stenosis following catheter ablation of atrial fibrillation. Catheter ablation involving the pulmonary veins and the surrounding left atrial tissue is increasingly used to treat atrial fibrillation. In parallel with the fact that these procedures may cure a substantial proportion of patients, severe complications have been observed. Pulmonary vein stenosis is a new clinical entity produced by radiofrequency energy delivery mainly within or at the orifice of the pulmonary veins. The exact incidence is currently unknown because the diagnosis is dependent on the imaging modality and on the rigor with which patients are followed up. The optimal method for screening patients has not been determined. Stenosis of a pulmonary vein may be assessed by combining anatomic and functional imaging using computed tomographic or magnetic resonance imaging, transesophageal echocardiography, and lung scanning. Symptoms vary considerably and may be misdiagnosed, leading to severe clinical consequences. Current treatment strategies involve pulmonary vein dilatation or stenting; however, the restenosis rate remains high. The long-term outcome in patients with pulmonary vein stenosis is unclear. Strategies under development to prevent pulmonary vein stenosis include alternate energy sources and modified ablation techniques. Pulmonary vein stenosis following catheter ablation is a new clinical entity that has been described in various reports recently. There is much uncertainty with respect to causative factors, incidence, diagnosis, and treatment, and long-term sequelae are unclear.

Re-entry using anatomically determined isthmuses: a curable ventricular tachycardia in repaired congenital heart disease.

PubMed

Kapel, Gijsbert F L; Reichlin, Tobias; Wijnmaalen, Adrianus P; Piers, Sebastiaan R D; Holman, Eduard R; Tedrow, Usha B; Schalij, Martin J; Stevenson, William G; Zeppenfeld, Katja

2015-02-01

Ventricular tachycardia (VT) is an important cause of late morbidity and mortality in repaired congenital heart disease. The substrate often includes anatomic isthmuses that can be transected by radiofrequency catheter ablation similar to isthmus block for atrial flutter. This study evaluates the long-term efficacy of isthmus block for treatment of re-entry VT in adults with repaired congenital heart disease. Thirty-four patients (49±13 years; 74% male) with repaired congenital heart disease who underwent radiofrequency catheter ablation of VT in 2 centers were included. Twenty-two (65%) had a preserved left and right ventricular function. Patients were inducible for 1 (interquartile range, 1-2) VT, median cycle length: 295 ms (interquartile range, 242-346). Ablation aimed to transect anatomic isthmuses containing VT re-entry circuit isthmuses. Procedural success was defined as noninducibility of any VT and transection of the anatomic isthmus and was achieved in 25 (74%) patients. During long-term follow-up (46±29 months), all patients with procedural success (18/25 with internal cardiac defibrillators) were free of VT recurrence but 7 of 18 experienced internal cardiac defibrillator-related complications. One patient with procedural success and depressed cardiac function received an internal cardiac defibrillator shock for ventricular fibrillation. None of the 18 patients (12/18 with internal cardiac defibrillators) with complete success and preserved cardiac function experienced any ventricular arrhythmia. In contrast, VT recurred in 4 of 9 patients without procedural success. Four patients died from nonarrhythmic causes. In patients with repaired congenital heart disease with preserved ventricular function and isthmus-dependent re-entry, VT isthmus ablation can be curative. © 2014 American Heart Association, Inc.

Contact force with magnetic-guided catheter ablation.

PubMed

Bessière, Francis; Zikry, Christopher; Rivard, Lena; Dyrda, Katia; Khairy, Paul

2018-05-01

Achieving adequate catheter tip-tissue contact is essential for delivering robust radiofrequency (RF) ablation lesions. We measured the contact force generated by a remote magnetic-guided catheter navigation system. A plexiglass model with an integrated scale was fashioned to mimic transvenous and retrograde access to sites in the right atrium and right and left ventricles. An 8 Fr RF ablation catheter was steered by remote magnetic guidance at fields of 0.08 and 0.10 T, with and without a long sheath positioned at the entrance of the chamber. Ten contact force readings were taken at each setting, with the scale recalibrated prior to each measurement. Generalized estimating equations were used to compare contact force measurements while adjusting for the non-independent data structure. A total of 240 contact force measurements were taken. Without a long sheath, contact forces with magnetic fields of 0.10 T (n = 60) and 0.08 T (n = 60) were similar (6.1 ± 1.4 g vs. 6.0 ± 1.3 g, P = 0.089). Contact forces were not significantly different with simulated transvenous (n = 80) and retrograde aortic (n = 40) approaches (6.2 ± 1.4 g vs. 5.7 ± 1.2 g, P = 0.132). The contact force increased substantially with a long sheath (P < 0.001) and was significantly higher with 0.10 T (n = 60) vs. 0.08 T (n = 60) fields (20.4 ± 0.6 g vs. 18.0 ± 0.5 g, P < 0.001). Magnetic fields of 0.08 and 0.10 T provide stable catheter contact forces, as reflected by the small variability between measurements. The average contact force is approximately 6 g without a sheath and increases to 20 g with a long sheath positioned at the entrance of the chamber of interest.

Urinary catheters

MedlinePlus

... drainage bag. The condom catheter must be changed every day. INTERMITTENT CATHETERS You would use an intermittent catheter ... and the catheter itself with soap and water every day. Also clean the area after every bowel movement ...

[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.

Hydrophilic Catheters

PubMed Central

2006-01-01

Executive Summary Objective To review the evidence on the effectiveness of hydrophilic catheters for patients requiring intermittent catheterization. Clinical Need There are various reasons why a person would require catheterization, including surgery, urinary retention due to enlargement of the prostate, spinal cord injuries, or other physical disabilities. Urethral catheters are the most prevalent cause of nosocomial urinary tract infections, that is, those that start or occur in a hospital. A urinary tract infection (UTI) occurs when bacteria adheres to the opening of the urethra. Most infections arise from Escherichia coli, from the colon. The bacteria spread into the bladder, resulting in the development of an infection. The prevalence of UTIs varies with age and sex. There is a tenfold increase in incidence for females compared with males in childhood and throughout adult life until around 55 years, when the incidence of UTIs in men and women is equal, mostly as a consequence of prostatic problems in men. Investigators have reported that urethritis (inflammation of the urethra) is found in 2% to 19% of patients practising intermittent catheterization. The Technology Hydrophilic catheters have a polymer coating that binds o the surface of the catheter. When the polymer coating is submersed in water, it absorbs and binds the water to the catheter. The catheter surface becomes smooth and very slippery. This slippery surface remains intact upon insertion into the urethra and maintains lubrication through the length of the urethra. The hydrophilic coating is designed to reduce the friction, as the catheter is inserted with the intention of reducing the risk of urethral damage. It has been suggested that because the hydrophilic catheters do not require manual lubrication they are more sterile and thus less likely to cause infection. Most hydrophilic catheters are prepackaged in sterile water, or there is a pouch of sterile water that is broken and released into the

Voltage-based device tracking in a 1.5 Tesla MRI during imaging: initial validation in swine models.

PubMed

Schmidt, Ehud J; Tse, Zion T H; Reichlin, Tobias R; Michaud, Gregory F; Watkins, Ronald D; Butts-Pauly, Kim; Kwong, Raymond Y; Stevenson, William; Schweitzer, Jeffrey; Byrd, Israel; Dumoulin, Charles L

2014-03-01

Voltage-based device-tracking (VDT) systems are commonly used for tracking invasive devices in electrophysiological cardiac-arrhythmia therapy. During electrophysiological procedures, electro-anatomic mapping workstations provide guidance by integrating VDT location and intracardiac electrocardiogram information with X-ray, computerized tomography, ultrasound, and MR images. MR assists navigation, mapping, and radiofrequency ablation. Multimodality interventions require multiple patient transfers between an MRI and the X-ray/ultrasound electrophysiological suite, increasing the likelihood of patient-motion and image misregistration. An MRI-compatible VDT system may increase efficiency, as there is currently no single method to track devices both inside and outside the MRI scanner. An MRI-compatible VDT system was constructed by modifying a commercial system. Hardware was added to reduce MRI gradient-ramp and radiofrequency unblanking pulse interference. VDT patches and cables were modified to reduce heating. Five swine cardiac VDT electro-anatomic mapping interventions were performed, navigating inside and thereafter outside the MRI. Three-catheter VDT interventions were performed at >12 frames per second both inside and outside the MRI scanner with <3 mm error. Catheters were followed on VDT- and MRI-derived maps. Simultaneous VDT and imaging was possible in repetition time >32 ms sequences with <0.5 mm errors, and <5% MRI signal-to-noise ratio (SNR) loss. At shorter repetition times, only intracardiac electrocardiogram was reliable. Radiofrequency heating was <1.5°C. An MRI-compatible VDT system is feasible. Copyright © 2013 Wiley Periodicals, Inc.

Can a new antiseptic agent reduce the bacterial colonization rate of central venous lines in post-cardiac surgery patients?

PubMed

Yousefshahi, Fardin; Azimpour, Khashayar; Boroumand, Mohammad Ali; Najafi, Mahdi; Barkhordari, Khosro; Vaezi, Mitra; Rouhipour, Nahid

2013-04-01

Central venous (CV) catheters play an essential role in the management of critically ill patients in the Intensive Care Unit (ICU). CV lines are, however, allied to catheter-associated blood stream infections. Bacterial colonization of CV lines is deemed the main cause of catheter-associated infection. The purpose of our study was to compare bacterial colony counts in the catheter site before CV line insertion in two groups of post-cardiac surgery patients: a group receiving Sanosil (an antiseptic agent composed of H2O2 and silver) and a control group. This interventional prospective double-blinded clinical trial recruited the patients in three post-cardiac surgery ICUs of a heart center. The participants were divided into interventional (113 patients) and control (136 patients) groups. Sanosil was added to the routine preparation procedure (Chlorhexidine bath one day before and scrub with Povidone-Iodine just before the CV line insertion). After the removal of the CV lines, the catheters tips were sent for culture and evaluation of colony counts. Catheter colonization occurred in 55 (22.1%) patients: 26 (23%) patients in the Sanosil group and 29 (21.3%) in the control group; there was no significant statistical difference between the two groups (p value = 0.75, RR = 1.05, 95% CI: 0.76-1.45). The most common organism having colonized in the cultures of the catheter tips was staphylococcus epidermis: 20 cases in the control group and 16 cases in the intervention group. Catheter colonization frequently occurs in post-cardiac surgery patients. However, our results did not indicate the effectiveness of adding Sanosil to the routine preparation procedure with respect to reducing catheter bacterial colonization.

An Intelligent Catheter System Robotic Controlled Catheter System

PubMed Central

Negoro, M.; Tanimoto, M.; Arai, F.; Fukuda, T.; Fukasaku, K.; Takahashi, I.; Miyachi, S.

2001-01-01

Summary We have developed a novel catheter system, an intelligent catheter system, which is able to control a catheter by an externally-placed controller. This system has made from master-slave mechanism and has following three components; 1) a joy stick as a master (for operators) 2)a catheter controller as a slave (for a patient),3)a micro force sensor as a sensing device. This catheter tele-guiding system has abilities to perform intravascular procedures from the distant places. It may help to reduce the radiation exposures to the operators and also to help train young doctors. PMID:20663387

Renal denervation using catheter-based radiofrequency ablation with temperature control: renovascular safety profile and underlying mechanisms in a hypertensive canine model.

PubMed

Li, Huijie; Yu, Hang; Zeng, Chunyu; Fang, Yuqiang; He, Duofen; Zhang, Xiaoqun; Wen, Chunlan; Yang, Chengming

2015-01-01

Renal denervation is a novel method for hypertension treatment. In this study, we aimed to investigate the safety and efficacy of radiofrequency ablation (RFA) at ablation temperatures of 45 °C or 50 °C and its possible mechanisms. A hypertensive canine model was established by abdominal aortic constriction in 20 healthy hybrid dogs. These dogs were then randomly assigned to the treatment and the control groups, with dogs in the treatment group further randomly assigned to receive RFA at ablation temperatures of 45 °C or 50 °C. In the treatment group, RFA was performed at 1 month after modeling; renal angiography was performed at 2 months after ablation. The arterial vessels of the dogs were examined histologically with hematoxylin and eosin staining. Changes in blood pressure in the foreleg and whole-body norepinephrine spillover rate were also assessed. No arterial stenosis, dissection, thrombosis or other abnormalities were detected in the treated vessels by renal angiography, yet histology results showed minimal to mild renal arterial injury. Renal denervation resulted in a marked decrease in the whole-body norepinephrine spillover rate (p < 0.05) in addition to significantly reducing blood pressure (p < 0.05), with no significant differences detected between the 45 °C and 50 °C subgroups for both (p > 0.05). Renal denervation can be performed without acute major adverse events, using catheter-based RFA with temperature control. The procedure was feasible in reducing blood pressure by at least partially inhibiting sympathetic drive and systemic sympathetic outflow.

The pulmonary artery catheter: a critical reappraisal.

PubMed

Gidwani, Umesh K; Mohanty, Bibhu; Chatterjee, Kanu

2013-11-01

Balloon floatation pulmonary artery catheters (PACs) have been used for hemodynamic monitoring in cardiac, medical, and surgical intensive care units since the 1970s. With the availability of newer noninvasive diagnostic modalities, particularly echocardiography, the frequency of diagnostic pulmonary artery catheterization has declined. In this review, the evolution of PACs, the results of nonrandomized and randomized studies in various clinical conditions, the uses and abuses of bedside hemodynamic monitoring, and current indications for pulmonary artery catheterization are discussed. Copyright © 2013 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.

Reducing catheter-associated urinary tract infections: a quality-improvement initiative.

PubMed

Davis, Katherine Finn; Colebaugh, Ann M; Eithun, Benjamin L; Klieger, Sarah B; Meredith, Dennis J; Plachter, Natalie; Sammons, Julia Shaklee; Thompson, Allison; Coffin, Susan E

2014-09-01

Catheter-associated urinary tract infections (CAUTIs) are among the most common health care-associated infections in the United States, yet little is known about the prevention and epidemiology of pediatric CAUTIs. An observational study was conducted to assess the impact of a CAUTI quality improvement prevention bundle that included institution-wide standardization of and training on urinary catheter insertion and maintenance practices, daily review of catheter necessity, and rapid review of all CAUTIs. Poisson regression was used to determine the impact of the bundle on CAUTI rates. A retrospective cohort study was performed to describe the epidemiology of incident pediatric CAUTIs at a tertiary care children's hospital over a 3-year period (June 2009 to June 2012). Implementation of the CAUTI prevention bundle was associated with a 50% reduction in the mean monthly CAUTI rate (95% confidence interval: -1.28 to -0.12; P = .02) from 5.41 to 2.49 per 1000 catheter-days. The median monthly catheter utilization ratio remained unchanged; ∼90% of patients had an indication for urinary catheterization. Forty-four patients experienced 57 CAUTIs over the study period. Most patients with CAUTIs were female (75%), received care in the pediatric or cardiac ICUs (70%), and had at least 1 complex chronic condition (98%). Nearly 90% of patients who developed a CAUTI had a recognized indication for initial catheter placement. CAUTI is a common pediatric health care-associated infection. Implementation of a prevention bundle can significantly reduce CAUTI rates in children. Copyright © 2014 by the American Academy of Pediatrics.

Radiofrequency wire for the recanalization of central vein occlusions that have failed conventional endovascular techniques.

PubMed

Guimaraes, Marcelo; Schonholz, Claudio; Hannegan, Christopher; Anderson, Michael Bret; Shi, June; Selby, Bayne

2012-08-01

To report the technique and acute technical results associated with the PowerWire Radiofrequency (RF) Guidewire used to recanalize central vein occlusions (CVOs) after the failure of conventional endovascular techniques. A retrospective study was conducted from January 2008 to December 2011, which identified all patients with CVOs who underwent treatment with a novel RF guide wire. Forty-two symptomatic patients (with swollen arm or superior vena cava [SVC] syndrome) underwent RF wire recanalization of 43 CVOs, which were then implanted with stents. The distribution of CVOs in central veins was as follows: six subclavian, 29 brachiocephalic, and eight SVC. All patients had a history of central venous catheter placement. Patients were monitored with regular clinical evaluations and central venography after treatment. All 42 patients had successful recanalization of CVOs facilitated by the RF wire technique. There was one complication, which was not directly related to the RF wire: one case of cardiac tamponade attributed to balloon angioplasty after stent placement. Forty of 42 patients (95.2%) had patent stents and were asymptomatic at 6 and 9 months after treatment. The present results suggest that the RF wire technique is a safe and efficient alternative in the recanalization of symptomatic and chronic CVOs when conventional endovascular techniques have failed. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Cardiac pacemaker dysfunction in children after thoracic drainage catheter manipulation.

PubMed

Lobdell, K W; Walters, H L; Hudson, C; Hakimi, M

1997-05-01

Two children underwent placement of permanent, epicardial-lead, dual-chamber, unipolar pacemaker systems for complete heart block. Postoperatively, both patients demonstrated subcutaneous emphysema-in the area of their pulse generators-temporally related to thoracic catheter manipulation. Acutely, each situation was managed with manual compression of the pulse generator, ascertaining appropriate pacemaker sensing and pacing. Maintenance of compression with pressure dressings, vigilant observation/monitoring, and education of the care givers resulted in satisfactory pacemaker function without invasive intervention.

Can a New Antiseptic Agent Reduce the Bacterial Colonization Rate of Central Venous Lines in Post-Cardiac Surgery Patients?

PubMed Central

Yousefshahi, Fardin; Azimpour, Khashayar; Boroumand, Mohammad Ali; Najafi, Mahdi; Barkhordari, Khosro; Vaezi, Mitra; Rouhipour, Nahid

2013-01-01

Background: Central venous (CV) catheters play an essential role in the management of critically ill patients in the Intensive Care Unit (ICU). CV lines are, however, allied to catheter-associated blood stream infections. Bacterial colonization of CV lines is deemed the main cause of catheter-associated infection. The purpose of our study was to compare bacterial colony counts in the catheter site before CV line insertion in two groups of post-cardiac surgery patients: a group receiving Sanosil (an antiseptic agent composed of H2O2 and silver) and a control group. Methods: This interventional prospective double-blinded clinical trial recruited the patients in three post-cardiac surgery ICUs of a heart center. The participants were divided into interventional (113 patients) and control (136 patients) groups. Sanosil was added to the routine preparation procedure (Chlorhexidine bath one day before and scrub with Povidone-Iodine just before the CV line insertion). After the removal of the CV lines, the catheters tips were sent for culture and evaluation of colony counts. Results: Catheter colonization occurred in 55 (22.1%) patients: 26 (23%) patients in the Sanosil group and 29 (21.3%) in the control group; there was no significant statistical difference between the two groups (p value = 0.75, RR = 1.05, 95% CI: 0.76–1.45). The most common organism having colonized in the cultures of the catheter tips was staphylococcus epidermis: 20 cases in the control group and 16 cases in the intervention group. Conclusion: Catheter colonization frequently occurs in post-cardiac surgery patients. However, our results did not indicate the effectiveness of adding Sanosil to the routine preparation procedure with respect to reducing catheter bacterial colonization. PMID:23967028

JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricci, Carmelo; Ceccherini, Claudio, E-mail: claudiocec@hotmail.it; Leonini, Sara

An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

Evaluation of renal nerve morphological changes and norepinephrine levels following treatment with novel bipolar radiofrequency delivery systems in a porcine model

PubMed Central

Cohen-Mazor, Meital; Mathur, Prabodh; Stanley, James R.L.; Mendelsohn, Farrell O.; Lee, Henry; Baird, Rose; Zani, Brett G.; Markham, Peter M.; Rocha-Singh, Krishna

2014-01-01

Objective: To evaluate the safety and effectiveness of different bipolar radiofrequency system algorithms in interrupting the renal sympathetic nerves and reducing renal norepinephrine in a healthy porcine model. Methods: A porcine model (N = 46) was used to investigate renal norepinephrine levels and changes to renal artery tissues and nerves following percutaneous renal denervation with radiofrequency bipolar electrodes mounted on a balloon catheter. Parameters of the radiofrequency system (i.e. electrode length and energy delivery algorithm), and the effects of single and longitudinal treatments along the artery were studied with a 7-day model in which swine received unilateral radiofrequency treatments. Additional sets of animals were used to examine norepinephrine and histological changes 28 days following bilateral percutaneous radiofrequency treatment or surgical denervation; untreated swine were used for comparison of renal norepinephrine levels. Results: Seven days postprocedure, norepinephrine concentrations decreased proportionally to electrode length, with 81, 60 and 38% reductions (vs. contralateral control) using 16, 4 and 2-mm electrodes, respectively. Applying a temperature-control algorithm with the 4-mm electrodes increased efficacy, with a mean 89.5% norepinephrine reduction following a 30-s treatment at 68°C. Applying this treatment along the entire artery length affected more nerves vs. a single treatment, resulting in superior norepinephrine reduction 28 days following bilateral treatment. Conclusion: Percutaneous renal artery application of bipolar radiofrequency energy demonstrated safety and resulted in a significant renal norepinephrine content reduction and renal nerve injury compared with untreated controls in porcine models. PMID:24875181

Registry of Malignant Arrhythmias and Sudden Cardiac Death - Influence of Diagnostics and Interventions

ClinicalTrials.gov

2016-11-30

Ventricular Tachycardia; Ventricular Fibrillation; Sudden Cardiac Death; Coronary Angiography; Electrophysiologic Testing (EP); Catheter Ablation; Percutaneous Coronary Intervention (PCI); Internal Cardioverter Defibrillator (ICD)

Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes.

PubMed

Kocaturk, Ozgur; Saikus, Christina E; Guttman, Michael A; Faranesh, Anthony Z; Ratnayaka, Kanishka; Ozturk, Cengizhan; McVeigh, Elliot R; Lederman, Robert J

2009-08-12

Catheter visualization and tracking remains a challenge in interventional MR.Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance. The incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2 degrees C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo. We have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures.

Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes

PubMed Central

Kocaturk, Ozgur; Saikus, Christina E; Guttman, Michael A; Faranesh, Anthony Z; Ratnayaka, Kanishka; Ozturk, Cengizhan; McVeigh, Elliot R; Lederman, Robert J

2009-01-01

Background Catheter visualization and tracking remains a challenge in interventional MR. Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance. Results The incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2°C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo. Conclusion We have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures. PMID:19674464

Real-Time MRI-Guided Cardiac Cryo-Ablation: A Feasibility Study.

PubMed

Kholmovski, Eugene G; Coulombe, Nicolas; Silvernagel, Joshua; Angel, Nathan; Parker, Dennis; Macleod, Rob; Marrouche, Nassir; Ranjan, Ravi

2016-05-01

MRI-based ablation provides an attractive capability of seeing ablation-related tissue changes in real time. Here we describe a real-time MRI-based cardiac cryo-ablation system. Studies were performed in canine model (n = 4) using MR-compatible cryo-ablation devices built for animal use: focal cryo-catheter with 8 mm tip and 28 mm diameter cryo-balloon. The main steps of MRI-guided cardiac cryo-ablation procedure (real-time navigation, confirmation of tip-tissue contact, confirmation of vessel occlusion, real-time monitoring of a freeze zone formation, and intra-procedural assessment of lesions) were validated in a 3 Tesla clinical MRI scanner. The MRI compatible cryo-devices were advanced to the right atrium (RA) and right ventricle (RV) and their position was confirmed by real-time MRI. Specifically, contact between catheter tip and myocardium and occlusion of superior vena cava (SVC) by the balloon was visually validated. Focal cryo-lesions were created in the RV septum. Circumferential ablation of SVC-RA junction with no gaps was achieved using the cryo-balloon. Real-time visualization of freeze zone formation was achieved in all studies when lesions were successfully created. The ablations and presence of collateral damage were confirmed by T1-weighted and late gadolinium enhancement MRI and gross pathological examination. This study confirms the feasibility of a MRI-based cryo-ablation system in performing cardiac ablation procedures. The system allows real-time catheter navigation, confirmation of catheter tip-tissue contact, validation of vessel occlusion by cryo-balloon, real-time monitoring of a freeze zone formation, and intra-procedural assessment of ablations including collateral damage. © 2016 Wiley Periodicals, Inc.

[Evaluation of the radiofrequency ablation effectiveness in patients with the Wolff-Parkinson-White syndrome].

PubMed

Ushakov, I B; Ardashev, A V; Ardashev, V N; Voronkov, Iu I; Sharoĭko, M V; Akimova, O S

2012-01-01

A one-year prospective study involved 22 patients with the Wolff-Parkinson-White syndrome (WPW) and 20 healthy people. Means age of patients was 34.3 +/- 16.3 years. All 22 patients were successfully treated with radiofrequency ablation (RFA) of additional pathways. RFA effectiveness was evaluated with the help of clinical questionnaire, data of ECG, EchoCG, heart rate variability (HRV), frequency response and nonlinear dynamics. Cardiac rhythm disturbances were verified using Holter monitoring applied to all patients. Positive clinical effect was achieved in all the WPW patients, as RFA arrested cardiac arrhythmias completely. Holter monitoring did not register cardiac disturbances which points to high RFA effectiveness in WPW patients. HRV, frequency response and nonlinear dynamics reassumed their normal patterns.

[Complications of tongue base reduction with radiofrequency tissue ablation on obstructive sleep apnea hypopnea syndrome].

PubMed

Chen, Jin-hui; Luo, Zhi-hong; Xu, Hong-xing; Yang, Xi-lin; Zhu, Ming-wan; Tao, Ze-zhang

2010-07-01

To investigate the complications of tongue base reduction with radiofrequency tissue ablation on patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and find out the effective prevention strategies. One hundred and ninety three OSAHS patients diagnosed by polysomnography were received tongue base reduction with radiofrequency tissue ablation between March 2008 and December 2009. The intraoperative and postoperative complications including bleeding, hematoma of tongue base, abscess of tongue base, altered taste, tongue numbness, deviation of tongue extension movement, dysfunctions of pronunciation and swallowing as well as the managements were analyzed retrospectively. No perioperative complications occurred. There were 186 cases with postoperative pain (96.4%), 155 cases with submandibular edema (80.3%). Nocturnal sudden cardiac death was encountered in 1 case and secondary bleeding in 1 case. There was no ulceration of tongue base mucose, hematoma or abscess of tongue base, altered taste, tongue numbness, tongue deviations, speech, swallowing and taste disorder after operation. The scale of postoperative pain claimed by patients was ranged between mild to moderate. Diclofenac suppository had analgesic effect for these patients. The quantity of bleeding in patient with secondary hemorrhage was so little that after proper treatment the bleeding was stopped and never happened again. Patient with nocturnal sudden cardiac death occurred at thirty-seven hours after operation, because of swelling and pain of tongue base aggravated sleep apnea and night hypoxemia inducing fatal arrhythmia. Postoperative pain and submandibular edema were 2 most common postoperative complications which can be easily controlled by antibiotics, Glucocorticoids and Diclofenac suppository. For those severe OSAHS patients accompanied by cardiopulmonary diseases, the tongue base reduction with radiofrequency tissue ablation can induce nocturnal sudden cardiac death. It is important to

Minimally invasive per-catheter occlusion and dilation procedures for congenital cardiovascular abnormalities in dogs.

PubMed

Tobias, Anthony H; Stauthammer, Christopher D

2010-07-01

With ever-increasing sophistication of veterinary cardiology, minimally invasive per-catheter occlusion and dilation procedures for the treatment of various congenital cardiovascular abnormalities in dogs have become not only available, but mainstream. Much new information about minimally invasive per-catheter patent ductus arteriosus occlusion has been published and presented during the past few years. Consequently, patent ductus arteriosus occlusion is the primary focus of this article. Occlusion of other less common congenital cardiac defects is also briefly reviewed. Balloon dilation of pulmonic stenosis, as well as other congenital obstructive cardiovascular abnormalities is discussed in the latter part of the article.

Radiofrequency multielectrode catheter ablation in the atrium.

PubMed

Panescu, D; Fleischman, S D; Whayne, J G; Swanson, D K; Mirotznik, M S; McRury, I; Haines, D E

1999-04-01

We developed a temperature-controlled radiofrequency (RF) system which can ablate by delivering energy to up to six 12.5 mm long coil electrodes simultaneously. Temperature feedback was obtained from temperature sensors placed at each end of coil electrodes, in diametrically opposite positions. The coil electrodes were connected in parallel, via a set of electronic switches, to a 150 W 500 kHz temperature-controlled RF generator. Temperatures measured at all user-selected coil electrodes were processed by a microcontroller which sent the maximum value to the temperature input of the generator. The generator adjusted the delivered power to regulate the temperature at its input within a 5 degrees C interval about a user-defined set point. The microcontroller also activated the corresponding electronic switches so that temperatures at all selected electrodes were controlled within a 5 degrees C interval with respect to each other. Physical aspects of tissue heating were first analysed using finite element models and current density measurements. Results from these analyses also constituted design input. The performance of this system was studied in vitro and in vivo. In vitro, at set temperatures of 70 degrees C, 85% of the lesions were contiguous. All lesions created at set temperatures of 80 and 90 degrees C were contiguous. The lesion length increased almost linearly with the number of electrodes. Power requirements to reach a set temperature were larger as more electrodes were driven by the generator. The system impedance decreased as more electrodes were connected in the ablation circuit and reached a low of 45.5 ohms with five coil electrodes in the circuit. In vivo, right atrial lesions were created in eight mongrel canines. The power needed to reach 70 degrees C set temperature varied between 15 and 114 W. The system impedance was 105+/-16 ohms, with one coil electrode in the circuit, and dropped to 75+/-12 ohms when two coil electrodes were simultaneously

Catheter indwell time and phlebitis development during peripheral intravenous catheter administration.

PubMed

Pasalioglu, Kadriye Burcu; Kaya, Hatice

2014-07-01

Intravenous catheters have been indispensable tools of modern medicine. Although intravenous applications can be used for a multitude of purposes, these applications may cause complications, some of which have serious effects. Of these complications, the most commonly observed is phlebitis. This study was conducted to determine the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. This study determined the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. The study included a total of 103 individuals who were administered 439 catheters and satisfied the study enrollment criteria at one infectious diseases clinic in Istanbul/Turkey. Data were compiled from Patient Information Forms, Peripheral Intravenous Catheter and Therapy Information Forms, reported grades based on the Visual Infusion Phlebitis Assessment Scale, and Peripheral Intravenous Catheter Nurse Observation Forms. The data were analyzed using SPSS. Results : The mean patient age was 53.75±15.54 (standard deviation) years, and 59.2% of the study participants were men. Phlebitis was detected in 41.2% of peripheral intravenous catheters, and the rate decreased with increased catheter indwell time. Analyses showed that catheter indwell time, antibiotic usage, sex, and catheterization sites were significantly associated with development of phlebitis. The results of this study show that catheters can be used for longer periods of time when administered under optimal conditions and with appropriate surveillance.

Parameter Optimization of Pseudo-Rigid-Body Models of MRI-Actuated Catheters

PubMed Central

Greigarn, Tipakorn; Liu, Taoming; Çavuşoğlu, M. Cenk

2016-01-01

Simulation and control of a system containing compliant mechanisms such as cardiac catheters often incur high computational costs. One way to reduce the costs is to approximate the mechanisms with Pseudo-Rigid-Body Models (PRBMs). A PRBM generally consists of rigid links connected by spring-loaded revolute joints. The lengths of the rigid links and the stiffnesses of the springs are usually chosen to minimize the tip deflection differences between the PRBM and the compliant mechanism. In most applications, only the relationship between end load and tip deflection is considered. This is obviously not applicable for MRI-actuated catheters which is actuated by the coils attached to the body. This paper generalizes PRBM parameter optimization to include loading and reference points along the body. PMID:28261009

Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections.

PubMed

Lorente, Leonardo

2016-05-04

Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it.

Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections

PubMed Central

Lorente, Leonardo

2016-01-01

Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it. PMID:27152256

Characterisation of three-dimensional mapping in Wolff-Parkinson-White syndrome with septal aneurysmal dyskinesis.

PubMed

Okada, Seigo; Muneuchi, Jun; Origuchi, Hideki

2018-01-01

A 21-year-old man with Wolff-Parkinson-White syndrome and aneurysmal septal dyskinesis underwent radiofrequency catheter ablation of the accessory pathways. Before radiofrequency catheter ablation, the activation wavefront arose from the aneurysmal septum, whereas the propagation of the left ventricle was normalised after radiofrequency catheter ablation. These findings demonstrate the importance of the electro-mechanical interaction in patients with Wolff-Parkinson-White syndrome and ventricular dysfunction.

The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.

PubMed

Dobson, Laura E; Musa, Tarique A; Uddin, Akhlaque; Fairbairn, Timothy A; Bebb, Owen J; Swoboda, Peter P; Haaf, Philip; Foley, James; Garg, Pankaj; Fent, Graham J; Malkin, Christopher J; Blackman, Daniel J; Plein, Sven; Greenwood, John P

2017-02-22

Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m 2 , p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB

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.

Infraclavicular versus axillary nerve catheters: A retrospective comparison of early catheter failure rate.

PubMed

Quast, Michaela B; Sviggum, Hans P; Hanson, Andrew C; Stoike, David E; Martin, David P; Niesen, Adam D

2018-05-01

Continuous brachial plexus catheters are often used to decrease pain following elbow surgery. This investigation aimed to assess the rate of early failure of infraclavicular (IC) and axillary (AX) nerve catheters following elbow surgery. Retrospective study. Postoperative recovery unit and inpatient hospital floor. 328 patients who received IC or AX nerve catheters and underwent elbow surgery were identified by retrospective query of our institution's database. Data collected included unplanned catheter dislodgement, catheter replacement rate, postoperative pain scores, and opioid administration on postoperative day 1. Catheter failure was defined as unplanned dislodging within 24 h of placement or requirement for catheter replacement and evaluated using a covariate adjusted model. 119 IC catheters and 209 AX catheters were evaluated. There were 8 (6.7%) failed IC catheters versus 13 (6.2%) failed AX catheters. After adjusting for age, BMI, and gender there was no difference in catheter failure rate between IC and AX nerve catheters (p = 0.449). These results suggest that IC and AX nerve catheters do not differ in the rate of early catheter failure, despite differences in anatomic location and catheter placement techniques. Both techniques provided effective postoperative analgesia with median pain scores < 3/10 for patients following elbow surgery. Reasons other than rate of early catheter failure should dictate which approach is performed. Copyright © 2018. Published by Elsevier Inc.

Catheter indwell time and phlebitis development during peripheral intravenous catheter administration

PubMed Central

Pasalioglu, Kadriye Burcu; Kaya, Hatice

2014-01-01

Objective: Intravenous catheters have been indispensable tools of modern medicine. Although intravenous applications can be used for a multitude of purposes, these applications may cause complications, some of which have serious effects. Of these complications, the most commonly observed is phlebitis. This study was conducted to determine the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. Methods: This study determined the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. The study included a total of 103 individuals who were administered 439 catheters and satisfied the study enrollment criteria at one infectious diseases clinic in Istanbul/Turkey. Data were compiled from Patient Information Forms, Peripheral Intravenous Catheter and Therapy Information Forms, reported grades based on the Visual Infusion Phlebitis Assessment Scale, and Peripheral Intravenous Catheter Nurse Observation Forms. The data were analyzed using SPSS. Results : The mean patient age was 53.75±15.54 (standard deviation) years, and 59.2% of the study participants were men. Phlebitis was detected in 41.2% of peripheral intravenous catheters, and the rate decreased with increased catheter indwell time. Analyses showed that catheter indwell time, antibiotic usage, sex, and catheterization sites were significantly associated with development of phlebitis. Conclusion: The results of this study show that catheters can be used for longer periods of time when administered under optimal conditions and with appropriate surveillance. PMID:25097505

Ablation of hypertrophic septum using radiofrequency energy: an alternative for gradient reduction in patient with hypertrophic obstructive cardiomyopathy?

PubMed

Riedlbauchová, Lucie; Janoušek, Jan; Veselka, Josef

2013-06-01

Alcohol septal ablation and surgical myectomy represent accepted therapeutic options for treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy. Long-term experience with radiofrequency ablation of arrhythmogenic substrates raised a question if this technique might be effective for left ventricular outflow tract (LVOT) gradient reduction. We report on a 63-year-old patient with recurrence of symptoms 1 year after alcohol septal ablation (ASA) leading originally to a significant reduction of both symptoms and gradient. Due to a new increase of gradient in the LVOT up to 200 mm Hg with corresponding worsening of symptoms and due to refusal of surgical myectomy by the patient, endocardial radiofrequency ablation of the septal hypertrophy (ERASH) was indicated. Radiofrequency ablation was performed in the LVOT using irrigated-tip ablation catheter; the target site was identified using intracardiac echocardiography and electroanatomical CARTO mapping. ERASH caused an immediate gradient reduction due to hypokinesis of the ablated septum. At 2-month follow-up exam, significant clinical improvement was observed, together with persistent gradient reduction assessed with Doppler echocardiography. Echocardiography and magnetic resonance revealed persistent septal hypokinesis and slight thinning of the ablated region. Septal ablation using radiofrequency energy may be a promising alternative or adjunct to the treatment of hypertrophic obstructive cardiomyopathy. Intracardiac echocardiography and electroanatomical CARTO mapping enable exact lesion placement and preservation of atrioventricular conduction.

RF HEATING OF MRI-ASSISTED CATHETER STEERING COILS FOR INTERVENTIONAL MRI

PubMed Central

Settecase, Fabio; Hetts, Steven W.; Martin, Alastair J.; Roberts, Timothy P. L.; Bernhardt, Anthony F.; Evans, Lee; Malba, Vincent; Saeed, Maythem; Arenson, Ronald L.; Kucharzyk, Walter; Wilson, Mark W.

2010-01-01

RATIONALE AND OBJECTIVES To assess magnetic resonance imaging (MRI) radiofrequency (RF) related heating of conductive wire coils used in magnetically steerable endovascular catheters. MATERIALS AND METHODS A 3-axis microcoil was fabricated onto a 1.8 Fr catheter tip. In vitro testing was performed in a 1.5 T MRI system using an agarose gel filled vessel phantom, a transmit/receive body RF coil and a steady state free precession (SSFP) pulse sequence, and a fluoroptic thermometry system. Temperature was measured without simulated blood flow at varying distances from magnet isocenter and varying flip angles. Additional experiments were performed with laser-lithographed single-axis microcoil-tipped microcatheters in air and in a saline bath with varied grounding of the microcoil wires. Preliminary in vivo evaluation of RF heating was performed in pigs at 1.5 T with coil-tipped catheters in various positions in the common carotid arteries with SSFP pulse sequence on and off, and under physiologic flow and zero flow conditions. RESULTS In tissue-mimicking agarose gel, RF heating resulted in a maximal temperature increase of 0.35°C after 15 minutes of imaging, 15 cm from magnet isocenter. For a single axis microcoil, maximal temperature increases were 0.73-1.91°C in air and 0.45-0.55°C in saline. In vivo, delayed contrast enhanced MRI revealed no evidence of vascular injury and histopathological sections from the common carotid arteries confirmed the lack of vascular damage. CONCLUSIONS Microcatheter tip microcoils for endovascular catheter steering in MRI experience minimal RF heating under the conditions tested. These data provide the basis for further in vivo testing of this promising technology for endovascular interventional MRI. PMID:21075019

RF Heating of MRI-Assisted Catheter Steering Coils for Interventional MRI.

PubMed

Settecase, Fabio; Hetts, Steven W; Martin, Alastair J; Roberts, Timothy P L; Bernhardt, Anthony F; Evans, Lee; Malba, Vincent; Saeed, Maythem; Arenson, Ronald L; Kucharzyk, Walter; Wilson, Mark W

2011-03-01

The aim of this study was too assess magnetic resonance imaging (MRI) radiofrequency (RF)-related heating of conductive wire coils used in magnetically steerable endovascular catheters. A three-axis microcoil was fabricated onto a 1.8Fr catheter tip. In vitro testing was performed on a 1.5-T MRI system using an agarose gel-filled vessel phantom, a transmit-receive body RF coil, a steady-state free precession pulse sequence, and a fluoroptic thermometry system. Temperature was measured without simulated blood flow at varying distances from the magnet isocenter and at varying flip angles. Additional experiments were performed with laser-lithographed single-axis microcoil-tipped microcatheters in air and in a saline bath with varied grounding of the microcoil wires. Preliminary in vivo evaluation of RF heating was performed in pigs at 1.5 T with coil-tipped catheters in various positions in the common carotid arteries with steady-state free precession pulse sequence on and off and under physiologic-flow and zero-flow conditions. In tissue-mimicking agarose gel, RF heating resulted in a maximal temperature increase of 0.35°C after 15 minutes of imaging, 15 cm from the magnet isocenter. For a single-axis microcoil, maximal temperature increases were 0.73°C to 1.91°C in air and 0.45°C to 0.55°C in saline. In vivo, delayed contrast-enhanced MRI revealed no evidence of vascular injury, and histopathologic sections from the common carotid arteries confirmed the lack of vascular damage. Microcatheter tip microcoils for endovascular catheter steering in MRI experience minimal RF heating under the conditions tested. These data provide the basis for further in vivo testing of this promising technology for endovascular interventional MRI. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

NASA Astrophysics Data System (ADS)

Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

2014-03-01

Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

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

Feasibility study of an active soft catheter actuated by SMA wires

NASA Astrophysics Data System (ADS)

Konh, Bardia; Karimi, Saeed; Miller, Scott

2018-03-01

This study aims to assess the feasibility of using a combination of thin elastomer tubes and SMA wires to develop an active catheter. Cardiac catheters have been widely used in investigational and interventional procedures such as angiography, angioplasty, electro- physiology, and endocardial ablation. The commercial models manually steer inside the patient's body via internally installed pull wires. Active catheters, on the other hand, have the potential to revolutionize surgical procedures because of their computer-controlled and enhanced motion. Shape memory alloys have been used for almost a decade as a trustworthy actuator for biomedical applications. In this work, SMA wires were attached to a small pressurized elastomer tube to realize deflection. The tube was pressurized to maintain a constant stress on the SMA wires. The tip motion via actuation of SMA wires was then measured and reported. The results of this study showed that by adopting an appropriate training process for the SMA wires prior to performing the experiments and adopting an appropriate internal pressure for the elastomer tube, less external loads on SMA wires would be needed for a consistent actuation.

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.

Acoustic reflectors are visible in the right heart during radiofrequency ablation of varicose veins.

PubMed

Sounderajah, V; Moore, H M; Thapar, A; Lane, T R A; Fox, K; Franklin, I J; Davies, A H

2015-09-01

Cerebrovascular events have been noted after foam sclerotherapy for varicose veins. One hypothesis is migration of microemboli to the brain through a cardiac septal defect. The aim of this study was to identify whether acoustic reflectors are found in the right side of the heart during radiofrequency ablation of varicose veins, as neurological events are not reported during these procedures. Transthoracic echocardiography was performed during local anaesthetic radiofrequency ablation (VNUS ClosureFast) of the great saphenous vein in 14 patients. An apical view was captured at the start of the procedure, during each cycle of heating and at 1 min post-treatment. Patients were monitored for 1 h. Video loops were read by an independent cardiologist. The presence of acoustic reflectors was classified as: 0 = absent, 1 = occasional, 2 = stream, 3 = complete opacification. Loops were of diagnostic quality in 11/14 (79%) patients. After the second cycle of heating, acoustic reflectors moving through the right heart were seen in 5/11 (45%) patients. These were classified as grade 1 in four patients and grade 2 in one patient. No acoustic reflectors were seen in the left heart. No neurological symptoms were reported. Acoustic reflectors in the right heart are a common finding during radiofrequency ablation of varicose veins. Considering the prevalence of cardiac septal defects (17%), more neurological events would be expected if these particles were indeed responsible for these events. Further work is required to elicit the mechanisms underlying neurological complications following sclerotherapy. © The Author(s) 2014.

Evaluation of left ventricular scar identification from contrast enhanced magnetic resonance imaging for guidance of ventricular catheter ablation therapy

NASA Astrophysics Data System (ADS)

Rettmann, M. E.; Lehmann, H. I.; Johnson, S. B.; Packer, D. L.

2016-03-01

Patients with ventricular arrhythmias typically exhibit myocardial scarring, which is believed to be an important anatomic substrate for reentrant circuits, thereby making these regions a key target in catheter ablation therapy. In ablation therapy, a catheter is guided into the left ventricle and radiofrequency energy is delivered into the tissue to interrupt arrhythmic electrical pathways. Low bipolar voltage regions are typically localized during the procedure through point-by-point construction of an electroanatomic map by sampling the endocardial surface with the ablation catheter and are used as a surrogate for myocardial scar. This process is time consuming, requires significant skill, and has the potential to miss low voltage sites. This has led to efforts to quantify myocardial scar preoperatively using delayed, contrast-enhanced MRI. In this paper, we evaluate the utility of left ventricular scar identification from delayed contrast enhanced magnetic resonance imaging for guidance of catheter ablation of ventricular arrhythmias. Myocardial infarcts were created in three canines followed by a delayed, contrast enhanced MRI scan and electroanatomic mapping. The left ventricle and myocardial scar is segmented from preoperative MRI images and sampled points from the procedural electroanatomical map are registered to the segmented endocardial surface. Sampled points with low bipolar voltage points visually align with the segmented scar regions. This work demonstrates the potential utility of using preoperative delayed, enhanced MRI to identify myocardial scarring for guidance of ventricular catheter ablation therapy.

[Magnetic navigation for ablation of cardiac arrhythmias].

PubMed

Chen, Jian; Hoff, Per Ivar; Solheim, Eivind; Schuster, Peter; Off, Morten Kristian; Ohm, Ole-Jørgen

2010-08-12

The first use of magnetic navigation for radiofrequency ablation of supraventricular tachycardias, was published in 2004. Subsequently, the method has been used for treatment of most types of tachyarrhythmias. This paper provides an overview of the method, with special emphasis on usefulness of a new remote-controlled magnetic navigation system. The paper is based on our own scientific experience and literature identified through a non-systematic search in PubMed. The magnetic navigation system consists of two external electromagnets (to be placed on opposite sides of the patient), which guide an ablation catheter (with a small magnet at the tip of the catheter) to the target area in the heart. The accuracy of this procedure is higher than that with manual navigation. Personnel can be quickly trained to use remote magnetic navigation, but the procedure itself is time-consuming, particularly for patients with atrial fibrillation. The major advantage is a considerably lower radiation burden to both patient and operator, in some studies more than 50 %, and a corresponding reduction in physical strain on the operator. The incidence of procedure-related complications seems to be lower than that observed with use of manually operated ablation catheters. Work is ongoing to improve magnetic ablation catheters and methods that can simplify mapping procedures and improve efficacy of arrhythmia ablation. The basic cost for installing a complete magnetic navigation laboratory may be three times that of a conventional electrophysiological laboratory. The new magnetic navigation system has proved to be applicable during ablation for a variety of tachyarrhythmias, but is still under development.

Measurement of Cardiac Index by Transpulmonary Thermodilution Using an Implanted Central Venous Access Port: A Prospective Study in Patients Scheduled for Oncologic High-Risk Surgery

PubMed Central

Suria, Stéphanie; Wyniecki, Anne; Eghiaian, Alexandre; Monnet, Xavier; Weil, Grégoire

2014-01-01

Background Transpulmonary thermodilution allows the measurement of cardiac index for high risk surgical patients. Oncologic patients often have a central venous access (port-a-catheter) for chronic treatment. The validity of the measurement by a port-a-catheter of the absolute cardiac index and the detection of changes in cardiac index induced by fluid challenge are unknown. Methods We conducted a monocentric prospective study. 27 patients were enrolled. 250 ml colloid volume expansions for fluid challenge were performed during ovarian cytoreductive surgery. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution by a central venous access (CIcvc) and by a port-a-catheter (CIport) were recorded. Results 23 patients were analyzed with 123 pairs of measurements. Using a Bland and Altman for repeated measurements, the bias (lower and upper limits of agreement) between CIport and CIcvc was 0.14 (−0.59 to 0.88) L/min/m2. The percentage error was 22%. The concordance between the changes in CIport and CIcvc observed during volume expansion was 92% with an r = 0.7 (with exclusion zone). No complications (included sepsis) were observed during the follow up period. Conclusions The transpulmonary thermodilution by a port-a-catheter is reliable for absolute values estimation of cardiac index and for measurement of the variation after fluid challenge. Trial Registration clinicaltrials.gov NCT02063009 PMID:25136951

Measurement of cardiac index by transpulmonary thermodilution using an implanted central venous access port: a prospective study in patients scheduled for oncologic high-risk surgery.

PubMed

Suria, Stéphanie; Wyniecki, Anne; Eghiaian, Alexandre; Monnet, Xavier; Weil, Grégoire

2014-01-01

Transpulmonary thermodilution allows the measurement of cardiac index for high risk surgical patients. Oncologic patients often have a central venous access (port-a-catheter) for chronic treatment. The validity of the measurement by a port-a-catheter of the absolute cardiac index and the detection of changes in cardiac index induced by fluid challenge are unknown. We conducted a monocentric prospective study. 27 patients were enrolled. 250 ml colloid volume expansions for fluid challenge were performed during ovarian cytoreductive surgery. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution by a central venous access (CIcvc) and by a port-a-catheter (CIport) were recorded. 23 patients were analyzed with 123 pairs of measurements. Using a Bland and Altman for repeated measurements, the bias (lower and upper limits of agreement) between CIport and CIcvc was 0.14 (-0.59 to 0.88) L/min/m2. The percentage error was 22%. The concordance between the changes in CIport and CIcvc observed during volume expansion was 92% with an r = 0.7 (with exclusion zone). No complications (included sepsis) were observed during the follow up period. The transpulmonary thermodilution by a port-a-catheter is reliable for absolute values estimation of cardiac index and for measurement of the variation after fluid challenge. clinicaltrials.gov NCT02063009.

Visualizing intramyocardial steam formation with a radiofrequency ablation catheter incorporating near-field ultrasound.

PubMed

Wright, Matthew; Harks, Erik; Deladi, Szabolcs; Fokkenrood, Steven; Zuo, Fei; Van Dusschoten, Anneke; Kolen, Alexander F; Belt, Harm; Sacher, Frederic; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre

2013-12-01

Steam pops are a risk of irrigated RF ablation even when limiting power delivery. There is currently no way to predict gas formation during ablation. It would be useful to visualize intramyocardial gas formation prior to a steam pop occurring using near-field ultrasound integrated into a RF ablation catheter. In an in vivo open-chest ovine model (n = 9), 86 lesions were delivered to the epicardial surface of the ventricles. Energy was delivered for 15-60 seconds, to achieve lesions with and without steam pops, based on modeling data. The ultrasound image was compared to a digital audio recording from within the pericardium by a blinded observer. Of 86 lesions, 28 resulted in an audible steam pop. For lesions that resulted in a steam pop compared to those that did not (n = 58), the mean power delivered was 8.0 ± 1.8 W versus 6.7 ± 2.0 W, P = 0.006. A change in US contrast due to gas formation in the tissue occurred in all lesions that resulted in a steam pop. In 4 ablations, a similar change in US contrast was observed in the tissue and RF delivery was stopped; in these cases, no pop occurred. The mean depth of gas formation was 0.9 ± 0.8 mm, which correlated with maximal temperature predicted by modeling. Changes in US contrast occurred 7.6 ± 7.2 seconds before the impedance rise and 7.9 ± 6.2 seconds (0.1-17.0) before an audible pop. Integrated US in an RF ablation catheter is able to visualize gas formation intramyocardially several seconds prior to a steam pop occurring. This technology may help prevent complications arising from steam pops. © 2013 Wiley Periodicals, Inc.

Hybrid laparoscopic and robotic ultrasound-guided radiofrequency ablation-assisted clampless partial nephrectomy.

PubMed

Nadler, Robert B; Perry, Kent T; Smith, Norm D

2009-07-01

To describe a clampless approach made possible by creating an avascular plane of tissue with radiofrequency ablation. Laparoscopic partial nephrectomy is slowly gaining acceptance as a method to treat small (<4 cm) and select moderate (<7 cm) renal masses. The intricacies of laparoscopic suturing, which result in prolonged warm ischemia times, have delayed the widespread acceptance of this technique among urologists. Laparoscopic suturing to close the collecting system was done using the da Vinci robot. An avascular plane of tissue from coagulation necrosis was achieved with the Habib 4X radiofrequency ablation device and the Rita 1500X generator. Typically, we used a power setting of 50 W but have found settings as low as 25 W necessary to provide hemostasis for larger vessels. The tumor was then sharply excised with a negative margin using robotic scissors and electrocautery to facilitate tissue cutting. Retrograde injection of methylthioninium chloride and saline through an externalized ureteral catheter allowed for precise sutured closure of the collecting system. FloSeal and BioGlue were then applied, making surgical bolsters or parenchymal sutures unnecessary. Intraoperative histologic evaluation of the surgical margin and repeat resection of the tumor bed was possible because the renal hilum was not clamped, and no warm ischemia was used. This technique, which combines the improving technologies of robotic surgery, intraoperative laparoscopic ultrasonography, and radiofrequency ablation, might make more surgeons comfortable with the intricacies of laparoscopic suturing and eliminate prolonged warm ischemia times. Overall, this method should result in more patients being able to undergo minimally invasive laparoscopic partial nephrectomy.

Real-time magnetic resonance imaging-guided radiofrequency atrial ablation and visualization of lesion formation at 3 Tesla.

PubMed

Vergara, Gaston R; Vijayakumar, Sathya; Kholmovski, Eugene G; Blauer, Joshua J E; Guttman, Mike A; Gloschat, Christopher; Payne, Gene; Vij, Kamal; Akoum, Nazem W; Daccarett, Marcos; McGann, Christopher J; Macleod, Rob S; Marrouche, Nassir F

2011-02-01

Magnetic resonance imaging (MRI) allows visualization of location and extent of radiofrequency (RF) ablation lesion, myocardial scar formation, and real-time (RT) assessment of lesion formation. In this study, we report a novel 3-Tesla RT -RI based porcine RF ablation model and visualization of lesion formation in the atrium during RF energy delivery. The purpose of this study was to develop a 3-Tesla RT MRI-based catheter ablation and lesion visualization system. RF energy was delivered to six pigs under RT MRI guidance. A novel MRI-compatible mapping and ablation catheter was used. Under RT MRI, this catheter was safely guided and positioned within either the left or right atrium. Unipolar and bipolar electrograms were recorded. The catheter tip-tissue interface was visualized with a T1-weighted gradient echo sequence. RF energy was then delivered in a power-controlled fashion. Myocardial changes and lesion formation were visualized with a T2-weighted (T2W) half Fourier acquisition with single-shot turbo spin echo (HASTE) sequence during ablation. RT visualization of lesion formation was achieved in 30% of the ablations performed. In the other cases, either the lesion was formed outside the imaged region (25%) or the lesion was not created (45%) presumably due to poor tissue-catheter tip contact. The presence of lesions was confirmed by late gadolinium enhancement MRI and macroscopic tissue examination. MRI-compatible catheters can be navigated and RF energy safely delivered under 3-Tesla RT MRI guidance. Recording electrograms during RT imaging also is feasible. RT visualization of lesion as it forms during RF energy delivery is possible and was demonstrated using T2W HASTE imaging. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Preliminary experiments of a single x-ray view catheter 3D localization algorithm for targeted stem cell injections

NASA Astrophysics Data System (ADS)

Iovea, M.; Creed, J.; Perin, E.; Neagu, M.; Mateiasi, G.

2009-02-01

The aim of this study was to conduct a preliminary check of a new method for measuring the 3D catheter position based on only one X-Ray view (image) and a simple pre-calibration procedure for catheters that could be equipped with high-opacity equal-spaced markers. The application chosen for this experiment is the targeted delivery of cell based therapeutic via a transendocardial retrograde approach into the left ventricle. This approach has shown promising therapeutic retention data when injected directly into the myocardial tissue, but lacks in the ability of the user to confidently manipulate the catheter within the left ventricle cavity space under traditional fluoroscopic guidance using a needle based catheter. The need for a new technique arose from the potential for increased safety and therapeutic efficacy by improving the targeting of the agent. The new technique, destined for Image guided catheter navigation systems for cardiac interventions, is based on a measurement of the marker's size and distance between them and followed by a comparison with the referenced catheter position. Preliminary experiments made with a simple phantom are presented, emphasizing the ability of the new technique in measuring the markers and the catheter tip 3D position. An overall maximum error in positioning markers and catheter tip below 12% has been obtained, yielding a promising result for continuing the future work of improving the algorithm accuracy.

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.

SvO2 Trigger in Transfusion Strategy After Cardiac Surgery

ClinicalTrials.gov

2018-03-27

Undergoing Nonemergent Cardiac Surgery; Central Venous Catheter on the Superior Vena Cava (to Perform ScVO2 Measure); Anemia (<9g/dL) Requiring Blood Transfusion; Hemodynamic and Respiratory Stability; Bleeding Graded as Insignificant, Mild, Moderate of Universal Definition of Perioperative Bleeding

Effect of radiofrequency energy emitted from monopolar "Bovie" instruments on cardiac implantable electronic devices.

PubMed

Robinson, Thomas N; Varosy, Paul D; Guillaume, Girard; Dunning, James E; Townsend, Nicole T; Jones, Edward L; Paniccia, Alessandro; Stiegmann, Greg V; Weyer, Christopher; Rozner, Marc A

2014-09-01

The monopolar "Bovie" instrument emits radiofrequency energy that can disrupt the function of other implanted electronic devices through a phenomenon termed electromagnetic interference. The purpose of this study was to quantify the electromagnetic interference occurring on cardiac implantable devices (CIEDs) resulting from monopolar instrument use in common, modifiable clinical scenarios. Three anesthetized pigs underwent CIED placement (1 pacemaker and 2 defibrillators). Electromagnetic interference was quantified when changing the monopolar instrument parameters of generator power, generator mode, surgical technique, orientation of active electrode cord, pathway of current vector, and proximity of active electrode to the CIED. Monopolar instrument parameters that decreased the electromagnetic interference occurring on the CIED included decreasing generator power from 60 W to 30 W (p < 0.001), using cut mode rather than coag mode (p < 0.001), using desiccation technique rather than fulguration technique (p < 0.001), orienting the active electrode cord from the feet rather than across the chest wall (p < 0.001), and avoiding the current vector from crossing the CIED system (p < 0.001). Increasing the distance between the active electrode tool and the CIED system decreased electromagnetic interference occurring on the CIED in a dose-response fashion up to a distance of 10 cm (ANOVA, p < 0.001), after which the magnitude of electromagnetic interference remained constant. Electromagnetic interference occurring on CIEDs resulting from monopolar instruments is minimized by decreasing generator power, using cut mode, using desiccation technique, orienting the active electrode cord from the feet, avoiding the current vector for crossing the CIED system, and increasing the distance between the active electrode and the CIED. Surgeons and operating room staff can minimize electromagnetic interference on CIEDs during monopolar instrument use by accounting for these

Hemodialysis Tunneled Catheter Noninfectious Complications

PubMed Central

Miller, Lisa M.; MacRae, Jennifer M.; Kiaii, Mercedeh; Clark, Edward; Dipchand, Christine; Kappel, Joanne; Lok, Charmaine; Luscombe, Rick; Moist, Louise; Oliver, Matthew; Pike, Pamela; Hiremath, Swapnil

2016-01-01

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined. PMID:28270922

Microwave, irrigated, pulsed, or conventional radiofrequency energy source: which energy source for which catheter ablation?

PubMed

Erdogan, Ali; Grumbrecht, Stephan; Neumann, Thomas; Neuzner, Joerg; Pitschner, Heinz F

2003-01-01

The aim of the study was to compare the diameter of endomyocardial lesions induced with the delivery of microwave, cooled, or pulsed energy versus conventional RF energy. In vitro tests were performed in fresh endomyocardial preparations of pig hearts in a 10-L bath of NaCl 0.9% solution at 37 degrees C and constant 1.5 L/min flow. Ablation 7 Fr catheters with 4-mm tip electrodes were used, except for the delivery of microwave energy. Energy delivery time was set to 60 s/50 W in all experiments. Cooled energy delivery was performed with a closed irrigation catheter. Pulsed energy delivery was performed using a special controller with a duty-cycle of 5 ms. Microwave energy was delivered with a 2.5-GHz generator and 10-mm antenna. Electrode temperature and impedance were measured simultaneously. After ablation, lesion length, width, and depth were measured with microcalipers, and volume calculated by a formula for ellipsoid bodies. Each energy delivery mode was tested in ten experiments. The deepest lesions were created with cooled energy delivery, and the largest volume by microwave energy delivery. Pulsed RF produced significantly deeper lesions than conventional RF energy delivery. Cooled or pulsed RF energy delivery created deeper transmural lesions than conventional RF. To create linear lesions at anatomically complex sites (isthmus), microwave energy seemed superior by rapidly creating deep and long lesions.

Peritoneal Dialysis Catheter Insertion.

PubMed

Crabtree, John H; Chow, Kai-Ming

2017-01-01

The success of peritoneal dialysis as renal-replacement therapy depends on a well-functioning peritoneal catheter. Knowledge of best practices in catheter insertion can minimize the risk of catheter complications that lead to peritoneal dialysis failure. The catheter placement procedure begins with preoperative assessment of the patient to determine the most appropriate catheter type, insertion site, and exit site location. Preoperative preparation of the patient is an instrumental step in facilitating the performance of the procedure, avoiding untoward events, and promoting the desired outcome. Catheter insertion methods include percutaneous needle-guidewire with or without image guidance, open surgical dissection, peritoneoscopic procedure, and surgical laparoscopy. The insertion technique used often depends on the geographic availability of material resources and local provider expertise in placing catheters. Independent of the catheter implantation approach, adherence to a number of universal details is required to ensure the best opportunity for creating a successful long-term peritoneal access. Finally, appropriate postoperative care and catheter break-in enables a smooth transition to dialysis therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Six-month follow-up of isthmus-dependent right atrial flutter ablation using a remote magnetic catheter navigation system: a case-control study.

PubMed

Huo, Yan; Hindricks, Gerhard; Piorkowski, Christopher; Bollmann, Andreas; Wetzel, Ulrike; Sommer, Phillip; Gaspar, Thomas; Kottkamp, Hans; Arya, Arash

2010-06-01

The objective of this study was to compare results between the magnetic navigation system (MNS) and conventional catheter ablation of cavo-tricuspid isthmus (CTI)-dependent right atrial flutter (AFL) in a case control study. A remote MNS has been used for ablation of various arrhythmias including CTI-dependent AFL but comparative results between MNS and conventional ablation are not available. Between May and September 2007, a total of 51 consecutive patients (45 men, mean age 65.4 +/- 9.4 years) had undergone catheter ablation for CTI-dependent AFL. The catheter ablation (70 degrees C, 70 W, 90 s) was performed with either an 8-mm-tip magnetic catheter using MNS (case group, n = 26, 23 men, mean age 64.6 +/- 9.6 y) or a conventional 8-mm catheter (case group, n = 25, 22 men, mean age 65.4 +/- 9.1 y). Acute procedural success was defined as complete bidirectional isthmus block and success at six months was defined as absence of AFL during the six months follow-up. With respect to baseline characteristics there were no differences between the two groups. The procedure time in MNS and conventional group was [median (range)] 53 (30-130) min and 45 (30-100) min, respectively (P = 0.12). Acute success was achieved by MNS and conventional ablation in 25/26 (96.2%) and 25/25 (100%) of patients, respectively (P = 0.53). During the six months of follow-up 4 patients, 2 in each group, experienced recurrence (P = 0.90). No major complication occurred during the procedure. Charring on the catheter tip occurred in 5 patients (19.2%) in MNS and none of the patients in the control group (P <0.05). This case-control study demonstrated the acute and mid-term efficacy and safety of catheter ablation by MNS for CTI-dependent AFL, similar to rates achieved by conventional radiofrequency catheter ablation.

RF induced energy for partially implanted catheters: a computational study

PubMed Central

Lucano, Elena; Liberti, Micaela; Lloyd, Tom; Apollonio, Francesca; Wedan, Steve; Kainz, Wolfgang; Angelone, Leonardo M.

2018-01-01

Magnetic Resonance Imaging (MRI) is a radiological imaging technique widely used in clinical practice. MRI has been proposed to guide the catheters for interventional procedures, such as cardiac ablation. However, there are risks associated with this procedure, such as RF-induced heating of tissue near the catheters. The aim of this study is to develop a quantitative RF-safety method for patients with partially implanted leads at 64 MHz. RF-induced heating is related to the electric field incident along the catheter, which in turns depends on several variables, including the position of the RF feeding sources and the orientation of the polarization, which are however often unknown. This study evaluates the electric field profile along the lead trajectory using simulations with an anatomical human model landmarked at the heart. The energy absorbed in the volume near the tip of ageneric partially implanted lead was computed for all source positions and field orientation. The results showed that varying source positions and field orientation may result in changes of up to 18% for the E-field magnitude and up to 60% for the 10g-averaged specific absorption rate (SAR) in the volume surrounding the tip of the lead. PMID:28268553

A deflectable guiding catheter for real-time MRI-guided interventions.

PubMed

Bell, Jamie A; Saikus, Christina E; Ratnayaka, Kanishka; Wu, Vincent; Sonmez, Merdim; Faranesh, Anthony Z; Colyer, Jessica H; Lederman, Robert J; Kocaturk, Ozgur

2012-04-01

To design a deflectable guiding catheter that omits long metallic components yet preserves mechanical properties to facilitate therapeutic interventional MRI procedures. The catheter shaft incorporated Kevlar braiding. A 180° deflection was attained with a 5-cm nitinol slotted tube, a nitinol spring, and a Kevlar pull string. We tested three designs: passive, passive incorporating an inductively coupled coil, and active receiver. We characterized mechanical properties, MRI properties, RF induced heating, and in vivo performance in swine. Torque and tip deflection force were satisfactory. Representative procedures included hepatic and azygos vein access, laser cardiac septostomy, and atrial septal defect crossing. Visualization was best in the active configuration, delineating profile and tip orientation. The passive configuration could be used in tandem with an active guidewire to overcome its limited conspicuity. There was no RF-induced heating in all configurations under expected use conditions in vitro and in vivo. Kevlar and short nitinol component substitutions preserved mechanical properties. The active design offered the best visibility and usability but reintroduced metal conductors. We describe versatile deflectable guiding catheters with a 0.057" lumen for interventional MRI catheterization. Implementations are feasible using active, inductive, and passive visualization strategies to suit application requirements. Copyright © 2011 Wiley Periodicals, Inc.

A deflectable guiding catheter for real-time MRI-guided interventions

PubMed Central

Bell, Jamie A.; Saikus, Christina E.; Ratnakaya, Kanishka; Wu, Vincent; Sonmez, Merdim; Faranesh, Anthony Z.; Colyer, Jessica H.; Lederman, Robert J.; Kocaturk, Ozgur

2011-01-01

Purpose To design a deflectable guiding catheter that omits long metallic components yet preserves mechanical properties to facilitate therapeutic interventional MRI procedures. Materials and Methods The catheter shaft incorporated Kevlar braiding. 180° deflection was attained with a 5 cm nitinol slotted tube, a nitinol spring, and a Kevlar pull string. We tested three designs: passive, passive incorporating an inductively-coupled coil, and active receiver. We characterized mechanical properties, MRI properties, RF induced heating, and in vivo performance in swine. Results Torque and tip deflection force were satisfactory. Representative procedures included hepatic and azygos vein access, laser cardiac septostomy, and atrial septal defect crossing. Visualization was best in the active configuration, delineating profile and tip orientation. The passive configuration could be used in tandem with an active guidewire to overcome its limited conspicuity. There was no RF-induced heating in all configurations under expected use conditions in vitro and in vivo. Conclusion Kevlar and short nitinol component substitutions preserved mechanical properties. The active design offered the best visibility and usability but reintroduced metal conductors. We describe versatile deflectable guiding catheters with a 0.057” lumen for interventional MRI catheterization. Implementations are feasible using active, inductive, and passive visualization strategies to suit application requirements. PMID:22128071

Cardiac memory in patients with Wolff-Parkinson-White syndrome: noninvasive imaging of activation and repolarization before and after catheter ablation.

PubMed

Ghosh, Subham; Rhee, Edward K; Avari, Jennifer N; Woodard, Pamela K; Rudy, Yoram

2008-08-26

Cardiac memory refers to a change in ventricular repolarization induced by and persisting for minutes to months after cessation of a period of altered ventricular activation (eg, resulting from pacing or preexcitation in patients with Wolff-Parkinson-White syndrome). ECG imaging (ECGI) is a novel imaging modality for noninvasive electroanatomic mapping of epicardial activation and repolarization. Fourteen pediatric patients with Wolff-Parkinson-White syndrome and no other congenital disease, were imaged with ECGI a day before and 45 minutes, 1 week, and 1 month after successful catheter ablation. ECGI determined that preexcitation sites were consistent with sites of successful ablation in all cases to within a 1-hour arc of each atrioventricular annulus. In the preexcited rhythm, activation-recovery interval (ARI) was the longest (349+/-6 ms) in the area of preexcitation leading to high average base-to-apex ARI dispersion of 95+/-9 ms (normal is approximately 40 ms). The ARI dispersion remained the same 45 minutes after ablation, although the activation sequence was restored to normal. ARI dispersion was still high (79+/-9 ms) 1 week later and returned to normal (45+/-6 ms) 1 month after ablation. The study demonstrates that ECGI can noninvasively localize ventricular insertion sites of accessory pathways to guide ablation and evaluate its outcome in pediatric patients with Wolff-Parkinson-White syndrome. Wolff-Parkinson-White is associated with high ARI dispersion in the preexcited rhythm that persists after ablation and gradually returns to normal over a period of 1 month, demonstrating the presence of cardiac memory. The 1-month time course is consistent with transcriptional reprogramming and remodeling of ion channels.

Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

PubMed

Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

2015-03-18

evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. We included in the analysis one small sham-controlled randomised trial of 173 women performed in the United States. Participants enrolled in this study had been diagnosed with stress UI and were randomly assigned to transurethral radiofrequency collagen denaturation (treatment) or a sham surgery using a non-functioning catheter (no treatment). Mean age of participants in the 12-month multi-centre trial was 50 years (range 22 to 76 years).Of three patient-important primary outcomes selected for this systematic review, the number of women reporting UI symptoms after intervention was not reported. No serious adverse events were reported for the transurethral radiofrequency collagen denaturation arm or the sham treatment arm during the 12-month trial. Owing to high risk of bias and imprecision, we downgraded the quality of evidence for this outcome to low. The effect of transurethral radiofrequency collagen denaturation on the number of women with an incontinence quality of life (I-QOL) score improvement ≥ 10 points at 12 months was as follows: RR 1.11, 95% CI 0.77 to 1.62; participants = 142, but the confidence interval was wide. For this outcome, the quality of evidence was also low as the result of high risk of bias and imprecision.We found no evidence on the number of women undergoing repeat continence surgery. The risk of other adverse events (pain/dysuria (RR 5.73, 95% CI 0.75 to 43.70; participants = 173); new detrusor overactivity (RR 1.36, 95% CI 0.63 to 2.93; participants = 173); and urinary tract infection (RR 0.95, 95% CI 0.24 to 3.86; participants = 173) could not be established reliably as the trial was small. Evidence was insufficient for assessment of whether use of transurethral radiofrequency collagen denaturation was associated with an increased rate of urinary retention, haematuria and hesitancy compared with sham treatment in 173 participants. The GRADE

Catheter-related bloodstream infection.

PubMed

Goede, Matthew R; Coopersmith, Craig M

2009-04-01

Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed.

The benefits of the Atlas of Human Cardiac Anatomy website for the design of cardiac devices.

PubMed

Spencer, Julianne H; Quill, Jason L; Bateman, Michael G; Eggen, Michael D; Howard, Stephen A; Goff, Ryan P; Howard, Brian T; Quallich, Stephen G; Iaizzo, Paul A

2013-11-01

This paper describes how the Atlas of Human Cardiac Anatomy website can be used to improve cardiac device design throughout the process of development. The Atlas is a free-access website featuring novel images of both functional and fixed human cardiac anatomy from over 250 human heart specimens. This website provides numerous educational tutorials on anatomy, physiology and various imaging modalities. For instance, the 'device tutorial' provides examples of devices that were either present at the time of in vitro reanimation or were subsequently delivered, including leads, catheters, valves, annuloplasty rings and stents. Another section of the website displays 3D models of the vasculature, blood volumes and/or tissue volumes reconstructed from computed tomography and magnetic resonance images of various heart specimens. The website shares library images, video clips and computed tomography and MRI DICOM files in honor of the generous gifts received from donors and their families.

Comparison of heat induced damage at the saphenofemoral junction after ablation with 1,470 nm laser or radiofrequency.

PubMed

Ozcinar, Evren; Cakici, Mehmet; Korun, Oktay; Han, Unsal; Kiziltepe, Ugursay

2017-03-01

The aim of this study was to evaluate the heat induced damage at the saphenofemoral junction level according to histopathological changes after radiofrequency or 1,470 nm radial tip laser ablation. Varicose vein segments of 6-10 mm in diameter were exposed to radiofrequency (Closure Fast catheter, 7 cm heat segment, one cycle, 15 seconds, 10 Watt, 120 °C) or laser ablation (1,470 nm radial tip, continuous wave, vein diameter: 6 cm/8 cm/10 cm-power: 10 Watt-pullback speed: 2.2 mm/s, 1.7 mm/s, 1.3 mm/s-LEED: 45J/cm, 60J/cm, 75J/cm-EFE 25J/cm 2 , respectively). Approximate 2 cm segments of the vein were left untreated, then histopathological examinations of the untouched segments (5 slices: level 1 - furthest segment, level 2 - nearest segment) for heat induced damage were performed. A total damage scoring system was established, including the presence of endothelial swelling, intimal thickening, cellular vacuolisation in the muscle layer, oedema in the tunica media, and extent of necrosis. At level 1, the furthest segment of the specimen, there was no significant difference between the laser and control group, while the total damage score of the radiofrequency group was significantly higher than the control group (p < 0.01). Radiofrequency group had higher total damage score compared to the laser group at level 1 (p < 0.01), 2 (p < 0.01), and 5 (p < 0.01); while no significant difference was observed at level 3 (p = 0.46) and 4 (p = 0.13). Significant heat induced damage may be seen even if the 2 cm segment of the vessel is left unablated. Radiofrequency ablation seems to cause more histological damage than laser ablation in this ex vivo study. Further in vivo studies are necessary, in order to validate these findings.

Wolff-Parkinson-White Syndrome with Ventricular Hypertrophy in a Brazilian Family

PubMed Central

de Paula van der Steld, Lenises; Campuzano, Oscar; Pérez-Serra, Alexandra; de Barros Zamorano, Mabel Moura; Matos, Selma Sousa; Brugada, Ramon

2017-01-01

Case series Patient: — Final Diagnosis: PRKAG2 syndrome Symptoms: Palpitation • dyspnea and fatigue • syncope Medication: — Clinical Procedure: Radiofrequency catheter ablation • pacemaker implantion • antiarrhythmic drugs Specialty: Cardiology Objective: Rare disease Background: PRKAG2 syndrome diagnosis is already well-defined as Wolff-Parkinson-White syndrome (WPW), ventricular hypertrophy (VH) due to glycogen accumulation, and conduction system disease (CSD). Because of its rarity, there is a lack of literature focused on the treatment. The present study aimed to describe appropriate strategies for the treatment of affected family members with PRKAG2 syndrome with a long follow-up period. Case Report: We studied 60 selected individuals from 84 family members (32 males, 53.3%) (mean age 27±16 years). Patients with WPW and/or VH were placed in a group of 18 individuals, in which 11 (61.1%) had VH and WPW, 6 (33.3%) had isolated WPW, and 1 (5.6%) had isolated VH. Palpitations occurred in 16 patients (88.9%), chest pain in 11 (61.1%), dizziness in 13 (72.2%), syncope in 15 (83.3%), and dyspnea in 13 (72%). Sudden cardiac death (SCD) occurred in 2 (11.1%), and 2 patients with cardiac arrest (CA) had asystole and pre-excited atrial flutter-fibrillation (AFL and AF) as the documented mechanism. Transient ischemic attack (TIA) and learning/language disabilities with delayed development were observed. Genetic analysis identified a new missense pathogenic variant (p.K290I) in the PRKAG2 gene. Cardiac histopathology demonstrated the predominance of vacuoles containing glycogen derivative and fibrosis. The treatment was based on hypertension and diabetes mellitus (DM) control, antiarrhythmic drugs (AD), anticoagulation, and radiofrequency catheter ablation (RCA). Six patients (33.3%) underwent pacemaker implantation (PM). Conclusions: The present study describes the clinical treatment for a rare cardiac syndrome caused by a PRKAG2 mutation. PMID:28690312

Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation

PubMed Central

Muñoz-Romero, Sergio; Erazo-Rodas, Mayra; Sánchez-Muñoz, Juan José; García-Alberola, Arcadi

2018-01-01

The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity. The present paper is devoted to determining the criteria and force signal profiles that guarantee the contact of the electrode with the tissue. In this study, we analyzed 1391 force signals and their associated EGM recorded during 2 and 8 s, respectively, in 17 patients (82 ± 60 points per patient). We aimed to establish a contact pattern by first visually examining and classifying the signals, according to their likely-contact joint profile and following the suggestions from experts in the doubtful cases. First, we used Principal Component Analysis to scrutinize the force signal dynamics by analyzing the main eigen-directions, first globally and then grouped according to the certainty of their tissue-catheter contact. Second, we used two different linear classifiers (Fisher discriminant and support vector machines) to identify the most relevant components of the previous signal models. We obtained three main types of eigenvectors, namely, pulsatile relevant, non-pulsatile relevant, and irrelevant components. The classifiers reached a moderate to sufficient discrimination capacity (areas under the curve between 0.84 and 0.95 depending on the contact certainty and on the classifier), which allowed us to analyze the relevant properties in the force signals. We conclude that the catheter-tissue contact profiles in force recordings are complex and do not depend only on the signal intensity being above a threshold at a single time instant, but also on time pulsatility and trends. These

Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation.

PubMed

Rivas-Lalaleo, David; Muñoz-Romero, Sergio; Huerta, Mónica; Erazo-Rodas, Mayra; Sánchez-Muñoz, Juan José; Rojo-Álvarez, José Luis; García-Alberola, Arcadi

2018-05-02

The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity. The present paper is devoted to determining the criteria and force signal profiles that guarantee the contact of the electrode with the tissue. In this study, we analyzed 1391 force signals and their associated EGM recorded during 2 and 8 s, respectively, in 17 patients (82 ± 60 points per patient). We aimed to establish a contact pattern by first visually examining and classifying the signals, according to their likely-contact joint profile and following the suggestions from experts in the doubtful cases. First, we used Principal Component Analysis to scrutinize the force signal dynamics by analyzing the main eigen-directions, first globally and then grouped according to the certainty of their tissue-catheter contact. Second, we used two different linear classifiers (Fisher discriminant and support vector machines) to identify the most relevant components of the previous signal models. We obtained three main types of eigenvectors, namely, pulsatile relevant, non-pulsatile relevant, and irrelevant components. The classifiers reached a moderate to sufficient discrimination capacity (areas under the curve between 0.84 and 0.95 depending on the contact certainty and on the classifier), which allowed us to analyze the relevant properties in the force signals. We conclude that the catheter-tissue contact profiles in force recordings are complex and do not depend only on the signal intensity being above a threshold at a single time instant, but also on time pulsatility and trends

A central venous catheter coated with benzalkonium chloride for the prevention of catheter-related microbial colonization.

PubMed

Moss, H A; Tebbs, S E; Faroqui, M H; Herbst, T; Isaac, J L; Brown, J; Elliott, T S

2000-11-01

In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P = 0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.

Photoacoustic characterization of radiofrequency ablation lesions

NASA Astrophysics Data System (ADS)

Bouchard, Richard; Dana, Nicholas; Di Biase, Luigi; Natale, Andrea; Emelianov, Stanislav

2012-02-01

Radiofrequency ablation (RFA) procedures are used to destroy abnormal electrical pathways in the heart that can cause cardiac arrhythmias. Current methods relying on fluoroscopy, echocardiography and electrical conduction mapping are unable to accurately assess ablation lesion size. In an effort to better visualize RFA lesions, photoacoustic (PA) and ultrasonic (US) imaging were utilized to obtain co-registered images of ablated porcine cardiac tissue. The left ventricular free wall of fresh (i.e., never frozen) porcine hearts was harvested within 24 hours of the animals' sacrifice. A THERMOCOOLR Ablation System (Biosense Webster, Inc.) operating at 40 W for 30-60 s was used to induce lesions through the endocardial and epicardial walls of the cardiac samples. Following lesion creation, the ablated tissue samples were placed in 25 °C saline to allow for multi-wavelength PA imaging. Samples were imaged with a VevoR 2100 ultrasound system (VisualSonics, Inc.) using a modified 20-MHz array that could provide laser irradiation to the sample from a pulsed tunable laser (Newport Corp.) to allow for co-registered photoacoustic-ultrasound (PAUS) imaging. PA imaging was conducted from 750-1064 nm, with a surface fluence of approximately 15 mJ/cm2 maintained during imaging. In this preliminary study with PA imaging, the ablated region could be well visualized on the surface of the sample, with contrasts of 6-10 dB achieved at 750 nm. Although imaging penetration depth is a concern, PA imaging shows promise in being able to reliably visualize RF ablation lesions.

Comparison of catheter ablation for paroxysmal atrial fibrillation between cryoballoon and radiofrequency: a meta-analysis.

PubMed

Chen, Chao-Feng; Gao, Xiao-Fei; Duan, Xu; Chen, Bin; Liu, Xiao-Hua; Xu, Yi-Zhou

2017-04-01

The present systematic review and meta-analysis aimed to assess and compare the safety and efficacy of radiofrequency (RF) and cryoballoon (CB) ablation for paroxysmal atrial fibrillation (PAF). RF and CB ablation are two frequently used methods for pulmonary vein isolation in PAF, but which is a better choice for PAF remains uncertain. A systematic review was conducted in Medline, PubMed, Embase, and Cochrane Library. All trials comparing RF and CB ablation were screened and included if the inclusion criteria were met. A total of 38 eligible studies, 9 prospective randomized or randomized controlled trials (RCTs), and 29 non- RCTs were identified, adding up to 15,496 patients. Pool analyses indicated that CB ablation was more beneficial in terms of procedural time [standard mean difference = -0.58; 95% confidence interval (CI), -0.85 to -0.30], complications without phrenic nerve injury (PNI) [odds ratio (OR) = 0.79; 95% CI, 0.67-0.93; I 2  = 16%], and recrudescence (OR = 0.83; 95% CI, 0.70-0.97; I 2  = 63%) for PAF; however, the total complications of CB was higher than RF. The subgroup analysis found that, compared with non-contact force radiofrequency (non-CF-RF), both first-generation cryoballoon (CB1) and second-generation cryoballoon (CB2) ablation could reduce complications with PNI, procedural time, and recrudescence. However, the safety and efficacy of CB2 was similar to those of CF-RF. Available overall and subgroup data suggested that both CB1 and CB2 were more beneficial than RF ablation, and the main advantages were reflected in comparing them with non-CF-RF. However, CF-RF and CB2 showed similar clinical benefits.

Catheter associated urinary tract infections

PubMed Central

2014-01-01

Urinary tract infection attributed to the use of an indwelling urinary catheter is one of the most common infections acquired by patients in health care facilities. As biofilm ultimately develops on all of these devices, the major determinant for development of bacteriuria is duration of catheterization. While the proportion of bacteriuric subjects who develop symptomatic infection is low, the high frequency of use of indwelling urinary catheters means there is a substantial burden attributable to these infections. Catheter-acquired urinary infection is the source for about 20% of episodes of health-care acquired bacteremia in acute care facilities, and over 50% in long term care facilities. The most important interventions to prevent bacteriuria and infection are to limit indwelling catheter use and, when catheter use is necessary, to discontinue the catheter as soon as clinically feasible. Infection control programs in health care facilities must implement and monitor strategies to limit catheter-acquired urinary infection, including surveillance of catheter use, appropriateness of catheter indications, and complications. Ultimately, prevention of these infections will require technical advances in catheter materials which prevent biofilm formation. PMID:25075308

Foley catheter balloon endometrial ablation: successful treatment of three cases.

PubMed

Api, Murat; Api, Olus

2012-03-01

Endometrial ablation is one of the most effective methods for treatment of dysfunctional uterine bleeding (DUB). Balloon devices with circulating hot water inside or electrodes on the outer surface and radiofrequency-induced thermal destructors are the most recently introduced available tools for endometrial ablation. All of these methods are effective and simple but expensive technologies. The aim of this brief report is to evaluate the effectiveness and safety of a new, simple and money-saving procedure, namely foley catheter balloon endometrial ablation (FCBEA), for treatment of DUB. We present our experience with FCBEA performed on 3 women with severe meno-metrorrhagia unresponsive to medical therapy. There were no procedure-related complications with achievement of complete amenorrhea for a 19 months follow-up period. Although FCBA has yielded encouraging results, there exists a need for further investigation and validation on larger groups, before its universal application.

Radiotherapy beyond cancer: Target localization in real-time MRI and treatment planning for cardiac radiosurgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ipsen, S.; Blanck, O.; Rades, D.

2014-12-15

Purpose: Atrial fibrillation (AFib) is the most common cardiac arrhythmia that affects millions of patients world-wide. AFib is usually treated with minimally invasive, time consuming catheter ablation techniques. While recently noninvasive radiosurgery to the pulmonary vein antrum (PVA) in the left atrium has been proposed for AFib treatment, precise target location during treatment is challenging due to complex respiratory and cardiac motion. A MRI linear accelerator (MRI-Linac) could solve the problems of motion tracking and compensation using real-time image guidance. In this study, the authors quantified target motion ranges on cardiac magnetic resonance imaging (MRI) and analyzed the dosimetric benefitsmore » of margin reduction assuming real-time motion compensation was applied. Methods: For the imaging study, six human subjects underwent real-time cardiac MRI under free breathing. The target motion was analyzed retrospectively using a template matching algorithm. The planning study was conducted on a CT of an AFib patient with a centrally located esophagus undergoing catheter ablation, representing an ideal case for cardiac radiosurgery. The target definition was similar to the ablation lesions at the PVA created during catheter treatment. Safety margins of 0 mm (perfect tracking) to 8 mm (untracked respiratory motion) were added to the target, defining the planning target volume (PTV). For each margin, a 30 Gy single fraction IMRT plan was generated. Additionally, the influence of 1 and 3 T magnetic fields on the treatment beam delivery was simulated using Monte Carlo calculations to determine the dosimetric impact of MRI guidance for two different Linac positions. Results: Real-time cardiac MRI showed mean respiratory target motion of 10.2 mm (superior–inferior), 2.4 mm (anterior–posterior), and 2 mm (left–right). The planning study showed that increasing safety margins to encompass untracked respiratory motion leads to overlapping structures even

Agreement of Bioreactance Cardiac Output Monitoring With Thermodilution During Hemorrhagic Shock and Resuscitation in Adult Swine.

PubMed

Berlin, David A; Peprah-Mensah, Harrison; Manoach, Seth; Heerdt, Paul M

2017-02-01

The study tests the hypothesis that noninvasive cardiac output monitoring based upon bioreactance (Cheetah Medical, Portland, OR) has acceptable agreement with intermittent bolus thermodilution over a wide range of cardiac output in an adult porcine model of hemorrhagic shock and resuscitation. Prospective laboratory animal investigation. Preclinical university laboratory. Eight ~ 50 kg Yorkshire swine with a femoral artery catheter for blood pressure measurement and a pulmonary artery catheter for bolus thermodilution. With the pigs anesthetized and mechanically ventilated, 40 mL/kg of blood was removed yielding marked hypotension and a rise in plasma lactate. After 60 minutes, pigs were resuscitated with shed blood and crystalloid. Noninvasive cardiac output monitoring and intermittent thermodilution cardiac output were simultaneously measured at nine time points spanning baseline, hemorrhage, and resuscitation. Simultaneous noninvasive cardiac output monitoring and thermodilution measurements of cardiac output were compared by Bland-Altman analysis. A plot was constructed using the difference of each paired measurement expressed as a percentage of the mean of the pair plotted against the mean of the pair. Percent bias was used to scale the differences in the measurements for the magnitude of the cardiac output. Method concordance was assessed from a four-quadrant plot with a 15% zone of exclusion. Overall, noninvasive cardiac output monitoring percent bias was 1.47% (95% CI, -2.5 to 5.4) with limits of agreement of upper equal to 33.4% (95% CI, 26.5-40.2) and lower equal to -30.4% (95% CI, -37.3 to -23.6). Trending analysis demonstrated a 97% concordance between noninvasive cardiac output monitoring and thermodilution cardiac output. Over the wide range of cardiac output produced by hemorrhage and resuscitation in large pigs, noninvasive cardiac output monitoring has acceptable agreement with thermodilution cardiac output.

Endovascular brain intervention and mapping in a dog experimental model using magnetically-guided micro-catheter technology.

PubMed

Kara, Tomas; Leinveber, Pavel; Vlasin, Michal; Jurak, Pavel; Novak, Miroslav; Novak, Zdenek; Chrastina, Jan; Czechowicz, Krzysztof; Belehrad, Milos; Asirvatham, Samuel J

2014-06-01

Despite the substantial progress that has been achieved in interventional cardiology and cardiac electrophysiology, endovascular intervention for the diagnosis and treatment of central nervous system (CNS) disorders such as stroke, epilepsy and CNS malignancy is still limited, particularly due to highly tortuous nature of the cerebral arterial and venous system. Existing interventional devices and techniques enable only limited and complicated access especially into intra-cerebral vessels. The aim of this study was to develop a micro-catheter magnetically-guided technology specifically designed for endovascular intervention and mapping in deep CNS vascular structures. Mapping of electrical brain activity was performed via the venous system on an animal dog model with the support of the NIOBE II system. A novel micro-catheter specially designed for endovascular interventions in the CNS, with the support of the NIOBE II technology, was able to reach safely deep intra-cerebral venous structures and map the electrical activity there. Such structures are not currently accessible using standard catheters. This is the first study demonstrating successful use of a new micro-catheter in combination with NIOBE II technology for endovascular intervention in the brain.

Comparison of branch and distally focused main renal artery denervation using two different radio-frequency systems in a porcine model.

PubMed

Mahfoud, Felix; Pipenhagen, Catherine A; Boyce Moon, L; Ewen, Sebastian; Kulenthiran, Saarraaken; Fish, Jeffrey M; Jensen, James A; Virmani, Renu; Joner, Michael; Yahagi, Kazuyuki; Tsioufis, Costas; Böhm, Michael

2017-08-15

Anatomic placement of lesions may impact efficacy of radio-frequency (RF) catheter renal denervation (RDN). However, it is unclear if it is necessary to perform treatments post bifurcation with systems that may provide deeper penetration to achieve successful RDN. Sixteen domestic swine (n=16) were randomly assigned to 4 groups: 1) 8 lesions created in the branch arteries using the Spyral catheter (SP8); 2) 8 lesions created in the branch arteries plus 4 lesions created in the main artery using the SP catheter (SP12); 3) 8 lesions created in the main artery using the EnligHTN catheter with the distal position as close as possible to the bifurcation (EN8); and 4) 12 lesions created in the main artery using the EN catheter with the distal position as close as possible to the bifurcation (EN12). Each arm showed statistically significant changes in kidney norepinephrine (NE, ng/g) between treated kidneys vs. untreated contralateral control. There were no statistically significant differences in tissue NE% reductions across each arm based on catheter, anatomic location, & number of lesions (p=0.563): EN8 -74±34%, EN12 -95±3%, SP8 -76±16%, SP12 -82±17% (p=0.496). A total of 46 lesions were measured for lesion depth: EN main (3.3±2.8mm) vs. SP branch (2.0±1.0mm, p=0.039), SP main (2.9±1.6mm) vs. SP branch (p=0.052), and EN main vs. SP main (p=0.337). Distally-focused main renal artery treatment using the EN system appears to be equally efficacious in reducing tissue NE levels compared with SP treatment in the branches plus main renal arteries, advocating for device-specific procedure execution. Copyright © 2017 Elsevier B.V. All rights reserved.

Zero-fluoroscopy cryothermal ablation of atrioventricular nodal re-entry tachycardia guided by endovascular and endocardial catheter visualization using intracardiac echocardiography (Ice&ICE Trial).

PubMed

Luani, Blerim; Zrenner, Bernhard; Basho, Maksim; Genz, Conrad; Rauwolf, Thomas; Tanev, Ivan; Schmeisser, Alexander; Braun-Dullaeus, Rüdiger C

2018-01-01

Stochastic damage of the ionizing radiation to both patients and medical staff is a drawback of fluoroscopic guidance during catheter ablation of cardiac arrhythmias. Therefore, emerging zero-fluoroscopy catheter-guidance techniques are of great interest. We investigated, in a prospective pilot study, the feasibility and safety of the cryothermal (CA) slow-pathway ablation in patients with symptomatic atrioventricular-nodal-re-entry-tachycardia (AVNRT) using solely intracardiac echocardiography (ICE) for endovascular and endocardial catheter visualization. Twenty-five consecutive patients (mean age 55.6 ± 12.0 years, 17 female) with ECG-documentation or symptoms suggesting AVNRT underwent an electrophysiology study (EPS) in our laboratory utilizing ICE for catheter navigation. Supraventricular tachycardia was inducible in 23 (92%) patients; AVNRT was confirmed by appropriate stimulation maneuvers in 20 (80%) patients. All EPS in the AVNRT subgroup could be accomplished without need for fluoroscopy, relying solely on ICE-guidance. CA guided by anatomical location and slow-pathway potentials was successful in all patients, median cryo-mappings = 6 (IQR:3-10), median cryo-ablations = 2 (IQR:1-3). Fluoroscopy was used to facilitate the trans-septal puncture and localization of the ablation substrate in the remaining 3 patients (one focal atrial tachycardia and two atrioventricular-re-entry-tachycardias). Mean EPS duration in the AVNRT subgroup was 99.8 ± 39.6 minutes, ICE guided catheter placement 11.9 ± 5.8 minutes, time needed for diagnostic evaluation 27.1 ± 10.8 minutes, and cryo-application duration 26.3 ± 30.8 minutes. ICE-guided zero-fluoroscopy CA in AVNRT patients is feasible and safe. Real-time visualization of the true endovascular borders and cardiac structures allow for safe catheter navigation during the ICE-guided EPS and might be an alternative to visualization technologies using geometry reconstructions. © 2017 Wiley Periodicals, Inc.

Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation

PubMed Central

Chen, Xiaodong; Chen, Minglong; Wang, Yingying; Yang, Bing; Ju, Weizhu; Zhang, Fengxiang; Cao, Kejiang

2016-01-01

Abstract We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler (PW) and pulse tissue Doppler imaging (PW-TDI). A total of 25 consecutive in-patients with persistent atrial fibrillation, who restored sinus rhythm after ablation procedure, were recruited in our cardiac center. Echocardiography was performed on each patient at 2 hours, 1 day, 5 days, 1 month and 3 months after the ablation therapy, and atrial electromechanical delay was measured simultaneously by PW and PW-TDI. There was no significant difference between PW and TDI in measuring atrial electromechanical delay. However, at postoperative 2 hours, peak A detection rates were mathematically but nonsignificantly greater by PW-TDI than by PW. Second, there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months, but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time. Lastly, patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval, by the PW or by PW-TDI, respectively. In patients with persistent atrial fibrillation, atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later, and was significantly related to patients’ duration of atrial fibrillation. Atrial electromechanical interval, as a potential predicted factor, is recommended to be measured by either PW or TDI after 24 hours, when patients had recovered sinus rhythm by radiofrequency ablation. PMID:27924066

The effects of nuclear magnetic resonance on patients with cardiac pacemakers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlicek, W.; Geisinger, M.; Castle, L.

1983-04-01

The effect of nuclear magnetic resonance (NMR) imaging on six representative cardiac pacemakers was studied. The results indicate that the threshold for initiating the asynchronous mode of a pacemaker is 17 gauss. Radiofrequency levels are present in an NMR unit and may confuse or possibly inhibit demand pacemakers, although sensing circuitry is normally provided with electromagnetic interference discrimination. Time-varying magnetic fields can generate pulse amplitudes and frequencies to mimic cardiac activity. A serious limitation in the possibility of imaging a patient with a pacemaker would be the alteration of normal pulsing parameters due to time-varying magnetic fields.

Use of peripherally inserted central catheters as an alternative to central catheters in neurocritical care units.

PubMed

DeLemos, Christi; Abi-Nader, Judy; Akins, Paul T

2011-04-01

Patients in neurological critical care units often have lengthy stays that require extended vascular access and invasive hemodynamic monitoring. The traditional approach for these patients has relied heavily on central venous and pulmonary artery catheters. The aim of this study was to evaluate peripherally inserted central catheters as an alternative to central venous catheters in neurocritical care settings. Data on 35 patients who had peripherally inserted central catheters rather than central venous or pulmonary artery catheters for intravascular access and monitoring were collected from a prospective registry of neurological critical care admissions. These data were cross-referenced with information from hospital-based data registries for peripherally inserted central catheters and subarachnoid hemorrhage. Complete data were available on 33 patients with Hunt-Hess grade IV-V aneurysmal subarachnoid hemorrhage. Catheters remained in place a total of 649 days (mean, 19 days; range, 4-64 days). One patient (3%) had deep vein thrombosis in an upper extremity. In 2 patients, central venous pressure measured with a peripherally inserted catheter was higher than pressure measured concurrently with a central venous catheter. None of the 33 patients had a central catheter bloodstream infection or persistent insertion-related complications. CONCLUSIONS Use of peripherally inserted central catheters rather than central venous catheters or pulmonary artery catheters in the neurocritical care unit reduced procedural and infection risk without compromising patient management.

Catheter ablation of junctional ectopic tachycardia in children, with preservation of atrioventricular conduction.

PubMed

Emmel, M; Sreeram, N; Brockmeier, K

2005-04-01

Idiopathic junctional ectopic tachycardia is a rare arrhythmia in children. Several studies have demonstrated that drug therapy is often ineffective and sometimes the only achieved effect is rate control. Early presentation and frequent recurrence are associated with adverse outcome. Three consecutive children, aged 9, 7 and 12 years respectively, underwent radiofrequency catheter ablation for junctional ectopic tachycardia, after having failed antiarrhythmic drug therapy. The entire His bundle was plotted out and marked, using the Localisa navigation system. The arrhythmia was readily and repeatedly inducible using intravenous isoprenaline infusion and the site of earliest retrograde conduction during tachycardia could be assessed. Ablations were performed in sinus rhythm, empirically targeting the site of earliest retrograde conduction during tachycardia. This approach was successful in abolishing tachyarrhythmia in the first two patients, in whom the successful ablation site was located superoparaseptally. In the third patient, junctional ectopic tachycardia was inducible, despite abolishing retrograde atrial activation, in a septal location on the tricuspid valve annulus. Further ablations in the superoparaseptal region, closer to the His bundle, were successful in rendering tachyarrhythmia noninducible. Over a median follow-up of 10 months, none of the patients has had recurrence of arrhythmia, despite discontinuing all antiarrhythmic medications. Radio frequency catheter ablation of junctional ectopic tachycardia is feasible with preservation of atrioventricular conduction.

Catheter interventions in the staged management of hypoplastic left heart syndrome.

PubMed

Reinhardt, Zdenka; De Giovanni, Joseph; Stickley, John; Bhole, Vinay K; Anderson, Benjamin; Murtuza, Bari; Mehta, Chetan; Miller, Paul; Dhillon, Rami; Stumper, Oliver

2014-04-01

To analyse the current practice and contribution of catheter interventions in the staged management of patients with hypoplastic left heart syndrome. This study is a retrospective case note review of 527 patients undergoing staged Norwood/Fontan palliation at a single centre between 1993 and 2010. Indications and type of catheter interventions were reviewed over a median follow-up period of 7.5 years. A staged Norwood/Fontan palliation for hypoplastic left heart syndrome was performed in 527 patients. The 30-day survival rate after individual stages was 76.5% at Stage I, 96.3% at Stage II, and 99.4% at Stage III. A total of 348 interventions were performed in 189 out of 527 patients. Freedom from catheter intervention in survivors was 58.2% before Stage II and 46.7% before Stage III. Kaplan-Meier freedom from intervention post Fontan completion was 55% at 10.8 years of follow-up. Post-stage I interventions were mostly directed to relieve aortic arch obstruction--84 balloon angioplasties--and augment pulmonary blood flow--15 right ventricle-to-pulmonary conduit interventions; post-Stage II interventions centred on augmenting size of the left pulmonary artery--73 procedures and abolishing systemic venous collaterals--32 procedures. After Stage III, the focus was on manipulating the size of the fenestration--42 interventions--and the left pulmonary artery -31 procedures. Interventional cardiac catheterisation constitutes an integral part in the staged palliative management of patients with hypoplastic left heart syndrome. Over one-third (37%) of patients undergoing staged palliation required catheter intervention over the follow-up period.

Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state.

PubMed

Femnou, Armel N; Kuzmiak-Glancy, Sarah; Covian, Raul; Giles, Abigail V; Kay, Matthew W; Balaban, Robert S

2017-12-01

Absorbance spectroscopy of intrinsic cardiac chromophores provides nondestructive assessment of cytosolic oxygenation and mitochondria redox state. Isolated perfused heart spectroscopy is usually conducted by collecting reflected light from the heart surface, which represents a combination of surface scattering events and light that traversed portions of the myocardium. Reflectance spectroscopy with complex surface scattering effects in the beating heart leads to difficulty in quantitating chromophore absorbance. In this study, surface scattering was minimized and transmural path length optimized by placing a light source within the left ventricular chamber while monitoring transmurally transmitted light at the epicardial surface. The custom-designed intrachamber light catheter was a flexible coaxial cable (2.42-Fr) terminated with an encapsulated side-firing LED of 1.8 × 0.8 mm, altogether similar in size to a Millar pressure catheter. The LED catheter had minimal impact on aortic flow and heart rate in Langendorff perfusion and did not impact stability of the left ventricule of the working heart. Changes in transmural absorbance spectra were deconvoluted using a library of chromophore reference spectra to quantify the relative contribution of specific chromophores to the changes in measured absorbance. This broad-band spectral deconvolution approach eliminated errors that may result from simple dual-wavelength absorbance intensity. The myoglobin oxygenation level was only 82.2 ± 3.0%, whereas cytochrome c and cytochrome a + a 3 were 13.3 ± 1.4% and 12.6 ± 2.2% reduced, respectively, in the Langendorff-perfused heart. The intracardiac illumination strategy permits transmural optical absorbance spectroscopy in perfused hearts, which provides a noninvasive real-time monitor of cytosolic oxygenation and mitochondria redox state. NEW & NOTEWORTHY Here, a novel nondestructive real-time approach for monitoring intrinsic indicators of cardiac

BIOPHYSICAL PARAMETERS DURING RADIOFREQUENCY CATHETER ABLATION OF SCAR-MEDIATED VENTRICULAR TACHYCARDIA: EPICARDIAL AND ENDOCARDIAL APPLICATIONS VIA MANUAL AND MAGNETIC NAVIGATION

PubMed Central

Bourke, Tara; Buch, Eric; Mathuria, Nilesh; Michowitz, Yoav; Yu, Ricky; Mandapati, Ravi; Shivkumar, Kalyanam; Tung, Roderick

2014-01-01

Background There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT). Methods and Results Data was collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data was available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs 76%, p=0.002) and loss of capture (46% vs 27%, p<0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs 71%, p=0.02) and an EGM reduction (71% vs 40%, p< 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed. Conclusions VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted. PMID:24946895

Biophysical parameters during radiofrequency catheter ablation of scar-mediated ventricular tachycardia: epicardial and endocardial applications via manual and magnetic navigation.

PubMed

Bourke, Tara; Buch, Eric; Mathuria, Nilesh; Michowitz, Yoav; Yu, Ricky; Mandapati, Ravi; Shivkumar, Kalyanam; Tung, Roderick

2014-11-01

There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT). Data were collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data were available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs. 76%, P = 0.002) and loss of capture (46% vs. 27%, P < 0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs. 71%, P = 0.02) and an EGM reduction (71% vs. 40%, P < 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed. VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions, and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted. © 2014 Wiley Periodicals, Inc.

PRE-INOCULATION OF URINARY CATHETERS WITH ESCHERICHIA COLI 83972 INHIBITS CATHETER COLONIZATION BY ENTEROCOCCUS FAECALIS

PubMed Central

TRAUTNER, BARBARA W.; DAROUICHE, RABIH O.; HULL, RICHARD A.; HULL, SHEILA; THORNBY, JOHN I.

2010-01-01

Purpose The capacity of a preexisting coating of Escherichia coli 83972 to reduce catheter colonization by Enterococcus faecalis 210 was investigated. Enterococcus was chosen for these trials since it is a common urinary pathogen in patients with an indwelling urinary catheter. Materials and Methods Each experiment tested 3 growth conditions. Group 1 or E. coli plus Enterococcus catheters were exposed to E. coli 83972 for 24 hours and then to Enterococcus for 30 minutes. Group 2 or E. coli alone catheters were incubated in E. coli for 24 hours and then in sterile broth for 30 minutes. Group 3 or Enterococcus alone catheters did not undergo the initial incubation with E. coli before the 30-minute incubation with Enterococcus: All catheters were then incubated in sterile human urine for 24 hours. Catheters were washed with saline and cut into 5, 1 cm. segments. Each segment was sonicated and the sonication fluid was diluted and plated. The results of each of the 5 segments were averaged and the set of experiments was repeated 7 times. Results A preexisting coating of E. coli 83972 reduced catheter colonization by E. faecalis 210 more than 10-fold. Enterococcus alone catheters had a median of 9.7 × 105 enterococci per cm., whereas E. coli plus Enterococcus catheters had a median of 0.38 × 105 enterococci per cm. (p = 0.016). Conclusions Pre-inoculating urinary catheters with E. coli 83972 significantly impedes catheter colonization by Enterococcus: These promising in vitro results prompt the clinical investigation of this particular application of bacterial interference. PMID:11743359

Prophylactic Catheter Ablation for the Prevention of Defibrillator Therapy

PubMed Central

Reddy, Vivek Y.; Reynolds, Matthew R.; Neuzil, Petr; Richardson, Allison W.; Taborsky, Milos; Jongnarangsin, Krit; Kralovec, Stepan; Sediva, Lucie; Ruskin, Jeremy N.; Josephson, Mark E.

2008-01-01

BACKGROUND For patients who have a ventricular tachyarrhythmic event, implantable cardioverter–defibrillators (ICDs) are a mainstay of therapy to prevent sudden death. However, ICD shocks are painful, can result in clinical depression, and do not offer complete protection against death from arrhythmia. We designed this randomized trial to examine whether prophylactic radiofrequency catheter ablation of arrhythmogenic ventricular tissue would reduce the incidence of ICD therapy. METHODS Eligible patients with a history of a myocardial infarction underwent defibrillator implantation for spontaneous ventricular tachycardia or fibrillation. The patients did not receive antiarrhythmic drugs. Patients were randomly assigned to defibrillator implantation alone or defibrillator implantation with adjunctive catheter ablation (64 patients in each group). Ablation was performed with the use of a substrate-based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm. The primary end point was survival free from any appropriate ICD therapy. RESULTS The mortality rate 30 days after ablation was zero, and there were no significant changes in ventricular function or functional class during the mean (±SD) follow-up period of 22.5±5.5 months. Twenty-one patients assigned to defibrillator implantation alone (33%) and eight patients assigned to defibrillator implantation plus ablation (12%) received appropriate ICD therapy (antitachycardia pacing or shocks) (hazard ratio in the ablation group, 0.35; 95% confidence interval, 0.15 to 0.78, P = 0.007). Among these patients, 20 in the control group (31%) and 6 in the ablation group (9%) received shocks (P = 0.003). Mortality was not increased in the group assigned to ablation as compared with the control group (9% vs. 17%, P = 0.29). CONCLUSIONS In this randomized trial, prophylactic substrate-based catheter ablation reduced the incidence of ICD therapy in patients with a

Catheter-based high-intensity ultrasound for epicardial ablation of the left ventricle: device design and in vivo feasiblity

NASA Astrophysics Data System (ADS)

Salgaonkar, Vasant A.; Nazer, Babak; Jones, Peter D.; Tanaka, Yasuaki; Martin, Alastair; Ng, Bennett; Duggirala, Srikant; Diederich, Chris J.; Gerstenfeld, Edward P.

2015-03-01

The development and in vivo testing of a high-intensity ultrasound thermal ablation catheter for epicardial ablation of the left ventricle (LV) is presented. Scar tissue can occur in the mid-myocardial and epicardial space in patients with nonischemic cardiomyopathy and lead to ventricular tachycardia. Current ablation technology uses radiofrequency energy, which is limited epicardially by the presence of coronary vessels, phrenic nerves, and fat. Ultrasound energy can be precisely directed to deliver targeted deep epicardial ablation while sparing intervening epicardial nerve and vessels. The proof-of-concept ultrasound applicators were designed for sub-xyphoid access to the pericardial space through a steerable 14-Fr sheath. The catheter consists of two rectangular planar transducers, for therapy (6.4 MHz) and imaging (5 MHz), mounted at the tip of a 3.5-mm flexible nylon catheter coupled and encapsulated within a custom-shaped balloon for cooling. Thermal lesions were created in the LV in a swine (n = 10) model in vivo. The ultrasound applicator was positioned fluoroscopically. Its orientation and contact with the LV were verified using A-mode imaging and a radio-opaque marker. Ablations employed 60-s exposures at 15 - 30 W (electrical power). Histology indicated thermal coagulation and ablative lesions penetrating 8 - 12 mm into the left ventricle on lateral and anterior walls and along the left anterior descending artery. The transducer design enabled successful sparing from the epicardial surface to 2 - 4 mm of intervening ventricle tissue and epicardial fat. The feasibility of targeted epicardial ablation with catheter-based ultrasound was demonstrated.

21 CFR 882.4725 - Radiofrequency lesion probe.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

21 CFR 882.4725 - Radiofrequency lesion probe.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

21 CFR 882.4725 - Radiofrequency lesion probe.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

21 CFR 882.4725 - Radiofrequency lesion probe.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

21 CFR 882.4725 - Radiofrequency lesion probe.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

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.

Performance of magnetic field‐guided navigation system for interventional neurosurgical and cardiac procedures

PubMed Central

Chu, James C.H.; Hsi, Wen Chien; Hubbard, Lincoln; Zhang, Yunkai; Bernard, Damian; Reeder, Pamela; Lopes, Demetrius

2005-01-01

A hospital‐based magnetic guidance system (MGS) was installed to assist a physician in navigating catheters and guide wires during interventional cardiac and neurosurgical procedures. The objective of this study is to examine the performance of this magnetic field‐guided navigation system. Our results show that the system's radiological imaging components produce images with quality similar to that produced by other modern fluoroscopic devices. The system's magnetic navigation components also deflect the wire and catheter tips toward the intended direction. The physician, however, will have to oversteer the wire or catheter when defining the steering angle during the procedure. The MGS could be clinically useful in device navigation deflection and vessel access. PACS numbers: 07.55.Db, 07.85.‐m PMID:16143799

47 CFR 2.801 - Radiofrequency device defined.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2... MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device defined. As used in this part, a radiofrequency device is any device which in its operation is capable of...

Model-based imaging of cardiac electrical function in human atria

NASA Astrophysics Data System (ADS)

Modre, Robert; Tilg, Bernhard; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Hintringer, Florian; Roithinger, Franz

2003-05-01

Noninvasive imaging of electrical function in the human atria is attained by the combination of data from electrocardiographic (ECG) mapping and magnetic resonance imaging (MRI). An anatomical computer model of the individual patient is the basis for our computer-aided diagnosis of cardiac arrhythmias. Three patients suffering from Wolff-Parkinson-White syndrome, from paroxymal atrial fibrillation, and from atrial flutter underwent an electrophysiological study. After successful treatment of the cardiac arrhythmia with invasive catheter technique, pacing protocols with stimuli at several anatomical sites (coronary sinus, left and right pulmonary vein, posterior site of the right atrium, right atrial appendage) were performed. Reconstructed activation time (AT) maps were validated with catheter-based electroanatomical data, with invasively determined pacing sites, and with pacing at anatomical markers. The individual complex anatomical model of the atria of each patient in combination with a high-quality mesh optimization enables accurate AT imaging, resulting in a localization error for the estimated pacing sites within 1 cm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias.

Atriocaval Rupture After Right Atrial Isthmus Ablation for Atrial Flutter.

PubMed

Vloka, Caroline; Nelson, Daniel W; Wetherbee, Jule

2016-06-01

A patient with symptomatic typical atrial flutter (AFL) underwent right atrial isthmus ablation with an 8-mm catheter. Eight months later, his typical AFL recurred. Ten months later, he underwent a repeat right atrial isthmus ablation with an irrigated tip catheter and an 8-mm tip catheter. Six weeks after his second procedure, while performing intense sprint intervals on a treadmill, he developed an abrupt onset of chest pain, hypotension, and cardiac tamponade. He underwent emergency surgery to repair an atriocaval rupture and has done well since. Our report suggests that an association of multiple radiofrequency ablations with increased risk for delayed atriocaval rupture occurring 1 to 3 months after ablation. In conclusion, although patients generally were advised to limit exercise for 1 to 2 weeks after AFL ablation procedures in the past, it may be prudent to avoid intense exercise for at least 3 months after procedure. Copyright © 2016 Elsevier Inc. All rights reserved.

Indwelling catheter care

MedlinePlus

... it overnight. You will be shown how to disconnect the bags from the Foley catheter in order ... bags through a separate valve without needing to disconnect the bag from the Foley catheter. Making Sure ...

Urinary tract infection in children after cardiac surgery: Incidence, causes, risk factors and outcomes in a single-center study.

PubMed

Kabbani, Mohamed S; Ismail, Sameh R; Fatima, Anis; Shafi, Rehana; Idris, Julinar A; Mehmood, Akhter; Singh, Reetam K; Elbarabry, Mahmoud; Hijazi, Omar; Hussein, Mohamed A

2016-01-01

Nosocomial urinary tract infection (UTI) increases hospitalization, cost and morbidity. In this cohort study, we aimed to determine the incidence, risk factors, etiology and outcomes of UTIs in post-operative cardiac children. To this end, we studied all post-operative patients admitted to the Pediatric Cardiac Intensive Care Unit (PCICU) in 2012, and we divided the patients into two groups: the UTI (UTI group) and the non-UTI (control group). We compared both groups for multiple peri-operative risk factors. We included 413 children in this study. Of these, 29 (7%) had UTIs after cardiac surgery (UTI group), and 384 (93%) were free from UTIs (control group). All UTI cases were catheter-associated UTIs (CAUTIs). A total of 1578 urinary catheter days were assessed in this study, with a CAUTI density rate of 18 per 1000 catheter days. Multivariate logistic regression analysis demonstrated the following risk factors for CAUTI development: duration of urinary catheter placement (p<0.001), presence of congenital abnormalities of kidney and urinary tract (CAKUT) (p<0.0041) and the presence of certain syndromes (Down, William, and Noonan) (p<0.02). Gram-negative bacteria accounted for 63% of the CAUTI. The main causes of CAUTI were Klebsiella (27%), Candida (24%) and Escherichia coli (21%). Resistant organisms caused 34% of CAUTI. Two patients (7%) died in the UTI group compared with the one patient (0.3%) who died in the control group (p<0.05). Based on these findings, we concluded that an increased duration of the urinary catheter, the presence of CAKUT, and the presence of syndromes comprised the main risk factors for CAUTI. Gram-negative organisms were the main causes for CAUTI, and one-third of them found to be resistant in this single-center study. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Cardiac output monitoring using indicator-dilution techniques: basics, limits, and perspectives.

PubMed

Reuter, Daniel A; Huang, Cecil; Edrich, Thomas; Shernan, Stanton K; Eltzschig, Holger K

2010-03-01

The ability to monitor cardiac output is one of the important cornerstones of hemodynamic assessment for managing critically ill patients at increased risk for developing cardiac complications, and in particular in patients with preexisting cardiovascular comorbidities. For >30 years, single-bolus thermodilution measurement through a pulmonary artery catheter for assessment of cardiac output has been widely accepted as the "clinical standard" for advanced hemodynamic monitoring. In this article, we review this clinical standard, along with current alternatives also based on the indicator-dilution technique, such as the transcardiopulmonary thermodilution and lithium dilution techniques. In this review, not only the underlying technical principles and the unique features but also the limitations of each application of indicator dilution are outlined.

Differentiation of tumor from viable myocardium using cardiac tagging with MR imaging.

PubMed

Bouton, S; Yang, A; McCrindle, B W; Kidd, L; McVeigh, E R; Zerhouni, E A

1991-01-01

We report the application of myocardial tagging by MR to define tissue planes and differentiate contractile from noncontractile tissue in a neonate with congenital cardiac rhabdomyoma. Using custom-written pulse programming software, six 2 mm thick radiofrequency (RF) slice-selective presaturation pulses (tags) were used to label the chest wall and myocardium in a star pattern in diastole, approximately 60 ms before the R-wave gating trigger. This method successfully delineated the myocardium from noncontractile tumor, providing information that influenced clinical management. This RF tagging technique allowed us to confirm the exact intramyocardial location of a congenital cardiac tumor.

Risk factors for nosocomial infections after cardiac surgery in newborns with congenital heart disease.

PubMed

García, Heladia; Cervantes-Luna, Beatriz; González-Cabello, Héctor; Miranda-Novales, Guadalupe

2017-11-23

Congenital heart diseases are among the most common congenital malformations. Approximately 50% of the patients with congenital heart disease undergo cardiac surgery. Nosocomial infections (NIs) are the main complications and an important cause of increased morbidity and mortality associated with congenital heart diseases. This study's objective was to identify the risk factors associated with the development of NIs after cardiac surgery in newborns with congenital heart disease. This was a nested case-control study that included 112 newborns, including 56 cases (with NI) and 56 controls (without NI). Variables analyzed included perinatal history, associated congenital malformations, Risk-Adjusted Congenital Heart Surgery (RACHS-1) score, perioperative and postoperative factors, transfusions, length of central venous catheter, nutritional support, and mechanical ventilation. Differences were calculated with the Mann-Whitney-U test, Pearson X 2 , or Fisher's exact test. A multivariate logistic regression was used to determine the independent risk factors. Sepsis was the most common NI (37.5%), and the main causative microorganisms were gram-positive cocci. The independent risk factors associated with NI were non-cardiac congenital malformations (OR 6.1, CI 95% 1.3-29.4), central venous catheter indwelling time > 14 days (OR 3.7, CI 95% 1.3-11.0), duration of mechanical ventilation > 7 days (OR 6.6, CI 95% 2.1-20.1), and ≥5 transfusions of blood products (OR 3.1, CI 95% 1.3-8.5). Mortality attributed to NI was 17.8%. Newborns with non-cardiac congenital malformations and with >7 days of mechanical ventilation were at higher risk for a postoperative NI. Efforts must focus on preventable infections, especially in bloodstream catheter-related infections, which account for 20.5% of all NIs. Copyright © 2017. Published by Elsevier B.V.

Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the pro perspective.

PubMed

Pappone, Carlo; Santinelli, Vincenzo

2015-09-01

Important advances in the natural history and diagnosis of, and therapy for, asymptomatic Wolff-Parkinson-White (WPW) syndrome have been made in the last decade by our group. These data have necessitated revisiting current practice guidelines to decide on the optimal management of the asymptomatic WPW population. There has also been an emphasis on identifying initially asymptomatic individuals who are at risk by nationwide screening programs using the electrocardiogram for prophylactic catheter ablation to prevent the lifetime risk of sudden cardiac death, particularly in young asymptomatic people, because only a subgroup of them is at high risk, requiring early catheter ablation. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Iatrogenic hyperthermia during cardiac magnetic resonance imaging.

PubMed

Kussman, Barry D; Mulkern, Robert V; Holzman, Robert S

2004-10-01

We report the occurrence of accidental hyperthermia in a young child undergoing anesthesia for cardiac magnetic resonance imaging. Although the tendency during anesthesia is to develop hypothermia, the absorbed radiofrequency energy from magnetic resonance scanning is added to metabolic energy and must be balanced by appropriate heat loss to maintain normothermia. In addition to stressing the clinical importance of temperature monitoring, this report suggests that the recommended specific absorption rates to prevent excessive patient heating may need to be revised for infants and young children.

Determining the best catheter for sonohysterography.

PubMed

Dessole, S; Farina, M; Capobianco, G; Nardelli, G B; Ambrosini, G; Meloni, G B

2001-09-01

To compare the characteristics of six different catheters for performing sonohysterography (SHG) to identify those that offer the best compromise between reliability, tolerability, and cost. Prospective study. University hospital. Six hundred ten women undergoing SHG. We performed SHG with six different types of catheters: Foleycath (Wembley Rubber Products, Sepang, Malaysia), Hysca Hysterosalpingography Catheter (GTA International Medical Devices S.A., La Caleta D.N., Dominican Republic), H/S Catheter Set (Ackrad Laboratories, Cranford, NJ), PBN Balloon Hystero-Salpingography Catheter (PBN Medicals, Stenloese, Denmark), ZUI-2.0 Catheter (Zinnanti Uterine Injection; BEI Medical System International, Gembloux, Belgium), and Goldstein Catheter (Cook, Spencer, IN). We assessed the reliability, the physician's ease of use, the time requested for the insertion of the catheter, the volume of contrast medium used, the tolerability for the patients, and the cost of the catheters. In 568 (93%) correctly performed procedures, no statistically significant differences were found among the catheters. The Foleycath was the most difficult for the physician to use and required significantly more time to position correctly. The Goldstein catheter was the best tolerated by the patients. The Foleycath was the cheapest whereas the PBN Balloon was the most expensive. The choice of the catheter must be targeted to achieving a good balance between tolerability for the patients, efficacy, cost, and the personal preference of the operator.

Feasibility and safety of catheter ablation of electrical storm in ischemic dilated cardiomyopathy.

PubMed

Dello Russo, Antonio; Casella, Michela; Pelargonio, Gemma; Santangeli, Pasquale; Bartoletti, Stefano; Bencardino, Gianluigi; Al-Mohani, Ghaliah; Innocenti, Ester; Di Biase, Luigi; Avella, Andrea; Pappalardo, Augusto; Carbucicchio, Corrado; Bellocci, Fulvio; Fiorentini, Cesare; Natale, Andrea; Tondo, Claudio

2016-06-01

Electrical storm is an emergency in 'implantation of a cardioverter defibrillator' carriers with ischemic dilated cardiomyopathy (DCM) and negatively impacts long-term prognosis. We evaluated the feasibility, safety, and effectiveness of radiofrequency catheter ablation (RFCA) in controlling electrical storm and its impact on survival and ventricular tachycardia/fibrillation recurrence. We enrolled 27 consecutive patients (25 men, age 73.1 ± 6.5 years) with ischemic DCM and an indication to RFCA for drug-refractory electrical storm. The immediate outcome was defined as failure or success, depending on whether the patient's clinical ventricular tachycardia could still be induced after RFCA; electrical storm resolution was defined as no sustained ventricular tachycardia/ventricular fibrillation in the next 7 days. Of the 27 patients, 1 died before RFCA; in the remaining 26 patients, a total of 33 RFCAs were performed. In all 26 patients, RFCA was successful, although in 6/26 patients (23.1%), repeated procedures were needed, including epicardial ablation in 3/26 (11.5%). In 23/26 patients (88.5%), electrical storm resolution was achieved. At a follow-up of 16.7 ± 8.1 months, 5/26 patients (19.2%) had died (3 nonsudden cardiac deaths, 2 noncardiac deaths) and 10/26 patients (38.5%) had ventricular tachycardia recurrence; none had electrical storm recurrence. A worse long-term outcome was associated with lower glomerular filtration rate, wider baseline QRS, and presence of atrial fibrillation before electrical storm onset. In patients with ischemic DCM, RFCA is well tolerated, feasible and effective in the acute management of drug-refractory electrical storm. It is associated with a high rate of absence of sustained ventricular tachycardia episodes over the subsequent 7 days. After successful ablation, long-term outcome was mainly predicted by baseline clinical variables.

Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective

NASA Astrophysics Data System (ADS)

Klimas, Aleksandra; Entcheva, Emilia

2014-08-01

The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.

Exploring relationships of catheter-associated urinary tract infection and blockage in people with long-term indwelling urinary catheters.

PubMed

Wilde, Mary H; McMahon, James M; Crean, Hugh F; Brasch, Judith

2017-09-01

To describe and explore relationships among catheter problems in long-term indwelling urinary catheter users, including excess healthcare use for treating catheter problems. Long-term urinary catheter users experience repeated problems with catheter-related urinary tract infection and blockage of the device, yet little has been reported of the patterns and relationships among relevant catheter variables. Secondary data analysis was conducted from a sample in a randomised clinical trial, using data from the entire sample of 202 persons over 12 months' participation. Descriptive statistics were used to characterise the sample over time. Zero-inflated negative binomial models were employed for logistic regressions to evaluate predictor variables of the presence/absence and frequencies of catheter-related urinary tract infection and blockage. Catheter-related urinary tract infection was marginally associated with catheter blockage. Problems reported at least once per person in the 12 months were as follows: catheter-related urinary tract infection 57%, blockage 34%, accidental dislodgment 28%, sediment 87%, leakage (bypassing) 67%, bladder spasms 59%, kinks/twists 42% and catheter pain 49%. Regression analysis demonstrated that bladder spasms were significantly related to catheter-related urinary tract infection and sediment amount, and catheter leakages were marginally significantly and positively related to catheter-related urinary tract infection. Frequencies of higher levels of sediment and catheter leakage were significantly associated with higher levels of blockage, and being female was associated with fewer blockages. Persons who need help with eating (more disabled) were also more likely to have blockages. Catheter-related urinary tract infection and blockage appear to be related and both are associated with additional healthcare expenditures. More research is needed to better understand how to prevent adverse catheter outcomes and patterns of problems in

Rational choice of peritoneal dialysis catheter.

PubMed

Dell'Aquila, Roberto; Chiaramonte, Stefano; Rodighiero, Maria Pia; Spanó, Emilia; Di Loreto, Pierluigi; Kohn, Catalina Ocampo; Cruz, Dinna; Polanco, Natalia; Kuang, Dingwei; Corradi, Valentina; De Cal, Massimo; Ronco, Claudio

2007-06-01

The peritoneal catheter should be a permanent and safe access to the peritoneal cavity. Catheter-related problems are often the cause of permanent transfer to hemodialysis (HD) in up to 20% of peritoneal dialysis (PD) patients; in some cases, these problems require a temporary period on HD. Advances in connectology have reduced the incidence of peritonitis, and so catheter-related complications during PD have become a major concern. In the last few years, novel techniques have emerged in the field of PD: new dialysis solutions, better connectology, and cyclers for automated PD. However, extracorporeal dialysis has continued to improve in terms of methods and patient survival, but PD has failed to do so. The main reason is that peritoneal access has remained problematical. The peritoneal catheter is the major obstacle to wide-spread use of PD. Overcoming catheter-related problems means giving a real chance to development of the peritoneal technique. Catheters should be as efficient, safe, and acceptable as possible. Since its introduction in the mid-1960s, the Tenckhoff catheter has not become obsolete: dozens of new models have been proposed, but none has significantly reduced the pre-dominance of the first catheter. No convincing prospective data demonstrate the superiority of any peritoneal catheter, and so it seems that factors other than choice of catheter are what affect survival and complication rates. Efforts to improve peritoneal catheter survival and complication rates should probably focus on factors other than the choice of catheter. The present article provides an overview of the characteristics of the best-known peritoneal catheters.

Catheter-based renal denervation as therapy for chronic severe kidney-related pain.

PubMed

de Jager, Rosa L; Casteleijn, Niek F; de Beus, Esther; Bots, Michiel L; Vonken, Evert-Jan E; Gansevoort, Ron T; Blankestijn, Peter J

2017-06-22

Loin pain haematuria syndrome (LPHS) and autosomal dominant polycystic kidney disease (ADPKD) are the most important non-urological conditions to cause chronic severe kidney-related pain. Multidisciplinary programmes and surgical methods have shown inconsistent results with respect to pain reduction. Percutaneous catheter-based renal denervation (RDN) could be a less invasive treatment option for these patients. Our aim was to explore the change in perceived pain and use of analgesic medication from baseline to 3, 6 and 12 months after RDN. Patients with LPHS or ADPKD, who experienced kidney-related pain ≥3 months with a visual analogue scale (VAS) score ≥ 50/100 could be included. Percutaneous RDN was performed with a single-electrode radiofrequency ablation catheter. RDN was performed in 11 patients (6 with LPHS and 5 with ADPKD). Perceived pain declined in the whole group by 23 mm (P = 0.012 for the total group). In patients with LPHS and ADPKD, the median daily defined dosage of analgesic medication decreased from 1.6 [interquartile range (IQR) 0.7-2.3] and 1.4 (IQR 0.0-7.4) at baseline to 0.3 (IQR 0.0-1.9; P = 0.138) and 0.0 (IQR 0.0-0.8; P = 0.285) at 12 months, respectively. Mean estimated glomerular filtration rate decreased in the whole group by 5.4 mL/min/1.73 m 2 at 6 months compared with baseline (P = 0.163). These results suggest that percutaneous catheter-based RDN reduces pain complaints and the use of analgesic medication in patients with LPHS or ADPKD. The present results can serve as the rationale for a larger, preferably randomized (sham) controlled study. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Acute urinary retention: which catheter?

PubMed Central

Allardice, J. T.; Standfield, N. J.; Wyatt, A. P.

1988-01-01

There is no scientific data on which is the best method and catheter to use in acute urinary retention in males. We therefore compared the efficiency of a size 12 G latex rubber balloon catheter with a similar calibre but more expensive catheter made of polyvinyl-chloride (PVC). A total of 50 patients was studied and a 100% successful catheterisation rate was recorded at first attempt with both catheters, with no significant complications. The importance of the correct management of acute urinary retention, especially adequate analgesia, is stressed and it is concluded that either catheter is satisfactory. PMID:3207328

Predicting nurses' acceptance of radiofrequency identification technology.

PubMed

Norten, Adam

2012-10-01

The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

In vivo evaluation of virtual electrode mapping and ablation utilizing a direct endocardial visualization ablation catheter.

PubMed

Chik, William W B; Barry, M A; Malchano, Zach; Wylie, Bryan; Pouliopoulos, Jim; Huang, Kaimin; Lu, Juntang; Thavapalachandran, Sujitha; Robinson, David; Saadat, Vahid; Thomas, Stuart P; Ross, David L; Kovoor, Pramesh; Thiagalingam, Aravinda

2012-01-01

Radiofrequency (RF) ablation utilizing direct endocardial visualization (DEV) requires a "virtual electrode" to deliver RF energy while preserving visualization. This study aimed to: (1) examine the virtual electrode RF ablation efficacy; (2) determine the optimal power and duration settings; and (3) evaluate the utility of virtual electrode unipolar electrograms. The DEV catheter lesions were compared to lesions formed using a 3.5 mm open irrigated tip catheter within the right atria of 12 sheep. Generator power settings for DEV were titrated from 12W, 14W and 16W for 20, 30 and 40 seconds duration with 25 mL/min saline irrigation. Standard irrigated tip catheter settings of 30W, 50°C for 30 seconds and 30 mL/min were used. The DEV lesions were significantly greater in surface area and both major and minor axes compared to irrigated tip lesions (surface area 19.43 ± 9.09 vs 10.88 ± 4.72 mm, P<0.01) with no difference in transmurality (93/94 vs 46/47) or depth (1.86 ± 0.75 vs 1.85 ± 0.57 mm). Absolute electrogram amplitude reduction was greater for DEV lesions (1.89 ± 1.31 vs 1.49 ± 0.78 mV, P = 0.04), but no difference in percentage reduction. Pre-ablation pacing thresholds were not different between DEV (0.79 ± 0.36 mA) and irrigated tip (0.73 ± 0.25 mA) lesions. There were no complications noted during ablation with either catheter. Virtual electrode ablation consistently created wider lesions at lower power compared to irrigated tip ablation. Virtual electrode electrograms showed a comparable pacing and sensing efficacy in detecting local myocardial electrophysiological changes. © 2011 Wiley Periodicals, Inc.

Detection of ventricular fibrillation with a ventricular monopolar catheter electrode.

PubMed

Voelz, M B; Wessale, J L; Geddes, L A; Patel, U H

1991-01-01

This report describes the use of right ventricular impedance (RVZ) sensing with a monopolar electrode to identify the cessation of pumping with the onset of ventricular fibrillation. RVZ, ECG (lead II), and femoral artery pressure were monitored in seven anesthetized dogs. An impedance recorder (10-kHz, 100-microA peak-to-peak current) was used to measure RVZ between a monopolar, catheter-mounted electrode placed in the right ventricle and an indifferent electrode (8.5-cm diameter plate) sutured to the right chest wall. The catheter electrode was either 0.4 cm or 1.2 cm long and had a surface area of 0.50 cm2 or 1.50 cm2, respectively. A monopolar electrode was positioned at the apex of the right ventricle or midway between the apex and the tricuspid valve. The peak-to-peak amplitude of the pulsatile cardiac-induced impedance change was measured prior to and throughout an episode of ventricular fibrillation lasting up to 1 minute. On the average, the amplitude of the pulsatile RVZ signal after 10 seconds of fibrillation decreased by 79% of the prefibrillation amplitude. The 1.2-cm electrode located at the middle of the ventricle showed the largest reduction in pulsatile impedance, the amplitude being very small at 10 seconds. It is concluded that sensing RVZ by a monopolar electrode located on a catheter in the mid-ventricle can provide the mechanical information needed to identify the onset of ventricular fibrillation.

Conventional Radiofrequency Thermocoagulation vs Pulsed Radiofrequency Neuromodulation of Ganglion Impar in Chronic Perineal Pain of Nononcological Origin.

PubMed

Usmani, Hammad; Dureja, G P; Andleeb, Roshan; Tauheed, Nazia; Asif, Naiyer

2018-01-10

Chronic nononcological perineal pain has been effectively managed by ganglion Impar block. Chemical neurolysis, cryoablation, and radiofrequency ablation have been the accepted methods of blockade. Recently, pulsed radiofrequency, a novel variant of conventional radiofrequency, has been used for this purpose. This was a prospective, randomized, double-blind study. Two different interventional pain management centers in India. To compare the efficacy of conventional radiofrequency and pulsed radiofrequency for gangliom Impar block. The patients were randomly allocated to one of two groups. In the conventional radiofrequency (CRF) group (N = 34), conventional radiofrequency ablation was done, and in the PRF pulsed radiofrequency (PRF) group (N = 31), pulsed radiofrequency ablation was done. After informed and written consent, fluoroscopy-guided ganglion Impar block was performed through the first intracoccygeal approach. The extent of pain relief was assessed by visual analog scale (VAS) at 24 hours, and at the first, third, and sixth weeks following the intervention. A questionnaire to evaluate subjective patient satisfaction was also used at each follow-up visit. In the CRF group, the mean VAS score decreased significantly from the baseline value at each follow-up visit. But in the PRF group, this decrease was insignificant except at 24-hour follow-up. Intergroup comparison also showed significantly better pain relief in the CRF group as compared with the PRF group. At the end of follow-up, 28 patients (82%) in the CRF group and four patients (13%) in the PRF group had excellent results, as assessed by the subjective patient satisfaction questionnaire. There was no complication in any patient of either study group, except for short-lived infection at the site of skin puncture in a few. Ganglion Impar block by conventional radiofrequency provided a significantly better quality of pain relief with no major side effects in patients with chronic

Echogenic Catheters and Embryo Transfer Standardization.

PubMed

Urbina, Maria Teresa; Benjamin, Isaac; Medina, Randolfo; Lerner, Jorge

2015-05-01

1.To describe the standardization process and protocols of the ET method at our center. 2.To compare the performance of non-echogenic catheters with echogenic catheters during ultrasound-guided ET. Retrospective analysis of 2630 ET performed at UNIFERTES during 1997-2014, to describe standardization process and to compare the percentage of difficult ET between echogenic and non-echogenic catheters. We tested 17 non-echogenic and three echogenic catheters. Many variables were associated with the ease of ET: informed patients, waiting time for the procedure, speculum use, clinical touch, uterine contractions, cervical mucus removal, presence of blood before or after the procedure, full bladder, ultrasound guidance, uterocervical angle, mock transfer, catheter type (soft or hard, echogenic or non-echogenic, with stylet or not), catheter loading technique, duration of embryo loading (time interval since the embryos were removed from the incubator for loading until the catheter is passed to the physician), transfer procedure (time interval from the catheter was handed to the physician until the embryos were discharged in the uterus), catheter tip placement, retained embryos, bed rest after ET, operator´s proficiency. The diversity of catheters used and the percentage of difficult transfers decrease as the use of echogenic catheters increases. This process is necessary to minimize variation, ensure high quality, safe and evidence-based practice, and improve outcomes. To standardize the ET method allowed a quicker and easier transfer. The use of echogenic catheters simplified ET procedures guided by abdominal ultrasound.

Central venous catheter-associated bloodstream infections in a pediatric intensive care unit: effect of the location of catheter insertion.

PubMed

Krishnaiah, Anil; Soothill, James; Wade, Angie; Mok, Quen Q; Ramnarayan, Padmanabhan

2012-05-01

To compare the rate of central venous catheter-associated bloodstream infections between pediatric intensive care unit admissions where central venous catheters were inserted within the same hospital (internal central venous catheters) and those where central venous catheters were inserted before transfer from other hospitals (external central venous catheters). Retrospective analysis of prospectively collected data. A tertiary care pediatric intensive care unit in London, UK. Consecutive pediatric intensive care unit admissions between May 2007 and March 2009. None. Catheter-associated bloodstream infections were identified using a widely accepted surveillance definition. The rate and time to occurrence of catheter-associated bloodstream infection were compared between internal and external nontunneled central venous catheters. A multilevel Cox-regression model was used to study the association between location of central venous catheter insertion and time to catheter-associated bloodstream infection. In total, 382 central venous catheters were studied (245 internal; 137 external) accounting for a total of 1,737 central venous catheter days. There was a higher catheter-associated bloodstream infection incidence density among external central venous catheters (23.1 [95% confidence interval 11.0-35.2] vs. 9.7 [95% confidence interval 3.9-15.5] per 1,000 catheter-days). Multivariable analyses demonstrated higher infection risk with external central venous catheters (hazard ratio 2.65 [95% confidence interval 1.18-5.96]) despite adjustment for confounding variables. The rate of catheter-associated bloodstream infections in the pediatric intensive care unit is significantly affected by external insertion of the central venous catheter. Future interventions to reduce nosocomial infections on pediatric intensive care units will need to be specifically targeted at this high-risk patient group.

Rotors and the Dynamics of Cardiac Fibrillation

PubMed Central

Pandit, Sandeep V.; Jalife, José

2013-01-01

The objective of this article is to present a broad review on the role of cardiac electrical rotors and their accompanying spiral waves in the mechanism of cardiac fibrillation. At the outset, we present a brief historical overview regarding reentry, and then discuss the basic concepts and terminologies pertaining to rotors and their initiation. Thereafter, the intrinsic properties of rotors and spiral waves, including phase singularities, wavefront curvature and dominant frequency maps are discussed. The implications of rotor dynamics for the spatio-temporal organization of fibrillation, independent of the species being studied are touched upon next. The knowledge gained regarding the role of cardiac structure in the initiation and/or maintenance of rotors and the ionic bases of spiral waves in the last two decades, and its significance for drug therapy is reviewed subsequently. We conclude by looking at recent evidence suggesting that rotors are critical in sustaining both atrial and ventricular fibrillation (AF, VF) in the human heart, and its implications for treatment with radio-frequency ablation. PMID:23449547

Remote controlled robot assisted cardiac navigation: feasibility assessment and validation in a porcine model.

PubMed

Ganji, Yusof; Janabi-Sharifi, Farrokh; Cheema, Asim N

2011-12-01

Despite the recent advances in catheter design and technology, intra-cardiac navigation during electrophysiology procedures remains challenging. Incorporation of imaging along with magnetic or robotic guidance may improve navigation accuracy and procedural safety. In the present study, the in vivo performance of a novel remote controlled Robot Assisted Cardiac Navigation System (RACN) was evaluated in a porcine model. The navigation catheter and target sensor were advanced to the right atrium using fluoroscopic and intra-cardiac echo guidance. The target sensor was positioned at three target locations in the right atrium (RA) and the navigation task was completed by an experienced physician using both manual and RACN guidance. The navigation time, final distance between the catheter tip and target sensor, and variability in final catheter tip position were determined and compared for manual and RACN guided navigation. The experiments were completed in three animals and five measurements recorded for each target location. The mean distance (mm) between catheter tip and target sensor at the end of the navigation task was significantly less using RACN guidance compared with manual navigation (5.02 ± 0.31 vs. 9.66 ± 2.88, p = 0.050 for high RA, 9.19 ± 1.13 vs. 13.0 ± 1.00, p = 0.011 for low RA and 6.77 ± 0.59 vs. 15.66 ± 2.51, p = 0.003 for tricuspid valve annulus). The average time (s) needed to complete the navigation task was significantly longer by RACN guided navigation compared with manual navigation (43.31 ± 18.19 vs. 13.54 ± 1.36, p = 0.047 for high RA, 43.71 ± 11.93 vs. 22.71 ± 3.79, p = 0.043 for low RA and 37.84 ± 3.71 vs. 16.13 ± 4.92, p = 0.003 for tricuspid valve annulus. RACN guided navigation resulted in greater consistency in performance compared with manual navigation as evidenced by lower variability in final distance measurements (0.41 vs. 0.99 mm, p = 0

Radiofrequency ablation versus electrocautery in tonsillectomy.

PubMed

Hall, Daniel J; Littlefield, Philip D; Birkmire-Peters, Deborah P; Holtel, Michael R

2004-03-01

The objective of this study was to compare the safety, difficulty of removal, and postoperative pain profile of radiofrequency ablation versus standard electrocautery removal of tonsils. A prospective, blinded study was designed to remove 1 tonsil with each of the 2 methods. Time of operation, estimated blood loss, difficulty of operation, postoperative pain, rate of postoperative hemorrhage, and the patient's preferred technique were evaluated. The operating time was significantly longer (P < 0.007) and the patients reported significantly less pain (P < 0.001) with radiofrequency ablation. There were no differences in blood loss, difficulty of operation, or postoperative hemorrhage rates. The patients preferred the radiofrequency ablation technique (P < 0.001). Radiofrequency ablation is a viable method to remove tonsillar tissue. Operating time for this procedure will likely decrease with experience. There was significantly less pain reported with radiofrequency ablation compared with standard electrocautery.

Analysis of left atrial respiratory and cardiac motion for cardiac ablation therapy

NASA Astrophysics Data System (ADS)

Rettmann, M. E.; Holmes, D. R.; Johnson, S. B.; Lehmann, H. I.; Robb, R. A.; Packer, D. L.

2015-03-01

Cardiac ablation therapy is often guided by models built from preoperative computed tomography (CT) or magnetic resonance imaging (MRI) scans. One of the challenges in guiding a procedure from a preoperative model is properly synching the preoperative models with cardiac and respiratory motion through computational motion models. In this paper, we describe a methodology for evaluating cardiac and respiratory motion in the left atrium and pulmonary veins of a beating canine heart. Cardiac catheters were used to place metal clips within and near the pulmonary veins and left atrial appendage under fluoroscopic and ultrasound guidance and a contrast-enhanced, 64-slice multidetector CT scan was collected with the clips in place. Each clip was segmented from the CT scan at each of the five phases of the cardiac cycle at both end-inspiration and end-expiration. The centroid of each segmented clip was computed and used to evaluate both cardiac and respiratory motion of the left atrium. A total of three canine studies were completed, with 4 clips analyzed in the first study, 5 clips in the second study, and 2 clips in the third study. Mean respiratory displacement was 0.2+/-1.8 mm in the medial/lateral direction, 4.7+/-4.4 mm in the anterior/posterior direction (moving anterior on inspiration), and 9.0+/-5.0 mm superior/inferior (moving inferior with inspiration). At end inspiration, the mean left atrial cardiac motion at the clip locations was 1.5+/-1.3 mm in the medial/lateral direction, and 2.1+/-2.0 mm in the anterior/posterior and 1.3+/-1.2 mm superior/inferior directions. At end expiration, the mean left atrial cardiac motion at the clip locations was 2.0+/-1.5mm in the medial/lateral direction, 3.0+/-1.8mm in the anterior/posterior direction, and 1.5+/-1.5 mm in the superior/inferior directions.

[The role of the uretral catheter in the development of catheter- related urinary tract infection].

PubMed

Vasilyev, A O; Govorov, A V; Shiryaev, A A; Pushkar, D Yu

2017-12-01

The most common source of nosocomial infection is the urinary tract, especially if they it is drained with a urethral catheter. Catheter-associated urinary tract infections account for at least 80% of all complicated urinary tract infections and are the most common type of hospital-acquired infection. Intestinal microflora plays the leading role in the pathogenesis of catheter-associated urinary tract infections, whereas the most important risk factor for their development is the long duration of urinary catheter drainage. In the case of short-term and intermittent catheterization, routine antibiotic prophylaxis is not required, but if a patient develops clinically significant infection, antibiotic therapy is required followed by definitive therapy based on culture. Urethral catheters coated with antimicrobial substances and anti-inflammatory agents can significantly reduce the adhesion and migration of bacteria, thereby reducing the incidence of urinary tract infections. Despite this, the incidence of catheter-associated infection remains high. We have reviewed recent literature related to catheter-associated urinary tract infections and the best means of preventing this condition.

Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation.

PubMed

Chen, Xiaodong; Chen, Minglong; Wang, Yingying; Yang, Bing; Ju, Weizhu; Zhang, Fengxiang; Cao, Kejiang

2016-11-01

We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler (PW) and pulse tissue Doppler imaging (PW-TDI). A total of 25 consecutive in-patients with persistent atrial fibrillation, who restored sinus rhythm after ablation procedure, were recruited in our cardiac center. Echocardiography was performed on each patient at 2 hours, 1 day, 5 days, 1 month and 3 months after the ablation therapy, and atrial electromechanical delay was measured simultaneously by PW and PW-TDI. There was no significant difference between PW and TDI in measuring atrial electromechanical delay. However, at postoperative 2 hours, peak A detection rates were mathematically but nonsignificantly greater by PW-TDI than by PW. Second, there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months, but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time. Lastly, patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval, by the PW or by PW-TDI, respectively. In patients with persistent atrial fibrillation, atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later, and was significantly related to patients' duration of atrial fibrillation. Atrial electromechanical interval, as a potential predicted factor, is recommended to be measured by either PW or TDI after 24 hours, when patients had recovered sinus rhythm by radiofrequency ablation. © 2016 by the Journal of Biomedical Research. All rights reserved.

[Urinary catheter biofilm infections].

PubMed

Holá, V; Růzicka, F

2008-04-01

Urinary tract infections, most of which are biofilm infections in catheterized patients, account for more than 40% of hospital infections. Bacterial colonization of the urinary tract and catheters causes not only infection but also other complications such as catheter blockage by bacterial encrustation, urolithiasis and pyelonephritis. About 50% of long-term catheterized patients face urinary flow obstruction due to catheter encrustation, but no measure is currently available to prevent it. Encrustation has been known either to result from metabolic dysfunction or to be of microbial origin, with urease positive bacterial species implicated most often. Infectious calculi account for about 15-20% of all cases of urolithiasis and are often associated with biofilm colonization of a long-term indwelling urinary catheter or urethral stent. The use of closed catheter systems is helpful in reducing such problems; nevertheless, such a system only delays the inevitable, with infections emerging a little later. Various coatings intended to prevent the bacterial adhesion to the surface of catheters and implants and thus also the emergence of biofilm infections, unfortunately, do not inhibit the microbial adhesion completely and permanently and the only reliable method for biofilm eradication remains the removal of the foreign body from the patient.

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

[Rotational stability of angiography catheters].

PubMed

Schröder, J; Weber, M

1992-10-01

Rotatory stability is a parameter that reflects the ability of a catheter to transmit a rotation applied at the outer end to the catheter tip for the purpose of selective probing. A method for measuring the rotatory stability is described, and the results of rotatory stability measurements of 70 different commercially available catheters are reported. There is an almost linear correlation between the rotatory stability and the difference between the respective fourth power of the external and internal diameter or, approximately, to the fourth power of the external diameter for catheters without wire reinforcement. With the same cross-sectional dimensions, the rotatory stability of teflon, polyethylene, and nylon catheters has an approximate ratio of 1:2:4. Wire reinforcement increases rotatory stability by an average factor of about 3. For catheters of calibers 5 F and 6 F, a correlation between the rotatory stability and the weight of the reinforcing wire mesh is apparent.

[Catheter fracture and pulmonary embolization of the distal fragment: a rare complication of the totally implantable venous access port].

PubMed

Rebahi, H; El Adib, A G; Mouaffak, Y; El Hattaoui, M; Chaara, A; Sadek, H; Khouchani, M; Mahmal, L; Younous, S

2015-01-01

Totally implantable venous access port plays a crucial role in the treatment of patients in oncology. However, its use can result sporadically in catheter fracture with catheter tip embolization into pulmonary arteries. We report this unusual but potentially serious complication in four patients. In these patients, the port had been inserted percutaneously into the subclavian vein using the infra-clavicular approach. This side effect occurred late in three patients. In all patients, the catheter fracture was asymptomatic or pauci-symptomatic and was caused by the pinch-off syndrome. The retrieval of the embolized fragments was successfully performed by transcatheter procedure in the cardiac catheterisation laboratory. We reviewed the literature and the newest guidelines and recommendations to detail the clinico-radiological features, the possible causes of this complication and discussed means to recognize, manage and prevent it. Copyright © 2013 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

21 CFR 882.4400 - Radiofrequency lesion generator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4400 Radiofrequency lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

Experimental, Pathologic, and Clinical Findings of Radiofrequency Catheter Ablation of Para-Hisian Region From the Right Ventricle in Dogs and Humans.

PubMed

Xue, Yumei; Zhan, Xianzhang; Wu, Shulin; Wang, Hongyue; Liu, Yang; Liao, Zili; Deng, Hai; Duan, Xuejing; Zeng, Shaoying; Liang, Dongpo; Elvan, Arif; Fang, Xianhong; Liao, Hongtao; Ramdat Misier, Anand R; Smit, Jaap Jan J; Metzner, Andreas; Heeger, Christian-Hendrik; Liu, Fangzhou; Wang, Feng; Zhang, Zhiwei; Kuck, Karl-Heinz; Yen Ho, Siew; Ouyang, Feifan

2017-06-01

Ablation of para-Hisian accessory pathway (AP) poses high risks of atrioventricular block. We developed a pacing technique to differentiate the near-field (NF) from far-field His activations to avoid the complication. Three-dimensional mapping of the right ventricle was performed in 15 mongrel dogs and 23 patients with para-Hisian AP. Using different pacing outputs, the NF- and far-field His activation was identified on the ventricular aspect. Radiofrequency application was delivered at the NF His site in 8 (group 1) and the far-field His site in 7 dogs (group 2), followed by pathologic examination after 14 days. NF His activation was captured with 5 mA/1 ms in 10 and 10 mA/1 ms in 5 dogs. In group 1, radiofrequency delivery resulted in complete atrioventricular block in 3, right bundle branch block with HV (His-to-ventricular) interval prolongation in 1, and only right bundle branch block in 2 dogs, whereas no changes occurred in group 2. Pathologic examination in group-1 dogs showed complete or partial necrosis of the His bundle in 4 and complete necrosis of the right bundle branch in 5 dogs. In group 2, partial necrosis in the right bundle branch was found only in 1 dog. Using this pacing technique, the APs were 5.7±1.2 mm away from the His bundle located superiorly in 20 or inferiorly in 3 patients. All APs were successfully eliminated with 1 to 3 radiofrequency applications. No complications and recurrence occurred during a follow-up of 11.8±1.4 months. Differentiating the NF His from far-field His activations led to a high ablation success without atrioventricular block in para-Hisian AP patients. © 2017 American Heart Association, Inc.

16-channel bow tie antenna transceiver array for cardiac MR at 7.0 tesla.

PubMed

Oezerdem, Celal; Winter, Lukas; Graessl, Andreas; Paul, Katharina; Els, Antje; Weinberger, Oliver; Rieger, Jan; Kuehne, Andre; Dieringer, Matthias; Hezel, Fabian; Voit, Dirk; Frahm, Jens; Niendorf, Thoralf

2016-06-01

To design, evaluate, and apply a bow tie antenna transceiver radiofrequency (RF) coil array tailored for cardiac MRI at 7.0 Tesla (T). The radiofrequency (RF) coil array comprises 16 building blocks each containing a bow tie shaped λ/2-dipole antenna. Numerical simulations were used for transmission field homogenization and RF safety validation. RF characteristics were examined in a phantom study. The array's suitability for high spatial resolution two-dimensional (2D) CINE imaging and for real time imaging of the heart was examined in a volunteer study. The arrays transmission fields and RF characteristics are suitable for cardiac MRI at 7.0T. The coil performance afforded a spatial resolution as good as (0.8 × 0.8 × 2.5) mm(3) for segmented 2D CINE MRI at 7.0T which is by a factor of 12 superior versus standardized protocols used in clinical practice at 1.5T. The proposed transceiver array supports 1D acceleration factors of up to R = 6 without impairing image quality significantly. The 16-channel bow tie antenna transceiver array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0 Tesla. Magn Reson Med 75:2553-2565, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Anaesthesia for caesarean section in patients with cardiac disease.

PubMed

Chohan, Ursula; Afshan, Gauhar; Mone, Abdul

2006-01-01

This review contains material sourced from Med-Line and Pub-Med, search year 2002-2004. Material selected was pertaining to common cardiac ailments in pregnancy. Congenital cardiac problems i.e. Tetralogy of Fallot (TOF), Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), Eisenmengers syndrome, valvular heart disease, i.e. mitral stenosis, mitral regurgitation, aortic stensois and aortic regurgitation are discussed. Other cardiac conditions associated with pregnancy are pulmonary hypertension and peri-partum cardiomyopathy. Arrhythmias during pregnancy, vary from isolated premature to supra-ventricular and ventricular tachycardia, management is similar to non-pregnant patients. This review summarizes the current management of a parturient with cardiac disease requiring surgical delivery. Regional anaesthesia techniques are preferred as reflected in the current literature for patient with cardiac disease with minor alterations such as slow establishment of epidural for caesarean section or continuous spinal anaesthesia with very small incremental doses of local anaesthesia, maintaining the patient's SVR with vasopressors and fluid, monitoring of the fluid regimen with CVP and in some cardiac function with Swan Ganz catheter. Patients with Eisenmenger syndrome, pulmonary hypertension, should be advised to avoid pregnancy. In conclusion with vast advancements in obsterics care, improvements in cardiac surgery, many patients with cardiac disease can now be safely delivered surgically by skillful anaesthesiologists who are aware of the common potential intra-operative problems and the ability to respond to undesired events immediately.

Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

PubMed

Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

2018-02-16

Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

Bladder Morphology Using 2 Different Catheter Designs

ClinicalTrials.gov

2017-04-10

Urologic Injuries; Urologic Diseases; Bladder Infection; Urinary Tract Infections; Mucosal Inflammation; Mucosal Infection; Bladder Injury; Catheter-Related Infections; Catheter Complications; Catheter; Infection (Indwelling Catheter); Pelvic Floor Disorders; Urinary Incontinence

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.

Embryo Transfer Catheters: Softer is Easier.

PubMed

Ruhlmann, Claudio; Gnocchi, Diego C; Cattaneo, Antonio R; Molina, Lucas G; Rivadeneira, Luciano Ruiz; Tessari, Lautaro; Martínez, Alejandro G

2015-11-01

This study aimed to compare the use of semi-rigid and flexible catheters in terms of pregnancy rate and level of difficulty of the embryo transfer (ET) procedure. Seven hundred and thirty-nine consecutive follicular aspirations for IVF or ICSI performed in our private fertility clinic within a 30-month period were randomly divided into two groups. Patients were allocated to either of the groups at the time of follicular retrieval with the aid of a random number generator according to the catheter used in ET: Group 1 (n = 370) - Frydman Classic Catheter 4.5 catheters; and Group 2 (n = 369) - Frydman Ultrasoft 4.5 catheters. Only patients offered ET in the randomized cycle were included (Group 1 = 363 and Group 2 = 340). Patients did not change groups after catheter allocation. Statistical analysis was carried out using an unpaired t-test or a chi square test as appropriate. Differences with P<0.05 were considered. A statistically significant difference in favor of the use of the Ultrasoft catheter was evident for parameters use of a tenaculum (19.8% vs. 5.9%) or a hysterometer (5.0% vs. 1.2%), presence of blood during post-ET inspection of the catheter (9.9% vs. 3.8%), and implantation rate (13.0% vs. 16.4%). Clinical pregnancy and delivery rates were comparable in both groups. Our results suggest that a softer catheter may help with difficult ETs. Softer catheters, as also reported by other authors, resulted in better implantation rates.

Lagrangian displacement tracking using a polar grid between endocardial and epicardial contours for cardiac strain imaging.

PubMed

Ma, Chi; Varghese, Tomy

2012-04-01

Accurate cardiac deformation analysis for cardiac displacement and strain imaging over time requires Lagrangian description of deformation of myocardial tissue structures. Failure to couple the estimated displacement and strain information with the correct myocardial tissue structures will lead to erroneous result in the displacement and strain distribution over time. Lagrangian based tracking in this paper divides the tissue structure into a fixed number of pixels whose deformation is tracked over the cardiac cycle. An algorithm that utilizes a polar-grid generated between the estimated endocardial and epicardial contours for cardiac short axis images is proposed to ensure Lagrangian description of the pixels. Displacement estimates from consecutive radiofrequency frames were then mapped onto the polar grid to obtain a distribution of the actual displacement that is mapped to the polar grid over time. A finite element based canine heart model coupled with an ultrasound simulation program was used to verify this approach. Segmental analysis of the accumulated displacement and strain over a cardiac cycle demonstrate excellent agreement between the ideal result obtained directly from the finite element model and our Lagrangian approach to strain estimation. Traditional Eulerian based estimation results, on the other hand, show significant deviation from the ideal result. An in vivo comparison of the displacement and strain estimated using parasternal short axis views is also presented. Lagrangian displacement tracking using a polar grid provides accurate tracking of myocardial deformation demonstrated using both finite element and in vivo radiofrequency data acquired on a volunteer. In addition to the cardiac application, this approach can also be utilized for transverse scans of arteries, where a polar grid can be generated between the contours delineating the outer and inner wall of the vessels from the blood flowing though the vessel.

Emergency coronary angioplasty with stenting using Cordis® diagnostic coronary catheters when there is difficulty in engaging guide catheters and bench evaluation of diagnostic and guide catheters.

PubMed

Arokiaraj, Mark Christopher

2018-02-01

Difficulty in engaging with guide catheters is not uncommon in acute emergencies. We aimed to evaluate the use of Cordis ® INFINITI diagnostic catheters to perform angioplasty in patients in whom the coronaries cannot be engaged using standard guide catheters. In 34 cases of acute coronary syndrome, when difficulty in engagement with two standard guide catheters was encountered with reasonable manipulations, angioplasty was performed using diagnostic catheters. In total, 40 stents were placed by this technique. Pushability and trackability, distal tip flexion and three-point bending tests were performed to evaluate the performance of the guide and diagnostic catheters. Angioplasty was performed easily in a setting where it would have been very difficult to perform. Coronary dissection occurred in one patient, treated by a stent. The stent and dilatation balloons were easily passed through the diagnostic catheters. Pressure tracings were clearly preserved with certain stent delivery systems, and at angioplasty, although there was slightly reduced opacification of the respective artery, the coronary anatomy was sufficiently visualized to perform angioplasty. No periprocedural target lesion complications were seen in any cases. Pushability and trackability tests showed good force transmission along a tortuous path with diagnostic catheters, and balanced force-displacement curves from three-point bending tests and distal tip softness tests. Angioplasty with stenting can be performed safely through 6F Cordis ® infiniti diagnostic catheters when difficulty in engaging guide catheters is encountered. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Catheter-related bloodstream infection with removal of catheter in pediatric oncology patients: a 10-year experience in Taiwan.

PubMed

Chen, Shih-Hsiang; Yang, Chao-Ping; Jaing, Tang-Her; Lai, Jin-Yao; Hung, Iou-Jih

2012-04-01

Long-term central venous catheter (CVC) implantation has become more affordable in Taiwan since 1995. Surgical removal of the catheter may be the essential treatment for catheter-related bloodstream infections (CRBSI). The aim of this study was to evaluate the clinical features and microbial isolates in pediatric cancer patients with removal of CVC for CRBSI. The records of positive blood culture from hospitalized pediatric oncology patients between 1995 and 2004 were reviewed. One hundred and forty-three patients implanted with a long-term CVC were further identified. Seventeen catheters in 16 patients developed catheter-related bacteremia that needed catheter removal. The rate of catheter removal was 11.9%. The median device life was 7.7 months. Six catheters were removed within 3 months of insertion. Nine of the 17 catheters were removed from patient younger than 2 years. Eight infections occurred during severe neutropenia, and 6 patients had refractory or relapsed underlying disease. The cultural isolates were Gram-negative bacilli in 7, Gram-positive in 5, fungi in 5, and atypical mycobacterium in 1. The frequency of catheter removal for infection control was significantly higher in the first 5 years (1994-1999) compared to the last 5 years (2000-2004) (30.9 vs. 4.0%, p = 2.3 × 10(-4)). Factors such as microbiological isolates, age of infection, the status of malignancy, and neutropenia are related to catheter outcome. The reduction in patients with positive cultures needing removal of the catheters can be related to improved nursing care and more aggressive antibiotic therapy.

Radiofrequency Identification

PubMed Central

Jones, Terry L.

2017-01-01

A national campaign is underway to increase the amount of time staff nurses spend at the bedside of hospitalized patients through redesign of the work environment. This kind of work redesign requires robust data depicting what nurses do and how they spend their time. Historically, these kinds of data have been difficult, costly, and time consuming to collect. Wireless capture of data on the movement of humans within the work environment (ie, time and motion) is now possible through radiofrequency identification technology. When small tracking devices the size of a quarter are affixed to their clothing, the movement of nurses throughout a patient care unit can be monitored. The duration and frequency of patient interaction are captured along with the duration of time spent in other locations of interest to include nurses’ station, supply room, medication room, doctors’ station, electronic documentation stations, family waiting rooms, and the hallway. Patterns of nurse movement and time allocation can be efficiently identified, and the effects of staffing practices, workflows, and unit layout evaluated. Integration of radiofrequency identification time and motion data with other databases enables nurse leaders to link nursing time to important cost and quality outcomes. Nurse leaders should explore the usefulness of radiofrequency identification technology in addressing data needs for nurse time and motion. PMID:22592451

Is it feasible to diagnose catheter-related candidemia without catheter withdrawal?

PubMed

Fernández-Cruz, Ana; Martín-Rabadán, Pablo; Suárez-Salas, Marisol; Rojas-Wettig, Loreto; Pérez, María Jesús; Guinea, Jesús; Guembe, María; Peláez, Teresa; Sánchez-Carrillo, Carlos; Bouza, Emilio

2014-07-01

Many bloodstream infections (BSI) in patients with central venous catheters (CVC) are not catheter-related (CR). Assessment of catheter involvement without catheter withdrawal has not been studied in candidemia. We assessed the value of conservative techniques to evaluate catheters as the origin of candidemia in patients with CVC in a prospective cohort study (superficial Gram stain and culture, Kite technique (Gram stain and culture of the first 1 cm blood drawn from the CVC), proportion of positive blood cultures (PPBCs), differential time to positivity (DTP), and minimal time to positivity (MTP)). All catheters were cultured at withdrawal. From June 2008 to January 2012, 22 cases fulfilled the inclusion criteria. CR-candidemia (CRC) was confirmed in 10. Validity values for predicting CRC were: superficial Gram stain (S, 30%; Sp, 81.83%; PPV, 60%; NPV, 56.3%; Ac, 57.1%), superficial cultures (S, 40%; Sp, 75%; PPV, 57.1%; NPV, 60%; Ac, 59.1%), Kite Gram stain (S, 33.3%; Sp, 66.7%; PPV, 50%; NPV, 50%; Ac, 50%), Kite culture (S, 80%; Sp, 66.7%; PPV, 66.7%; NPV, 80%; Ac, 72.7%), PPBC (S, 50%; Sp, 41.7%; PPV, 41.7%; NPV, 50.0%; Ac, 45.5%), DTP (S, 100%; Sp, 33.3%; PPV, 55.6%; NPV, 100%; Ac, 63.6%), and MTTP (S, 70%; Sp, 58.3%; PPV, 58.3%; NPV, 70%; Ac, 63.6%). While combinations of two tests improved sensitivity and NPV, more than two tests did not improve validity values. Classic tests to assess CR-BSI caused by bacteria cannot be reliably used to diagnose CRC. Combinations of tests could be useful, but more and larger studies are required. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Light modulated electron beam driven radiofrequency emitter

DOEpatents

Wilson, M.T.; Tallerico, P.J.

1979-10-10

The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

Pulse-dose radiofrequency treatment in pain management-initial experience.

PubMed

Ojango, Christine; Raguso, Mario; Fiori, Roberto; Masala, Salvatore

2018-05-01

Radiofrequency procedures have been used for treating various chronic pain conditions for decades. These minimally invasive percutaneous treatments employ an alternating electrical current with oscillating radiofrequency wavelengths to eliminate or alter pain signals from the targeted site. The aim of the continuous radiofrequency procedure is to increase the temperature sufficiently to create an irreversible thermal lesion on nerve fibres and thus permanently interrupt pain signals. The pulsed radiofrequency procedure utilises short pulses of radiofrequency current with intervals of longer pauses to avert a temperature increase to the level of permanent tissue damage. The goal of these pulses is to alter the processing of pain signals, but to avoid relevant structural damage to nerve fibres, as seen in the continuous radiofrequency procedure. The pulse-dose radiofrequency procedure is a technical improvement of the pulsed radiofrequency technique in which the delivery mode of the current is adapted. During the pulse-dose radiofrequency procedure thermal damage is avoided. In addition, the amplitude and width of the consecutive pulses are kept the same. The method ensures that each delivered pulse keeps the same characteristics and therefore the dose is similar between patients. The current review outlines the pulse-dose radiofrequency procedure and presents our institution's chronic pain management studies.

Evaluation of urinary catheters coated with sustained-release varnish of chlorhexidine in mitigating biofilm formation on urinary catheters in dogs.

PubMed

Segev, G; Bankirer, T; Steinberg, D; Duvdevani, M; Shapur, N K; Friedman, M; Lavy, E

2013-01-01

Biofilm formation occurs commonly on urinary catheters. To assess the efficacy of urinary catheters coated with sustained-release varnish of chlorhexidine in decreasing catheter-associated biofilm formation in dogs. Thirty client-owned dogs. Prospective study. Thirteen dogs were catheterized with urinary catheters coated with sustained-release varnish of chlorhexidine (study group), and 13 dogs were catheterized with an untreated urinary catheter (control group). Presence and intensity of biofilm formation on the urinary catheters were assessed and compared between the groups by evaluating colony-forming units (CFU) of biofilm bacteria, and semiquantitatively, using confocal laser scanning microscopy and electron microscopy. None of the dogs experienced adverse effects associated with the presence of the urinary catheters. Median CFU count of biofilm bacteria at all portions of the urinary catheter was significantly (P < .001) lower in the study compared with the control group. The degree of biofilm formation on the urinary catheters, as evaluated by confocal laser scanning microscopy and electron microscopy, was significantly lower in the study compared with the control group. Electron microscopy examination identified crystals on some of the urinary catheters. The proportion of catheters on which crystals were observed was significantly lower on the distal part of the urinary catheter in the study group compared with the control group (16.7% versus 66.7%, respectively; P = .04). Chlorhexidine sustained-release varnish-coated urinary catheters effectively decrease urinary catheter-associated biofilm formation in dogs. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Toxicity testing of urinary catheters.

PubMed

Talja, M; Andersson, L C; Ruutu, M; Alfthan, O

1985-10-01

The tissue toxicity of 23 urinary catheter batches (6 latex and 2 non-latex brands) was tested in vitro and in vivo. In vitro, a human T-cell leukemia line (JM) was cultured in the presence of different concentrations of eluates made from the catheters. The cytotoxicity of the eluates was assessed from their ability to inhibit DNA synthesis measured by incorporation of 3H-thymidine. In vivo, two methods were used. Strips of catheters were implanted into the rabbit dorsal muscle and pieces of catheters were implanted into the rat peritoneal cavity. After four days, the foreign body reaction, type of inflammation and necrosis were quantified macroscopically and by light microscopy. The results of the in vitro cytotoxicity test were correlated with those of in vivo methods. The rat peritoneal implantation test correlated better with the cell culture test (P less than 0.01) than with the rabbit muscle implantation test (P less than 0.05). Based on the clinical experience of urethral stricture complications caused by urinary catheters, catheters yielding eluate which at 30% dilution inhibited 50% DNA synthesis were regarded as toxic. According to this, the rabbit muscle implantation test was not reliable in testing the tissue toxicity of urinary catheters, while the cell culture test was quantitative and seemed to correlate with both the rat peritoneal implantation test and with the clinical complications observed.

A survey on monopolar radiofrequency treatment.

PubMed

Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

2017-09-01

This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm 2 , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

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.

Image-guided radiofrequency ablation of spinal tumors: preliminary experience with an expandable array electrode.

PubMed

Grönemeyer, Dietrich H W; Schirp, Sven; Gevargez, Athour

2002-01-01

Metastases to the spine are a challenging problem. Percutaneous, image-guided tumor ablation with a thermal energy source, such as radiofrequency, has received increasing attention as a promising technique for the treatment of focal malignant disease. We used radiofrequency ablation for patients with unresectable, osteolytic spine metastases under computed tomographic and fluoroscopic guidance. The purpose of this study was to determine the feasibility, effectiveness, and safety of radiofrequency ablation as a palliative procedure to reduce pain and back pain-related disability in patients with vertebral and paravertebral spine tumors who were not able to benefit from radiotherapy, chemotherapy, or surgery. Between November 1999 and January 2001, 10 patients with unresectable spine metastases were treated with radiofrequency ablation. For the ablation we used a 50-W radiofrequency generator that is connected to an expandable electrode catheter (RITA Medical System Inc., Mountain View, CA). The mean patient age was 64.4 years. Metastases were ablated in the thoracic spine, the lumbar spine, and/or the sacral bone. Tumor diameter ranged from 1.5 to 9 cm. Combined computed tomographic and fluoroscopic guidance was used to guide the procedure. Operations were carried out without heavy sedation with the patient under local anesthesia only. The thermal lesion was produced by applying temperatures of 50 degrees to 120 degrees C for 8-12 minutes. Vertebroplasty was performed in four patients by use of 3 to 5.5 mL of polymethyl methacrylate. Therapy outcome was documented by magnet resonance imaging. Before the therapy and on follow-up of an average of 5.8 months, pain was assessed with the help of the Visual Analogue Scale. Back pain-related disability was measured with the Hannover Functional Ability Questionnaire. Neurologic and health status were documented on the Frankel score and the Karnofsky index. At follow-up, 9 of 10 patients reported reduced pain (Visual

Value of an old school approach: safety and long-term success of radiofrequency current catheter ablation of atrioventricular nodal reentrant tachycardia in children and young adolescents.

PubMed

Siebels, Henrike; Sohns, Christian; Nürnberg, Jan-Hendrik; Siebels, Jürgen; Langes, Klaus; Hebe, Joachim

2018-05-15

Radiofrequency current energy (RFC) ablation is still considered as the gold standard for atrioventricular nodal reentrant tachycardia (AVNRT). Success-rates for AVNRT ablation vary irrespective of the ablation technology and strategy. This study aimed to access safety, efficacy, and long-term outcome of RFC catheter ablation for the treatment of AVNRT in children and adolescents aged < 19 years with special focus on modulation versus ablation of the AV nodal slow pathway (SP). A total number of 1143 patients (pts) < 19 years were referred for invasive electrophysiological testing due to paroxysmal supraventricular tachycardia (SVT). Diagnosis of AVNRT was confirmed in 412 pts, and RFC-guided ablation was attempted in 386 pts (age 13.0 ± 3.5 years). No permanent complications were observed. RFC application resulted in SP-ablation in 171/386 (44.3%) and in SP modulation in 208/386 (53.9%) children, whereas attempts for RFC treatment failed in 7 pts. Follow-up was completed for 396/412 patients (96.1%). Within a mean follow-up period of 54.9 ± 39.7 months, in 51/379 pts (13.5%) AVNRT recurrence was observed. The median time until tachycardia recurrence was 19.5 months. No difference for AVNRT recurrence was found comparing SP ablation versus SP modulation (p > 0.05), whereas the recurrence rate was significantly higher in patients with non-inducible SVT and therefore empiric SP treatment as compared to patients with inducible AVNRT (p = 0.01). RFC-guided ablation for AVNRT in children and adolescents is safe and leads to an acceptable long-term freedom from recurrences. SP modulation and SP ablation resulted in comparable acute and long-term success rates. Late AVNRT recurrences can occur even after years of freedom from tachycardia-related symptoms.

High-risk Trans-Catheter Aortic Valve Replacement in a Failed Freestyle Valve with Low Coronary Height: A Case Report.

PubMed

Karimi, Ashkan; Pourafshar, Negiin; Dibu, George; Beaver, Thomas M; Bavry, Anthony A

2017-06-01

A 55-year-old male with a history of two prior cardiac surgeries presented with decompensated heart failure due to severe bioprosthetic aortic valve insufficiency. A third operation was viewed prohibitively high risk and valve-in-valve trans-catheter aortic valve replacement was considered. There were however several high-risk features and technically challenging aspects including low coronary ostia height, poor visualization of the aortic sinuses, and difficulty in identification of the coplanar view due to severe aortic insufficiency, and a highly mobile aortic valve mass. After meticulous peri-procedural planning, trans-catheter aortic valve replacement was carried out with a SAPIEN 3 balloon-expandable valve without any complication. Strategies undertaken to navigate the technically challenging aspects of the case are discussed.

Cardiac veins: collateral venous drainage pathways in chronic hemodialysis patients.

PubMed

Ozmen, Evrim; Algin, Oktay

2016-07-12

Venous anomalies are diagnostic and therapeutic challenges. Subclavian or superior vena cava stenosis can be developed and venous return can be achieved via cardiac veins and coronary sinus in patients with central venous catheter for long-term hemodialysis. These types of abnormalities are not extremely rare especially in patients with a history of central venous catheter placement. Detection of these anomalies and subclavian vein stenosis before the surgical creation of hemodialysis fistulae or tunneled central venous catheter placement may prevent unnecessary interventions in those patients. Multidetector computed tomography (MDCT) technique can give further information when compared with fluoroscopy or digital subtraction angiography in the management of these patients. This case report describes interesting aspects of central vein complications in hemodialysis patients. As a conclusion, there are limited data about thoracic venous return, and further prospective studies with large patient number are required. MDCT with 3D reconstruction is particularly useful for the accurate evaluation of venous patency, variations, and collateral circulation. Also it is an excellent tool for choosing and planning treatment.

Myotonic Dystrophy Initially Presenting as Tachycardiomyopathy Successful Catheter Ablation of Atrial Flutter

PubMed Central

Asbach, S.; Gutleben, K. J.; Dahlem, P.; Brachmann, J.; Nölker, G.

2010-01-01

Myotonic dystrophy is a genetic muscular disease that is frequently associated with cardiac arrhythmias. Bradyarrhythmias, such as sinus bradycardia and atrioventricular block, are more common than tachyarrhythmias. Rarely, previously undiagnosed patients with myotonic dystrophy initially present with a tachyarrhythmia. We describe the case of a 14-year-old boy, who was admitted to the hospital with clinical signs and symptoms of decompensated heart failure and severely reduced left ventricular function. Electrocardiography showed common-type atrial flutter with 2 : 1 conduction resulting in a heart rate of 160 bpm. Initiation of medical therapy for heart failure as well as electrical cardioversion led to a marked clinical improvement. Catheter ablation of atrial flutter was performed to prevent future cardiac decompensations and to prevent development of tachymyopathy. Left ventricular function normalized during followup. Genetic analysis confirmed the clinical suspicion of myotonic dystrophy as known in other family members in this case. PMID:20871860

Radio-frequency measurement in semiconductor quantum computation

NASA Astrophysics Data System (ADS)

Han, TianYi; Chen, MingBo; Cao, Gang; Li, HaiOu; Xiao, Ming; Guo, GuoPing

2017-05-01

Semiconductor quantum dots have attracted wide interest for the potential realization of quantum computation. To realize efficient quantum computation, fast manipulation and the corresponding readout are necessary. In the past few decades, considerable progress of quantum manipulation has been achieved experimentally. To meet the requirements of high-speed readout, radio-frequency (RF) measurement has been developed in recent years, such as RF-QPC (radio-frequency quantum point contact) and RF-DGS (radio-frequency dispersive gate sensor). Here we specifically demonstrate the principle of the radio-frequency reflectometry, then review the development and applications of RF measurement, which provides a feasible way to achieve high-bandwidth readout in quantum coherent control and also enriches the methods to study these artificial mesoscopic quantum systems. Finally, we prospect the future usage of radio-frequency reflectometry in scaling-up of the quantum computing models.

Catheter-associated urinary tract infection.

PubMed

Tambyah, Paul A; Oon, Jolene

2012-08-01

Catheter-associated urinary tract infection (CAUTI) is the commonest nosocomial infection worldwide. Here we review the recent advances in the prevention of CAUTI. After more than 30 years, new guidelines were issued in 2008-2011 by the Infectious Diseases Society of America, Society for Healthcare Epidemiology of America, Healthcare Infection Control Practices Advisory Committee and European Association of Urology. These guidelines addressed novel technologies such as silver alloy or antimicrobial coatings on catheters, hydrophilic catheters, urethral stents, use of sealed catheter-tube junctions and antiinfective bladder irrigation. In addition, multiple trials have been published recently on the reduction of inappropriate urinary tract catheterization. Numerous strategies have been developed to reduce the incidence of CAUTI but few have proven effective. Reducing the inappropriate use of catheters and development of novel technologies targeted against these increasingly multidrug-resistant pathogens may be useful in the prevention of CAUTI in our vulnerable patients.

Insertion of tunneled hemodialysis catheters without fluoroscopy.

PubMed

Motta Elias, Rosilene; da Silva Makida, Sonia Cristina; Abensur, Hugo; Martins Castro, Manuel Carlos; Affonso Moysés, Rosa Maria; Pereira, Benedito Jorge; Bueno de Oliveira, Rodrigo; Luders, Cláudio; Romão, João Egidio

2010-01-01

The tunneled cuffed catheter (TCC) is used as a bridge access for hemodialysis. Few prospective studies have been designed to evaluate conversion from non-tunneled to TCC without the use of fluoroscopy when performed by nephrologists. We performed an observational prospective cohort in incident patients receiving hemodialysis through a non-tunneled right jugular vein catheter. 130 procedures were performed in 122 patients (51+/-18 years). The success rate was 100%. There was a total of 26,546 catheter days. Ninety-one of the 130 catheters were removed during the study period. Life table analysis revealed primary patency rates of 92%, 82%, and 68% at 30, 60, and 120 days, respectively. Infection requiring catheter removal occurred at a frequency of 0.09 per 100 catheter days. Catheter malfunction requiring intervention occurred at a rate of 0.03 per 100 catheter days. Hypertension and duration of existing non-tunneled catheter of less than 2 weeks were independently associated with better TCC survival. The conversion from non-tunneled to TCC performed by nephrologists and without fluoroscopy may be safe by using the internal right jugular vein. The ideal time to do this procedure is within less than 2 weeks of existing non-tunneled catheter.

Consensus for the Treatment of Varicose Vein with Radiofrequency Ablation

PubMed Central

Joh, Jin Hyun; Kim, Woo-Shik; Jung, In Mok; Park, Ki-Hyuk; Lee, Taeseung; Kang, Jin Mo

2014-01-01

The objective of this paper is to introduce the schematic protocol of radiofrequency (RF) ablation for the treatment of varicose veins. Indication: anatomic or pathophysiologic indication includes venous diameter within 2–20 mm, reflux time ≥0.5 seconds and distance from the skin ≥5 mm or subfascial location. Access: it is recommended to access at or above the knee joint for great saphenous vein and above the mid-calf for small saphenous vein. Catheter placement: the catheter tip should be placed 2.0 cm inferior to the saphenofemoral or saphenopopliteal junction. Endovenous heat-induced thrombosis ≥class III should be treated with low-molecular weight heparin. Tumescent solution: the composition of solution can be variable (e.g., 2% lidocaine 20 mL+500 mL normal saline+bicarbonate 2.5 mL with/without epinephrine). Infiltration can be done from each direction. Ablation: two cycles’ ablation for the first proximal segment of saphenous vein and the segment with the incompetent perforators is recommended. The other segments should be ablated one time. During RF energy delivery, it is recommended to apply external compression. Concomitant procedure: It is recommended to do simultaneously ambulatory phlebectomy. For sclerotherapy, it is recommended to defer at least 2 weeks. Post-procedural management: post-procedural ambulation is encouraged to reduce the thrombotic complications. Compression stocking should be applied for at least 7 days. Minor daily activity is not limited, but strenuous activities should be avoided for 2 weeks. It is suggested to take showers after 24 hours and tub baths, swimming, or soaking in water after 2 weeks. PMID:26217628

Bacterial contamination of epidural catheters: microbiological examination of 502 epidural catheters used for postoperative analgesia.

PubMed

Steffen, Peter; Seeling, Wulf; Essig, Andreas; Stiepan, Erika; Rockemann, Michael Georg

2004-03-01

To investigate the frequency of bacterial colonization of epidural catheters used for postoperative pain treatment longer than 24 hours in abdominal, thoracic, or trauma surgery patients. Retrospective study. Intermediate care facility and general ward of a university hospital. 502 patients who received epidural catheters after abdominal, thoracic, or vascular surgery at our institution from January 1996 to December 2000. Placement of an epidural catheter, which was used for postoperative pain treatment, for more than 24 hours. The puncture site dressing included saturation each day with povidone-iodine. Microbiologic monitoring of epidural catheter tips and daily examination of puncture sites with regard to signs of inflammation took place. Four times daily patients were examined to check adequacy of pain treatment and neurologic deficits. Catheter tip cultures were positive in 29 patients (5.8%). Staphylococcus epidermidis was isolated in 22 cases (76%). No case of spinal epidural abscess was observed within 6 months after epidural catheterization. The average catheterization time was 5 days (quartile range: 4 to 6 days). Meticulous management ensures a relatively low level of bacterial contamination in epidural catheters applied for postoperative pain treatment greater than 5 days. Contamination rarely leads to spinal epidural infection.

Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

PubMed

Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

2016-03-01

Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P < 0.001) and tumor size (P = 0.023) were independent predictors of radiofrequency failure. Failure rate was lower with the multipolar technique for tumors < 25 mm (P = 0.023) and for tumors between 25 and 45 mm (P = 0.082). There was no difference for tumors ≥ 45 mm (P = 0.552). Compared to monopolar radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

A Magnetic Resonance Imaging-Conditional External Cardiac Defibrillator for Resuscitation Within the Magnetic Resonance Imaging Scanner Bore.

PubMed

Schmidt, Ehud J; Watkins, Ronald D; Zviman, Menekhem M; Guttman, Michael A; Wang, Wei; Halperin, Henry A

2016-10-01

Subjects undergoing cardiac arrest within a magnetic resonance imaging (MRI) scanner are currently removed from the bore and then from the MRI suite, before the delivery of cardiopulmonary resuscitation and defibrillation, potentially increasing the risk of mortality. This precludes many higher-risk (acute ischemic and acute stroke) patients from undergoing MRI and MRI-guided intervention. An MRI-conditional cardiac defibrillator should enable scanning with defibrillation pads attached and the generator ON, enabling application of defibrillation within the seconds of MRI after a cardiac event. An MRI-conditional external defibrillator may improve patient acceptance for MRI procedures. A commercial external defibrillator was rendered 1.5 Tesla MRI-conditional by the addition of novel radiofrequency filters between the generator and commercial disposable surface pads. The radiofrequency filters reduced emission into the MRI scanner and prevented cable/surface pad heating during imaging, while preserving all the defibrillator monitoring and delivery functions. Human volunteers were imaged using high specific absorption rate sequences to validate MRI image quality and lack of heating. Swine were electrically fibrillated (n=4) and thereafter defibrillated both outside and inside the MRI bore. MRI image quality was reduced by 0.8 or 1.6 dB, with the generator in monitoring mode and operating on battery or AC power, respectively. Commercial surface pads did not create artifacts deeper than 6 mm below the skin surface. Radiofrequency heating was within US Food and Drug Administration guidelines. Defibrillation was completely successful inside and outside the MRI bore. A prototype MRI-conditional defibrillation system successfully defibrillated in the MRI without degrading the image quality or increasing the time needed for defibrillation. It can increase patient acceptance for MRI procedures. © 2016 American Heart Association, Inc.

Large eccentric laser angioplasty catheter

NASA Astrophysics Data System (ADS)

Taylor, Kevin D.; Reiser, Christopher

1997-05-01

In response to recent demand for increased debulking of large diameter coronary vascular segments, a large eccentric catheter for excimer laser coronary angioplasty has been developed. The outer tip diameter is 2.0 mm and incorporates approximately 300 fibers of 50 micron diameter in a monorail- type percutaneous catheter. The basic function of the device is to ablate a coronary atherosclerotic lesion with 308 nm excimer laser pulses, while passing the tip of the catheter through the lesion. By employing multiple passes through the lesion, rotating the catheter 90 degrees after each pass, we expect to create luminal diameters close to 3 mm with this device. Design characteristics, in-vitro testing, and initial clinical experience is presented.

Minilaparotomy salvage of malfunctioning catheters in peritoneal dialysis.

PubMed

Li, Jian-Ri; Cheng, Chi-Hung; Chiu, Kun-Yuan; Cheng, Chen-Li; Yang, Chi-Rei; Ho, Hao-Chung; Ko, Jiunn-Liang; Ou, Yen-Chuan

2013-01-01

Catheter malfunction is a common and significant complication during peritoneal dialysis (PD). We developed a minilaparotomy procedure to rescue malfunctioning catheters and to prevent recurrence of malfunction. From 2006 to 2011, 11 patients receiving PD had a malfunctioning catheter. In all patients, a 2-cm incision, 5 cm caudally to the previous peritoneal entry site was used to correct the malfunctioning catheter, with concomitant fixation of the catheter to the peritoneum. Catheter tip migration occurred in 7 patients, omental wrapping in 3, and blood clot obstruction in 1. The mean onset time to catheter malfunction was 197.5 days (range: 4 - 1270 days), and the mean operating time was 41 minutes (range: 35 - 56 minutes). There was no recurrence of catheter malfunction and no surgery-related peritonitis. Our minilaparotomy procedure is safe and feasible for the salvage of malfunctioning PD catheters.

The effect of peripherally inserted central catheter (PICC) valve technology on catheter occlusion rates--the 'ELeCTRiC' study.

PubMed

Johnston, Andrew J; Streater, Carmel T; Noorani, Remy; Crofts, Joanne L; Del Mundo, Aldwin B; Parker, Richard A

2012-01-01

Peripherally Inserted Central Catheters (PICCs) are increasingly being used to provide short to medium-term central venous access. The current study was designed to test the hypothesis that PICC valve technology does not influence PICC occlusion rates. Intensive care unit (ICU) patients who required a PICC were randomized to one of three types of dual lumen PICC (open ended non-valved, Groshong valve, PASV valve). PICC occlusions were recorded and managed with a protocol that used urokinase. A total of 102 patients were recruited to the study. The overall risk of occlusion per catheter was 35% (95% CI 26% to 44%). The overall rate of occlusion was 76 occlusions per 1000 catheter days (95% CI 61 to 95). Presence or type of valve did not significantly influence this rate (open-ended non-valved PICC 38% of catheters, 79 occlusions per 1000 catheter days; Groshong 38% of catheters, 60 occlusions per 1000 catheter days; PASV 27% of catheters, 99 occlusions per 1000 catheter days). The dose of urokinase required to treat PICC occlusions did not significantly differ between PICC types. Valved PICCs do not appear to influence PICC occlusion rates.

Cardiac tamponade due to umbilical venous catheter in the new born

PubMed Central

Abdellatif, Mohamed; Ahmed, Ashfag; Alsenaidi, Khalfan

2012-01-01

With more and more extreme premature and very low-birth weight babies being resuscitated, umbilical central venous catheterisation is now being used more frequently in neonatal intensive care. The authors present a case of cardiac tamponade following umbilical venous catheterisation in a neonate, an uncommon, yet potentially fatal complication. The patient was diagnosed at the appropriate time by echocardiography and urgent pericardiocentesis proved lifesaving. PMID:22802560

Soft J-tipped guide wire-induced cardiac perforation in a patient with right ventricular lipomatosis and wall thinning.

PubMed

Hiroshima, Yuki; Tajima, Katsushi; Shiono, Yousuke; Suzuki, Ikuko; Kohno, Kei; Kato, Yuichi; Shunji, Kawamura; Kato, Takeo

2012-01-01

Cardiac tamponade caused by perforation is a rare but potentially lethal complication of central venous catheter (CVC) insertion. We herein report a case of cardiac perforation associated with the use of a soft J-tipped guide wire. Twenty minutes after the insertion of a CVC, the patient developed unexpected cardiac arrest. An autopsy revealed 400 mL of pericardial blood. The right ventricular wall was 1 mm thick with about 10 myocyte layers, which is one-third that of the normal heart. A histological analysis revealed widespread fatty infiltration of the right ventricular wall (right ventricular lipomatosis).

Catheter interventional treatment of congenital portosystemic venous shunts in childhood.

PubMed

Knirsch, Walter; Benz, Dominik C; Bühr, Patrick; Quandt, Daniel; Weber, Roland; Kellenberger, Christian; Braegger, Christian P; Kretschmar, Oliver

2016-06-01

The study aimed on the catheter interventional treatment of congenital portosystemic venous shunt (CPSVS) in childhood and the impact on vascular growth of hypoplastic portal veins. Clinical course and follow up of partial or complete closure of CPSVS are described. CPSVS is a very rare vascular malformation of the portal venous drainage resulting in potentially life threatening abdominal, pulmonary, cerebral, and cardiac complications. The anatomic type, clinical course, and diagnosis must be determined for optimal management. Single centre case series. Eight (6 female) children with extrahepatic (n = 5) and intrahepatic (n = 3) CPSVS were diagnosed invasively by catheterization, including test balloon occlusion of the shunt and simultaneous retrograde angiography, and treated by catheter interventions (n = 5) with partial (n = 2) and complete (n = 3) occlusion of CPSVS at a median age of 3.9 years (range 0.7-21). Congenital heart disease (CHD) was the most frequent associated organ manifestation (n = 5) followed by mild to severe pulmonary arterial hypertension (n = 4), hepatopulmonary syndrome (n = 2), and portosystemic encephalopathy (n = 1). CHD was simple (n = 3) or complex type (n = 2). Three patients were untreated so far, because they were in excellent clinical condition at an age <1 year, refused treatment, or planned for later treatment. Accurate invasive diagnosis of CPSVS with test balloon occlusion of the shunt is mandatory to depict the anatomic situation. Catheter interventional treatment of CPSVS offers a feasible and safe approach with complete or partial closure of the vascular malformation inducing potentially significant vascular growth of a former hypoplastic portal venous system. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Effects of catheter-based renal denervation on cardiac sympathetic activity and innervation in patients with resistant hypertension.

PubMed

Donazzan, Luca; Mahfoud, Felix; Ewen, Sebastian; Ukena, Christian; Cremers, Bodo; Kirsch, Carl-Martin; Hellwig, Dirk; Eweiwi, Tareq; Ezziddin, Samer; Esler, Murray; Böhm, Michael

2016-04-01

To investigate, whether renal denervation (RDN) has a direct effect on cardiac sympathetic activity and innervation density. RDN demonstrated its efficacy not only in reducing blood pressure (BP) in certain patients, but also in decreasing cardiac hypertrophy and arrhythmias. These pleiotropic effects occur partly independent from the observed BP reduction. Eleven patients with resistant hypertension (mean office systolic BP 180 ± 18 mmHg, mean antihypertensive medications 6.0 ± 1.5) underwent I-123-mIBG scintigraphy to exclude pheochromocytoma. We measured cardiac sympathetic innervation and activity before and 9 months after RDN. Cardiac sympathetic innervation was assessed by heart to mediastinum ratio (H/M) and sympathetic activity by wash out ratio (WOR). Effects on office BP, 24 h ambulatory BP monitoring, were documented. Office systolic BP and mean ambulatory systolic BP were significantly reduced from 180 to 141 mmHg (p = 0.006) and from 149 to 129 mmHg (p = 0.014), respectively. Cardiac innervation remained unchanged before and after RDN (H/M 2.5 ± 0.5 versus 2.6 ± 0.4, p = 0.285). Cardiac sympathetic activity was significantly reduced by 67 % (WOR decreased from 24.1 ± 12.7 to 7.9 ± 25.3 %, p = 0.047). Both, responders and non-responders experienced a reduction of cardiac sympathetic activity. RDN significantly reduced cardiac sympathetic activity thereby demonstrating a direct effect on the heart. These changes occurred independently from BP effects and provide a pathophysiological basis for studies, investigating the potential effect of RDN on arrhythmias and heart failure.

Noninvasive estimation of cardiac systolic function using continuous-wave Doppler echocardiography in dogs with experimental mitral regurgitation.

PubMed

Asano, K; Masui, Y; Masuda, K; Fujinaga, T

2002-01-01

To evaluate the feasibility of noninvasive estimation of cardiac systolic function using transthoracic continuous-wave Doppler echocardiography in dogs with mitral regurgitation. Seven mongrel dogs with experimental mitral regurgitation were used. Left ventriculography and measurement of pulmonary capillary wedge pressure were performed under inhalational anaesthesia. A micromanometer-tipped catheter was placed into the left ventricle and transthoracic echocardiography was carried out. The peak rate of left ventricular pressure rise (peak dP/dt) was derived simultaneously by continuous-wave Doppler and manometer measurements. The Doppler-derived dP/dt was compared with the catheter-measured peak dP/dt in the dogs. Classification of the severity of mitral regurgitation in the dogs was as follows: 1+, 2 dogs; 2+, 1 dog; 3+, 2 dogs; 4+, 1 dog; and not examined, 1 dog. We were able to derive dP/dt from the transthoracic continuous-wave Doppler echocardiography in all dogs. Doppler-derived dP/dt had a significant correlation with the catheter-measured peak dP/dt (r = 0.90, P < 0.0001). It was demonstrated that transthoracic continuous-wave Doppler echocardiography is a feasible method of noninvasive estimation of cardiac systolic function in dogs with experimental mitral regurgitation and may have clinical usefulness in canine patients with spontaneous mitral regurgitation.

21 CFR 876.5130 - Urological catheter and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... device that is inserted through the urethra and used to pass fluids to or from the urinary tract. This..., coude catheters, balloon retention type catheters, straight catheters, upper urinary tract catheters...

21 CFR 870.1210 - Continuous flush catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer system...

21 CFR 870.1210 - Continuous flush catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer system...

21 CFR 870.1210 - Continuous flush catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer system...

Anti-fouling strategies for central venous catheters

PubMed Central

Albadawi, Hassan; Patel, Nikasha; Khademhosseini, Ali; Zhang, Yu Shrike; Naidu, Sailendra; Knuttinen, Grace; Oklu, Rahmi

2017-01-01

Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections. Antimicrobial coatings can play a major role in preventing disease. These coatings can be divided into two major categories: drug eluting and non-drug eluting. Much of these catheter designs are targeted at preventing the formation of microbial biofilms that make treatment of CRBSI nearly impossible without removal of the intravenous device. Exciting developments in catheter impregnation with antibiotics as well as nanoscale surface design promise innovative changes in the way that physicians manage intravenous catheters. Occlusion of a catheter renders the catheter unusable and is often treated by tissue plasminogen activator administration or replacement of the line. Prevention of this complication requires a thorough understanding of the mechanisms of platelet aggregation, signaling and cross-linking. This article will look at the advances in biomaterial design specifically drug eluting, non-drug eluting, lubricious coatings and micropatterning as well as some of the characteristics of each as they relate to CVCs. PMID:29399528

Anti-fouling strategies for central venous catheters.

PubMed

Wallace, Alex; Albadawi, Hassan; Patel, Nikasha; Khademhosseini, Ali; Zhang, Yu Shrike; Naidu, Sailendra; Knuttinen, Grace; Oklu, Rahmi

2017-12-01

Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections. Antimicrobial coatings can play a major role in preventing disease. These coatings can be divided into two major categories: drug eluting and non-drug eluting. Much of these catheter designs are targeted at preventing the formation of microbial biofilms that make treatment of CRBSI nearly impossible without removal of the intravenous device. Exciting developments in catheter impregnation with antibiotics as well as nanoscale surface design promise innovative changes in the way that physicians manage intravenous catheters. Occlusion of a catheter renders the catheter unusable and is often treated by tissue plasminogen activator administration or replacement of the line. Prevention of this complication requires a thorough understanding of the mechanisms of platelet aggregation, signaling and cross-linking. This article will look at the advances in biomaterial design specifically drug eluting, non-drug eluting, lubricious coatings and micropatterning as well as some of the characteristics of each as they relate to CVCs.

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.

Outcomes after peritoneal dialysis catheter placement.

PubMed

Carpenter, Jennifer L; Fallon, Sara C; Swartz, Sarah J; Minifee, Paul K; Cass, Darrell L; Nuchtern, Jed G; Pimpalwar, Ashwin P; Brandt, Mary L

2016-05-01

The purpose of this study was to review surgical outcomes after elective placement of peritoneal dialysis (PD) catheters in children with end-stage renal disease. Children with PD catheters placed between February 2002 and July 2014 were retrospectively reviewed. Outcomes were catheter life, late (>30days post-op) complications (catheter malfunction, catheter malposition, infection), and re-operation rates. Comparison groups included laparoscopic versus open placement, age<2, and weight<10kg. Univariate and multivariate analysis were performed. One hundred sixteen patients had 173 catheters placed (122 open, 51 laparoscopic) with an average patient age of 9.7±6.3years. Mean catheter life was similar in the laparoscopic and open groups (581±539days versus 574±487days, p=0.938). The late complication rate was higher for open procedures (57% versus 37%, p=0.013). Children age<2 or weight<10kg had higher re-operation rates (64% versus 42%, p=0.014 and 73% versus 40%, p=0.001, respectively). Adjusted for age and weight, open technique remained a risk factor for late complications (OR 2.44, 95% CI 1.20-4.95) but not re-operation. Laparoscopic placement appears to reduce the rate of late complications in children who require PD dialysis catheters. Children <2years age or <10kg remain at risk for complications regardless of technique. Copyright © 2016 Elsevier Inc. All rights reserved.

Surgical site infection after central venous catheter-related infection in cardiac surgery. Analysis of a cohort of 7557 patients.

PubMed

Le Guillou, V; Tavolacci, M-P; Baste, J-M; Hubscher, C; Bedoit, E; Bessou, J-P; Litzler, P-Y

2011-11-01

The aim of this study was to establish the relationship between the occurrence of a surgical site infection (SSI) and the presence of a central venous catheter-related infection (CVCRI). The Department of Thoracic and Cardiovascular Surgery, University Hospital, Rouen, has carried out a prospective epidemiological survey of all nosocomial infections (pneumonia, SSI and CVCRI) since 1997. The study group included all consecutive patients who underwent cardiac surgery over a 10-year period from 1997 to 2007. A nested case-control study was conducted to identify the risk factors for SSI after CVCRI. Cases were patients with SSI after CVCRI and controls were randomized from patients who presented with CVCRI not followed by SSI. In total, 7557 patients were included and 133 SSIs (1.7%) were identified. The rate of superficial SSI was 0.7% [95% confidence interval (CI): 0.5-0.9] and of mediastinitis was 1.0% (95% CI: 0.8-1.2). Among the 133 cases of SSI, 12 (9.0%; 95% CI: 5.0-14.8) occurred after a CVCRI with identical micro-organisms. CVCRI [adjusted odds ratio (aOR): 5.2; 95% CI: 3.2-8.5], coronary artery bypass grafting (aOR: 2.9; 95% CI: 1.6-5.2), and obesity (aOR: 11.4; 95% CI: 1.0-130.1) were independent factors associated with SSI. The new finding of this study is that patients with CVCRI were 5.2 times more likely to develop SSI compared to patients without CVCRI. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Advanced Imaging Catheter: Final Project Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krulevitch, P; Colston, B; DaSilva, L

2001-07-20

Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area.more » The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body

Radiofrequency Neurotomy

MedlinePlus

... Radiofrequency neurotomy might also be recommended to treat neck pain associated with whiplash. Risks Common side effects include: ... isn't a permanent fix for back or neck pain. Studies on the success of treatment have been ...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

[Incidence of phlebitis due to peripherally inserted venous catheters: impact of a catheter management protocol].

PubMed

Ferrete-Morales, C; Vázquez-Pérez, M A; Sánchez-Berna, M; Gilabert-Cerro, I; Corzo-Delgado, J E; Pineda-Vergara, J A; Vergara-López, S; Gómez-Mateos, J

2010-01-01

To assess the impact on the incidence of PPIVC by implementing a catheter management protocol and to determine risk factors for PPIVC development in hospitalized patients. A total of 3978 episodes of venous catheterization were prospectively included from September 2002 to December 2007. A catheter management protocol was implemented during this period of time. The incidence and variables associated to the occurrence of PPIVC were determined. The incidence of PPIVC from 2002 to 2007 was 4.8%, 4.3%, 3.6%, 2.5%, 1.3% and 1.8% (p<0.001). Perfusion of amiodarone [adjusted OR (AOR) 25.97; 95% CI=7.29-92.55, p=0.0001] and cefotaxime (AOR 2.90; 95% CI=1.29-6.52, p=0.01) and the shift when the catheters were placed (AOR for morning vs. night shift 0.60; 95% CI=0.35-1.02, p=0.063) were independently associated to the development of PPIVC. A history of phlebitis was the only factor independently associated to phlebitis due to peripherally inserted central venous catheters (AOR 3.24; CI at 95% CI= 1.05-9.98, p=0.04). A catheter management protocol decreases the incidence of PPIVC in hospitalized patients. The risk of PPIVC increases for peripherally inserted central venous catheters when the patients have a history of phlebitis and for peripheral venous catheters when amiodarone or cefotaxime are infused. Catheterization of peripheral veins performed during morning shifts is associated with a lower incidence of PPIVC when compared with night shift catheterizations.

Radiofrequency (RF) effects on blood cells, cardiac, endocrine, and immunological functions.

PubMed

Black, David R; Heynick, Louis N

2003-01-01

Effects of radiofrequency electromagnetic fields (RFEMF) on the pituitary adrenocortical (ACTH), growth (GH), and thyroid (TSH) hormones have been extensively studied, and there is coherent research on reproductive hormones (FSH and LH). Those effects which have been identified are clearly caused by heating. The exposure thresholds for these effects in living mammals, including primates, have been established. There is limited evidence that indicates no interaction between RFEMF and the pineal gland or an effect on prolactin from the pituitary gland. Studies of RFEMF exposed blood cells have shown that changes or damage do not occur unless the cells are heated. White cells (leukocytes) are much more sensitive than red cells (erythrocytes) but white cell effects remain consistent with normal physiological responses to systemic temperature fluctuation. Lifetime studies of RFEMF exposed animals show no cumulative adverse effects in their endocrine, hematological, or immune systems. Cardiovascular tissue is not directly affected adversely in the absence of significant RFEMF heating or electric currents. The regulation of blood pressure is not influenced by ultra high frequency (UHF) RFEMF at levels commonly encountered in the use of mobile communication devices. Copyright 2003 Wiley-Liss, Inc.

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

[Possibilities of minimal invasive cardiac catheter interventions in the dog].

PubMed

Glaus, T M; Unterer, S; Tomsa, K; Baumgartner, C; Geissbühler, U; Gardelle, O; Reusch, C

2003-09-01

The therapeutic possibilities in veterinary cardiology have developed rapidly in the past few years. Whereas until recently cardiac intervention in dogs could only be performed by thoracotomy, new minimally invasive techniques are adopted. Procedures like balloondilatation of pulmonic stenosis, coil embolisation of patent ductus arteriosus, pacemaker implantation in symptomatic bradyarrhyhtmia, and palliative balloon pericardiotomy are becoming more and more established. These alternative interventional methods are attractive, because no postsurgical pain and no complications potentially associated with thoracotomy ensue. The knowledge of such new treatment modalities and particularly the indications for an intervention are prerequisites to apply them optimally and broadly.

Prevention of catheter-related blood stream infection.

PubMed

Byrnes, Matthew C; Coopersmith, Craig M

2007-08-01

Catheter-related blood stream infections are a morbid complication of central venous catheters. This review will highlight a comprehensive approach demonstrated to prevent catheter-related blood stream infections. Elements of prevention important to inserting a central venous catheter include proper hand hygiene, use of full barrier precautions, appropriate skin preparation with 2% chlorhexidine, and using the subclavian vein as the preferred anatomic site. Rigorous attention needs to be given to dressing care, and there should be daily assessment of the need for central venous catheters, with prompt removal as soon as is practicable. Healthcare workers should be educated routinely on methods to prevent catheter-related blood stream infections. If rates remain higher than benchmark levels despite proper bedside practice, antiseptic or antibiotic-impregnated catheters can also prevent infections effectively. A recent program utilizing these practices in 103 ICUs in Michigan resulted in a 66% decrease in infection rates. There is increasing recognition that a comprehensive strategy to prevent catheter-related blood stream infections can prevent most infections, if not all. This suggests that thousands of infections can potentially be averted if the simple practices outlined herein are followed.

New-generation radiofrequency technology.

PubMed

Krueger, Nils; Sadick, Neil S

2013-01-01

Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation.

Virtual-Reality Simulator System for Double Interventional Cardiac Catheterization Using Fractional-Order Vascular Access Tracker and Haptic Force Producer

PubMed Central

Chen, Guan-Chun; Lin, Chia-Hung; Hsieh, Kai-Sheng; Du, Yi-Chun; Chen, Tainsong

2015-01-01

This study proposes virtual-reality (VR) simulator system for double interventional cardiac catheterization (ICC) using fractional-order vascular access tracker and haptic force producer. An endoscope or a catheter for diagnosis and surgery of cardiovascular disease has been commonly used in minimally invasive surgery. It needs specific skills and experiences for young surgeons or postgraduate year (PGY) students to operate a Berman catheter and a pigtail catheter in the inside of the human body and requires avoiding damaging vessels. To improve the training in inserting catheters, a double-catheter mechanism is designed for the ICC procedures. A fractional-order vascular access tracker is used to trace the senior surgeons' consoled trajectories and transmit the frictional feedback and visual feedback during the insertion of catheters. Based on the clinical feeling through the aortic arch, vein into the ventricle, or tortuous blood vessels, haptic force producer is used to mock the elasticity of the vessel wall using voice coil motors (VCMs). The VR establishment with surgeons' consoled vessel trajectories and hand feeling is achieved, and the experimental results show the effectiveness for the double ICC procedures. PMID:26171419

Prevention of catheter-associated urinary tract infection

PubMed Central

Trautner, Barbara W.; Hull, Richard A.; Darouiche, Rabih O.

2010-01-01

Purpose of review The underlying cause of catheter-associated urinary tract infection is biofilm formation by uropathogens on the urinary catheter. Biofilm is a relatively new concept in medicine, and current measures to prevent biofilm formation are inadequate. Considerable work is being done in this area, but little clinical progress has been made. The purpose of this review is to analyze recent publications concerning prevention of catheter-associated urinary tract infection. Recent findings Several recent studies have elucidated aspects of biofilm formation in catheter-associated urinary tract infection. Other researchers are working on methods to disrupt biofilm formation on catheter surfaces. At the same time, the magnitude of the problem of catheter-associated urinary tract infection has increased awareness of the effectiveness of basic infection control measures. A modern approach to infection control may include computerized ordering systems that minimize unnecessary days of catheterization. Finally, consumption of cranberry juice products and bacterial interference are two novel approaches to urinary tract infection prevention. Summary Biofilm-disrupting strategies offer promise for the future but have little immediate applicability. Implementation of infection control measures to improve catheter function and remove unnecessary catheters can be done at the present time. In general, prevention of catheter-associated urinary tract infection remains an elusive goal. More basic research at the level of pathogenesis is needed so that novel strategies can be designed. PMID:15647698

Therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia and the risk factors for postoperative recurrence

PubMed Central

Li, Chunli; Jia, Libo; Wang, Zhenzhou; Niu, Ling; An, Xinjiang

2018-01-01

independent risk factors for postoperative recurrence (P<0.05). Although radiofrequency ablation can damage the cardiac vagal nerve, resulting in an increase in the heart rate after ablation during the course of the tilt table test and changed hemagglutination state within one week after ablation, those changes returned to normal after one week. The efficacy of radiofrequency ablation in the treatment of pediatric SVT is clear, and recurrence rate is low. Residual slow pathway and inaccurate targeting were independent risk factors for postoperative recurrence. PMID:29725383

Therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia and the risk factors for postoperative recurrence.

PubMed

Li, Chunli; Jia, Libo; Wang, Zhenzhou; Niu, Ling; An, Xinjiang

2018-05-01

independent risk factors for postoperative recurrence (P<0.05). Although radiofrequency ablation can damage the cardiac vagal nerve, resulting in an increase in the heart rate after ablation during the course of the tilt table test and changed hemagglutination state within one week after ablation, those changes returned to normal after one week. The efficacy of radiofrequency ablation in the treatment of pediatric SVT is clear, and recurrence rate is low. Residual slow pathway and inaccurate targeting were independent risk factors for postoperative recurrence.

Comparison of an Endotracheal Cardiac Output Monitor to a Pulmonary Artery Catheter

DTIC Science & Technology

2017-12-04

of a FDA approved device, the CONMED endotracheal cardiac output monitor (ECOM) ™ apparatus, by comparing it to the Edwards Vig ilance II monitor...and Use Committee (FWH 20140100A). Results Using GraphPad Prism® to conduct non-linear fit analyses comparing the slopes of the curves for ECOM

FAQs about Catheter-Associated Urinary Tract Infection

MedlinePlus

... and nurses take the following actions. Catheter insertion o Catheters are put in only when necessary and they are removed as soon as possible. o Only properly trained persons insert catheters using sterile (“ ...

Central Venous Catheter (Central Line)

MedlinePlus

... the skin entry site. With care, central venous catheters can remain in the body for several months without becoming infected. ■ ■ Blocking or kinking— Blood clots may begin to form in the catheter but ...

Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC).

PubMed

Abdullah, B J J; Mohammad, N; Sangkar, J V; Abd Aziz, Y F; Gan, G G; Goh, K Y; Benedict, I

2005-07-01

The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).

78 FR 33633 - Human Exposure to Radiofrequency Electromagnetic Fields

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-04

..., and 15, et al. Human Exposure to Radiofrequency Electromagnetic Fields; Reassessment of Exposure to Radiofrequency Electromagnetic Fields Limits and Policies; Final Rule and Proposed Rule #0;#0;Federal Register... Radiofrequency Electromagnetic Fields AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY...

Usefulness of gram staining of blood collected from total parenteral nutrition catheter for rapid diagnosis of catheter-related sepsis.

PubMed Central

Moonens, F; el Alami, S; Van Gossum, A; Struelens, M J; Serruys, E

1994-01-01

The accuracy of Gram staining of blood drawn from catheters used to administer total parenteral nutrition was compared with paired quantitative blood cultures for the diagnosis of catheter-related sepsis. Gram staining was positive in 11 of 18 episodes of catheter-related sepsis documented by quantitative culture (sensitivity, 61%) but in none of the 5 episodes of fever unrelated to catheter infection. Thus, this procedure enabled the rapid presumptive diagnosis and guidance of antimicrobial therapy for total parenteral nutrition catheter sepsis, with a positive predictive value of 100% and a negative predictive value of 42%. PMID:7521359

Cooled radiofrequency ablation for bilateral greater occipital neuralgia.

PubMed

Vu, Tiffany; Chhatre, Akhil

2014-01-01

This report describes a case of bilateral greater occipital neuralgia treated with cooled radiofrequency ablation. The case is considered in relation to a review of greater occipital neuralgia, continuous thermal and pulsed radiofrequency ablation, and current medical literature on cooled radiofrequency ablation. In this case, a 35-year-old female with a 2.5-year history of chronic suboccipital bilateral headaches, described as constant, burning, and pulsating pain that started at the suboccipital region and radiated into her vertex. She was diagnosed with bilateral greater occipital neuralgia. She underwent cooled radiofrequency ablation of bilateral greater occipital nerves with minimal side effects and 75% pain reduction. Cooled radiofrequency ablation of the greater occipital nerve in challenging cases is an alternative to pulsed and continuous RFA to alleviate pain with less side effects and potential for long-term efficacy.

Cooled Radiofrequency Ablation for Bilateral Greater Occipital Neuralgia

PubMed Central

Chhatre, Akhil

2014-01-01

This report describes a case of bilateral greater occipital neuralgia treated with cooled radiofrequency ablation. The case is considered in relation to a review of greater occipital neuralgia, continuous thermal and pulsed radiofrequency ablation, and current medical literature on cooled radiofrequency ablation. In this case, a 35-year-old female with a 2.5-year history of chronic suboccipital bilateral headaches, described as constant, burning, and pulsating pain that started at the suboccipital region and radiated into her vertex. She was diagnosed with bilateral greater occipital neuralgia. She underwent cooled radiofrequency ablation of bilateral greater occipital nerves with minimal side effects and 75% pain reduction. Cooled radiofrequency ablation of the greater occipital nerve in challenging cases is an alternative to pulsed and continuous RFA to alleviate pain with less side effects and potential for long-term efficacy. PMID:24716017

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.

Endovascular Radiofrequency Ablation for Varicose Veins

PubMed Central

2011-01-01

or worse as other chronic diseases such as back pain and arthritis. Lower limb VV is a very common disease affecting adults – estimated to be the 7th most common reason for physician referral in the US. There is a very strong familial predisposition to VV. The risk in offspring is 90% if both parents affected, 20% when neither affected and 45% (25% boys, 62% girls) if one parent affected. The prevalence of VV worldwide ranges from 5% to 15% among men and 3% to 29% among women varying by the age, gender and ethnicity of the study population, survey methods and disease definition and measurement. The annual incidence of VV estimated from the Framingham Study was reported to be 2.6% among women and 1.9% among men and did not vary within the age range (40-89 years) studied. Approximately 1% of the adult population has a stasis ulcer of venous origin at any one time with 4% at risk. The majority of leg ulcer patients are elderly with simple superficial vein reflux. Stasis ulcers are often lengthy medical problems and can last for several years and, despite effective compression therapy and multilayer bandaging are associated with high recurrence rates. Recent trials involving surgical treatment of superficial vein reflux have resulted in healing and significantly reduced recurrence rates. Endovascular Radiofrequency Ablation for Varicose Veins RFA is an image-guided minimally invasive treatment alternative to surgical stripping of superficial venous reflux. RFA does not require an operating room or general anaesthesia and has been performed in an outpatient setting by a variety of medical specialties including surgeons and interventional radiologists. Rather than surgically removing the vein, RFA works by destroying or ablating the refluxing vein segment using thermal energy delivered through a radiofrequency catheter. Prior to performing RFA, color-flow Doppler ultrasonography is used to confirm and map all areas of venous reflux to devise a safe and effective

[Peripheral intravenous catheter-related phlebitis].

PubMed

van der Sar-van der Brugge, Simone; Posthuma, E F M Ward

2011-01-01

Phlebitis is a very common complication of the use of intravenous catheters. Two patients with an i.v. catheter complicated by thrombophlebitis are described. Patient A was immunocompromised due to chronic lymphatic leukaemia and developed septic thrombophlebitis with positive blood cultures for S. Aureus. Patient B was being treated with flucloxacillin because of an S. Aureus infection and developed chemical phlebitis. Septic phlebitis is rare, but potentially serious. Chemical or mechanical types of thrombophlebitis are usually less severe, but happen very frequently. Risk factors include: female sex, previous episode of phlebitis, insertion at (ventral) forearm, emergency placement and administration of antibiotics. Until recently, routine replacement of peripheral intravenous catheters after 72-96 h was recommended, but randomised controlled trials have not shown any benefit of this routine. A recent Cochrane Review recommends replacement of peripheral intravenous catheters when clinically indicated only.

The impact of dual-source parallel radiofrequency transmission with patient-adaptive shimming on the cardiac magnetic resonance in children at 3.0 T.

PubMed

Wang, Haipeng; Qiu, Liyun; Wang, Guangbin; Gao, Fei; Jia, Haipeng; Zhao, Junyu; Chen, Weibo; Wang, Cuiyan; Zhao, Bin

2017-06-01

The cardiac magnetic resonance (CMR) of children at 3.0 T presents a unique set of technical challenges because of their small cardiac anatomical structures, fast heart rates, and the limited ability to keep motionless and hold breathe, which could cause problems associated with field inhomogeneity and degrade the image quality. The aim of our study was to evaluate the effect of dual-source parallel radiofrequency (RF) transmission on the B1 homogeneity and image quality in children with CMR at 3.0 T. The study was approved by the institutional ethics committee and written informed consent was obtained. A total of 30 free-breathing children and 30 breath-hold children performed CMR examinations with dual-source and single-source RF transmission. The B1 homogeneity, contrast ratio (CR) of cine images, and off-resonance artifacts in cine images between dual-source and single-source RF transmission were assessed in free-breathing and breath-hold groups, respectively. In both free-breathing and breath-hold groups, higher mean percentage of flip angle (free-breathing group: 104.2 ± 4.6 vs 95.5 ± 6.3, P < .001; breath-hold group: 101.5 ± 5.1 vs 92.5 ± 6.3, P < .001) and lower coefficient of variation (free-breathing group: 0.06 ± 0.02 vs 0.09 ± 0.03, P < .001; breath-hold group: 0.07 ± 0.03 vs 0.10 ± 0.04, P = .005) were found with dual-source than with single-source RF transmission. Both the CRs in the horizontal long axis (HLA) and short axis of cine images with dual-source RF transmission was improved (P < .05 for all). The scores of off-resonance artifacts in the HLA with dual-source RF transmission were higher in both free-breathing and breath-hold groups (P < .05 for all), with substantial interreader agreement (kappa values from 0.68 to 0.74). Compared with conventional single-source, dual-source parallel RF transmission could significantly improve the B1 homogeneity and image quality for CMR in

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques.

PubMed

Chen, Shaojie; Schmidt, Boris; Bordignon, Stefano; Bologna, Fabrizio; Perrotta, Laura; Nagase, Takahiko; Chun, K R Julian

2018-04-16

Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients' life quality, deteriorated cardiac function, and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, "single shot" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden. © 2018 Wiley Periodicals, Inc.

Radiofrequency and microwave radiation in the microelectronics industry.

PubMed

Cohen, R

1986-01-01

The microscopic precision required to produce minute integrated circuits is dependent on several processes utilizing radiofrequency and microwave radiation. This article provides a review of radiofrequency and microwave exposures in microelectronics and of the physical and biologic properties of these types of radiation; summarizes the existing, relevant medical literature; and provides the clinician with guidelines for diagnosis and treatment of excessive exposures to microwave and radiofrequency radiation.

Catheter-based photoacoustic endoscope

PubMed Central

Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2014-01-01

Abstract. We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique’s benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument’s flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system. PMID:24887743

Slow pathway radiofrequency ablation in patients with AVNRT: junctional rhythm is less frequent during magnetic navigation ablation than with the conventional technique.

PubMed

Ricard, Philippe; Latcu, Decebal Gabriel; Yaïci, Khelil; Zarqane, Naima; Saoudi, Nadir

2010-01-01

The occurrence of accelerated junctional rhythm (JR) during radiofrequency ablation of the slow pathway in patients with atrioventricular nodal reentrant tachycardia (AVNRT) is frequent. The aim of the present study was to compare the occurrence of JR during magnetic remote catheter ablation to the conventional manual ablation. Twenty six patients (males: seven; age: 51 + or - 15 years) underwent slow pathway ablation with magnetic navigation (MN) system (Niobe, Stereotaxis Inc., St. Louis, MO, USA) and were compared to a control group of 11 patients (males: three; age: 53 + or - 16 years) treated with conventional manual ablation. A 4-mm nonirrigated tip catheter was used in both groups with a maximum of 30 W and 60 degrees C. Acute success was obtained in all patients. In the MN group, three patients out of 24 had no junctional beat (JB) at all and seven patients had 10 or less JB. In contrast, in the conventional group no patient had less than 10 JB. The mean number of JB in the MN group was 66 + or - 94.9 (0-410) and 200 + or - 243.1 (43-914) in the control group (P = 0.019). In the MN group one patient had a first-degree atrioventricular block. No other complication occurred. Magnetic remote catheter ablation of AVNRT is effective and is associated with less JB than the manual conventional technique. Therefore, JB may not be considered as a mandatory indicator for successful AVNRT ablation with MN system.

21 CFR 868.5120 - Anesthesia conduction catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to inject...

21 CFR 868.5120 - Anesthesia conduction catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to inject...

21 CFR 868.5120 - Anesthesia conduction catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to inject...

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result.

PubMed

Xia, Ning; Gong, Ju; Lu, Jian; Chen, Zhi-Jin; Zhang, Li-Yun; Wang, Zhong-Min

2017-03-14

To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction. We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter. Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients' stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d. This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach.

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result

PubMed Central

Xia, Ning; Gong, Ju; Lu, Jian; Chen, Zhi-Jin; Zhang, Li-Yun; Wang, Zhong-Min

2017-01-01

AIM To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction. METHODS We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter. RESULTS Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients’ stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d. CONCLUSION This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach. PMID:28348491

S-Nitroso-N-acetylpenicillamine (SNAP) Impregnated Silicone Foley Catheters: A Potential Biomaterial/Device To Prevent Catheter-Associated Urinary Tract Infections

PubMed Central

2016-01-01

Urinary Foley catheters are utilized for management of hospitalized patients and are associated with high rates of urinary tract infections (UTIs). Nitric oxide (NO) potently inhibits microbial biofilm formation, which is the primary cause of catheter associated UTIs (CAUTIs). Herein, commercial silicone Foley catheters are impregnated via a solvent swelling method with S-nitroso-N-acetyl-D-penicillamine (SNAP), a synthetic NO donor that exhibits long-term NO release and stability when incorporated into low water-uptake polymers. The proposed catheters generate NO surface-fluxes >0.7 × 10–10 mol min–1 cm–2 for over one month under physiological conditions, with minimal SNAP leaching. These biomedical devices are demonstrated to significantly decrease formation of biofilm on the surface of the catheter tubings over 3, 7, and 14 day periods by microbial species (Staphylococcus epidermidis and Proteus mirabilis) commonly causing CAUTIs. Toxicity assessment demonstrates that the SNAP-impregnated catheters are fully biocompatible, as extracts of the catheter tubings score 0 on a 3-point grading scale using an accepted mouse fibroblast cell-line toxicity model. Consequently, SNAP-impregnated silicone Foley catheters can likely provide an efficient strategy to greatly reduce the occurrence of nosocomial CAUTIs. PMID:26462294

Early removal of urethral catheter with suprapubic tube drainage versus urethral catheter drainage alone after robot-assisted laparoscopic radical prostatectomy.

PubMed

Prasad, Sandip M; Large, Michael C; Patel, Amit R; Famakinwa, Olufenwa; Galocy, R Matthew; Karrison, Theodore; Shalhav, Arieh L; Zagaja, Gregory P

2014-07-01

Retrospective single institution data suggest that postoperative pain after robot-assisted laparoscopic radical prostatectomy is decreased by early removal of the urethral catheter with suprapubic tube drainage. In a randomized patient population we determined whether suprapubic tube drainage with early urethral catheter removal would improve postoperative pain compared with urethral catheter drainage alone. Men with a body mass index of less than 40 kg/m(2) who had newly diagnosed prostate cancer and elected robot-assisted laparoscopic radical prostatectomy were included in analysis. Block randomization by surgeon was used and randomization assignment was done after completing the urethrovesical anastomosis. In patients assigned to suprapubic tube drainage the urethral catheter was removed on postoperative day 1 and all catheters were removed on postoperative day 7. Visual analog pain scale and satisfaction questionnaires were administered on postoperative days 0, 1 and 7. A total of 29 patients were randomized to the urethral catheter vs 29 to the suprapubic tube plus early urethral catheter removal at the time of interim futility analysis. Mean visual analog pain scale scores did not differ between the groups at any time point and a similar percent of patients cited the catheter as the greatest bother with nonsignificant differences in treatment related satisfaction. Complications during postoperative week 1 did not vary between the groups. Based on interim results the trial was terminated due to lack of effect. Patients randomized to suprapubic tube vs urethral catheter drainage for the week after prostatectomy had similar pain, catheter related bother and treatment related satisfaction in the perioperative period. We no longer routinely offer suprapubic tube drainage with early urethral catheter removal at our institution. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The dangers of long-term catheter drainage.

PubMed

Lowthian, P

There are many dangers associated with long-term urinary bladder drainage by catheter. For various reasons, the choice of catheter is important, and its initial insertion can be particularly hazardous. All catheterizations should, however, be safer when there is some urine (or other fluid) in the bladder. The appropriate choice of drainage system attached to the catheter can delay bacterial invasion of the bladder. Great care is needed to prevent blockage of the system, particularly when bacteriuria is present. Recent evidence indicates that some bacteria encourage the development of encrustations, so that, in some circumstances, catheters may become blocked within 24 hours. This, together with other considerations, strongly suggests that indwelling catheters should be changed at intervals of not more than 5 days. The practical implications of this are considered, as are the benefits that may accrue. Accidental catheter traction is another danger, and some possible methods of avoiding this are discussed. Finally, the need for a new kind of drainage-bag support is highlighted.

Heart catheter cable and connector

NASA Technical Reports Server (NTRS)

Harrison, D. R.; Cota, F. L.; Sandler, H.

1972-01-01

Ultraminiature catheter cables that are stiff enough for intravenous insertion yet flexible at the tip, sterilizable, and economical are fabricated entirely from commercially available parts. Assembly includes air passageway for reference pressures and coaxial cable for transmission of signals from the tip of catheter.

Trans-catheter aortic valve implantation after previous aortic homograft surgery.

PubMed

Drews, Thorsten; Pasic, Miralem; Buz, Semih; Unbehaun, Axel

2011-12-01

In patients with previous heart surgery, the operative risk is elevated during conventional aortic valve re-operations. Trans-catheter aortic valve implantation is a new method for the treatment of high-risk patients. Nevertheless, this new procedure carries potential risks in patients with previous homograft implantation in aortic position. Between April 2008 and February 2011, 345 consecutive patients (mean EuroSCORE (European System for Cardiac Operative Risk Evaluation): 38 ± 20%; mean Society of Thoracic Surgeons (STS) Mortality Score: 19 ± 16%; mean age: 80 ± 8 years; 111 men and 234 women) underwent trans-apical aortic valve implantation. In three patients, previous aortic homograft implantation had been performed. Homograft degeneration causing combined valve stenosis and incompetence made re-operation necessary. In all three patients, the aortic valve could be implanted using the trans-apical approach, and the procedure was successful. In two patients, there was slight paravalvular leakage of the aortic prosthesis and the other patient had slight central leakage. Neither ostium obstruction nor mitral valve damage was observed. Trans-catheter valve implantation can be performed successfully after previous homograft implantation. Particular care should be taken to achieve optimal valve positioning, not to obstruct the ostium of the coronary vessels due to the changed anatomic situation and not to cause annulus rupture. Copyright © 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

47 CFR 2.801 - Radiofrequency device defined.

Code of Federal Regulations, 2011 CFR

2011-10-01

....801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device..., but are not limited to: (a) The various types of radio communication transmitting devices described...

Initial clinical experience with a remote magnetic catheter navigation system for ablation of cavotricuspid isthmus-dependent right atrial flutter.

PubMed

Arya, Arash; Kottkamp, Hans; Piorkowski, Christopher; Bollmann, Andreas; Gerdes-Li, Jin-Hong; Riahi, Sam; Esato, Masahiro; Hindricks, Gerhard

2008-05-01

A remote magnetic navigation system (MNS) is available and has been used with a 4-mm-tip magnetic catheter for radiofrequency (RF) ablation of some supraventricular and ventricular arrhythmias; however, it has not been evaluated for the ablation of cavotricuspid isthmus-dependent right atrial flutter (AFL). The present study evaluates the feasibility and efficiency of this system and the newly available 8-mm-tip magnetic catheter to perform RF ablation in patients with AFL. Twenty-six consecutive patients (23 men, mean age 64.6 +/- 9.6 years) underwent RF ablation using a remote MNS. RF ablation was performed with an 8-mm-tip magnetic catheter (70 degrees C, maximum power 70 W, 90 seconds). The endpoint of ablation was complete bidirectional isthmus block. To assess a possible learning curve, procedural data were compared between the first 14 (group 1) and the rest (group 2) of the patients. The initial rhythm during ablation was AFL in 20 (19 counterclockwise and 1 clockwise) and sinus rhythm in six patients. Due to technical issues, the ablation in the 18th patient could not be done with the MNS, and so we switched to conventional ablation. The remote magnetic navigation and ablation procedure was successful in 24 of the 25 (96%) remaining patients with AFL. In one patient (patient 2), conventional catheter was used to complete the isthmus block after termination of AFL. The procedure, preparation, ablation, and fluoroscopy times (median [range]) were 53 (30-130) minutes, 28 (10-65) minutes, 25 (12-78) minutes, and 7.5 (3.2-20.8) minutes, respectively. Patients in group 2 had shorter procedure (45 [30-70] min vs 80 [57-130] min, P = 0.0001), preparation (25 [10-30] min vs 42 [30-65] min, P = 0.0001), ablation (20 [12-40] min vs 31 [20-78] min, P = 0.002), and fluoroscopy (7.2 [3.2-12.2] min vs 11.0 [5.4-20.8] min, P = 0.014) times. No complication occurred during the procedure. Using a remote MNS and an 8-mm-tip magnetic catheter, ablation of AFL is feasible

Hydrophilic-coated catheters for intermittent catheterisation reduce urethral micro trauma: a prospective, randomised, participant-blinded, crossover study of three different types of catheters.

PubMed

Stensballe, J; Looms, D; Nielsen, P N; Tvede, M

2005-12-01

To compare two hydrophilic-coated (SpeediCath and LoFric and one uncoated gel-lubricated catheter (InCare Advance Plus) concerning withdrawal friction force and urethral micro trauma. 49 healthy male volunteers participated in this prospective, randomised, blinded, crossover study of three different bladder catheters. The withdrawal friction force was measured, and urine analysis of blood, nitrite and leucocytes, microbiological analysis of urine cultures and subjective evaluation of the catheters were performed. 40 participants completed the study and were included in the analysis. SpeediCath exerted a significantly lower mean withdrawal friction force and work than the gel-lubricated uncoated catheter, whereas LoFric exerted a significantly higher mean friction force than both of the other catheters. The hydrophilic catheters caused less microscopic haematuria and less pain than the gel-lubricated uncoated catheter. Furthermore, 93% of the participants preferred the hydrophilic catheters. Hydrophilic-coated catheters perform better than uncoated catheters with regard to haematuria and preference. SpeediCath, but not LoFric, exerts less withdrawal friction force than InCare Advance Plus.

Geraniol alleviates diabetic cardiac complications: Effect on cardiac ischemia and oxidative stress.

PubMed

El-Bassossy, Hany M; Ghaleb, Hanna; Elberry, Ahmed A; Balamash, Khadijah S; Ghareib, Salah A; Azhar, Ahmad; Banjar, Zainy

2017-04-01

The present study was planned to assess the possible protective effect of geraniol on cardiovascular complications in an animal model with diabetes. Diabetes was induced in rats by a single streptozotocin injection. In the treated group, geraniol (150mgkg -1 day -1 ) was administered orally starting from the 15th day after induction of diabetes, and ending after 7 weeks; diabetic control rats were given vehicle for the same period. At the end of the study, cardiac contractility was assessed by using a Millar microtip catheter in anesthetised rats, and cardiac conductivity determined by a surface ECG. Serum levels of glucose, cholesterol, triglyceride and adiponectin as well as urine 8-isoprostane were determined. In addition, cardiac superoxide dismutase (SOD) and catalase activity were measured. Geraniol administration significantly alleviated the attenuated cardiac systolic function associated with diabetes as indicated by inhibiting the decrease in the rate of rise (dP/dt max ) in ventricular pressure and the increase in systolic duration observed in diabetic rats. In addition, geraniol alleviated impaired diastolic function as shown by inhibiting the decrease in the rate of fall (dP/dt min ) in ventricular pressure and increased isovolumic relaxation constant (Tau) observed in diabetic rats. ECG recordings showed that geraniol prevented any increase in QTc and T-peak-T-end intervals, and markers of LV ischemia and arrhythmogenesis, seen in diabetic animals. Geraniol suppressed the exaggerated oxidative stress as evidenced by preventing the increase in 8-isoprotane. In diabetic heart tissue, geraniol prevented the inhibition in catalase activity but did not affect the heart SOD. Geraniol partially reduced hyperglycemia, prevented the hypercholesterolemia, but did not affect the serum level of adiponectin in diabetic animals. Results obtained in this study suggest that geraniol provides a potent protective effect against cardiac dysfunction induced by diabetes

Sudden cardiac death in adults with congenital heart disease.

PubMed

Yap, Sing-Chien; Harris, Louise

2009-12-01

Sudden cardiac death is one of the leading causes of death in patients with congenital heart disease, especially in patients with repaired cyanotic and left heart obstructive lesions. While the overall annual incidence of sudden cardiac death is relatively low, estimated at 0.09% per year, this nonetheless represents a many-fold increase over that of comparable age-matched control populations. The most frequent cause of sudden cardiac death is believed to be arrhythmic, usually ventricular arrhythmia. Most studies investigating risk factors for ventricular arrhythmia and/or sudden cardiac death have focused on patients with repaired tetralogy of Fallot and patients with Mustard/Senning repair for complete transposition of the great arteries. Despite a multitude of risk factors, their predictive value for the occurrence of sudden cardiac death is relatively low. Current experience with implantable cardioverter defibrillators in this patient population is limited to observational studies and the selection of patients for prophylactic implantable cardioverter defibrillator implantation is impeded both by the absence of randomized trials and weak predictors. Catheter ablation of ventricular tachycardia has emerged as a promising therapy for abolishing or reducing the burden of arrhythmia but experience is still limited and the impact on long-term outcome uncertain. Future studies will have to focus on improving risk stratification of patients with congenital heart disease.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio.

PubMed

Spencer, Timothy R; Mahoney, Keegan J

2017-11-01

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33 to 45% of the vessels diameter. There has been evidence on larger diameter catheters and increased thrombosis risk in recent literature, while insufficient information established on what relationship to vessel size is appropriate for any intra-vascular device. Earlier references to clinical standards and guidelines did not clearly address vessel size in relation to the area consumed or external catheter diameter. The aim of this manuscript is to present catheter-related thrombosis evidence and develop a standardized process of ultrasound-guided vessel assessment, integrating CVR, Virchow's triad phenomenon and vessel health and preservation strategies, empowering an evidence-based approach to device placement. Through review, calculation and assessment on the areas of the 33 and 45% rule, a preliminary clinical tool was developed to assist clinicians make cognizant decisions when placing intravascular devices relating to target vessel size, focusing on potential reduction in catheter-related thrombosis. Increasing the understanding and utilization of CVRs will lead to a safer, more consistent approach to device placement, with potential thrombosis reduction strategies. The future of evidence-based data relies on the clinician to capture accurate vessel measurements and device-related outcomes. This will lead to a more dependable data pool, driving the relationship of catheter-related thrombosis and vascular assessment.

21 CFR 870.1330 - Catheter guide wire.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Catheter guide wire. 870.1330 Section 870.1330...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1330 Catheter guide wire. (a) Identification. A catheter guide wire is a coiled wire that is designed to fit inside a...

21 CFR 870.1330 - Catheter guide wire.

Code of Federal Regulations, 2010 CFR