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Sample records for atrial appendage flow

  1. Applying non-linear dynamics to atrial appendage flow data to understand and characterize atrial arrhythmia

    SciTech Connect

    Chandra, S.; Grimm, R.A.; Katz, R.; Thomas, J.D.

    1996-06-01

    The aim of this study was to better understand and characterize left atrial appendage flow in atrial fibrillation. Atrial fibrillation and flutter are the most common cardiac arrhythmias affecting 15% of the older population. The pulsed Doppler velocity profile data was recorded from the left atrial appendage of patients using transesophageal echocardiography. The data was analyzed using Fourier analysis and nonlinear dynamical tools. Fourier analysis showed that appendage mechanical frequency ({ital f{sub f}}) for patients in sinus rhythm was always lower (around1 Hz) than that in atrial fibrillation (5-8 Hz). Among patients with atrial fibrillation spectral power below {ital f{sub f}} was significantly different suggesting variability within this group of patients. Results that suggested the presence of nonlinear dynamics were: a) the existence of two arbitrary peak frequencies {ital f{sub 1}, f{sub 2}}, and other peak frequencies as linear combinations thereof ({ital mf{sub 1}{+-}nf{sub 2}}), and b) the similarity between the spectrum of patient data and that obtained using the Lorenz equation. Nonlinear analysis tools, including Phase plots and differential radial plots, were also generated from the velocity data using a delay of 10. In the phase plots, some patients displayed a torus-like structure, while others had a more random-like pattern. In the differential radial plots, the first set of patients (with torus-like phase plots) showed fewer values crossing an arbitrary threshold of 10 than did the second set (8 vs. 27 in one typical example). The outcome of cardioversion was different for these two set of patients. Fourier analysis helped to: differentiate between sinus rhythm and atrial fibrillation, understand the characteristics of the wide range of atrial fibrillation patients, and provide hints that atrial fibrillation could be a nonlinear process. Nonlinear dynamical tools helped to further characterize and sub-classify atrial fibrillation.

  2. The feasibility of substituting left atrial wall strain for flow velocity of left atrial appendage.

    PubMed

    Miyoshi, Akihito; Nakamura, Yoichi; Kazatani, Yukio; Ito, Hiroshi

    2017-07-28

    Non-valvular atrial fibrillation (NVAF) is frequently complicated by thromboembolism. Left atrial appendage (LAA) flow is a predictor of LAA thrombosis. LAA flow is measured by transesophageal echocardiography (TEE), which is a semi-invasive diagnostic tool. Recently, speckle-tracking methods have been adapted for the evaluation of local cardiac function. We hypothesised that if we could determine LAA wall motion utilising a speckle tracking technique, we could non-invasively analyse LAA flow. Sixty-three NVAF patients including 38 with chronic atrial fibrillation (CAF), 14 with paroxysmal AF (PAF) and 11 with atrial flutter (AFL) were enrolled in this study. Normal sinus rhythm (NSR) patients with non-thromboembolic cerebral infarction were also included. Immediately after obtaining a 2D movie of the LAA through the aortic oblique short axis view by transthoracic echocardiography, LAA flow velocity was measured by TEE. Mean strains between the posterior and anterior walls were measured using a speckle-tracking technique. Ten patients exhibited a thrombus and 11 had spontaneous echo contrast (SEC) in the auricle. Mean strain value was similar between CAF and PAF, although LAA flow velocity for CAF was significantly reduced compared with PAF (median value 13.7 cm/s versus 36.1 cm/s, p = <.00001). Mean strain of CAF with thrombus/SEC was significantly reduced compared with NSR patients (median value 1.52% versus 3.17%, p = .00181). Furthermore, mean strain was correlated with LAA flow velocity (R = 0.399, R2 = 0.1595, p = .000615). LAA wall strain identified via speckle-tracking methods may presage LAA peak flow velocity. This technique may contribute to stratification of thrombosis risks in the LAA.

  3. Low left atrial appendage flow velocity predicts recurrence of atrial fibrillation after catheter ablation of persistent atrial fibrillation.

    PubMed

    Kanda, Takashi; Masuda, Masaharu; Sunaga, Akihiro; Fujita, Masashi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Watanabe, Tetsuya; Takahara, Mitsuyoshi; Sakata, Yasushi; Uematsu, Masaaki

    2015-11-01

    Recurrence after catheter ablation of persistent atrial fibrillation (AF) remains an unsolved issue. This study aimed to explore the association between the left atrial appendage peak flow velocity (LAAV) and AF recurrence after ablation in persistent AF patients. Fifty-three consecutive patients who underwent an initial catheter ablation of persistent AF were enrolled [age, 65±10 years; male, 42 (79%)]. The LAAV was obtained by transesophageal echocardiography before ablation. All the patients underwent pulmonary vein isolation and were followed up for 12 months. The LAAV and other clinical factors (AF duration, CHA2DS2VASc score, left atrial diameter, left atrial volume, and left ventricular ejection fraction) were tested using a Cox proportional hazards regression analysis as predictors of AF recurrence during the 1-year follow-up. AF recurrence occurred in 16 (30%) patients. The patients with AF recurrences had lower LAAVs (23.3±7.2cm/s vs. 33.3±15.1cm/s, p=0.002) than those without AF recurrence. In the multivariable analysis, a low LAAV independently predicted AF recurrence (hazard ratio, 3.04; 95% confidence interval, 1.05-8.79; p=0.040). A Kaplan-Meier analysis also demonstrated a lower survival rate free from AF recurrence in the low LAAV group than in the high LAAV group (p=0.030). A low LAAV was associated with AF recurrence after the initial catheter ablation of persistent AF. Copyright © 2015. Published by Elsevier Ltd.

  4. Left Atrial Appendage Exclusion for Atrial Fibrillation

    PubMed Central

    Syed, Faisal F.; DeSimone, Christopher V.; Friedman, Paul A.; Asirvatham, Samuel J.

    2015-01-01

    SYNOPSIS Percutaneous left atrial appendage (LAA) closure is increasingly being used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. A number of approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. We review the published studies on surgical and percutaneous approaches to LAA closure; focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management. PMID:25443240

  5. Left Atrial Appendage Closure Devices

    PubMed Central

    Romero, Jorge; Perez, Irving E; Krumerman, Andrew; Garcia, Mario J; Lucariello, Richard J

    2014-01-01

    Atrial fibrillation (AF) increases the risk for thromboembolic stroke five-fold. The left atrial appendage (LAA) has been shown to be the main source of thrombus formation in the majority of strokes associated with AF. Oral anticoagulation with warfarin and novel anticoagulants remains the standard of care; however, it has several limitations, including bleeding and poor compliance. Occlusion of the LAA has been shown to be an alternative therapeutic approach to drug therapy. The purpose of this article is to review the different techniques and devices that have emerged for the purpose of occluding this structure, with a particular emphasis on the efficacy and safety studies published to date in the medical literature. PMID:24963274

  6. Left atrial appendage flow velocity and time from P-wave onset to tissue Doppler-derived A' predict atrial fibrillation recurrence after radiofrequency catheter ablation.

    PubMed

    Fukushima, Keiko; Fukushima, Noritoshi; Ejima, Koichiro; Kato, Ken; Sato, Yasuto; Uematsu, Shoko; Arai, Kotaro; Manaka, Tetsuyuki; Takagi, Atsushi; Ashihara, Kyomi; Shoda, Morio; Hagiwara, Nobuhisa

    2015-07-01

    Atrial fibrillation (AF) is associated with atrial remodeling. We investigate the abilities of preprocedural echocardiographic parameters reflecting atrial remodeling to predict AF recurrence after radiofrequency catheter ablation (RFCA) for paroxysmal AF (PAF). Preprocedural echocardiographic parameters were measured during sinus rhythm in 105 patients with PAF undergoing RFCA. Electrical remodeling was assessed by the time from the onset of the P-wave to the peak A'-wave on the tissue Doppler imaging (PA-TDI), functional remodeling was assessed by the left atrial appendage flow velocity (LAAFV), and structural remodeling was assessed by the left atrial volume index (LAVI). PA-TDI, LAAFV, and LAVI values were divided into tertiles, and their abilities to predict AF recurrence were assessed using Cox regression analysis. AF recurrence occurred in 39/105 (37.1%) patients. After adjustment for confounders, the rate of AF recurrence was significantly higher in the highest tertile of PA-TDI compared with the lowest tertile (≥151.3 msec vs. <131.0 msec; hazard ratio [HR]: 2.477, 95% confidence interval [CI]: 1.031-5.950; P = 0.042), and in the lowest tertile of LAAFV compared with the highest tertile (<48.5 cm/sec vs. ≥64.9 cm/sec; HR: 2.680, 95% CI: 1.136-6.318; P = 0.024). The risk of AF recurrence was also higher in the highest tertile of LAVI (≥34.2 mL/m(2) ) compared with the lowest tertile, but this difference was not significant (HR: 2.146, 95% CI: 0.834-5.523; P = 0.113). LAAFV (reflecting functional remodeling) and PA-TDI (reflecting electrical remodeling) are independent predictors of AF recurrence after RFCA for PAF. © 2014, Wiley Periodicals, Inc.

  7. A novel method to estimate blood flow velocity in the left atrial appendage using enhanced computed tomography: role of Hounsfield unit density ratio at two distinct points within the left atrial appendage.

    PubMed

    Yasuoka, Ryobun; Kurita, Takashi; Kotake, Yasuhito; Akaiwa, Yuzuru; Hashiguchi, Naotaka; Motoki, Koichiro; Yamamoto, Hiromi; Kobuke, Kazuhiro; Iwanaga, Yoshitaka; Hirano, Yutaka; Miyazaki, Shunichi

    2017-07-01

    Low blood flow velocity in the left atrial appendage (LAA) indicates a high risk of thromboembolism. Although transesophageal echocardiography (TEE) has been the standard method with which to evaluate the LAA blood flow velocity, a clinically noninvasive method is desired. We hypothesized that the ratio of the Hounsfield unit (HU) density at two distinct points within the LAA represents the blood flow velocity in the LAA. We retrospectively investigated 60 consecutive patients with atrial fibrillation (paroxysmal type, n = 29) who underwent enhanced computed tomography (CT) and TEE. The peak emptying flow velocity in the LAA (LAAPV) was evaluated using TEE. HU density was measured at proximal and distal sites of the LAA (LAAp and LAAd) on CT images. The LAAd/LAAp ratio was correlated with the LAAPV (P < 0.01, r = 0.69). Among several indices, the HU ratio was the most significant parameter associated with the LAAPV (β = 0.469, CI 28.602-68.286, P < 0.001). Receiver-operating characteristic analysis (area under the curve, 0.91) demonstrated that an HU density ratio cutoff of 0.32 discriminated a low LAAPV (<25 cm/s) with sensitivity of 90% and specificity of 84%. Flow velocity of the LAA can be estimated by the HU density ratio at distal and proximal sites within the LAA. Our method might be a feasible substitution for TEE to discriminate patients with a reduced LAAPV.

  8. Percutaneous vascular plug for incomplete surgical left atrial appendage closure.

    PubMed

    Levisay, Justin P; Sangodkar, Sandeep; Salinger, Michael H; Lampert, Mark; Feldman, Ted

    2014-04-01

    Surgical left atrial appendage (LAA) exclusion has a failure rate as high as 60% due to persistent residual flow in the LAA or large LAA remnants. We describe a novel technique for treatment of incomplete surgical LAA ligation, and define the mechanism that led to persistence of the remnant LAA without any thrombus formation.

  9. Assessment of left atrial appendage flow velocity and its relation to spontaneous echocardiographic contrast in 89 cats with myocardial disease.

    PubMed

    Schober, Karsten E; Maerz, Imke

    2006-01-01

    The hypotheses of this prospective study were that (1) left atrial appendage (LAA) blood flow velocities can be recorded in cats with myocardial disease by transthoracic Doppler echocardiography, (2) LA enlargement, LA mechanical dysfunction, and left ventricular (LV) diastolic abnormalities are associated with decreased LAA flow velocities, and (3) low LAA flow velocities predict the appearance of spontaneous echocardiographic contrast in cats with cardiomyopathy. Transthoracic 2-dimensional, M-mode, and Doppler echocardiographic studies were performed in 89 cats with hypertrophic, restrictive, dilated, or unclassified cardiomyopathy or with hyperthyroid heart disease. Maximal LAA flow velocity (LAAmax) was decreased (P < .001) in cats with cardiomyopathy (median, 0.28 m/s; range, 0.08-1.35) compared to normal cats. Associated with decreased LAA flow velocities were increased LA size, decreased LA function, increased severity of LV diastolic dysfunction, and the presence of congestive heart failure. Multivariate logistic regression analysis detected an LAAmax <0.20 m/s as the only independent variable to predict LA spontaneous echocardiographic contrast (odds ratio, 30.1; 95% confidence interval [CI], 4.1 222.3; P < .001). Receiver operating characteristic analysis performed to predict spontaneous echocardiographic contrast indicated an area under the curve of 0.88 (95% CI, 0.80-0.95; P < .001) with sensitivities of 100 and 74% and specificities of 69 and 83% for LAAmax <0.25 and <0.20 m/s, respectively. Thus, low LAA flow velocities identified a subgroup of patients at increased risk of spontaneous echocardiographic contrast and possible thromboembolism. These findings may have important clinical implications for anticoagulation therapy and prognostication in cats with cardiomyopathy.

  10. Aneurysm of the Left Atrial Appendage

    PubMed Central

    Victor, Solomon; Nayak, Vijaya M.

    2001-01-01

    A 43-year-old woman underwent excision of an aneurysm of the left atrial appendage, which had been causing cerebrovascular embolic episodes. We attribute the aneurysm to congenital dysplasia of the musculi pectinati in the left atrial appendage and of the bands of atrial muscle from which they arise. In Appendix I, we draw attention to the morphologically similar arrangements of inner and outer bands that emanate from a common transverse interatrial band and yield morphologically similar medial, descending, and ascending palm-leaf arrangements of musculi pectinati. In addition, we observe that the strap-like arrangements of musculi in both atria connect the outer band with the para-annular segment of the inner band. In Appendix II, we briefly review the literature concerning musculi pectinati and related bands. PMID:11453121

  11. Juxtaposed atrial appendages: A curiosity with some clinical relevance

    PubMed Central

    Singhi, Anil Kumar; Pradhan, Priya; Agarwal, Ravi; Sivakumar, Kothandum

    2016-01-01

    If the atrial appendages lie adjacent to each other on same side of the great arteries, instead of encircling their roots, they are referred as juxtaposed. Right juxtaposition of atrial appendages is less common than left juxtaposition. The images demonstrate the classical radiological, echocardiographic, and surgical images of juxtaposed atrial appendages. Their clinical incidence, associations, and relevance during interventional and surgical procedures are discussed. PMID:27212860

  12. Retrieval of embolized left atrial appendage devices.

    PubMed

    Fahmy, Peter; Eng, Lim; Saw, Jacqueline

    2016-09-28

    Percutaneous left atrial appendage (LAA) closure is gaining interest as an alternative option for prevention of strokes in patients with Atrial Fibrillation (AF), especially for those with contraindications to anticoagulation. Complications from these procedures are well described in the medical literature. LAA closures may lead to pericardial effusion, device-associated thrombus, and device embolization. Understanding the reasons for embolization, strategies to avoid embolization, and the techniques for retrieval of LAA devices (ACP/AMULET and WATCHMAN) should be appreciated by endovascular implanters. We describe two cases of LAA device embolization that were both successfully retrieved percutaneously and other percutaneous techniques to safely retrieve embolized LAA devices. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Managing the Left Atrial Appendage in Atrial Fibrillation: Current State of the Art.

    PubMed

    Khawar, Waqaar; Smith, Nathan; Masroor, Saqib

    2017-08-19

    Patients with atrial fibrillation are at increased risk for thromboembolic stroke originating predominantly in the left atrial appendage. To reduce the risk, the standard of care is anticoagulation. In addition, several devices for exclusion of the left atrial appendage have been developed. PubMed was searched for articles relevant to left atrial appendage management. The resulting articles were reviewed as were relevant articles in their bibliographies. Relevant journals were manually searched for sources. Devices are being used for left atrial appendage exclusion by percutaneous and surgical approaches. Their indications, limitations, and outcomes are reviewed. Excision and exclusion of the left atrial appendage is safe and as effective as medical management of atrial fibrillation for stroke prevention. The choice of treatment should be made based on patients' anatomy, history, and preference informed by an appropriate left atrial appendage management team. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Left atrial appendage mass: is it always a thrombus?

    PubMed Central

    Guler, Adem; Kurkluoglu, Mustafa; Yesil, Fahri Gurkan; Tavlasoglu, Murat; Cingoz, Faruk

    2016-01-01

    Myxoma is the most common benign tumor of the heart, but it is very rare for it to originate from the left atrial appendage. Distinguishing between a mass, a thrombus, and a tumor in the body of the left atrium with preoperative transthoracic or transesophageal echocardiography is very difficult, even more so in patients with mitral valve disease and chronic atrial fibrillation. A 50-year-old male patient was admitted for surgery with the diagnosis of mitral stenosis and chronic atrial fibrillation. Transesophageal echocardiography demonstrated a mass attached to the wall of the left atrial appendage. Histopathological examination of the mass showed an image compatible with a myxoma. We hereby describe a case of a left atrial appendage myxoma mimicking a left atrial appendage thrombus. PMID:28096835

  15. [Right atrial appendage thrombosis during atrial fibrillation: an element to look for].

    PubMed

    Barbati, Giovanni; De Domenico, Renato; Rossi, Stefania; Vecchiato, Elena; Zeppellini, Roberto

    2017-03-01

    Oral anticoagulant therapy (OAT) is a mainstay of atrial fibrillation (AF) pharmacological treatment. Left atrial appendage closure is a possible treatment, when feasible, in patients with intracerebral hemorrhage during OAT. We report a case of right atrial appendage thrombosis in a patient with chronic AF admitted for syncope due to diuretic-induced orthostatic hypotension. Two years previously, he had undergone left atrial appendage closure with the Amplatzer Cardiac Plug device because of intracerebral hemorrhage during OAT. After neurological consult, OAT was resumed with apixaban 5 mg twice daily, and transesophageal echocardiography performed two months later showed complete resolution of the right atrial appendage thrombosis. This particular case underlines the importance of searching for a possible right atrial appendage thrombosis in patients affected by AF, and suggests that left atrial appendage closure in AF patients not suitable for OAT does not fully eliminate the risk of thromboembolism.

  16. Left Atrial Appendage Occlusion for Stroke Prevention.

    PubMed

    Chanda, Arijit; Reilly, John P

    More than 2.3 million adults in the United States have atrial fibrillation (AF), which exposes them to a 5-fold increased risk of stroke. The left atrial appendage (LAA) appears to be the source of thrombus formation in the vast majority of these patients. Anticoagulation significantly reduces the risk of stroke, but often we encounter patients who have absolute or relative contraindication to anticoagulation. Percutaneous LAA exclusion offers an alternative to anticoagulation to decrease the risk of stroke. Three device systems are currently available in the United States. The WATCHMAN® device is the most studied and approved by Food and Drug Administration (FDA) to be used in patients with AF unsuitable for anticoagulation who are at a high risk of stroke. The Amulet® device is currently being used as part of the AMPLATZER® Amulet® LAA Occluder trial, which is a non-inferiority randomized trial comparing the Amulet® to the WATCHMAN® device. The third device in use is the LARIAT®, which is an FDA approved snare and pre-tied stich system. It is used to approximate soft tissue which in this case is the LAA. It is a hybrid system and requires both epicardial and endocardial access. The main obstacle to percutaneous LAA closure is procedural related complications, which can be minimized with optimum operator experience. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Right atrial tunnel to the left atrial appendage: a danger during balloon septostomy.

    PubMed

    Waldman, J D; McFeeley, P; Bornikova, L

    2001-01-01

    Right atrial tunnel to the left atrial appendage is a very rare anomaly not previously described. Per se, it has no physiological significance but is a source of potential disaster during balloon atrial septostomy. The precise anatomy is demonstrated and ways are proposed to avoid tearing the atrial wall during therapeutic cardiac catheterization.

  18. Percutaneous left atrial appendage closure: current state of the art.

    PubMed

    Jazayeri, Mohammad-Ali; Vuddanda, Venkat; Parikh, Valay; Lakkireddy, Dhanunjaya R

    2017-01-01

    The authors reviewed the seminal and more recent literature surrounding the major modalities for percutaneous left atrial appendage closure used in contemporary practice, with particular emphasis on safety and efficacy, technical challenges, and future developments. Along with the continued practice of surgical left atrial appendage closure, which has evolved substantially with the advent of clipping techniques, a number of percutaneous methods have been developed to close the left atrial appendage with endocardial, epicardial, and hybrid approaches. The last 18 months has seen the Food and Drug Administration approval of the WATCHMAN device for stroke prevention in the United States, the initiation of a randomized controlled trial to further examine the LARIAT device, and an increasing body of literature surrounding use of the AMPLATZER Amulet in Europe. Left atrial appendage closure is a promising alternative to systemic anticoagulation for stroke prevention in appropriate atrial fibrillation patients. The wealth of available data for the various modalities sheds light on the strengths and limitations of each, postprocedural complications and their management, and new areas for exploration. With a plethora of new devices on the horizon, it is a very exciting time in the field of 'appendage-ology' as we pursue new avenues to optimize care for atrial fibrillation patients.

  19. [Prophylaxis of thromboembolism in atrial fibrillation: new oral anticoagulants and left atrial appendage closure].

    PubMed

    Zeus, Tobias; Kelm, Malte; Bode, Christoph

    2015-08-01

    Thrombo-embolic prophylaxis is a key element within the therapy of atrial fibrillation/atrial flutter. Besides new oral anticoagulants the concept of left atrial appendage occlusion has approved to be a good alternative option, especially in patients with increased risk of bleeding.

  20. Frequency and significance of right atrial appendage thrombi in patients with persistent atrial fibrillation or atrial flutter.

    PubMed

    Cresti, Alberto; García-Fernández, Miguel Angel; Miracapillo, Gennaro; Picchi, Andrea; Cesareo, Francesca; Guerrini, Francesco; Severi, Silva

    2014-11-01

    Atrial fibrillation (AF) and atrial flutter (AFL) are strong atrial thrombosis (THR) risk factors. In recent-onset tachyarrhythmias, the incidence of left atrial appendage (LAA) THR, detected by transesophageal echocardiography (TEE), has been widely studied, ranging from 6% to 18% (AF) and 4% to 11% (AFL). On the contrary, few studies have assessed right atrial appendage (RAA) THR, and there is no information on the relation between the RAA flow characteristics and the presence of RAA THR. The aims of this study were to evaluate the incidence of RAA THR in a population of patients undergoing TEE-guided cardioversion for recent-onset atrial tachyarrhythmias and to analyze RAA Doppler flow and its relation to thrombus formation. From 1998 to 2012, patients admitted to the emergency department for persistent, non-self-terminating atrial tachyarrhythmia lasting >2 days who gave informed consent for TEE-guided cardioversion were prospectively enrolled in the study. Among 1,042 patients, complete anatomic and functional studies of the LAA and RAA were feasible in 983 (AF, n = 810 [23%]; AFL, n = 173 [5%]). The presence of RAA and LAA THR, appendage emptying velocities, and the presence of severe spontaneous echocardiographic contrast were studied. The overall incidence of atrial THR was 9.7% (96 of 983). The incidence of THR was 9.3% (91 of 983) in the LAA and 0.73% (seven of 983) in the RAA (P < .01). In the AF and AFL groups, the incidence of LAA THR was 10.3% (83 of 805), compared with 0.75% (six of 805) for RAA THR (P < .01). Among patients with AFL, the incidence of LAA THR was 6% (10 of 178), compared with 0.6% (one of 178) for RAA THR (P < .01). The mean LAA peak emptying velocity was 24 cm/sec (range, 10-32 cm/sec) in patients with LAA THR, compared with 38 cm/sec (range, 20-59 cm/sec) in those without THR; the mean RAA peak emptying velocity was 17 ± 7 cm/sec in patients with RAA THR, compared with 34 ± 13 cm/sec in those without THR (P

  1. Percutaneous occlusion of left atrial appendage with the Amplatzer Cardiac PlugTM in atrial fibrillation.

    PubMed

    Montenegro, Márcio José; Quintella, Edgard Freitas; Damonte, Aníbal; Sabino, Hugo de Castro; Zajdenverg, Ricardo; Laufer, Gustavo Pinaud; Amorim, Bernardo; Estrada, André Pereira Duque; Armas, Cristian Paul Yugcha; Sterque, Aline

    2012-02-01

    Atrial fibrillation is associated with embolic strokes that often result in death or disability. Effective in reducing these events, anticoagulation has several limitations and has been widely underutilized. Over 90% of thrombi identified in patients with atrial fibrillation without valvular disease originate in the left atrial appendage, whose occlusion is investigated as an alternative to anticoagulation. To determine the feasibility of percutaneous occlusion of the left atrial appendage in patients at high risk of embolic events and limitations to the use of anticoagulation. We report our initial experience with Amplatzer Cardiac Plug™ (St. Jude Medical Inc., Saint Paul, Estados Unidos) in patients with nonvalvular atrial fibrillation. We selected patients at high risk of thromboembolism, major bleeding, contraindications to the use or major instability in response to the anticoagulant. The procedures were performed percutaneously under general anesthesia and transesophageal echocardiography. The primary outcome was the presence of periprocedural complications and follow-up program included clinical and echocardiographic review within 30 days and by telephone contact after nine months. In five selected patients it was possible to occlude the left atrial appendage without periprocedural complications. There were no clinical events in follow-up. Controlled clinical trials are needed before percutaneous closure of the left atrial appendage should be considered an alternative to anticoagulation in nonvalvular atrial fibrillation. But the device has shown to be promissory in patients at high risk of embolism and restrictions on the use of anticoagulants.

  2. Possible role for cryoballoon ablation of right atrial appendage tachycardia when conventional ablation fails.

    PubMed

    Amasyali, Basri; Kilic, Ayhan

    2015-06-01

    Focal atrial tachycardia arising from the right atrial appendage usually responds well to radiofrequency ablation; however, successful ablation in this anatomic region can be challenging. Surgical excision of the right atrial appendage has sometimes been necessary to eliminate the tachycardia and prevent or reverse the resultant cardiomyopathy. We report the case of a 48-year-old man who had right atrial appendage tachycardia resistant to multiple attempts at ablation with use of conventional radiofrequency energy guided by means of a 3-dimensional mapping system. The condition led to cardiomyopathy in 3 months. The arrhythmia was successfully ablated with use of a 28-mm cryoballoon catheter that had originally been developed for catheter ablation of paroxysmal atrial fibrillation. To our knowledge, this is the first report of cryoballoon ablation without isolation of the right atrial appendage. It might also be an alternative to epicardial ablation or surgery when refractory atrial tachycardia originates from the right atrial appendage.

  3. Left atrial appendage occlusion: A better alternative to anticoagulation?

    PubMed Central

    Akin, Ibrahim; Nienaber, Christoph A

    2017-01-01

    Non-valvular atrial fibrillation is associated with a significantly increased risk of embolic stroke due to blood clot forming predominantly in the left atrial appendage (LAA). Preventive measures to avoid embolic events are permanent administration of anticoagulants or surgical closure of the LAA. Various clinical trials provide evidence about safety, effectiveness and therapeutic success of LAA occlusion using various cardiac occluder devices. The use of such implants for interventional closure of the LAA is likely to become a valuable alternative for stroke prevention, especially in patients with contraindication for oral anticoagulation as safety, clinical benefit and cost-effectiveness of LAA occlusion has recently been demonstrated. PMID:28289527

  4. Percutaneous left atrial appendage closure improves left atrial mechanical function through Frank-Starling mechanism.

    PubMed

    Coisne, Augustin; Pilato, Rosario; Brigadeau, François; Klug, Didier; Marquie, Christelle; Souissi, Zouheir; Richardson, Marjorie; Mouton, Stéphanie; Polge, Anne-Sophie; Lancellotti, Patrizio; Lacroix, Dominique; Montaigne, David

    2017-05-01

    Modifications in left atrial (LA) flow velocities after left atrial appendage (LAA) exclusion have been shown in animal and ex vivo models. In a substudy of PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation), an objective improvement in quality of life was observed after LAA closure. The purpose of this study was to investigate the impact of LAA closure on LA transport function. Comprehensive transthoracic echocardiography evaluation (2-dimensional [2D]/3-dimensional [3D], 2D speckle tracking) was prospectively performed before and after LAA closure (at discharge and 45 days after procedure) in 33 patients. LAA closure was associated with a significant improvement in LA reservoir function at discharge and 45 days after the procedure with (1) increased maximum LA volume index, (2) increased 2D-LA reservoir volume and expansion index, and (3) increased 2D speckle tracking-derived peak atrial longitudinal strain (PALS) (27.9 ± 14 and 26 ± 12.6 vs 21.7 ± 10.7%, P <.0001). LAA closure was also associated with a significant improvement in LA contractile function with (1) increased LA ejection fraction and (2) increased speckle tracking-derived peak atrial contraction strain (PACS) in sinus rhythm patients (19.1 ± 6.8 and 18.1 ± 5.4 vs 14.4 ± 6.4%, P = .0006). Conversely, the slope of the relation between PACS and PALS remained unchanged (0.5 ± 0.27 and 0.53 ± 0.3 vs 0.5 ± 0.25, P = .99), thus arguing for an improvement in LA contractile function secondary to a Frank-Starling effect rather than a modification in its intrinsic contractility. LAA closure was associated with an improvement in LA mechanical function. These changes appeared to be related to a modification in loading conditions, that is, a Frank-Starling effect. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. Transcatheter occlusion of left atrial appendage with persistent thrombus using a trans-radial embolic protection device.

    PubMed

    Cammalleri, Valeria; Ussia, Gian Paolo; Muscoli, Saverio; De Vico, Pasquale; Romeo, Francesco

    2016-12-01

    : The image describes a case of left atrial appendage occlusion in a patient with atrial fibrillation, previous haemorrhagic stroke, and left atrial appendage thrombosis. A cerebral vascular filter was used during the device implantation. The use of cerebral embolic protection device can increase the safety of left atrial appendage occlusion, in selected high-risk patients.

  6. Percutaneous closure of the left atrial appendage in patients with diabetes mellitus.

    PubMed

    Azizy, Obayda; Rammos, Christos; Lehmann, Nils; Rassaf, Tienush; Kälsch, Hagen

    2017-09-01

    Left atrial appendage closure is a preventive treatment of atrial fibrillation-related thrombo-embolism. Patients with diabetes mellitus have increased risk for a negative outcome in percutaneous cardiac interventions. We assessed whether percutaneous left atrial appendage closure is safe and effective in patients with diabetes mellitus. We included 78 patients (mean age of 74.4 ± 8.3 years) with indication for left atrial appendage closure in an open-label observational single-centre study. Patients with diabetes mellitus ( n = 31) were at higher thrombo-embolic and bleeding risk (CHA2DS2-VASc: 4.5 ± 0.9, HAS-BLED: 4.7 ± 0.7) compared to patients without diabetes mellitus ( n = 47, CHA2DS2-VASc: 3.5 ± 1.0, HAS-BLED: 4.1 ± 0.8; p < 0.001 for both). Pre- and periprocedural risk was elevated in patients with diabetes mellitus (Euro II-Score: 6.6 ± 3.7 vs 3.9 ± 1.9, p < 0.01; Society of Thoracic Surgeons (STS)-Score: 4.0 ± 2.5 vs 2.6 ± 1.2, p < 0.01). Procedural success was similar. Periprocedural major adverse cardiac and cerebrovascular events occurred in one patient from the control group (2.1%), whereas patients with diabetes mellitus had no events ( p = 0.672). Follow-up of 6 months revealed no bleeding complication in both groups. No stroke occurred in follow-up, and left atrial appendage flow velocity reduction (55.6 ± 38.6 vs 51.4 ± 19.1 cm/s, p = 0.474) and rate of postinterventional leakage in the left atrial appendage were comparable (0% vs 2.1%, p = 0.672). Despite patients with diabetes mellitus are high-risk patients, the outcome of percutaneous left atrial appendage closure is similar to patients without diabetes mellitus.

  7. Amplatzer Amulet left atrial appendage occluder entrapment through mitral valve.

    PubMed

    González-Santos, Jose María; Arnáiz-García, María Elena; Arribas-Jiménez, Antonio; López-Rodríguez, Javier; Rodríguez-Collado, Javier; Vargas-Fajardo, María del Carmen; Dalmau-Sorlí, María José; Bueno-Codoñer, María Encarnación; Arévalo-Abascal, R Adolfo

    2013-11-01

    We report on a 77-year-old woman in whom percutaneous left atrial appendage (LAA) closure was performed. The patient had a left atrial myxoma resection 3 years previously, and 2 years later, she suffered a transient ischemic attack. Atrial fibrillation was detected and anticoagulation therapy was established. An episode of intracranial bleeding forced interruption of anticoagulation. Thus, percutaneous LAA closure with an Amplatzer Amulet LAA Occluder (St Jude Medical) was proposed. During the procedure, the LAA occluder migrated and became trapped in the mitral valve. Secondary massive mitral regurgitation and hemodynamic instability forced emergent cardiac surgery. Successful removal of the Amplatzer Amulet LAA Occluder was achieved. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  8. Navx-guided Cryoablation of Atrial Tachycardia Inside the Left Atrial Appendage

    PubMed Central

    Pandozi, Claudio; Galeazzi, Marco; Lavalle, Carlo; Ficili, Sabina; Russo, Maurizio; Santini, Massimo

    2010-01-01

    Radiofrequency ablation procedures inside the left atrial appendage (LAA) are likely to involve dangerous complications because of a high thrombogenic effect. Cryoablation procedures are supposed to be safer. We describe two cases of successful cryoablation procedures. Two NavX-guided cryoablations of permanent focal atrial arrhythmias arising from the LAA were performed. Left atrial reconstruction and mapping allowed the zone of the earliest atrial potential to be recorded; the entire course of the ablation catheter was monitored. The arrhythmias were successfully ablated; no thrombotic complications were observed. PMID:21346824

  9. Percutaneous closure of a left atrial appendage with relevant suture dehiscence.

    PubMed

    Kleinebrecht, L; Veulemans, V; Polzin, A; Kelm, M; Zeus, T

    2017-02-01

    Atrial fibrillation is a widespread disease and highly relevant as it carries an extended risk for ischaemic stroke. Surgical closure of the left atrial appendage is routinely performed during open heart surgery in patients with atrial fibrillation with the aim of thromboembolic protection. In this report we present a successful percutaneous closure of a left atrial appendage, which showed clinically relevant suture dehiscence several years after surgical closure.

  10. Enlargement of the Excluded Left Atrial Appendage With Thrombus.

    PubMed

    Aoyagi, Shigeaki; Tobinaga, Satoru; Saisho, Hiroyuki

    2017-02-07

    We report progressive enlargement of the excluded left atrial appendage (LAA) with a thrombus in a patient who had undergone valve surgery and endocardial suture closure of the LAA previously. Echocardiography and CT detected no communication between the LAA and the left atrium. Magnetic resonance imaging showed the LAA was filled with fresh and old thrombi. Coronary arteriography demonstrated small left coronary artery-LAA fistulae. At surgery, successful exclusion of the LAA was confirmed after removal of the thrombi. Persistent inflow of blood through the coronary artery fistulae to the excluded LAA may be the primary mechanism of this pathology.

  11. Aneurysmal dilatation of left atrial appendage diagnosed by cross sectional echocardiography and surgically removed.

    PubMed Central

    Lipkin, D; Colli, A; Somerville, J

    1985-01-01

    An isolated aneurysmal dilatation of the left atrial appendage was found in an 18 year old girl who presented with atrial fibrillation and an unusual cardiac shadow on routine chest radiographs. The diagnosis was made by cross sectional echocardiography. The giant appendage was excised to remove the risk of systemic embolism and the need for life long anticoagulation. Images PMID:3966953

  12. Right Atrial Appendage Aneurysm in a Newborn Diagnosed with Fetal Echocardiography

    PubMed Central

    Yartaşı Tik, Elif; Öztarhan, Kazım; Dedeoğlu, Reyhan; Çetinkaya, Merih

    2016-01-01

    Right atrial appendage aneurysm is a very rare condition which can be asymptomatic or can cause arrhythmia or life-threatening thromboembolism. We report a case of newborn with right atrial appendage aneurysm who was diagnosed with fetal echocardiography. Anticoagulant therapy was applied to prevent thromboembolism and he is still going on follow-up without any complaint. PMID:27703828

  13. Left Atrial Appendage Ligation and Exclusion Technology in the Incubator

    PubMed Central

    Syed, Faisal F.; Noheria, Amit; DeSimone, Christopher V.; Asirvatham, Samuel J.

    2016-01-01

    Stroke is the most feared complication of atrial fibrillation (AF). Targeting the left atrial appendage (LAA) mechanically is attractive as a means to simultaneously reduce stroke risk, the need for anticoagulation, and hemorrhagic complications in patients with non-valvular AF. The results of the PROTECT-AF and PREVAIL randomized clinical trials support this approach as a viable therapeutic alternative to warfarin in selected patients and add to accumulating evidence regarding the importance of the LAA in thromboembolism in AF. A number of devices for percutaneous LAA closure are under investigation or development. In this article, key design features of these ligation and exclusion technologies will be discussed, with a focus on aspects of LAA morphology, relational anatomy, thrombosis, and thromboembolism relevant for successful device development and deployment. PMID:27087888

  14. Left-atrial-appendage occluder migrates in an asymptomatic patient.

    PubMed

    Pisani, Paolo; Sandrelli, Luca; Fabbrocini, Mario; Tesler, Ugo Filippo; Medici, Dante

    2014-08-01

    Percutaneous closure of the left atrial appendage (LAA) is a new approach to the prevention of cardioembolic events in patients with atrial fibrillation. We implanted an LAA occlusion device (Amplatzer™ Cardiac Plug) in a 70-year-old woman via a transseptal approach. Upon her discharge from the hospital, a transthoracic echocardiogram showed stable anchoring of the device; 6 months after implantation, a routine transthoracic echocardiogram revealed migration of the occluder into the left ventricular outflow tract, in the absence of symptoms. We surgically removed the device from the mitral subvalvular apparatus and closed the LAA with sutures. This case shows that percutaneous LAA occlusion can result in serious adverse events, including device migration in the absence of signs or symptoms; therefore, careful follow-up monitoring is mandatory.

  15. Left-Atrial-Appendage Occluder Migrates in an Asymptomatic Patient

    PubMed Central

    Sandrelli, Luca; Fabbrocini, Mario; Tesler, Ugo Filippo; Medici, Dante

    2014-01-01

    Percutaneous closure of the left atrial appendage (LAA) is a new approach to the prevention of cardioembolic events in patients with atrial fibrillation. We implanted an LAA occlusion device (Amplatzer™ Cardiac Plug) in a 70-year-old woman via a transseptal approach. Upon her discharge from the hospital, a transthoracic echocardiogram showed stable anchoring of the device; 6 months after implantation, a routine transthoracic echocardiogram revealed migration of the occluder into the left ventricular outflow tract, in the absence of symptoms. We surgically removed the device from the mitral subvalvular apparatus and closed the LAA with sutures. This case shows that percutaneous LAA occlusion can result in serious adverse events, including device migration in the absence of signs or symptoms; therefore, careful follow-up monitoring is mandatory. PMID:25120404

  16. Partial left pericardial defect with herniation of the left atrial appendage

    PubMed Central

    Pernot, C.; Hoeffel, J C.; Henry, M.; Frisch, R.; Brauer, B.

    1972-01-01

    A case is reported of herniation of the left atrial appendage through a partial pericardial defect, probably congenital. The diagnosis was suggested by the history of chest pain and bulging of the middle segment of the left heart border on the plain chest film, without other signs. Angiography revealed a dilated left atrial appendage. An artificial left pneumothorax confirmed the presence of a pleuropericardial defect. The surgical procedure included excision of the appendage and closure of the defect. Images PMID:5034603

  17. Structural Comparison between the Right and Left Atrial Appendages Using Multidetector Computed Tomography

    PubMed Central

    Shinoda, Koichi; Fukuoka, Daisuke; Torii, Ryo; Watanabe, Tsuneo; Nakano, Takashi

    2016-01-01

    The three-dimensional (3D) structures of the right atrial appendage (RAA) and left atrial appendage (LAA) were compared to clarify why thrombus formation less frequently occurs in RAA than in LAA. Morphological differences between RAA and LAA of 34 formalin-preserved cadaver hearts were investigated. Molds of RAA and LAA specimens were made and the neck areas, volumes of the atrial appendages (AA), and amount of pectinate muscles (PMs) were analyzed using multidetector computed tomography. In RAA, most PMs were connected to one another and formed a “dendritic” appearance and the inner surface area was smaller than in LAA. RAA had smaller volumes and larger neck areas than LAA. The ratios of the neck area/volume were larger and the amounts of PMs were smaller in RAA than in LAA. The volumes, neck areas, and amount of PMs of RAA were significantly correlated with those of LAA. According to the 3D structure, RAA appears to be suited for a more favorable blood flow, which may explain why the thrombus formation is less common in RAA than in LAA. Examining not only LAA but also RAA by transesophageal echocardiography may be useful in high-risk patients of thrombus formation in LAA because the volume, neck area, and amount of PMs of LAA reflect the shape of RAA. PMID:27900330

  18. Is percutaneous closure of the left atrial appendage comparable to anticoagulants for atrial fibrillation?

    PubMed

    Uslar, Thomas; Anabalón, Jaime

    2015-08-17

    For most atrial fibrillation patients oral anticoagulation constitutes the standard treatment to prevent stroke. However, they carry a risk of bleeding, which is why alternative treatments have been put into practice, such as percutaneous closure of the left atrial appendage. It is not clear whether this is as effective as the conventional treatment with anticoagulants. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified three systematic reviews including only one pertinent randomized controlled trial. We combined the evidence and generated a summary of findings following the GRADE approach. We concluded that percutaneous left atrial appendage occlusion may decrease stroke and mortality, but the certainty of the evidence is low. The effect on other outcomes is not clear because the certainty of the evidence is very low.

  19. Characterization of Cerebrovascular Events After Left Atrial Appendage Occlusion.

    PubMed

    Freixa, Xavier; Llull, Laura; Gafoor, Sameer; Cruz-Gonzalez, Ignacio; Shakir, Samera; Omran, Heyder; Berti, Sergio; Santoro, Gennaro; Kefer, Joelle; Landmesser, Ulf; Nielsen-Kudsk, Jens Erik; Kanagaratnam, Prapa; Nietlispach, Fabian; Gloekler, Steffen; Aminian, Adel; Danna, Paolo; Rezzaghi, Marco; Stock, Friederike; Stolcova, Miroslava; Paiva, Luis; Costa, Marco; Millán, Xavier; Ibrahim, Reda; Tichelbäcker, Tobias; Schillinger, Wolfgang; Park, Jai-Wun; Sievert, Horst; Meier, Bernhard; Tzikas, Apostolos

    2016-12-15

    Cardioembolic strokes are generally more lethal and disabling than other source of strokes. Data from PROTECT AF (Watchman Left Atrial Appendage Closure Technology for Embolic Protection in Patients With Atrial Fibrillation) suggest that strokes after left atrial appendage occlusion (LAAO) with the Watchman device are less disabling than those in the warfarin group. No data assessing the severity of strokes after LAAO with the AMPLATZER Cardiac Plug (ACP) are available. The objective of the study was to evaluate the severity of cerebrovascular events after LAAO with the ACP in a population mostly characterized by an absolute or relative contraindication to oral anticoagulation. Data from the ACP multicenter registry were analyzed. Disabling strokes were defined as those with a modified Rankin score of 3 to 6 at 90 days after the event. A total of 1,047 subjects were included. The mean age and CHADS2 score were 75 ± 8 years and 2.8 ± 1.3, respectively. Procedural success was achieved in 97.3% and 4.9% of the patients presented procedural major adverse events. Clinical follow-up was complete in 98.2% of patients with a median of 13 months. There were 9 strokes (0.9%), 9 transient ischemic attacks (0.9%), and no intracranial hemorrhages (0%) at follow-up. After excluding 2 patients with pre-LAAO disability, functional assessment showed disabling events in 3 (19%) of the remaining 16 patients. The median time of presentation was 420 days (interquartile range 234 to 671) after LAAO, and 17 patients (94%) were on single-antiplatelet therapy when the event occurred. According to our results, cerebrovascular events after LAAO with the ACP system were infrequent and mostly nondisabling. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Presence of accessory left atrial appendage/diverticula in a population with atrial fibrillation compared with those in sinus rhythm: a retrospective review.

    PubMed

    Troupis, John; Crossett, Marcus; Scneider-Kolsky, Michal; Nandurkar, Dee

    2012-02-01

    Accessory left atrial appendages and atrial diverticula have an incidence of 10-27%. Their association with atrial fibrillation needs to be confirmed. This study determined the prevalence, number, size, location and morphology of accessory left atrial appendages/atrial diverticula in patients with atrial fibrillation compared with those in sinus rhythm. A retrospective analysis of 47 consecutive patients with atrial fibrillation who underwent 320 multidetector Coronary CT angiography (CCTA) was performed. A random group of 47 CCTA patients with sinus rhythm formed the control group. The presence, number, size, location and morphology of accessory left atrial appendages and atrial diverticula in each group were analysed. Twenty one patients had a total of 25 accessory left atrial appendages and atrial diverticula in the atrial fibrillation group and 22 patients had a total of 24 accessory left atrial appendages and atrial diverticula in the sinus rhythm group. Twenty-one atrial diverticula were identified in 19 patients in the atrial fibrillation group and 19 atrial diverticula in 17 patients in the sinus rhythm group. The mean length and width of accessory left atrial appendage was 6.9 and 4.7 mm, respectively in the atrial fibrillation group and 12 and 4.6 mm, respectively, in the sinus rhythm group, P = ns (not significant). The mean length and width of atrial diverticulum was 4.7 and 3.6 mm, respectively in the atrial fibrillation group and 6.2 and 5 mm, respectively in the sinus rhythm group (P = ns). Eighty-four % and 96% of the accessory left atrial appendages/atrial diverticula in the atrial fibrillation and sinus rhythm groups were located along the right anterosuperior left atrial wall. Accessory left atrial appendages and atrial diverticula are common structures with similar prevalence in patients with atrial fibrillation and sinus rhythm.

  1. Effect of ramipril therapy on abnormal left atrial appendage function.

    PubMed

    Asker, M; Timucin, O B; Asker, S; Karadag, M F

    2011-01-01

    This study investigated whether ramipril treatment has a beneficial effect on left atrial appendage (LAA) function in patients with systemic hypertension in sinus rhythm. Patients with untreated systemic hypertension and normal left ventricular systolic function in sinus rhythm (n = 20; six males/14 females; age 35 - 69 years, mean ± SD 52.8 ± 8.9 years) were evaluated using transthoracic and transoesophageal echocardiography at baseline and after 6 months of treatment with 5 mg/day ramipril. Mean systolic and diastolic blood pressures decreased significantly after ramipril therapy. Baseline LAA emptying velocity was below the age-related reference value for this parameter, indicating abnormal LAA function. There were significant increases in the LAA filling and emptying velocities after ramipril treatment. It is concluded that the decrease in blood pressure and haemodynamic improvements brought about by ramipril therapy resulted in improved LAA function in hypertensive patients with normal left ventricular systolic function in sinus rhythm.

  2. Left Atrial Appendage Resection During Minimally Invasive Aortic Valve Surgery via Right Minithoracotomy.

    PubMed

    Kondo, Nobuo; Totsugawa, Toshinori; Hiraoka, Arudo; Tamura, Kentaro; Yoshitaka, Hidenori; Sakaguchi, Taichi

    2017-07-25

    Here, we report concomitant resection of the left atrial appendage through the transverse sinus during minimally invasive aortic valve replacement via right anterolateral thoracotomy. The left atrial appendage was exposed by raising the collapsed ascending aorta and was safely resected using a surgical stapling device. This procedure is a feasible option in elderly patients, for whom a percutaneous procedure would be inappropriate, and could be useful for preventing thromboembolic and hemorrhagic complications.

  3. Percutaneous epicardial ablation of incessant atrial tachycardia originating from the left atrial appendage

    PubMed Central

    Ban, Ji-Eun; Park, Tae Young

    2016-01-01

    A 38-year-old woman presented with antiarrhythmic drug-refractory atrial tachycardia (AT). Holter recording demonstrated incessant episodes of AT followed by a long sinus pause. Electrophysiologic study revealed that the earliest endocardial activation was observed at the neck of the left atrial appendage (LAA). After unsuccessful endocardial ablation, epicardial access via a percutaneous subxiphoid approach demonstrated that the earliest epicardial atrial activation was observed on the opposite site to the endocardial LAA neck suggestive of ligament of Marshall (LOM) muscle sleeve as regarding the epicardial sharp potentials under guidance of a circular mapping catheter. Application of radiofrequency (RF) energy at this site terminated the tachycardia. After tachycardia ablation, the sinus pause also resolved. PMID:28066659

  4. Relationship between body mass index and left atrial appendage thrombus in nonvalvular atrial fibrillation.

    PubMed

    Cohoon, Kevin P; McBane, Robert D; Ammash, Naser; Slusser, Joshua P; Grill, Diane E; Wysokinski, Waldemar E

    2016-05-01

    Atrial fibrillation and obesity are two major growing epidemics in the United States and globally. Obese people are at the increased risk of developing atrial fibrillation. The contribution of obesity as an independent risk factor for stroke in the setting of atrial fibrillation remains unclear. We tested the hypothesis that non-valvular atrial fibrillation (NVAF) patients with increased body mass index (BMI) would be at increased risk for the development of left atrial appendage thrombus (LAAT). Consecutive, anticoagulation naïve patients with NVAF referred for a transesophageal echocardiogram (TEE) between January 1, 2007 and October 21, 2009 were approached for study participation. All clinical, laboratory, and TEE measurement data were collected prospectively. Within a group of 400 anticoagulation naïve NVAF patients (mean age 63 ± 15 years, 28 % women; 17 % with LAAT) the prevalence of LAAT was similar across all BMI categories (normal 13 %, overweight 19 %, obese 16 %, morbidly obese 16 %; p = 0.71). Despite a higher CHADS2 score and a higher prevalence of both hypertension and diabetes mellitus, elevated BMI was not an independent predictor of LAAT when analyzed as either a continuous variable, across BMI WHO categories, a dichotomous variable stratified at values above versus below 27 kg/m(2), or BMI stratified on atrial fibrillation duration. Despite a higher prevalence of major risk factors for thromboembolism, the prevalence of LAAT was not increased in overweight, obese, and morbidly obese patients.

  5. Inferior and right-sided juxtaposition of the left atrial appendage with an unexpected type of inter-atrial communication.

    PubMed

    Sarwark, Anne E; Anderson, Robert H; Spicer, Diane E

    2016-01-01

    We have re-investigated an unusual cardiac specimen with juxtaposition of the atrial appendages. The original description dates to 1962, when the autopsy was performed at the Children's Memorial Hospital in Chicago, now Ann & Robert H. Lurie Children's Hospital of Chicago. The heart was subsequently stored in the Farouk S. Idriss Cardiac Registry at the same institution. The specimen shows usual atrial arrangement, but with the morphologically left appendage juxtaposed in a rightward manner, passing behind the heart rather than through the transverse sinus so as to reach its location inferior to the morphologically right appendage. The heart also demonstrated an inter-atrial communication between the cavities of the juxtaposed left appendage and the morphologically right atrium. We provide a detailed description of the morphology, and provide images of this lesion, which to the best of our knowledge has not previously been described.

  6. Left atrial appendage occlusion with the Amplatzer Amulet for stroke prevention in atrial fibrillation: the first case in Greece.

    PubMed

    Tzikas, Apostolos; Karagounis, Lambros; Bouktsi, Maria; Drevelegas, Antonios; Parcharidou, Despina; Ioannidis, Stathis; Krasopoulos, George; Giannakoulas, George

    2013-01-01

    Left atrial appendage (LAA) occlusion has been introduced into clinical practice as a valuable alternative to oral anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation. In this case presentation we describe the first LAA occlusion in Greece using the Amplatzer Amulet device. We also briefly discuss issues related to procedural safety and multimodality imaging for LAA occlusion.

  7. Role of Endovascular Closure of the Left Atrial Appendage in Stroke Prevention for Atrial Fibrillation.

    PubMed

    Kiani, Jawad; Holmes, David R

    2015-11-01

    The pathophysiologic mechanism of thromboembolic stroke in the setting of non-valvular atrial fibrillation (AF) resides in the left atrial appendage (LAA). In this setting, approximately 90 % of all strokes originate from this structure. Percutaneous left atrial appendage occlusion (LAAO) therapy has recently emerged as an important strategy for prevention of stroke and systemic embolism in patients with non-valvular AF. Systemic anticoagulation therapy in this AF population, while effective, is associated with a significant bleeding risk, drug compliance issues, and limited reversal strategies. In this manuscript, we will review the percutaneous devices and techniques that allow endovascular closure of the LAA, including their efficacy in stroke prevention, the safety profile of these local site-specific therapies, comparison of the multiple approaches being studied, the index patient populations involved, and long-term follow-up in comparison with systemic anticoagulation therapy. The percutaneous LAAO approach indeed represents an exciting and revolutionary advance in the field of stroke prevention in AF.

  8. Closure of Left Atrial Appendage With Persistent Distal Thrombus Using an Amplatzer Amulet Occluder.

    PubMed

    Lange, Mathias; Bültel, Helmut; Weglage, Heinrich; Löffeld, Patrick; Wichter, Thomas

    2016-09-01

    A 73-year-old patient with permanent atrial fibrillation presented for left atrial appendage (LAA) occlusion. Transesophageal echocardiography demonstrated a thrombus in the distal LAA. This image series illustrates a "no touch" technique that was used to ensure successful implantation of an Amplatzer Amulet LAA occlusion device without the use of an embolization protection system.

  9. Rationale of cerebral protection devices in left atrial appendage occlusion.

    PubMed

    Meincke, Felix; Spangenberg, Tobias; Kreidel, Felix; Frerker, Christian; Virmani, Renu; Ladich, Elena; Kuck, Karl-Heinz; Ghanem, Alexander

    2017-01-01

    Aims of this case-series were to assess the feasibility of cerebral protection devices in interventional left atrial appendage occlusion (iLAAO) procedures and to yield insight into the pathomorphological correlate of early, procedural cerebral embolization during iLAAO. Five consecutive patients underwent iLLO flanked by the Sentinel CPS® (Claret Medical, Inc., Santa Rosa, CA) cerebral protection system. Placement and recapture of the Sentinel(®) device as well as the iLAAO were successful and safe in all cases. Histomorphometric analysis of the collected filters showed embolized debris in all patients. Acute thrombus was found in three patients, organizing thrombus in four. Interestingly, two patients had endocardial or myocardial tissue in their filters. Cerebral protection during iLAAO with the Sentinel CPS(®) device is feasible. Furthermore, this dataset identifies the formation and embolization of thrombus and cardiac tissue as emboligeneic sources and potential future targets to reduce procedural complications. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation, Second Thoughts?

    PubMed Central

    Wagdi, Philipp; Salzer, Frank

    2012-01-01

    Life expectancy of the population is steadily increasing world wide. Consequently, the incidence and ultimately the prevalence of atrial fibrillation (AF) and it’s sequelae will be rising proportionately. It is estimated that 3-5% of persons above 65 years of age have chronic AF, 30% of which will suffer at least one stroke. On the other hand, chronic AF is responsible for about 20% of all cerebrovascular accidents. Predictors of stroke in AF have been defined by the CHADS2 score, and in these patients, oral anticoagulation has been the cornerstone of thromboembolic disease prevention. Because elderly patients have an increased risk of bleeding complications even under the newer antagonists of Factor Xa and direct Thrombin inhibitors, percutaneous occlusion of the left atrial appendage (LAA) as the main thrombogenic source offers an attractive alternative to permanent anticoagulation. This promising new therapeutic approach is put into clinical real world perspective.

  11. Left Atrial Appendage Closure in Atrial Fibrillation: A World without Anticoagulation?

    PubMed

    Contractor, Tahmeed; Khasnis, Atul

    2011-03-30

    Atrial Fibrillation (AF) is a common arrhythmia with an incidence that is as high as 10% in the elderly population. Given the large proportion of strokes caused by AF as well as the associated morbidity and mortality, reducing stroke burden is the most important part of AF management. While warfarin significantly reduces the risk of AF-related stroke, perceived bleeding risks and compliance limit its widespread use in the high-risk AF population. The left atrial appendage is believed to be the "culprit" for thrombogenesis in nonvalvular AF and is a new therapeutic target for stroke prevention. The purpose of this review is to explore the evolving field of percutaneous LAA occlusion. After briefly highlighting the risk of stroke with AF, problems with warfarin, and the role of the LAA in clot formation, this article discusses the feasibility and efficacy of various devices which have been developed for percutaneous LAA occlusion.

  12. Left atrial appendage exclusion for prevention of stroke in atrial fibrillation: review of minimally invasive approaches.

    PubMed

    Moss, Joshua D

    2014-02-01

    Stroke prevention is of vital importance in the management of atrial fibrillation (AF), though the proven strategy of systemic anticoagulation for thromboembolic prophylaxis is underutilized for a variety of reasons. The left atrial appendage (LAA) has long been suspected as the principal source of arterial emboli, particularly in nonvalvular AF, and a variety of techniques for its exclusion from the circulation have been developed. This review highlights the history of the LAA as a target of intervention, and the parallel advances in three minimally invasive strategies for its exclusion: percutaneous occlusion of the LAA orifice from within the left atrium, closed-chest ligation via a percutaneous pericardial approach, and minimally invasive thoracoscopic surgery. While further study is necessary, available evidence suggests that effective LAA exclusion is becoming a viable alternative to anticoagulation for stroke prevention in nonvalvular AF.

  13. Left atrial appendage occlusion with the WATCHMAN™ for stroke prevention in atrial fibrillation.

    PubMed

    Price, Matthew J

    2014-01-01

    Atrial fibrillation (AF) is a major cause of stroke and systemic embolism. Although warfarin and the novel oral anticoagulants reduce thromboembolic risk, they are associated with an ongoing bleeding hazard, in addition to other limitations that deter their use. The left atrial appendage (LAA) appears to be the primary source of thrombus in AF; therefore, LAA closure represents a mechanical strategy for stroke prevention in these patients. The WATCHMAN™ LAA closure device (Boston Scientific, Natick, MA) is a nitinol-framed occluder that is implanted percutaneously under echocardiographic and fluoroscopic guidance. Data from two randomized clinical trials support the clinical efficacy of transcatheter LAA occlusion with the WATCHMAN and demonstrate that procedural safety has improved significantly since initial experience. This article summarizes the rationale, procedural technique, safety, and clinical efficacy of the WATCHMAN device in patients with AF at high risk for thromboembolic events.

  14. Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion.

    PubMed

    Rodríguez Fernández, Antonio; Bethencourt González, Armando

    2016-08-01

    Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards.

  15. Imaging of thrombi and assessment of left atrial appendage function: a prospective study comparing transthoracic and transoesophageal echocardiography

    PubMed Central

    Omran, H; Jung, W; Rabahieh, R; Wirtz, P; Becher, H; Illien, S; Schimpf, R; Luderitz, B

    1999-01-01

    Objective—To compare the value of current transthoracic echocardiographic systems and transoesophageal echocardiography for assessing left atrial appendage function and imaging thrombi.
Design—Single blind prospective study. Patients were first investigated by transthoracic echocardiography and thereafter by a second investigator using transoesophageal echocardiography. The feasibility of imaging the left atrial appendage, recording its velocities, and identifying thrombi within the appendage were determined by both methods.
Patients—117 consecutive patients with a stroke or transient neurological deficit.
Setting—Tertiary cardiac and neurological care centre.
Results—Imaging of the complete appendage was feasible in 75% of the patients by transthoracic echocardiography and in 95% by transoesophageal echocardiography. Both methods were concordant for the detection of thrombi in 10 cases. Transoesophageal echocardiography revealed two additional thrombi. In one of these patients, transthoracic echocardiography was not feasible and in the other the thrombus had been missed by transthoracic examination. In patients with adequate transthoracic echogenicity, the specificity and sensitivity of detecting left atrial appendage thrombi were 100% and 91%, respectively. Recording of left atrial appendage velocities by transthoracic echocardiography was feasible in 69% of cases. None of the patients with a velocity > 0.3 m/s had left atrial appendage thrombi. In the one patient in whom transthoracic echocardiographic evaluation missed a left atrial appendage thrombus, the peak emptying velocity of the left atrial appendage was 0.25 m/s.
Conclusions—A new generation echocardiographic system allows for the transthoracic detection of left atrial appendage thrombi and accurate determination of left atrial appendage function in most patients with a neurological deficit.

 Keywords: echocardiography; left atrial appendage thrombi; stroke; thromboembolism

  16. Efficacy of anticoagulation in resolving left atrial and left atrial appendage thrombi: A transesophageal echocardiographic study

    NASA Technical Reports Server (NTRS)

    Jaber, W. A.; Prior, D. L.; Thamilarasan, M.; Grimm, R. A.; Thomas, J. D.; Klein, A. L.; Asher, C. R.

    2000-01-01

    BACKGROUND: Transesophageal echocardiography (TEE) is the gold standard for evaluation of the left atrium and the left atrial appendage (LAA) for the presence of thrombi. Anticoagulation is conventionally used for patients with atrial fibrillation to prevent embolization of atrial thrombi. The mechanism of benefit and effectiveness of thrombi resolution with anticoagulation is not well defined. METHODS AND RESULTS: We used a TEE database of 9058 consecutive studies performed between January 1996 and November 1998 to identify all patients with thrombi reported in the left atrium and/or LAA. One hundred seventy-four patients with thrombi in the left atrial cavity (LAC) and LAA were identified (1.9% of transesophageal studies performed). The incidence of LAA thrombi was 6.6 times higher than LAC thrombi (151 vs 23, respectively). Almost all LAC thrombi were visualized on transthoracic echocardiography (90.5%). Mitral valve pathology was associated with LAC location of thrombi (P <.0001), whereas atrial fibrillation or flutter was present in most patients with LAA location of thrombi. Anticoagulation of 47 +/- 18 days was associated with thrombus resolution in 80.1% of the patients on follow-up TEE. Further anticoagulation resulted in limited additional benefit. CONCLUSIONS: LAC thrombi are rare and are usually associated with mitral valve pathology. Transthoracic echocardiography is effective in identifying these thrombi. LAA thrombi occur predominantly in patients with atrial fibrillation or flutter. Short-term anticoagulation achieves a high rate of resolution of LAA and LAC thrombi but does not obviate the need for follow-up TEE.

  17. Left atrial appendage occlusion: initial experience with the Amplatzer™ Amulet™.

    PubMed

    Freixa, Xavier; Abualsaud, Ali; Chan, Jason; Nosair, Mohamed; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2014-07-01

    The Amplatzer™ Amulet™ (Amulet) is the evolution of the Amplatzer™ Cardiac Plug, a dedicated device for percutaneous left atrial appendage (LAA) occlusion. The new device has been designed to facilitate the implantation process, improve the sealing performance and further reduce the risk of complications. The objective of the study was to describe the initial experience with the Amplatzer Amulet for percutaneous LAA occlusion. This was a prospective single-center study of patients undergoing percutaneous LAA occlusion. The indication for LAA closure was a formal contraindication for oral anticoagulation or previous history of stroke due to INR lability. All procedures were done under general anesthesia and transesophageal echocardiography (TEE) guidance. Transthoracic echocardiography was performed 24h after the procedure in order to rule out procedural complications before discharge. Further follow-up was done with a clinical visit and TEE at 1-3 months. Between July-2012 and June-2013, 25 patients with a mean CHA2DS2-VASC of 4.3 ± 1.7 underwent LAA occlusion with the Amplatzer Amulet. The device was successfully implanted in 24 patients (96%) without any procedural stroke, pericardial effusion or device embolization. None of the patients presented any clinical event at follow-up. Follow-up TEE showed complete LAA sealing in all patients with no residual leaks >3mm and no device embolization. One patient (4.1%) presented a device thrombosis at follow-up without clinical expression. In this initial series of patients, the Amulet showed a remarkable acute and short-term performance in terms of feasibility and safety as depicted by the high successful implantation rate and the low incidence of complications. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Identifying Future Research Priorities Using Value of Information Analyses: Left Atrial Appendage Occlusion Devices in Atrial Fibrillation

    PubMed Central

    Micieli, Andrew; Bennell, Maria C.; Pham, Ba’; Krahn, Murray; Singh, Sheldon M.; Wijeysundera, Harindra C.

    2014-01-01

    Background Left atrial appendage occlusion devices are cost effective for stroke prophylaxis in atrial fibrillation when compared with dabigatran or warfarin. We illustrate the use of value‐of‐information analyses to quantify the degree and consequences of decisional uncertainty and to identify future research priorities. Methods and Results A microsimulation decision‐analytic model compared left atrial appendage occlusion devices to dabigatran or warfarin in atrial fibrillation. Probabilistic sensitivity analysis quantified the degree of parameter uncertainty. Expected value of perfect information analyses showed the consequences of this uncertainty. Expected value of partial perfect information analyses were done on sets of input parameters (cost, utilities, and probabilities) to identify the source of the greatest uncertainty. One‐way sensitivity analyses identified individual parameters for expected value of partial perfect information analyses. Population expected value of perfect information and expected value of partial perfect information provided an upper bound on the cost of future research. Substantial uncertainty was identified, with left atrial appendage occlusion devices being preferred in only 47% of simulations. The expected value of perfect information was $8542 per patient and $227.3 million at a population level. The expected value of partial perfect information for the set of probability parameters represented the most important source of uncertainty, at $6875. Identified in 1‐way sensitivity analyses, the expected value of partial perfect information for the odds ratio for stroke with left atrial appendage occlusion compared with warfarin was calculated at $7312 per patient or $194.5 million at a population level. Conclusion The relative efficacy of stroke reduction with left atrial appendage occlusion devices in relation to warfarin is an important source of uncertainty. Improving estimates of this parameter should be the priority

  19. Interatrial septum pacing decreases atrial dyssynchrony on strain rate imaging compared with right atrial appendage pacing.

    PubMed

    Yasuoka, Yoshinori; Abe, Haruhiko; Umekawa, Seiko; Katsuki, Keiko; Tanaka, Norio; Araki, Ryo; Imanaka, Takahiro; Matsutera, Ryo; Morisawa, Daisuke; Kitada, Hirokazu; Hattori, Susumu; Noda, Yoshiki; Adachi, Hidenori; Sasaki, Tatsuya; Miyatake, Kunio

    2011-03-01

    Interatrial septum pacing (IAS-P) decreases atrial conduction delay compared with right atrial appendage pacing (RAA-P). We evaluate the atrial contraction with strain rate of tissue Doppler imaging (TDI) during sinus activation or with IAS-P or RAA-P. Fifty-two patients with permanent pacemaker for sinus node disease were enrolled in the study. Twenty-three subjects were with IAS-P and 29 with RAA-P. The time from end-diastole to peak end-diastolic strain rate was measured and corrected with RR interval on electrocardiogram. It was defined as the time from end-diastole to peak end-diastolic strain rate (TSRc), and the balance between maximum and minimum TSRc at three sites (ΔTSRc) was compared during sinus activation and with pacing rhythm in each group. There were no significant differences observed in general characteristics and standard echocardiographic parameters except the duration of pacing P wave between the two groups. The duration was significantly shorter in the IAS-P group compared with the RAA-P group (95 ± 34 vs 138 ± 41; P = 0.001). TSRc was significantly different between sinus activation and pacing rhythm (36.3 ± 35.7 vs 61.6 ± 36.3; P = 0.003) in the RAA-P group, whereas no significant differences were observed in the IAS-P group (25.4 ± 12.1 vs 27.7 ± 14.7; NS). During the follow-up (mean 2.4 ± 0.7 years), the incidence of paroxysmal atrial fibrillation (AF) conversion to permanent AF was not significantly different between the two groups. IAS-P decreased the contraction delay on atrial TDI compared to RAA-P; however, it did not contribute to the reduction of AF incidence in the present study. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  20. Cardiac Plug I and Amulet Devices: Left Atrial Appendage Closure for Stroke Prophylaxis in Atrial Fibrillation.

    PubMed

    Parashar, Akhil; Tuzcu, E Murat; Kapadia, Samir R

    2015-01-01

    Percutaneous left atrial appendage (LAA) occlusion has emerged as an exciting and effective modality for stroke prophylaxis in patients with non-valvular atrial fibrillation who are deemed too high risk for anticoagulation with warfarin or newer anticoagulants. The Amplatzer devices have been used in LAA occlusion for more than a decade, starting with off label use of an atrial septal occluder device for LAA occlusion. This was followed by introduction of a dedicated Amplatzer cardiac plug (ACP) 1 for LAA occlusion, and more recently, the second generation Amulet device, with reported better stability enhancing features, has been introduced. Both these devices are widely used outside the United States, however in the US only the WATCHMAN device has been FDA approved. Unlike the WATCHMAN device, where the evidence is continuously building as the data from two pivotal randomized controlled trials are emerging, most of the evidence for ACP devices is from pooled multicenter registry data. In this article, we review the device design, implantation techniques and the most recently published evidence for both the Amplatzer cardiac plug 1 and the newer Amulet device. Our goal is to summarize the most recent literature and discuss the current role of the Amplatzer devices in the exciting and rapidly growing field of percutaneous LAA occlusion.

  1. [Giant congenital intrapericardial left atrial appendage aneurysm: about a case and review of the literature].

    PubMed

    Zhari, Bouchra; Bellamlih, Habib; Boumdine, Hassan; Amil, Touriya; Bamous, Mehdi; En-Nouali, Hassan

    2016-01-01

    Left atrial appendage aneurysm is a very rare heart anomaly. It may be congenital or acquired, secondary to inflammatory or degenerative processes. Most cases are asymptomatic. The prevalence of these lesions in pediatric age has been very rarely reported. As it can cause potentially fatal arrhythmias or thrombus, surgery is required immediately after diagnosis. This study reports the case of a 14-year-old boy with rapidly progressive dyspnea, palpitations, sensation of repetitive dizziness and fainting, in whom congenital left atrial appendage aneurysm was detected. Diagnosis was based on coronary CTA data. The patient was successfully treated with surgical resection of the aneurysm.

  2. Left atrial appendage exclusion for stroke prevention in patients with nonrheumatic atrial fibrillation.

    PubMed

    Onalan, Orhan; Crystal, Eugene

    2007-02-01

    The efficacy of oral anticoagulation (OAC) for stroke prevention in patients with nonrheumatic atrial fibrillation (AF) has clearly been established. However, a substantial number of patients with AF who are at high risk for thromboembolic events are not candidates for long-term OAC. The left atrial appendix (LAA) is the most common place of thrombosis in patients with AF, and it can easily be excluded from the systemic circulation at the time of cardiac surgery by excision, ligation, suturing, or stapling. Currently, removal of the LAA at the time of mitral valve surgery is recommended to reduce future stroke risk. The ongoing LAA Occlusion Study (LAAOS) is evaluating the efficacy of the routine LAA occlusion in patients undergoing elective coronary artery bypass graft surgery. Recently, two devices specifically designed for percutaneous transcatheter LAA occlusion have been introduced: the Percutaneous LAA Transcatheter Occlusion (PLAATO; Appriva Medical Inc) and WATCHMAN LAA system (Atritech, Inc). More than 200 PLAATO devices were implanted worldwide in patients with nonrheumatic AF who were at high risk for ischemic stroke and not candidates for long-term OAC. In a follow-up time of 258 patient-years, an estimated 61% reduction in stroke risk was achieved with PLAATO procedure. The WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation (PROTECT AF) study was designed to demonstrate the safety and efficacy of the WATCHMAN device in patients with nonvalvular AF who are eligible for long-term OAC. The trial is assessing whether the treatment arm (WATCHMAN device) is noninferior to the control arm (warfarin). Although present results suggest that LAA occlusion may reduce the long-term stroke risk, available data are still very limited. At present, percutaneous LAA occlusion may be an acceptable option in selected high-risk patients with AF who are not candidates for OAC. The current understanding of LAA exclusion for the

  3. Left Atrial Appendage Closure Guided by Integrated Echocardiography and Fluoroscopy Imaging Reduces Radiation Exposure

    PubMed Central

    Balzer, Jan; Eickholt, Christian; Petersen, Margot; Kehmeier, Eva; Veulemans, Verena; Kelm, Malte; Willems, Stephan; Meyer, Christian

    2015-01-01

    Aims To investigate whether percutaneous left atrial appendage (LAA) closure guided by automated real-time integration of 2D-/3D-transesophageal echocardiography (TEE) and fluoroscopy imaging results in decreased radiation exposure. Methods and Results In this open-label single-center study LAA closure (AmplatzerTM Cardiac Plug) was performed in 34 consecutive patients (8 women; 73.1±8.5 years) with (n = 17, EN+) or without (n = 17, EN-) integrated echocardiography/fluoroscopy imaging guidance (EchoNavigator® [EN]; Philips Healthcare). There were no significant differences in baseline characteristics between both groups. Successful LAA closure was documented in all patients. Radiation dose was reduced in the EN+ group about 52% (EN+: 48.5±30.7 vs. EN-: 93.9±64.4 Gy/cm2; p = 0.01). Corresponding to the radiation dose fluoroscopy time was reduced (EN+: 16.7±7 vs. EN-: 24.0±11.4 min; p = 0.035). These advantages were not at the cost of increased procedure time (89.6±28.8 vs. 90.1±30.2 min; p = 0.96) or periprocedural complications. Contrast media amount was comparable between both groups (172.3±92.7 vs. 197.5±127.8 ml; p = 0.53). During short-term follow-up of at least 3 months (mean: 8.1±5.9 months) no device-related events occurred. Conclusions Automated real-time integration of echocardiography and fluoroscopy can be incorporated into procedural work-flow of percutaneous left atrial appendage closure without prolonging procedure time. This approach results in a relevant reduction of radiation exposure. Trial Registration ClinicalTrials.gov NCT01262508 PMID:26465747

  4. Age-related changes in morphology of left atrial appendage in patients with atrial fibrillation.

    PubMed

    Hirata, Yukina; Kusunose, Kenya; Yamada, Hirotsugu; Shimizu, Rikuto; Torii, Yuta; Nishio, Susumu; Saijo, Yoshihito; Takao, Shoichiro; Soeki, Takeshi; Sata, Masataka

    2017-08-14

    The purpose of this study was to evaluate the relationship between age and frequency of left atrial appendage (LAA) morphology in patients with atrial fibrillation (AF) compared with sinus rhythm (SR). We enrolled 145 AF patients, and 199 SR patients for the control group without any cardiovascular disease. LAA volume index (LAAVi) and morphology were assessed by electrocardiogram-gated computed tomography angiography. LAA morphology was classified into "chicken wing" or "non-chicken wing" according to the previously described classification. There was no significant trend in frequency of non-chicken wing morphology among ages in the SR group (p = 0.36 for trend), whereas the frequency was negatively related to age in the AF group (p = 0.002 for trend). In multivariable logistic regression, age > 65 (odds ratio [OR] 0.42, p = 0.002) and duration of AF (OR 0.53, p = 0.010) and LAAVi (OR 0.62, p = 0.017) were independent factors of non-chicken wing LAA morphology in the AF group. LAA morphology is affected by age, especially in patients with AF. When we utilize non-chicken wing LAA morphology as a stroke risk factor in patients with AF, we should pay attention to their age.

  5. Left circumflex coronary artery occlusion due to a left atrial appendage closure device

    PubMed Central

    Katona, András; Temesvári, András; Szatmári, András; Forster, Tamás; Fontos, Géza

    2015-01-01

    Nowadays, percutaneous left atrial appendage (LAA) closure is spreading, and a large number of patients with this procedure have concomitant coronary artery disease. With the presented case it could be concluded that coronary angiography is recommended before LAA closure. PMID:25848378

  6. Left atrial appendage occlusion in high-risk patients with non-valvular atrial fibrillation.

    PubMed

    Berti, Sergio; Pastormerlo, Luigi Emilio; Rezzaghi, Marco; Trianni, Giuseppe; Paradossi, Umberto; Cerone, Elisa; Ravani, Marcello; De Caterina, Alberto Ranieri; Rizza, Antonio; Palmieri, Cataldo

    2016-12-15

    Percutaneous left atrial appendage (LAA) occlusion has been developed as a viable option for stroke and thromboembolism prevention in patients with non-valvular atrial fibrillation (NVAF) and at high risk for cerebral cardioembolic events. Data on device implantation and long-term follow-up from large cohorts are limited. 110 consecutive patients with NVAF and contraindications to oral anticoagulants (OACs) underwent LAA occlusion procedures and achieved a longer than 1 year follow-up. All patients were enrolled in a prospective registry. Procedures were performed using the Amplatzer Cardiac Plug or Amulet guided by fluoroscopy and intracardiac echocardiography. Mean age of the population was 77±6 years old; 68 were men. Atrial fibrillation was paroxysmal in 20%, persistent in 15.5% and permanent in 64.5% of cases, respectively. Mean CHA2DS2-VASc and HAS-BLED scores were 4.3±1.3 and 3.4±1, respectively. Technical success (successful deployment and implantation of device) was achieved in 100% of procedures. Procedural success (technical success without major procedure-related complications) was achieved in 96.4%, with a 3.6% rate of major procedural complications (three cases of pericardial tamponade requiring drainage and one case of major bleeding). Mean follow-up was 30±12 months (264 patient-years). Annual rates for ischaemic stroke and for other thromboembolic events were respectively 2.2% and 0%, and annual rate for major bleeding was 1.1%. Our data suggest LAA occlusion in high-risk patients with NVAF not suitable for OACs is feasible and associated with low complication rates as well as low rates of stroke and major bleeding at long-term follow-up. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  7. Coherex WAVECREST I Left Atrial Appendage Occlusion Study

    ClinicalTrials.gov

    2015-01-13

    Non-valvular Paroxysmal, Persistent, or Permanent Atrial Fibrillation; LAA Anatomy Amenable to Treatment by Percutaneous Technique; Anticoagulation Indication for Potential Thrombus Formation in the Left Atrium

  8. Obstructive membrane at the base of the left atrial appendage, a multi-imaging approach.

    PubMed

    Chejtman, Demián; Failo, Matías; Richarte Rueda, Valeria; Logarzo, Emilio; Barja, Luis; Benticuaga, Alejandro; Ayerdi, Maria Laura; Turri, Domingo; Baratta, Sergio; Aguirre, Pablo; Hita, Alejandro

    2015-05-01

    The left atrial appendage (LAA) is a small muscular extension that grows from the anterolateral wall of the left atrium, in the proximity of the left pulmonary veins. The presence of a membrane in the LAA is a rare clinical entity whose origin is not known. Its clinical implication in the genesis of atrial arrhythmias and thromboembolic risk remains unknown. We report a case of an obstructive membrane located at the base of the LAA, found incidentally in a young patient who was initially undergoing a transesophageal echocardiogram prior to an invasive treatment for atrial fibrillation.

  9. Transcatheter closure of the left atrial appendage: initial experience with the WATCHMAN device

    PubMed Central

    Ding, Jiandong; Zhu, Jian; Lu, Jing; Ding, Xiuxia; Zhang, Xiaoli; Lu, Wenbin; Ao, Mingqiang; Ma, Genshan

    2015-01-01

    Background: Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia, accounting for approximately one third of hospitalizations for cardiac rhythm disturbance. In patients with non-valvular AF, approximately 90% of thrombi are thought to arise from the left atrial appendage (LAA). Anticoagulation with warfarin has been the mainstay of therapy to reduce stroke risk in these patients; however, it is not without its complications including bleeding and drug interactions. Percutaneous left atrial appendage closure can be an alternative to warfarin treatment in patients with AF at high risk for thromboembolic events and/or bleeding complications. Methods: Patients with atrial fibrillation and CHADSVASc score ≥ 2, not eligible for anticoagulation, were submitted to left atrial appendage closure using the WATCHMAN device. The procedure was performed under general anaesthesia, and was guided by fluoroscopy and transoesophageal echocardiography. Results: Percutaneous LAA closure with the WATCHMAN device was performed in all patients. At 45-day follow-up no recurrent major adverse events and especially no thromboembolic events occurred. Conclusions: Transcatheter closure of the LAA with the WATCHMAN device is generally safe and feasible. Long-term follow-up will further reveal the risk and benefits of this therapy. PMID:26629008

  10. Cost effectiveness of left atrial appendage closure with the Watchman device for atrial fibrillation patients with absolute contraindications to warfarin

    PubMed Central

    Reddy, Vivek Y.; Akehurst, Ronald L.; Armstrong, Shannon O.; Amorosi, Stacey L.; Brereton, Nic; Hertz, Deanna S.; Holmes, David R.

    2016-01-01

    Aims Atrial fibrillation (AF) patients with contraindications to oral anticoagulation have had few options for stroke prevention. Recently, a novel oral anticoagulant, apixaban, and percutaneous left atrial appendage closure (LAAC) have emerged as safe and effective therapies for stroke risk reduction in these patients. This analysis assessed the cost effectiveness of LAAC with the Watchman device relative to apixaban and aspirin therapy in patients with non-valvular AF and contraindications to warfarin therapy. Methods and results A cost-effectiveness model was constructed using data from three studies on stroke prevention in patients with contraindications: the ASAP study evaluating the Watchman device, the ACTIVE A trial of aspirin and clopidogrel, and the AVERROES trial evaluating apixaban. The cost-effectiveness analysis was conducted from a German healthcare payer perspective over a 20-year time horizon. Left atrial appendage closure yielded more quality-adjusted life years (QALYs) than aspirin and apixaban by 2 and 4 years, respectively. At 5 years, LAAC was cost effective compared with aspirin with an incremental cost-effectiveness ratio (ICER) of €16 971. Left atrial appendage closure was cost effective compared with apixaban at 7 years with an ICER of €9040. Left atrial appendage closure was cost saving and more effective than aspirin and apixaban at 8 years and remained so throughout the 20-year time horizon. Conclusions This analysis demonstrates that LAAC with the Watchman device is a cost-effective and cost-saving solution for stroke risk reduction in patients with non-valvular AF who are at risk for stroke but have contraindications to warfarin. PMID:26838691

  11. Cost effectiveness of left atrial appendage closure with the Watchman device for atrial fibrillation patients with absolute contraindications to warfarin.

    PubMed

    Reddy, Vivek Y; Akehurst, Ronald L; Armstrong, Shannon O; Amorosi, Stacey L; Brereton, Nic; Hertz, Deanna S; Holmes, David R

    2016-07-01

    Atrial fibrillation (AF) patients with contraindications to oral anticoagulation have had few options for stroke prevention. Recently, a novel oral anticoagulant, apixaban, and percutaneous left atrial appendage closure (LAAC) have emerged as safe and effective therapies for stroke risk reduction in these patients. This analysis assessed the cost effectiveness of LAAC with the Watchman device relative to apixaban and aspirin therapy in patients with non-valvular AF and contraindications to warfarin therapy. A cost-effectiveness model was constructed using data from three studies on stroke prevention in patients with contraindications: the ASAP study evaluating the Watchman device, the ACTIVE A trial of aspirin and clopidogrel, and the AVERROES trial evaluating apixaban. The cost-effectiveness analysis was conducted from a German healthcare payer perspective over a 20-year time horizon. Left atrial appendage closure yielded more quality-adjusted life years (QALYs) than aspirin and apixaban by 2 and 4 years, respectively. At 5 years, LAAC was cost effective compared with aspirin with an incremental cost-effectiveness ratio (ICER) of €16 971. Left atrial appendage closure was cost effective compared with apixaban at 7 years with an ICER of €9040. Left atrial appendage closure was cost saving and more effective than aspirin and apixaban at 8 years and remained so throughout the 20-year time horizon. This analysis demonstrates that LAAC with the Watchman device is a cost-effective and cost-saving solution for stroke risk reduction in patients with non-valvular AF who are at risk for stroke but have contraindications to warfarin. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

  12. Impact of electrical cardioversion for atrial fibrillation on left atrial appendage function and spontaneous echo contrast: characterization by simultaneous transesophageal echocardiography.

    PubMed

    Grimm, R A; Stewart, W J; Maloney, J D; Cohen, G I; Pearce, G L; Salcedo, E E; Klein, A L

    1993-11-01

    This study assessed the function of the left atrial appendage in the pericardioversion period to gain insights into mechanisms involved in thromboembolism after cardioversion of atrial fibrillation. Systemic embolization associated with electrical cardioversion of atrial fibrillation is thought to originate from the left atrium or left atrial appendage, or both. However, the mechanism involved is poorly understood. We studied left atrial appendage function with transesophageal echocardiography in 20 patients with atrial fibrillation before and after successful electrical cardioversion. We measured left atrial appendage emptying and filling velocities by pulsed wave Doppler echocardiography, characterized Doppler emptying patterns, measured atrial appendage areas and assessed the presence or absence of spontaneous echo contrast or thrombus. Organized left atrial appendage function returned in 16 (80%) of 20 patients immediately after cardioversion. Atrial appendage emptying velocities before cardioversion were greater in patients without (0.39 +/- 0.02 m/s) than in those with (0.25 +/- 0.12 m/s) spontaneous echo contrast (p = 0.045). Furthermore, emptying velocities before cardioversion were significantly greater than late diastolic emptying velocities after cardioversion (0.31 +/- 0.15 vs. 0.14 +/- 0.12 m/s, p = 0.0001), as well as in both the group with (0.25 +/- 0.12 vs. 0.13 +/- 0.13 m/s, p = 0.001) and the group without (0.39 +/- 0.02 vs. 0.15 +/- 0.12 m/s, p = 0.01) spontaneous echo contrast. In addition, left atrial and atrial appendage spontaneous echo contrast developed in 4 of 20 patients and increased in intensity in 3 of 20 patients in the immediate postcardioversion period. Organized left atrial appendage function returns in most patients immediately after cardioversion of atrial fibrillation. However, its function is impaired compared with that before cardioversion. Furthermore, spontaneous echo contrast increased in 7 (35%) of 20 patients after

  13. Left atrial appendage closure in patients with intracranial haemorrhage and atrial fibrillation.

    PubMed

    Fayos-Vidal, F; Arzamendi-Aizpurua, D; Millán-Álvarez, X; Guisado-Alonso, D; Camps-Renom, P; Prats-Sánchez, L; Martínez-Domeño, A; Delgado-Mederos, R; Martí-Fàbregas, J

    2017-08-30

    The use of oral anticoagulants in patients with a history of atrial fibrillation (AF) and intracranial haemorrhage (ICH) is controversial on account of the risk of haemorrhagic stroke recurrence. This study presents our experience regarding the safety and efficacy of percutaneous left atrial appendage closure (LAAC), an alternative to anticoagulation in these patients. We conducted a retrospective, single-centre, observational study. LAAC was performed in patients with a history of ICH and non-valvular AF. Risk of ischaemic and haemorrhagic events was estimated using the CHA2DS2-VASc and HAS-BLED scales. We recorded periprocedural complications, IHC recurrence, cerebral/systemic embolism, mortality and use of antithrombotic drugs following the procedure. LAAC was performed in 9 patients (7 men, 2 women) using the AMPLATZER Amulet device in 7 cases and the AMPLATZER Cardiac Plug device in 2. Mean age was 72.7±8.2 years. Time between ICH and LAAC was less than one month in 5 patients and more than one month in 4 patients. Median CHA2DS2-VASc score was 4 (interquartile range of 2.5). Median HAS-BLED score was 3 (interquartile range of 0). No periprocedural complications were recorded. All patients received single anti-platelet therapy (clopidogrel in 5 patients, aspirin in 4) after the procedure; 5 patients received this treatment for 6 months and 4 received it indefinitely. No ischaemic or haemorrhagic events were recorded during follow-up (mean duration of 15 months). In our series, LAAC was found to be safe and effective in patients with a history of ICH who required anticoagulation due to AF. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Appendage flow computations using the INS3D computer code

    NASA Astrophysics Data System (ADS)

    Ohring, Samuel

    1989-10-01

    The INS3D code, a steady state incompressible, fully 3-D Navier-Stokes solver, was applied to the computation of flow past an appendage mounted between two parallel flat plates of infinite extent at a Reynolds number of one-half million. The Baldwin-Lomax turbulence model was used to compute the eddy viscosity. The appendage consisted of a 1.5:1 elliptical nose and a NACA 0020 tail joined at maximum thickness of 0.24 chordlengths. A detailed description of the flow results covers all the major features of appendage flow and the results, for an unfilleted appendage, are in general agreement with experimental and other numerical results, except that the lateral location of the horseshoe vortex is larger than that in the experimental results. A detailed description is presented of the important trailing edge vortex. Detailed results for a second flow case, in which filleting is applied mainly to the front and side of the aforementioned appendage, show a greatly weakened horseshoe vortex but a still significant trailing edge vortex, that prevented velocity-deficit reduction in the wake, compared to the unfilleted appendage flow case. The calculations for the filleted case also exhibited an upstream instability. The plotting program PLOT3D was used to obtain color photos for flow visualization.

  15. Association Between the Left Atrial and Left Atrial Appendages Systole Strain Rate in Patients with Atrial Fibrillation

    PubMed Central

    Tan, Changming; OuYang, Minzhi; Kong, Demiao; Zhou, Xinmin

    2016-01-01

    Background The aim of this research was to explore the association between the left atrial (LA) and left atrial appendages (LAA) systole strain rate (SSR) in patients with atrial fibrillation (AF), and to provide evidence to aid in the assessment of disease progression. Material/Methods A total of 180 patients with AF were selected for the study (130 patients with paroxysmal AF (Par AF) and 50 patients with persistence AF (PerAF). In addition, 60 healthy individuals were selected as a control group. The total and side wall SSRs were calculated. Results The total SSR in the control group was higher than in the ParAF and PerAF groups (2.87±0.45 vs. 2.15±0.56 vs. 1.92±0.62 and 6.24±1.61 vs. 4.45±1.42 vs. 3.66±1.55). The total SSR of LAA was correlated with that of LA in the AF patient groups and the control group; the correlation coefficients were 0.720, 0.563, and 0.421. However, the ratio of total SSR of LAA to that of LA was not significant statistically different among the three groups (2.24±0.41 vs. 2.35±0.58 vs. 2.03±0.56). The posterior wall had the lowest SSRs in the control group and ParAF group. Conclusions The SSRs of AF patients were lower than that of healthy individuals, and the degree was associated with disease progression. The SSR was different in different side walls, and gradually shorten with disease progression. PMID:27988786

  16. Etiologic significance of enlargement of the left atrial appendage in adults

    SciTech Connect

    Green, C.E.; Kelley, M.J.; Higgins, C.B.

    1982-01-01

    Fifty-one patients were divided into two groups: 20 patients with proven rheumatic mitral valve disease (RMVD) and 31 patients with left atrial enlargement (LAE) of a nonrheumatic etiology. The latter group included patients with ischemic papillary muscle dysfunction, mitral valve prolapse, and congestive cardiomyopathy. Radiographic studies showed that enlargement of the left atrial appendage (LAAE) was present in 18 of 20 rheumatics but in only one of 31 nonrheumatics. There was no direct relationship between enlargement of the LAA and radiographic or echocardiographic left atrial size, degree of pulmonary venous hypertension (PVH), or presence of atrial fibrillation. It is postulated that rheumatic influammation of the LAA allows it to dilate out of proportion to the body of the left atrium. In the adult patient with radiographic findings of PVH, LAAE is a valuable and specific radiographic sign of rheumatic mitral valve disease.

  17. Left Atrial Appendage Closure for Atrial Fibrillation Is Safe and Effective After Intracranial or Intraocular Hemorrhage.

    PubMed

    Fahmy, Peter; Spencer, Ryan; Tsang, Michael; Gooderham, Peter; Saw, Jacqueline

    2016-03-01

    Atrial fibrillation (AF) affects 1%-2% of the general population and 13% of individuals older than 80 years of age. Anticoagulation has been the mainstay therapy to reduce stroke risk. Patients with previous intracranial hemorrhage (ICH) or intraocular hemorrhage (IOH) are at increased risk of recurrence if anticoagulation is continued or initiated. Left atrial appendage (LAA) closure may obviate the need for long-term anticoagulation in these patients. We report our consecutive series of patients with nonvalvular AF with previous ICH or IOH who underwent LAA closure with the AMPLATZER Cardiac Plug (ACP; St Jude Medical, St Paul, MN), AMPLATZER Amulet, or WATCHMAN (Boston Scientific, Natick, MA) device. Demographics, clinical status, procedural outcomes, and complications were collected at baseline, during the procedure, at 3 months, at 1 year, and annually thereafter. Twenty-six patients with previous ICH (n = 24) or IOH (n = 2) underwent LAA closure (9 with the ACP, 3 with the Amulet, and 7 with the WATCHMAN). The mean age was 76 ± 7 years, and 61.5% were men with a mean CHADS2 (Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack) score of 3.2 ± 1.4 and CHA2DS2-VASc (Congestive Heart Failure, Hypertension, Age [≥ 75 years], Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age [65-74 years], Sex [Female] score) of 4.9 ± 1.7. No procedure-related complications occurred. Mean follow-up was 11.9 ± 13.3 months. One patient died at 13 months (this death was not related to the procedure), and 1 patient had a transient ischemic attack at 20.6 months after the procedure. No ischemic stroke, haemorrhagic stroke, or bleeding problems occurred during follow-up. In our consecutive series, LAA closure was found to be safe and effective in patients with AF and a history of ICH or IOH. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  18. Assessment of left atrial appendage function during sinus rhythm in patients with obstructive sleep apnea

    PubMed Central

    Vural, Mustafa Gökhan; Çetin, Süha; Gündüz, Hüseyin; Abacıoğlu, Özge Özcan; Akdemir, Ramazan; Fırat, Hikmet; Yeter, Ekrem

    2016-01-01

    Objective: Obstructive sleep apnea (OSA) is associated with thromboembolic events. Compromised left atrial appendage (LAA) function due to left ventricular (LV) performance abnormality, often present in patients with OSA, may play an important role. The purpose of this study is to evaluate LV and LAA mechanical functions during sinus rhythm (SR) in patients with OSA. Methods: LV and LAA functions were assessed in 43 OSA patients and compared with that of 20 control patients in SR. Tissue Doppler velocities of the LAA apex and emptying velocities (EV) of LAA were obtained on parasternal short-axis view. Results: The baseline clinical characteristics were similar except for AHI (apnea-hypopnea index), minimal SaO2, mean SaO2, hypertension, and body-surface area. Most of the LV echocardiographic parameters significantly deteriorated in OSA patients in comparison with those in the control group. LAA EV, LAA systolic relaxation velocity (SM), LAA early-diastolic velocity (EM), LAA contraction velocity (AM), left atrial (LA) minimum volume index, LA ejection fraction, LA conduit volume index, and LA reservoir volume index were lower in OSA patients compared with those in the control group (p<0.05). LAA AM was negatively correlated with AHI and the ratio of peak early diastolic flow velocity (E) to early-diastolic (E’) and positively correlated with LA conduit volume (p<0.05). Multiple predictors for LAA AM were AHI, presence of diastolic dysfunction, and E/E’ values (p<0.05). Conclusion: LAA mechanical function is significantly depressed in patients with OSA and SR. LAA dysfunction may predispose these patients to thromboembolic events. The evaluation of LAA mechanical function by tissue Doppler study using transthoracic echocardiography (TTE) may become an alternative for routine work-up in OSA patients. PMID:26467361

  19. Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

    PubMed Central

    Swaans, Martin J.; Alipour, Arash; Rensing, Benno J.W.M.; Post, Martijn C.; Boersma, Lucas V.A.

    2013-01-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope 4, 5. Patients with AF have a five-fold higher risk of stroke 6. Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64% 7. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range 8-11. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug 8. The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF 12,13, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers 4. CA is a well-established treatment for AF symptoms 14, 15, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy 16. Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation 17, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN

  20. Intra-procedural imaging of the left atrial appendage: implications for closure with the Amplatzer™ cardiac plug.

    PubMed

    Sobrino, Ayax; Tzikas, Apostolos; Freixa, Xavier; Pulido, Alicia; Chan, Jason; Garceau, Patrick; Ibrahim, Reda; Basmadjian, Arsène J

    2014-01-01

    To evaluate intra-procedural imaging with transesophageal echocardiography and angiography during left atrial appendage occlusion using the Amplatzer™ Cardiac Plug with regard to sizing and final device shape. Left atrial appendage ostium dimensions and diameter at a depth of 10mm from the ostium were measured by transesophageal echocardiography (0-180°) and angiography (RAO 30° - Cranial 20°) in consecutive patients undergoing left atrial appendage occlusion using the ACP with an oversizing strategy of 10-20% relative to the baseline measurements. After delivery, ACP dimensions were measured and device shape was assessed. Twenty-seven consecutive patients underwent successful uncomplicated left atrial appendage closure with Amplatzer™ Cardiac Plug. We found a significant difference between the largest and smallest left atrial appendage diameter measured with transesophageal echocardiography (22.3±4.2 vs. 18.1±4.1mm, p<0.001). By the end of the procedure (by angiography), ACP had an optimal shape in 17 patients (63%), a strawberry-like shape in 7 patients (26%), and a square-like shape in 3 patients (11%). ACP was oversized on average by 1.5±2.7 and 3.3±2.3mm compared to transesophageal echocardiography and angiography, respectively. The final shape of the device was not significantly associated with the degree of oversizing. We found a considerable variability in the assessment of the left atrial appendage, using transesophageal echocardiography and angiography. The degree of Amplatzer™ Cardiac Plug expansion within the left atrial appendage and the final shape of the device were not associated with the degree of oversizing. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  1. Percutaneous left atrial appendage closure devices: safety, efficacy, and clinical utility

    PubMed Central

    Swaans, Martin J; Wintgens, Lisette IS; Alipour, Arash; Rensing, Benno JWM; Boersma, Lucas VA

    2016-01-01

    Atrial fibrillation (AF) is the most common arrhythmia treated in the clinical practice. One of the major complications of AF is a thromboembolic cerebral ischemic event. Up to 20% of all strokes are caused by AF. Thromboembolic cerebral ischemic event in patients with AF occurs due to atrial thrombi, mainly from the left atrial appendage (LAA). Prevention of clot formation with antiplatelet agents and especially oral anticoagulants (vitamin K antagonists or newer oral anticoagulants) has been shown to be effective in reducing the stroke risk in patients with AF but has several drawbacks with (major) bleedings as the most important disadvantage. Therefore, physical elimination of the LAA, which excludes the site of clot formation by surgical or percutaneous techniques, might be a good alternative. In this review, we discuss the safety, efficacy, and clinical utility of the Watchman™ LAA closure device. PMID:27621674

  2. A Review of the Relevant Embryology, Pathohistology, and Anatomy of the Left Atrial Appendage for the Invasive Cardiac Electrophysiologist

    PubMed Central

    DeSimone, Christopher V.; Gaba, Prakriti; Tri, Jason; Syed, Faisal; Noheria, Amit; Asirvatham, Samuel J.

    2016-01-01

    The three-dimensional morphology of the left atrial appendage provides the substrate for thrombus generation, and is a harbinger for embolic material due to its direct connection to the left-sided circulation. Appreciating the development of the appendage from mesodermal layer to its adult form provides the basis to improve exclusion from the atrial circulation, and thereby can lead to a significant reduction in stroke risk. This process also provides insight into the role of the left atrial appendage as an endocrine organ, its involvement in fluid homeostasis, and its connection to the autonomic nervous system. Knowledge of the surrounding structural arrangement is critical to identify landmarks from both an endocardial and epicardial perspective to improve targeted device placement. Furthermore, correlation of the left atrial appendage body, neck, and ostium to the surrounding anatomy can also improve both procedural efficacy and safety. In addition, a working knowledge of the regional anatomy adds a prudent degree of awareness for procedural complications, and allows for early identification and timely intervention as these situations arise. A detailed understanding of the left atrial appendage embryology, histology, and gross anatomy is imperative to identify the correct device and approach for each individual patient. In addition, this increased awareness can identify areas that are in need of further innovation, and thus provide the ability to adapt and refine existing technologies to overcome pitfalls currently facing catheter-based approaches. PMID:27087889

  3. Peri-procedural silent cerebral infarcts after left atrial appendage occlusion.

    PubMed

    Laible, M; Möhlenbruch, M; Horstmann, S; Pfaff, J; Geis, N A; Pleger, S; Schüler, S; Rizos, T; Bendszus, M; Veltkamp, R

    2017-01-01

    To determine the rate of peri-interventional silent brain infarcts after left atrial appendage occlusion (LAAO). In this prospective, uncontrolled single-center pilot study, consecutive patients with atrial fibrillation undergoing LAAO between July 2013 and January 2016 were included. The Amplatzer Cardiac Plug, WATCHMAN or Amulet device was used. A neurological examination and cranial magnetic resonance imaging (MRI) were performed within 48 h before and after the procedure. MRI was evaluated for new diffusion-weighted imaging (DWI) hyperintensities, cerebral microbleeds (CMBs) and white-matter lesions (WMLs). Left atrial appendage occlusion was performed in 21 patients (mean age, 73.2 ± 9.5 years). Main reasons for LAAO were previous intracerebral hemorrhage (n = 11) and major systemic bleeding (n = 6). No clinically overt stroke occurred peri-interventionally. After the intervention, one patient had a small cerebellar hyperintensity on DWI (4.8%; 95% confidence interval, 0.0-14.3) that was not present on the MRI 1 day before the procedure. Among 11 patients with available MRI just before LAAO, there were no significant changes in the number of CMBs and the severity of WMLs after LAAO. This study of peri-interventional MRI in LAAO suggests a low rate of silent peri-procedural infarcts in this elderly population. Confirmation in larger studies is needed. © 2016 EAN.

  4. Effect of left atrial appendage excision on procedure outcome in patients with persistent atrial fibrillation undergoing surgical ablation.

    PubMed

    Romanov, Alexander; Pokushalov, Evgeny; Elesin, Dmitry; Bogachev-Prokophiev, Alexander; Ponomarev, Dmitry; Losik, Denis; Bayramova, Sevda; Strelnikov, Artem; Shabanov, Vitaliy; Pidanov, Oleg; Kropotkin, Evgeny; Ivanickii, Eduard; Karaskov, Alexander; Steinberg, Jonathan S

    2016-09-01

    Catheter ablation is less successful for treatment of persistent atrial fibrillation (PersAF) than for paroxysmal atrial fibrillation. Some studies suggest that left atrial appendage (LAA) isolation in addition to pulmonary vein isolation (PVI) is required to maximize the benefits for PersAF after ablation. The purpose of this study was to compare the efficacy and safety of 2 surgical ablation approaches for PersAF via video-assisted thoracoscopy: PVI + box lesion and PVI + box lesion + LAA excision. We randomly assigned 176 patients with PersAF to video-assisted thoracoscopic surgical ablation with PVI + box lesion (88 patients) or PVI + box lesion + LAA excision (88 patients). The primary endpoint was freedom from any documented atrial arrhythmia lasting >30 seconds after a single ablation procedure without antiarrhythmic drug (AAD). After 18 months of follow-up, 61 of 86 patients (70.9%) assigned to PVI + box lesion were free from recurrent atrial fibrillation compared to 64 of 87 patients (73.6%) assigned to PVI + box lesion + LAA excision after a single ablation procedure without AAD (P = .73). Freedom from any atrial arrhythmia after a single procedure with or without AAD was also nonsignificant (70.9% vs 74.7%, respectively). There were no significant differences between groups with regard to adverse events, including death, transient ischemic attack, stroke, pneumothorax, and hydrothorax. Among patients with PersAF, no reduction in the rate of recurrent atrial fibrillation was found when LAA excision was performed in addition to PVI and box lesion during surgical ablation. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. Cardiac embolism after implantable cardiac defibrillator shock in non-anticoagulated atrial fibrillation: The role of left atrial appendage occlusion

    PubMed Central

    Freixa, Xavier; Andrea, Rut; Martín-Yuste, Victoria; Fernández-Rodríguez, Diego; Brugaletta, Salvatore; Masotti, Mónica; Sabaté, Manel

    2014-01-01

    Cardioembolic events are one of the most feared complications in patients with non-valvular atrial fibrillation (NVAF) and a formal contraindication to oral anticoagulation (OAC). The present case report describes a case of massive peripheral embolism after an implantable cardiac defibrillator (ICD) shock in a patient with NVAF and a formal contraindication to OAC due to previous intracranial hemorrhage. In order to reduce the risk of future cardioembolic events, the patient underwent percutaneous left atrial appendage (LAA) occlusion. A 25 mm Amplatzer™ Amulet was implanted and the patient was discharged the following day without complications. The potential risk of thrombus dislodgement after an electrical shock in patients with NVAF and no anticoagulation constitutes a particular scenario that might be associated with an additional cardioembolic risk. Although LAA occlusion is a relatively new technique, its usage is rapidly expanding worldwide and constitutes a very valid alternative for patients with NVAF and a formal contraindication to OAC. PMID:24772261

  6. Cardiac embolism after implantable cardiac defibrillator shock in non-anticoagulated atrial fibrillation: The role of left atrial appendage occlusion.

    PubMed

    Freixa, Xavier; Andrea, Rut; Martín-Yuste, Victoria; Fernández-Rodríguez, Diego; Brugaletta, Salvatore; Masotti, Mónica; Sabaté, Manel

    2014-04-26

    Cardioembolic events are one of the most feared complications in patients with non-valvular atrial fibrillation (NVAF) and a formal contraindication to oral anticoagulation (OAC). The present case report describes a case of massive peripheral embolism after an implantable cardiac defibrillator (ICD) shock in a patient with NVAF and a formal contraindication to OAC due to previous intracranial hemorrhage. In order to reduce the risk of future cardioembolic events, the patient underwent percutaneous left atrial appendage (LAA) occlusion. A 25 mm Amplatzer™ Amulet was implanted and the patient was discharged the following day without complications. The potential risk of thrombus dislodgement after an electrical shock in patients with NVAF and no anticoagulation constitutes a particular scenario that might be associated with an additional cardioembolic risk. Although LAA occlusion is a relatively new technique, its usage is rapidly expanding worldwide and constitutes a very valid alternative for patients with NVAF and a formal contraindication to OAC.

  7. Novel stroke risk reduction in atrial fibrillation: left atrial appendage occlusion with a focus on the Watchman closure device

    PubMed Central

    Alipour, Arash; Wintgens, Lisette I S; Swaans, Martin J; Balt, Jippe C; Rensing, Benno J W M; Boersma, Lucas V A

    2017-01-01

    Atrial fibrillation (AF) remains an important clinical problem with severe complications such as stroke, which especially harms those with risk factors as calculated by the CHADS2 or CHA2DS2-VASc. Until now, no therapy has proven 100% effective against AF. Since the left atrial appendage (LAA) is the most prominent nonvalvular AF-related thromboembolic source and (novel) oral anticoagulant [(N)OAC] carries the hazard of bleeding, LAA occlusion may be an alternative, especially in patients who are ineligible for (N)OAC therapy. In this review, we discuss several LAA occlusion techniques with a focus on the Watchman device since this device is the most thoroughly studied device of all. PMID:28293114

  8. Localization of atrial natriuretic peptide mRNA and immunoreactivity in the rat heart and human atrial appendage

    SciTech Connect

    Hamid, Q.; Wharton, J.; Terenghi, G.; Hassall, C.J.S.; Aimi, J.; Taylor, K.M.; Nakazato, H.; Dixon, J.E.; Burnstock, G.; Polak, J.M.

    1987-10-01

    The localization of mRNA encoding preproatrial natriuretic peptide was investigated in tissue sections and cultures of rat heart and in sections of human right atrial appendage using the technique of in situ hybridization with /sup 32/P- and /sup 35/S-labeled RNA probes. Rat atrial natriuretic peptide (ANP) transcripts were demonstrated in numerous atrial myocytes and, to a lesser extent, in ventricular myocytes in both tissue sections and newborn rat heart cultures. These findings are consistent with those obtained by RNA blot analysis of rat heart total RNA, indicating that a single prepro-ANP transcript of approx. 900 nucleotides was present in the ventricles as well as the atria. Using a /sup 35/S-labeled RNA probe for human ANP mRNA, ANP transcripts were also localized to the majority of myocytes in the human right atrial appendage. Only background levels of autoradiographic labeling were obtained when RNA probes identical to the coding sequence of rat or human ANP mRNA were used. A close correlation was found between the distribution of ANP immunoreactivity and prepro-ANP mRNA in these preparations. These results provide unequivocal evidence for the expression of the ANP gene in the rat ventricles, as well as the atria, because myocytes in these tissues have been established as the sites of both ANP localization and precursor biosynthesis. The combined use of cardiac cultures and in situ hybridization may be of value in future studies investigating the regulation of ANP synthesis in cardiac myocytes.

  9. Cost-effectiveness analysis of left atrial appendage occlusion compared with pharmacological strategies for stroke prevention in atrial fibrillation.

    PubMed

    Lee, Vivian Wing-Yan; Tsai, Ronald Bing-Ching; Chow, Ines Hang-Iao; Yan, Bryan Ping-Yen; Kaya, Mehmet Gungor; Park, Jai-Wun; Lam, Yat-Yin

    2016-08-31

    Transcatheter left atrial appendage occlusion (LAAO) is a promising therapy for stroke prophylaxis in non-valvular atrial fibrillation (NVAF) but its cost-effectiveness remains understudied. This study evaluated the cost-effectiveness of LAAO for stroke prophylaxis in NVAF. A Markov decision analytic model was used to compare the cost-effectiveness of LAAO with 7 pharmacological strategies: aspirin alone, clopidogrel plus aspirin, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban. Outcome measures included quality-adjusted life years (QALYs), lifetime costs and incremental cost-effectiveness ratios (ICERs). Base-case data were derived from ACTIVE, RE-LY, ARISTOTLE, ROCKET-AF, PROTECT-AF and PREVAIL trials. One-way sensitivity analysis varied by CHADS2 score, HAS-BLED score, time horizons, and LAAO costs; and probabilistic sensitivity analysis using 10,000 Monte Carlo simulations was conducted to assess parameter uncertainty. LAAO was considered cost-effective compared with aspirin, clopidogrel plus aspirin, and warfarin, with ICER of US$5,115, $2,447, and $6,298 per QALY gained, respectively. LAAO was dominant (i.e. less costly but more effective) compared to other strategies. Sensitivity analysis demonstrated favorable ICERs of LAAO against other strategies in varied CHADS2 score, HAS-BLED score, time horizons (5 to 15 years) and LAAO costs. LAAO was cost-effective in 86.24 % of 10,000 simulations using a threshold of US$50,000/QALY. Transcatheter LAAO is cost-effective for prevention of stroke in NVAF compared with 7 pharmacological strategies. The transcatheter left atrial appendage occlusion (LAAO) is considered cost-effective against the standard 7 oral pharmacological strategies including acetylsalicylic acid (ASA) alone, clopidogrel plus ASA, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban for stroke prophylaxis in non-valvular atrial fibrillation management.

  10. Thromboembolism Prevention via Transcatheter Left Atrial Appendage Closure with Transeosophageal Echocardiography Guidance

    PubMed Central

    Palios, John; Paraskevaidis, Ioannis

    2014-01-01

    Atrial fibrillation (AF) is an independent risk factor for stroke. Anticoagulation therapy has a risk of intracerebral hemorrhage. The use of percutaneous left atrial appendage (LAA) closure devices is an alternative to anticoagulation therapy. Echocardiography has a leading role in LAA closure procedure in patient selection, during the procedure and during followup. A comprehensive echocardiography study is necessary preprocedural in order to identify all the lobes of the LAA, evaluate the size of the LAA ostium, look for thrombus or spontaneous echo contrast, and evaluate atrial anatomy, including atrial septal defect and patent foramen ovale. Echocardiography is used to identify potential cardiac sources of embolism, such as atrial septal aneurysm, mitral valve disease, and aortic debris. During the LAA occlusion procedure transeosophageal echocardiography provides guidance for the transeptal puncture and monitoring during the release of the closure device. Procedure-related complications can be evaluated and acceptable device release criteria such as proper position and seating of the occluder in the LAA, compression, and stability can be assessed. Postprocedural echocardiography is used for followup to assess the closure of the LAA ostium. This overview paper describes the emerging role of LAA occlusion procedure with transeosophageal echocardiography guidance as an alternative to anticoagulation therapy in patients with AF. PMID:24672720

  11. Fibrosis and electrophysiological characteristics of the atrial appendage in patients with atrial fibrillation and structural heart disease.

    PubMed

    van Brakel, Thomas J; van der Krieken, Thomas; Westra, Sjoerd W; van der Laak, Jeroen A; Smeets, Joep L; van Swieten, Henry A

    2013-11-01

    This study was conducted to investigate the degree of fibrosis in atrial appendages of patients with and without atrial fibrillation (AF) undergoing cardiac surgery. In addition, we hypothesized that areas of atrial fibrosis can be identified by electrogram fractionation and low voltage for potential ablation therapy. Interstitial fibrosis from right (RAA) and/or left atrial appendages (LAA) was studied in patients with sinus rhythm (SR, n = 8), paroxysmal (n = 21), and persistent AF (n = 20) undergoing coronary artery bypass and/or aortic or mitral valve surgery. Atrial fibrosis quantification was performed with Masson trichrome staining. Intraoperative bipolar epicardial electrophysiological measurements were performed to correlate fibrosis to electrogram fractionation, voltage, and AF cycle length. The average degree of fibrosis was 11.2 ± 7.2 % in the LAA and 22.8 ± 7.6 % in the RAA (p < 0.001). Fibrosis was not significantly higher in paroxysmal AF patients compared to SR subjects (18.2 ± 8.7 versus 20.7 ± 5.3 %). Persistent AF patients had a higher degree of LAA and RAA fibrosis compared to paroxysmal AF patients (LAA 14.6 ± 8.7 versus 8.6 ± 4.7 %, p = 0.02, and RAA 28.2 ± 7.9 versus 18.2 ± 8.7 %, respectively, p = 0.04). The left atrial end diastolic volume index was higher in persistent AF patients compared to SR controls (38.3 ± 16.4 and 28 ± 11 ml/m(2), respectively, p = 0.04). No correlation between atrial fibrosis and electrogram fractionation or voltage was found. Patients with structural heart disease undergoing cardiac surgery have more fibrosis in the RAA than in the LAA. Furthermore, RAA fibrosis is increased in persistent AF but not paroxysmal AF patients compared to control subjects. Electrogram fractionation and low voltage did not provide accurate identification of the fibrotic substrate.

  12. Percutaneous closure of a very large left atrial appendage using the Amplatzer amulet.

    PubMed

    Freixa, Xavier; Kwai Chan, Jason Leung; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2013-10-01

    Although percutaneous left atrial appendage (LAA) closure is becoming a common procedure worldwide, there are still some anatomic limitations. The size of the LAA is one of the current limitations as the most popular devices do not allow the closure of very large LAAs. The new Amplatzer Cardiac Plug 2, also called "Amulet," has been redesigned not only to improve delivery and safety but also to allow the closure of larger LAAs. The present report describes the successful closure of a very large LAA using the Amulet. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  13. Late MitraClip procedure after left atrial appendage occlusion: indication and procedure description.

    PubMed

    Cammalleri, Valeria; Scandura, Salvatore; Tamburino, Corrado; Ussia, Gian Paolo

    2014-02-01

    We report the first human case of percutaneous edge-to-edge mitral valve repair using MitraClip System (Abbott Vascular, Abbott Park, IL) in a patient, who previously underwent left atrial appendage closure with PLAATO™ System (ev3. Inc., Plymouth, MN). The procedure was successfully performed using the standard MitraClip technique, in the catheterization laboratory, with transesophageal echocardiographic and fluoroscopic guidance. We showed that a double percutaneous procedure for stroke prevention and mitral regurgitation treatment might be a valid approach in selected patients ineligible for chronic anticoagulation therapy and at high risk for conventional cardiac surgery. Copyright © 2013 Wiley Periodicals, Inc.

  14. Left atrial appendage closure: patient, device and post-procedure drug selection.

    PubMed

    Tzikas, Apostolos; Bergmann, Martin W

    2016-05-17

    Left atrial appendage closure (LAAC), a device-based therapy for stroke prevention in patients with atrial fibrillation, is considered an alternative to oral anticoagulation therapy, particularly for patients at high risk of bleeding. Proof of concept has been demonstrated by the PROTECT AF and PREVAIL trials which evaluated the WATCHMAN device (Boston Scientific, Marlborough, MA, USA) versus warfarin, showing favourable outcome for the device group. The most commonly used devices for LAAC are the WATCHMAN and its successor, the WATCHMAN FLX (Boston Scientific) and the AMPLATZER Cardiac Plug and more recently the AMPLATZER Amulet device (both St. Jude Medical, St. Paul, MN, USA). The procedure is typically performed via a transseptal puncture under fluoroscopic and echocardiographic guidance. Technically, it is considered quite demanding due to the anatomic variability and fragility of the appendage. Careful material manipulation, adequate operator training, and good cardiac imaging and device sizing allow a safe, uneventful procedure. Post-procedure antithrombotic drug selection is based on the patient's history, indication and quality of LAAC.

  15. Procedural success and intra-hospital outcome related to left atrial appendage morphology in patients that receive an interventional left atrial appendage closure.

    PubMed

    Fastner, Christian; Behnes, Michael; Sartorius, Benjamin; Wenke, Annika; El-Battrawy, Ibrahim; Ansari, Uzair; Gill, Ishar-Singh; Borggrefe, Martin; Akin, Ibrahim

    2017-08-01

    The interventional left atrial appendage (LAA) closure represents an emerging alternative to oral anticoagulation for stroke prevention in certain atrial fibrillation patients. Preliminary results have suggested high procedural success rates and fewer peri-interventional complications; however, there persists an insufficient understanding of the role of many underlying confounding variables (e.g., anatomical characteristics). It was investigated whether varying LAA morphologies influence procedural success as well as in-hospital outcome. Sixty-seven patients ineligible for long-term oral anticoagulation were included in this single-center, prospective, observational registry spanning from the years 2014 to 2016. Interventions were performed with the Watchman occluder (Boston Scientific, Natick, MA) or the Amplatzer Amulet (St. Jude Medical, St. Paul, MN), at the operator's discretion. Results derived from the data describing procedural success, fluoroscopy, and peri-interventional safety events were classified according to the presenting LAA morphology (cauliflower, cactus, windsock, and chicken wing). Rates of successful implantation were high across all groups (≥98%; P = 0.326). Surrogate parameters underlining procedural complexity like median total duration (P = 0.415), median fluoroscopy time (P = 0.459), median dose area product (P = 0.698), and the median amount of contrast agent (P = 0.076) demonstrated similar results across all groups. Likewise, the periprocedural complication rate was not significantly different and was mainly restricted to minor bleeding events. Irrespective of the varying morphological presentation of the LAA, the procedural success rates, interventional characteristics, and safety events did not significantly differ among patients receiving an interventional LAA closure. © 2017 Wiley Periodicals, Inc.

  16. Early results of first versus second generation Amplatzer occluders for left atrial appendage closure in patients with atrial fibrillation.

    PubMed

    Gloekler, Steffen; Shakir, Samera; Doblies, Janosch; Khattab, Ahmed A; Praz, Fabien; Guerios, Ênio; Koermendy, Dezsoe; Stortecky, Stefan; Pilgrim, Thomas; Buellesfeld, Lutz; Wenaweser, Peter; Windecker, Stephan; Moschovitis, Aris; Jaguszewski, Milosz; Landmesser, Ulf; Nietlispach, Fabian; Meier, Bernhard

    2015-08-01

    Transcatheter left atrial appendage (LAA) occlusion has been proven to be an effective treatment for stroke prophylaxis in patients with atrial fibrillation. For this purpose, the Amplatzer cardiac plug (ACP) was introduced. Its second generation, the Amulet, was developed for easier delivery, better coverage, and reduction of complications. To investigate the safety and efficacy of first generation versus second generation Amplatzer occluders for LAA occlusion. Retrospective analysis of prospectively collected data from the LAA occlusion registries of the Bern and Zurich university hospitals. Comparison of the last consecutive 50 ACP cases versus the first consecutive 50 Amulet cases in patients with non-valvular atrial fibrillation. For safety, a periprocedural combined endpoint, which is composed of death, stroke, cardiac tamponade, and bailout by surgery was predefined. For efficacy, the endpoint was procedural success. There were no differences between the two groups in baseline characteristics. The percentage of associated interventions during LAA occlusion was high in (78% with ACP vs. 70% with Amulet p = ns). Procedural success was similar in both groups (98 vs. 94%, p = 0.61). The combined safety endpoint for severe adverse events was reached by a similar rate of patients in both groups (6 vs. 8%, p = 0.7). Overall complication rate was insignificantly higher in the ACP group, which was mainly driven by clinically irrelevant pericardial effusions (24 vs. 14%, p = 0.31). Death, stroke, or tamponade were similar between the groups (0 vs. 2%, 0 vs. 0%, or 6 vs. 6%, p = ns). Transcatheter LAA occlusion for stroke prophylaxis in patients with atrial fibrillation can be performed with similarly high success rates with first and second generations of Amplatzer occluders. According to this early experience, the Amulet has failed to improve results of LAA occlusion. The risk for major procedural adverse events is acceptable but has to be taken into account when

  17. [Implantation of Watchman™ occluder of the left atrial appendage. Tips and tricks].

    PubMed

    Israel, Carsten W; Tschishow, Wladimir N; Ridjab, Denio; Kische, Stephan; Buddecke, Julia; Ince, Hüseyin

    2013-03-01

    The implantation of an occluder system for the left atrial appendage (LAA) represents an interesting alternative for patients with atrial fibrillation and a CHA2DS2-VASc-Score ≥ 2 who cannot take permanent anticoagulation for various reasons. As in other left cardiac interventions, there are potentially dangerous possibilities for complications that can limit the advantages of this therapy. This overview summarizes practical tips and tricks at the implantation of a Watchman™ occluder which may help to minimize the complication rate. These hints refer to peri-interventional anticoagulation as well as transseptal puncture (technique, imaging), exchange of catheters, left atrial pressure, intubation and fluoroscopy of the LAA, preparation of the device and sheath, delivery of the Watchman™ device, confirmation of optimal position, and partial or complete recapture. If these precautions are considered, the complication rate at implantation of a Watchman™ occluder should be < 5 %, the rate of complications with long-term consequences < 1 %, and the implant success should lie > 95 %.

  18. Cardiac procedures to prevent stroke: patent foramen ovale closure/left atrial appendage occlusion.

    PubMed

    Freixa, Xavier; Arzamendi, Dabit; Tzikas, Apostolos; Noble, Stephane; Basmadjian, Arsene; Garceau, Patrick; Ibrahim, Réda

    2014-01-01

    Stroke is a major contributor to population morbidity and mortality. Cardiac thromboembolic sources are an important potential cause of stroke. Left atrial appendage (LAA) thromboembolism in association with atrial fibrillation is a major contributor to stroke occurrence, particularly in elderly individuals. Patent foramen ovale (PFO) acts as a potential conduit from the right-sided circulation to the brain, and has been suggested to be an important factor in cryptogenic stroke in the young patients. Advances in interventional cardiology have made it possible to deal with these potential stroke sources (LAA and PFO), but the available methods have intrinsic limitations that must be recognized. Furthermore, the potential value of LAA and PFO closure depends on our ability to identify when the target structure is importantly involved in stroke risk; this is particularly challenging for PFO. This article addresses the clinical use of PFO and LAA closure in stroke prevention. We discuss technical aspects of closure devices and methods, questions of patient selection, and clinical trials evidence. We conclude that for PFO closure, the clinical trials evidence is thus far negative in the broad cryptogenic stroke population, but closure might nevertheless be indicated for selected high-risk patients. LAA closure has an acceptable balance between safety and efficacy for atrial fibrillation patients with high stroke risk and important contraindications to oral anticoagulation. Much more work needs to be done to optimize the devices and techniques, and better define patient selection for these potentially valuable procedures.

  19. Left Atrial Appendage Isolation in Patients With Longstanding Persistent AF Undergoing Catheter Ablation: BELIEF Trial.

    PubMed

    Di Biase, Luigi; Burkhardt, J David; Mohanty, Prasant; Mohanty, Sanghamitra; Sanchez, Javier E; Trivedi, Chintan; Güneş, Mahmut; Gökoğlan, Yalçın; Gianni, Carola; Horton, Rodney P; Themistoclakis, Sakis; Gallinghouse, G Joseph; Bailey, Shane; Zagrodzky, Jason D; Hongo, Richard H; Beheiry, Salwa; Santangeli, Pasquale; Casella, Michela; Dello Russo, Antonio; Al-Ahmad, Amin; Hranitzky, Patrick; Lakkireddy, Dhanunjaya; Tondo, Claudio; Natale, Andrea

    2016-11-01

    Longstanding persistent (LSP) atrial fibrillation (AF) is the most challenging type of AF. In addition to pulmonary vein isolation, substrate modification and triggers ablation have been reported to improve freedom from AF in patients with LSPAF. This study sought to assess whether the empirical electrical isolation of the left atrial appendage (LAA) could improve success at follow-up. This was an open-label, randomized study assessing the effectiveness of empirical electrical left atrial appendage isolation for the treatment of LSPAF. Patients were randomly assigned to undergo empirical electrical left atrial appendage isolation along with extensive ablation (group 1; n = 85) or extensive ablation alone (group 2; n = 88). Recurrence of atrial arrhythmias was the primary endpoint. Secondary endpoints included cardiac-related hospitalization, all-cause mortality, and stroke at follow-up. Major clinical characteristics were not different between the 2 groups. At 12-month follow-up, 48 (56%) patients in group 1 and 25 (28%) in group 2 were recurrence free after a single procedure (unadjusted hazard ratio [HR] for recurrence with standard ablation: 1.92; 95% confidence interval [CI]: 1.3 to 2.9; log-rank p = 0.001). After adjusting for age, sex, and left atrial size, standard ablation was predictive of recurrence (HR: 2.22; 95% CI: 1.29 to 3.81; p = 0.004). During repeat procedures, empirical electrical left atrial appendage isolation was performed in all patients. After an average of 1.3 procedures, cumulative success at 24-month follow-up was reported in 65 (76%) in group 1 and in 49 (56%) in group 2 (unadjusted HR: 2.24; 95% CI: 1.3 to 3.8; log-rank p = 0.003). This randomized study showed that both after a single procedure and after redo procedures in patients with LSPAF, empirical electrical isolation of the LAA improved long-term freedom from atrial arrhythmias without increasing complications. (Effect of Empirical Left Atrial Appendage Isolation on Long

  20. Left atrial appendage occlusion for stroke prevention in atrial fibrillation: multicentre experience with the AMPLATZER Cardiac Plug.

    PubMed

    Tzikas, Apostolos; Shakir, Samera; Gafoor, Sameer; Omran, Heyder; Berti, Sergio; Santoro, Gennaro; Kefer, Joelle; Landmesser, Ulf; Nielsen-Kudsk, Jens Erik; Cruz-Gonzalez, Ignacio; Sievert, Horst; Tichelbäcker, Tobias; Kanagaratnam, Prapa; Nietlispach, Fabian; Aminian, Adel; Kasch, Friederike; Freixa, Xavier; Danna, Paolo; Rezzaghi, Marco; Vermeersch, Paul; Stock, Friederike; Stolcova, Miroslava; Costa, Marco; Ibrahim, Reda; Schillinger, Wolfgang; Meier, Bernhard; Park, Jai-Wun

    2016-02-01

    To investigate the safety, feasibility, and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) for stroke prevention in patients with atrial fibrillation (AF). Data from consecutive patients treated in 22 centres were collected. A total of 1,047 patients were included in the study. Procedural success was 97.3%. There were 52 (4.97%) periprocedural major adverse events. Follow-up was complete in 1,001/1,019 (98.2%) of successfully implanted patients (average 13 months, total 1,349 patient-years). One-year all-cause mortality was 4.2%. No death at follow-up was reported as device-related. There were nine strokes (0.9%) and nine transient ischaemic attacks (0.9%) during follow-up. The annual rate of systemic thromboembolism was 2.3% (31/1,349 patient-years), which is a 59% risk reduction. There were 15 major bleedings (1.5%) during follow-up. The annual rate of major bleeding was 2.1% (28/1,349 patient-years), which is a 61% risk reduction. Patients with single LAAO on aspirin monotherapy or no therapy and longer follow-up had fewer cerebral and fewer bleeding events. In this multicentre study, LAAO with the ACP showed high procedural success and a favourable outcome for the prevention of AF-related thromboembolism. Modification in antithrombotic therapy after LAAO may result in reduction of bleeding events.

  1. Left Atrial Appendage Closure Guided by 3D Printed Cardiac Reconstruction: Emerging Directions and Future Trends.

    PubMed

    Pellegrino, Pier Luigi; Fassini, Gaetano; DI Biase, Matteo; Tondo, Claudio

    2016-06-01

    Percutaneous left atrial appendage (LAA) occlusion has emerged as an alternative therapeutic approach to medical therapy for stroke prevention in patients with atrial fibrillation. 3D printing is a novel technology able to create a patient specific model of any given anatomical portion of the heart. Herein we report the first 2 cases of LAA occlusion procedure with 2 different systems, the Wave Crest device (Coherex Medical, Inc., USA) and the Amplatzer Amulet device (St. Jude Medical, St. Paul, MN, USA), in which a 3D printed LAA model (Care Tronik, Prato, Italy) was used in a rehearse phase. Both patients had history of paroxysmal AF and previous transient ischemic attack (TIA) occurred during oral anticoagulation with correct INR. In the first patient the occlusive device was positioned within the LAA after a rehearse occlusion using the 3D printed LAA plus a 27 mm Coherex Wavecrest device, demonstrating a good compression and sealing, particularly considering a proximal lobe of the appendage. In the second patient an attempt with the 27 mm Amulet device delivered within the 3D printed LAA, based on angiography and transesophageal echocardiographic (TEE), revealed insufficient covering of the proximal part of LAA vestibule; the device was released only after a second test with the 31 mm Amulet demonstrating a good sealing. These 2 cases demonstrated that 3D model could help in finding the correct position within LAA, sizing the device and guiding the choice of the closure device despite the measurements provided by angiography and TEE. © 2016 Wiley Periodicals, Inc.

  2. Left atrial appendage closure for prevention of death, stroke, and bleeding in patients with nonvalvular atrial fibrillation.

    PubMed

    Gloekler, Steffen; Saw, Jacqueline; Koskinas, Konstantinos C; Kleinecke, Caroline; Jung, Werner; Nietlispach, Fabian; Meier, Bernhard

    2017-08-26

    Nonvalvular atrial fibrillation (AF) is the most frequent arrhythmia with a prevalence of 1%-2% in the general population. Its prevalence increases with age and its diagnosis benefits of improvement and simplification of technologies for its detection. Today, AF affects approximately 7% of individuals age>65years and 15%-20% of octogenarians. Due to stasis and activation of coagulation in a fibrillating atrium, patients are at increased risk of thromboembolism, in particular ischemic stroke, with an overall stroke risk of 5% per year. Since the left atrium itself is round and smooth-walled, thrombi typically do not form there, but almost exclusively in the left atrial appendage (LAA), a blind sac-like heterogeneous structure trabeculated by pectinate muscles. In the past five decades, oral anticoagulation (OAC) with vitamin K antagonists (VKA) has been the state-of-the art treatment to prevent stroke and systemic embolism from thrombi in AF. In the last decade, nonvitamin K dependant oral anticoagulants (NOAC) have been shown to be overall superior to VKA with respect to efficacy and safety in large trials and registries. Given the safety issues of indefinite OAC with either VKA or NOAC, it is plausible to consider left atrial appendage closure (LAAC) as an alternative strategy for prevention of all three catastrophes for patients with AF on anticoagulation: death, stroke or other systemic embolization, and bleeding. In the past years, LAAC has been compared to VKA in prospective randomized trials, yielding superior results regarding efficacy and non-inferiority regarding safety in the mid-term. Today, the decision to provide the most appropriate treatment for a patient with AF (OAC, NOAC, or LAAC) is complex and needs to be individualized. This review provides a comprehensive update on the current state of LAAC in the field of prevention of death, stroke and bleedings in patients suffering from nonvalvular AF. We describe the pathophysiology of the LAA with regard

  3. Association between left atrial appendage emptying velocity, N-terminal plasma brain natriuretic peptide levels, and recurrence of atrial fibrillation after catheter ablation.

    PubMed

    Ma, Xin-Xin; Zhang, Yue-Li; Hu, Bing; Jiang, Wen-Jun; Wang, Man; Zheng, Dong-Yan; Zhu, Meng-Ruo; Xue, Xiao-Pei

    2017-04-01

    Multiple studies have shown the efficacy and potentially curative effect of catheter ablation (CA). However, CA is always accompanied by a considerable recurrence rate for atrial fibrillation (AF). We hypothesized that pre-procedure assessments of baseline left atrial appendage emptying flow velocity (LAAFV) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels would help identify abnormal atrial substrate and offer preliminary evidence regarding susceptibility to AF recurrence in patients with paroxysmal or persistent AF, respectively. In 120 patients with AF (paroxysmal, 55; persistent, 65), transesophageal echocardiography was performed with assessment of LAAFV and NT-proBNP was measured before the first AF ablation. After 12 months of follow-up, 16 patients (29.1%) in the paroxysmal AF and 23 patients (35.4%) in the persistent AF experienced recurrence of AF. In ROC analysis, a NT-proBNP value of ≥291 pg/ml in the paroxysmal AF and ≥368 pg/ml in the persistent AF discriminated AFR and non-AFR with the greatest sensitivity and specificity. In multivariate regression analysis, LAAFV (OR 0.88, 95% CI 0.79-0.98, p = 0.023) was identified as an independent predictor of AFR in the paroxysmal AF population post-CA after adjustment for other risk factors; however, in the persistent AF population, LAAFV (OR 0.81, 95% CI 0.68-0.94, p = 0.007) and a NT-proBNP value ≥368 pg/ml (OR 18.29, 95% CI 1.32-252.84, p = 0.030) were identified as independent predictors for rhythm outcome compared to other parameters. In patients with persistent AF, elevated plasma NT-proBNP concentrations combined with low LAAFV were associated with rhythm outcome after AF ablation; however, LAAFV was the only independent predictor of CA efficacy in patients with paroxysmal AF.

  4. Left atrial strain as evaluated by two-dimensional speckle tracking predicts left atrial appendage dysfunction in patients with acute ischemic stroke.

    PubMed

    Sasaki, Shintaro; Watanabe, Tetsu; Tamura, Harutoshi; Nishiyama, Satoshi; Wanezaki, Masahiro; Sato, Chika; Yamaura, Gensai; Ishino, Mitsunori; Arimoto, Takanori; Takahashi, Hiroki; Shishido, Tetsuro; Miyamoto, Takuya; Kubota, Isao

    2014-12-01

    Left atrial appendage (LAA) dysfunction predisposes patients with atrial fibrillation (AF) to cardioembolic stroke. Two-dimensional (2D) speckle tracking was reported to be useful for evaluating left atrial (LA) regional function, as well as left ventricular function. However, it remains unclear whether 2D speckle tracking is useful for evaluating LAA dysfunction. Therefore, we investigated whether decreased LA strain may predict LAA dysfunction and thrombus formation in patients with acute ischemic stroke. We performed transthoracic and transesophageal echocardiography in 120 patients (83 males, mean age 72 ± 11 years) within 7 days of onset of an acute ischemic stroke. Longitudinal LA strain was evaluated using 2D speckle tracking imaging at each LA segment, and peak systolic strain was calculated by averaging the results for each segment. Forty-eight patients had LAA dysfunction as defined by the presence of LAA thrombus and/or severe spontaneous echo contrast. LA peak systolic strain was significantly decreased in patients with LAA dysfunction compared to those without (32.3 ± 13.7% vs. 12.1 ± 7.2%, p < 0.0001). LA peak systolic strain was significantly correlated with LAA emptying flow velocity (r = 0.693, p < 0.0001). The optimum LA peak systolic strain cut-off value for predicting LAA dysfunction was 19%. Multivariate logistic regression analysis showed that LA peak systolic strain was an independent predictor of LAA dysfunction (odds ratio 0.059, 95% confidence interval 0.018-0.146; p < 0.0001). Decreased LA peak systolic strain was independently associated with LAA dysfunction in patients with acute ischemic stroke.

  5. Percutaneous left atrial appendage closure: procedural techniques and outcomes.

    PubMed

    Saw, Jacqueline; Lempereur, Mathieu

    2014-11-01

    Percutaneous left atrial appendage closure technology for stroke prevention in patients with atrial fibrillation has significantly advanced in the past 2 decades. Several devices are under clinical investigation, and a few have already received Conformité Européene (CE)-mark approval and are available in many countries. The WATCHMAN device (Boston Scientific, Natick, Massachusetts) has the most supportive data and is under evaluation by the U.S. Food and Drug Administration for warfarin-eligible patients. The Amplatzer Cardiac Plug (St. Jude Medical, Plymouth, Minnesota) has a large real-world experience over the past 5 years, and a randomized trial comparing Amplatzer Cardiac Plug with the WATCHMAN device is anticipated in the near future. The Lariat procedure (SentreHEART Inc., Redwood City, California) has also gained interest lately, but early studies were concerning for high rates of serious pericardial effusion and major bleeding. The current real-world experience predominantly involves patients who are not long-term anticoagulation candidates or who are perceived to have high bleeding risks. This pattern of practice is expected to change when the U.S. Food and Drug Administration approves the WATCHMAN device for warfarin-eligible patients. This paper reviews in depth the procedural techniques, safety, and outcomes of the current leading devices. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. Percutaneous methods of left atrial appendage exclusion: an alternative to the internist.

    PubMed

    Le, Duong L; Khodjaev, Soidjon D; Morelli, Remo L

    2014-01-01

    Thromboembolic stroke from the left atrial appendage (LAA) is the most feared complication in patients with atrial fibrillation (AF). The cornerstone for the management of chronic non-valvular AF is stroke reduction with oral anticoagulation (OAC). However, poor compliance, maintaining a narrow therapeutic window, and major side effects such as bleeding have severely limited their use, which creates a therapeutic dilemma. As much as 20% of AF patients are not receiving OAC due to contraindications and less than half of AF patients are not on OAC due to reluctance of the prescribing physician and/or patient non-compliance. Fortunately, over the past decade, there have been great interests in providing an alternative strategy unbeknownst to the practicing internist. The introduction of percutaneous approaches for LAA occlusion has added a different dimension to the management of chronic AF in patients with OAC intolerance. Occlusion devices such as the Amplatzer Cardiac Plug and WATCHMAN device are currently being investigated for stroke prophylaxis. More recently, the LARIAT device may provide an alternative means for potential stroke prophylaxis without the need for short-term post-procedural OAC. We aim to review the current literature and bring attention to an alternative strategy for high-risk AF patients intolerant to OAC.

  7. Percutaneous methods of left atrial appendage exclusion: an alternative to the internist

    PubMed Central

    Le, Duong L.; Khodjaev, Soidjon D.; Morelli, Remo L.

    2014-01-01

    Thromboembolic stroke from the left atrial appendage (LAA) is the most feared complication in patients with atrial fibrillation (AF). The cornerstone for the management of chronic non-valvular AF is stroke reduction with oral anticoagulation (OAC). However, poor compliance, maintaining a narrow therapeutic window, and major side effects such as bleeding have severely limited their use, which creates a therapeutic dilemma. As much as 20% of AF patients are not receiving OAC due to contraindications and less than half of AF patients are not on OAC due to reluctance of the prescribing physician and/or patient non-compliance. Fortunately, over the past decade, there have been great interests in providing an alternative strategy unbeknownst to the practicing internist. The introduction of percutaneous approaches for LAA occlusion has added a different dimension to the management of chronic AF in patients with OAC intolerance. Occlusion devices such as the Amplatzer Cardiac Plug and WATCHMAN device are currently being investigated for stroke prophylaxis. More recently, the LARIAT device may provide an alternative means for potential stroke prophylaxis without the need for short-term post-procedural OAC. We aim to review the current literature and bring attention to an alternative strategy for high-risk AF patients intolerant to OAC. PMID:24596651

  8. Twelve-month follow-up of left atrial appendage occlusion with Amplatzer Amulet.

    PubMed

    Kleinecke, Caroline; Park, Jai-Wun; Gödde, Martin; Zintl, Konstantin; Schnupp, Steffen; Brachmann, Johannes

    2017-01-01

    The Amplatzer Amulet (St. Jude Medical, Minneapolis, MN, USA) is a second gen-eration Amplatzer device for left atrial appendage (LAA) occlusion (LAAO) for stroke prophylaxis in patients with atrial fibrillation. This research sought to assess the clinical performance of the Amplatzer Amulet device and in follow up for 12 months. In this single-center registry patients with atrial fibrillation and contraindication to oral anticoagulation underwent LAAO with the Amplatzer Amulet device. Follow-up was performed before discharge, by transesophageal echocardiography (TEE) after 6 weeks and telephone interview after 3, 6 and 12 months. Between October 2014 and August 2015 50 patients (76.1 ± 8.3 years; 30 male) were en-rolled. Procedural success was achieved in 49 (98%) patients. Major periprocedural adverse events were observed in 4 (8%) of patients: 1 device embolization, 2 pericardial effusions requiring pericardiocente-sis and 1 prolonged hospital stay due to retropharyngeal hematoma from the TEE probe. Follow-up TEE was available in 38 of 50 patients showing complete LAA sealing in all. 2 device-related thrombi were also documented. At 12-month follow-up 7 patients had died unrelated to the device. Ischemic stroke occurred in 3 patients. According to neurological examination two were classified as microangiopathic and not cardio-embolic. The other one could not be classified. Bleeding complications (5 minor, 3 major) were documented in 8 patients. Although minimizing procedure-related complications remains challenging, LAAO with the Amplatzer Amulet device showed high procedural success and excellent LAA sealing. (Cardiol J 2017; 24, 2: 131-138).

  9. Early Safety and Efficacy of Percutaneous Left Atrial Appendage Suture Ligation

    PubMed Central

    Price, Matthew J.; Gibson, Douglas N.; Yakubov, Steven J.; Schultz, Jason C.; Di Biase, Luigi; Natale, Andrea; Burkhardt, J. David; Pershad, Ashish; Byrne, Timothy J.; Gidney, Brett; Aragon, Joseph R.; Goldstein, Jeffrey; Moulton, Kriegh; Patel, Taral; Knight, Bradley; Lin, Albert C.; Valderrábano, Miguel

    2015-01-01

    BACKGROUND Transcatheter left atrial appendage (LAA) ligation may represent an alternative to oral anticoagulation for stroke prevention in atrial fibrillation.. OBJECTIVES This study sought to assess the early safety and efficacy of transcatheter ligation of the LAA for stroke prevention in atrial fibrillation.. METHODS This was a retrospective, multicenter study of consecutive patients undergoing LAA ligation with the Lariat device at 8 U.S. sites. The primary endpoint was procedural success, defined as device success (suture deployment and <5 mm leak by post-procedure transesophageal echocardiography), and no major complication at discharge (death, myocardial infarction, stroke, Bleeding Academic Research Consortium bleeding type 3 or greater, or cardiac surgery). Post-discharge management was per operator discretion. RESULTS A total of 154 patients were enrolled. Median CHADS2 score (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism [doubled]) was 3 (interquartile range: 2 to 4). Device success was 94%, and procedural success was 86%. A major complication occurred in 15 patients (9.7%). There were 14 major bleeds (9.1%), driven by the need for transfusion (4.5%). Significant pericardial effusion occurred in 16 patients (10.4%). Follow-up was available in 134 patients at a median of 112 days (interquartile range: 50 to 270 days): Death, myocardial infarction, or stroke occurred in 4 patients (2.9%). Among 63 patients with acute closure and transesophageal echocardiography follow-up, there were 3 thrombi (4.8%) and 13 (20%) with residual leak. CONCLUSIONS In this initial multicenter experience of LAA ligation with the Lariat device, the rate of acute closure was high, but procedural success was limited by bleeding. A prospective randomized trial is required to adequately define clinical efficacy, optimal post-procedure medical therapy, and the effect of operator experience on

  10. Percutaneous left atrial appendage occlusion - treatment outcomes and 6 months of follow-up - a single-center experience.

    PubMed

    Karczewski, Michał; Woźniak, Sebastian; Skowronek, Radomir; Burysz, Marian; Fischer, Marcin; Anisimowicz, Lech; Demkow, Marcin; Konka, Marek; Ogorzeja, Wojciech

    2016-06-01

    To present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO). Percutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30(th) postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation. In all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure. Percutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further observation is necessary to evaluate the

  11. Left Atrial Appendage Closure Device With Delivery System: A Health Technology Assessment

    PubMed Central

    Nevis, Immaculate; Falk, Lindsey; Wells, David; Higgins, Caroline

    2017-01-01

    Background Atrial fibrillation is a common cardiac arrhythmia, and 15% to 20% of those who have experienced stroke have atrial fibrillation. Treatment options to prevent stroke in people with atrial fibrillation include pharmacological agents such as novel oral anticoagulants or nonpharmacological devices such as the left atrial appendage closure device with delivery system (LAAC device). The objectives of this health technology assessment were to assess the clinical effectiveness and cost-effectiveness of the LAAC device versus novel oral anticoagulants in patients without contraindications to oral anticoagulants and versus antiplatelet agents in patients with contraindications to oral anticoagulants. Methods We performed a systematic review and network meta-analysis. We also conducted an economic literature review, economic evaluation, and budget impact analysis to assess the cost-effectiveness and budget impact of the LAAC device compared with novel oral anticoagulants and oral antiplatelet agents (e.g., aspirin). We also spoke with patients to better understand their preferences, perspectives, and values. Results Seven randomized controlled studies met the inclusion criteria for indirect comparison. Five studies assessed the effectiveness of novel oral anticoagulants versus warfarin, and two studies compared the LAAC device with warfarin. No studies were identified that compared the LAAC device with aspirin in patients in whom oral anticoagulants were contraindicated. Using the random effects model, we found that the LAAC device was comparable to novel oral anticoagulants in reducing stroke (odds ratio [OR] 0.85; credible interval [Cr.I] 0.63–1.05). Similarly, the reduction in the risk of all-cause mortality was comparable between the LAAC device and novel oral anticoagulants (OR 0.71; Cr.I 0.49–1.22). The LAAC device was found to be superior to novel oral anticoagulants in preventing hemorrhagic stroke (OR 0.45; Cr.I 0.29–0.79), whereas novel oral

  12. Single trans-septal access technique for left atrial intracardiac echocardiography to guide left atrial appendage closure.

    PubMed

    Aguirre, Daniel; Pincetti, Christian; Perez, Luis; Deck, Carlos; Alfaro, Mario; Vergara, Maria Jesus; Maluenda, Gabriel

    2017-08-24

    This registry aimed to describe the safety and feasibility of a single trans-septal (TS) access technique for left intracardiac echocardiography (ICE) guidance of left-atrial appendage (LAA) closure procedure. LAA closure is currently accepted as an alternative to oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (NVAF) who are at high-risk for bleeding. Currently, LAA closure procedure is typically performed under trans-esophageal echocardiogram (TEE) guidance. Although, ICE has the advantage of not requiring profound sedation/anesthesia, ICE-LAA imaging quality is often limited from the right atrium requiring double TS access. Twenty-two patients with NVAF underwent LAA closure using the Amplatzer Amulet™ device (St Jude Medical) under ICE guidance from the left atrium. The ICE AcuNav catheter (Biosense Webster) and the Amulet delivery sheath were advanced into the LA through single TS puncture technique. The population was predominately male (59.1%) with a mean age of 74 ± 9.3 years, at high-risk for stroke (mean CHADS2 score of 3.8 ± 1.1) and bleeding (mean HAS BLED score of 3.5 ± 1.3). The Amplatzer Amulet(TM) device was successfully implanted in all patients. No procedural related complications including device embolization were noted. No major cardiovascular events occurred and all patients were discharged alive. At 30-day follow-up all patients remained alive, free of ischemic stroke and with no residual leak or device thrombus on TEE. This initial experience suggests that LAA occlusion with the Amplatzer Amulet device using ICE guidance from the left atrium via a single trans-septal technique is feasible and safe. © 2017 Wiley Periodicals, Inc.

  13. Morphological features of the left atrial appendage in consecutive coronary computed tomography angiography patients with and without atrial fibrillation

    PubMed Central

    Parkkonen, Johannes; Hedman, Marja; Muuronen, Antti; Onatsu, Juha; Mustonen, Pirjo; Vanninen, Ritva; Taina, Mikko

    2017-01-01

    The majority of intracardiac thrombi form in the left atrial appendage (LAA). Enlargement of this structure, together with certain morphological features, may indicate a predisposition to the formation of thrombi and subsequent cardioembolic stroke. Thus far, studies on LAA morphology have largely focused on those patients with atrial fibrillation (AF). Taking a different approach, we investigated the variation in LAA morphology in a consecutive patient population with and without AF. We evaluated 808 consecutive patients (529 females; mean age 52.5±9.9 years) who underwent coronary artery computed tomography angiography (CCTA), the majority of whom (749) had no history of AF. We assessed the length, lobe number, and morphological classification of their LAAs. Demographic data and medical histories were collated from medical records and then correlated with LAA morphology. The proportions of each of the four morphological classes of LAA for the overall vs. non-AF population were: WindSock, 62.3/61.5%; Cactus, 18.6/18.8%; ChickenWing, 10.0/10.0%; and CauliFlower, 9.2/9.6%. Age (p<0.001; r = 0.156) and female gender (p<0.001) were both found to be associated with an increased body surface area (BSA)-related LAA length. Male patients were more likely to manifest multi-lobed (p = 0.003) LAAs, and overweight patients with a greater number of multi-lobed LAA morphological classes (p = 0.010). No associations with morphological LAA features could be found for patients with diabetes, hypertension, or dyslipidemia. Nor did the size of the left atrium exhibit any correlation with BSA-related LAA length. In the overall and non-AF populations, aging and female gender were associated with longer BSA-indexed LAAs. PMID:28288200

  14. The Amplatzer™ Cardiac Plug 2 for left atrial appendage occlusion: novel features and first-in-man experience.

    PubMed

    Freixa, Xavier; Chan, Jason L K; Tzikas, Apostolos; Garceau, Patrick; Basmadjian, Arsène; Ibrahim, Réda

    2013-01-22

    Percutaneous left atrial appendage (LAA) closure is becoming a frequently performed procedure for patients with atrial fibrillation and high haemorrhagic risk. The Amplatzer™ Cardiac Plug (ACP) is one of the most commonly used devices for this purpose. Despite high success rate and low procedure risk associated with the ACP, a second generation of the device is now available. The new ACP has been designed to facilitate the implantation process, improve sealing performance and further reduce the risk of complications. The present report focuses on the novel features of the second generation of the Amplatzer™ Cardiac Plug (ACP 2 or Amulet™) and describes the first-in-man experience.

  15. The feasibility of tissue Doppler acceleration as a new predictor of thrombogenesis in the left atrial appendage associated with nonvalvular atrial fibrillation.

    PubMed

    Takahashi, Noboru; Nakamura, Yoichi; Komatsu, Sumio; Kusano, Kengo F; Ohe, Tohru

    2008-01-01

    Tissue acceleration utilizing the tissue Doppler imaging (TDI) technique is a new marker of ventricular contraction. We evaluated whether the left atrial appendage (LAA) wall acceleration was associated with thrombosis in patients with nonvalvular atrial fibrillation (NVAF). Seven NVAF patients with thromboembolism (TE), eight without TE, and eight with normal sinus rhythm (NSR) were studied using transesophageal echocardiography. TDI was used to evaluate the LAA wall acceleration. There was a decrease in the peak flow velocity in the TE group compared with the other two groups. There was greater LAA expansion in NVAF with TE groups (with TE [8.9 +/- 2.1 cm(2)] compared with the group without TE [7.3 +/- 2.8 cm(2)]), but the difference was not statistically significant; the difference was statistically significant compared with the NSR group (5.3 +/- 1.2 cm(2); P = 0.0035). The average of the continuous 40-frames area where tissue Doppler acceleration (TDA) was >0.024 cm/sec(2) was significantly lower in the TE group (0.12 +/- 0.05 cm(2)) compared to the group without TE (0.33 +/- 0.17 cm(2); P = 0.0017) and NSR group (0.30 +/- 0.13 cm(2); P = 0.0042), although wall velocity was not significantly different comparing the two NVAF groups. Furthermore, peak flow velocity of LAA was well correlated with LAA wall acceleration (r = 0.864, P < 0.0001). LAA wall acceleration obtained utilizing the TDI technique may be a new predictor of thrombogenesis in patients with NVAF.

  16. Left atrial appendage closure using the Amulet device: an initial experience with the second generation amplatzer cardiac plug.

    PubMed

    Lam, Simon Cheung Chi; Bertog, Stefan; Gafoor, Sameer; Vaskelyte, Laura; Boehm, Patrick; Ho, Raymond Wei Jian; Franke, Jennifer; Hofmann, Ilona; Sievert, Horst

    2015-02-01

    Aim of this study was to demonstrate the feasibility, safety, and short-term outcome of left atrial appendage (LAA) closure with a new generation LAA closure device. The Amulet device (AGA, St Jude Medical, Minneapolis, MN) is a new generation of the amplatzer cardiac plug (ACP), specifically designed for LAA closure. This new version is designed to facilitate the implantation process and minimize procedural or device-related complications. The device was implanted in 17 patients with nonvalvular atrial fibrillation (AF). Clinical data were obtained at baseline, during the procedure, at discharge, at 30 and 90 days. All devices were implanted successfully. Device sizes ranged from 20 mm to 31 mm. A 12 French (Fr) or 14 Fr delivery sheath was used depending on the selected device size. Full and partial recapture was performed in 1 case and 3 cases, respectively. There was 1 procedure-related pericardial effusion successfully managed with pericardiocentesis. There was no device embolization. The mean length of stay was 2.1 ± 0.3 days. At 90 days, there were no deaths, strokes, systemic thromboembolism, or bleeding complications. There was no device-related thrombus or pericardial effusion at 90-day TEE. In 2 of the 17 patients minimal peridevice flow (smaller than 2 mm) was present. The Amulet device, which has new novel features as compared with the first generation ACP, is a feasible option for LAA closure. From our initial experience, implantation of the Amulet is associated with high success rate and good short-term outcome. © 2014 Wiley Periodicals, Inc.

  17. A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure

    PubMed Central

    Chow, Danny HF; Bieliauskas, Gintautas; Sawaya, Fadi J; Millan-Iturbe, Oscar; Kofoed, Klaus F; Søndergaard, Lars; De Backer, Ole

    2017-01-01

    Objectives Accurate sizing of the left atrial appendage (LAA) is essential when performing percutaneous LAA closure. This study aimed to compare different LAA imaging modalities and sizing methods in order to obtain successful LAA closure. Background Percutaneous LAA closure is an increasingly used treatment strategy to prevent stroke in patients with atrial fibrillation. LAA sizing has typically been done by 2D-transoesophageal echocardiography (TEE). Methods Patients who had a preprocedural TEE and preprocedural and postprocedural multislice CT (MSCT) were identified. Preprocedural measurements of LAA ostia and landing zones by 2D-TEE, MSCT and angiography were collected and analysed for those patients with successful LAA closure - i.e. with no contrast leakage at 3-month follow-up MSCT. Results The study population (n=67) had a mean CHA2DS2-VASc score of 3.0 and HAS-BLED score of 2.7. Fifty-eight patients (87%) were identified to have successful LAA closure. Based on MSCT, 48 LAA sizings (83%) resulted in a correct LAA closure device size selection, whereas with 2D-TEE sizing, only 33 measurements (57%) would have resulted in a correct device size selection (p<0.01). Using adapted Bland-Altman method, MSCT-based perimeter-derived mean diameter was shown to be the best parameter to guide LAA device size selection for ‘closed-end’ devices (Amulet, WatchmanFLX), whereas the maximal diameter was the best parameter for the ‘open-end’ Watchman device. Conclusions Preprocedural MSCT-based LAA closure device size selection proves to be a more accurate method than conventional 2D-TEE-based sizing. Depending on the LAA closure device design, perimeter-derived mean diameter or maximal diameter could be the better sizing method. PMID:28761682

  18. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure

    PubMed Central

    Saw, Jacqueline; Fahmy, Peter; DeJong, Peggy; Lempereur, Mathieu; Spencer, Ryan; Tsang, Michael; Gin, Kenneth; Jue, John; Mayo, John; McLaughlin, Patrick; Nicolaou, Savvas

    2015-01-01

    Aims Left atrial appendage (LAA) device imaging after endovascular closure is important to assess for device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion. Cardiac CT angiography (CCTA) is well suited to assess these non-invasively. Methods and results We report our consecutive series of non-valvular atrial fibrillation patients who underwent CCTA post-LAA closure with Amplatzer Cardiac Plug (ACP), Amulet (second generation ACP), or WATCHMAN devices. Patients underwent CCTA typically 1–6 months post-implantation. Prospective cardiac-gated CCTA was performed with Toshiba 320-detector or Siemens 2nd generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation™. GFR <30 mL/min/1.73 m2 was an exclusion. We assessed for device thrombus, residual LAA leak, device embolization, position, pericardial effusion, optimal implantation, and device lobe dimensions. Forty-five patients underwent CCTA at median 97 days post-LAA closure (18 ACP, 9 Amulet, 18 WATCHMAN). Average age was 75.5 ± 8.9 years, mean CHADS2 score 3.1 ± 1.3, and CHADS-VASc score 4.9 ± 1.6. All had contraindications to oral anticoagulation. Post-procedure, 41 (91.1%) were discharged on DAPT. There was one device embolization (ACP, successfully retrieved percutaneously) and one thrombus (WATCHMAN, resolved with 3 months of warfarin). There were two pericardial effusions, both pre-existing and not requiring intervention. Residual leak (patency) was seen in 28/44 (63.6%), and the mechanisms of leak were readily identified by CCTA (off-axis device, gaps at orifice, or fabric leak). Mean follow-up was 1.2 ± 1.1year, with no death, stroke, or systemic embolism. Conclusion CCTA appears to be a feasible alternative to transoesophageal echocardiography for post-LAA device surveillance to evaluate for device thrombus, residual leak, embolization, position, and pericardial effusion. PMID:25851318

  19. A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure.

    PubMed

    Chow, Danny Hf; Bieliauskas, Gintautas; Sawaya, Fadi J; Millan-Iturbe, Oscar; Kofoed, Klaus F; Søndergaard, Lars; De Backer, Ole

    2017-01-01

    Accurate sizing of the left atrial appendage (LAA) is essential when performing percutaneous LAA closure. This study aimed to compare different LAA imaging modalities and sizing methods in order to obtain successful LAA closure. Percutaneous LAA closure is an increasingly used treatment strategy to prevent stroke in patients with atrial fibrillation. LAA sizing has typically been done by 2D-transoesophageal echocardiography (TEE). Patients who had a preprocedural TEE and preprocedural and postprocedural multislice CT (MSCT) were identified. Preprocedural measurements of LAA ostia and landing zones by 2D-TEE, MSCT and angiography were collected and analysed for those patients with successful LAA closure - i.e. with no contrast leakage at 3-month follow-up MSCT. The study population (n=67) had a mean CHA2DS2-VASc score of 3.0 and HAS-BLED score of 2.7. Fifty-eight patients (87%) were identified to have successful LAA closure. Based on MSCT, 48 LAA sizings (83%) resulted in a correct LAA closure device size selection, whereas with 2D-TEE sizing, only 33 measurements (57%) would have resulted in a correct device size selection (p<0.01). Using adapted Bland-Altman method, MSCT-based perimeter-derived mean diameter was shown to be the best parameter to guide LAA device size selection for ‘closed-end’ devices (Amulet, WatchmanFLX), whereas the maximal diameter was the best parameter for the ‘open-end’ Watchman device. Preprocedural MSCT-based LAA closure device size selection proves to be a more accurate method than conventional 2D-TEE-based sizing. Depending on the LAA closure device design, perimeter-derived mean diameter or maximal diameter could be the better sizing method.

  20. Far field R-wave sensing in Myotonic Dystrophy type 1: right atrial appendage versus Bachmann's bundle region lead placement.

    PubMed

    Russo, Vincenzo; Nigro, Gerardo; Antonio Papa, Andrea; Rago, Anna; Di Meo, Federica; Cristiano, Anna; Molino, Antonio; Calabrò, Raffaele; Giovanna Russo, Maria; Politano, Luisa

    2014-10-01

    Aim of the present study was to investigate far field R-wave sensing (FFRS) timing and characteristics in 34 Myotonic Dystrophy type 1 (DM1) patients undergoing dual chamber pacemaker implantation, comparing Bachmann's bundle (BB) stimulation (16 patients) site with the conventional right atrial appendage (RAA) pacing site (18 patients). All measurements were done during sinus rhythm and in supine position, with unipolar (UP) and bipolar (BP) sensing configuration. The presence, amplitude threshold (FFRS trsh) and FFRS timing were determined. There were no differences between both atrial sites in the Pmin and Pmean values of sensed P-wave amplitudes, as well as between UP and BP sensing configurations. The FFRS trsh was lower at the BB region in comparison to the RAA site. The mean BP FFRS trsh was significantly lower than UP configuration in both atrial locations. There were no significant differences in atrial pacing threshold, sensing threshold and atrial lead impedances at the implant time and at FFRS measurements. Bachmann's bundle area is an optimal atrial lead position for signal sensing as well as conventional RAA, but it offers the advantage of reducing the oversensing of R-wave on the atrial lead, thus improving functioning of standard dual chamber pacemakers in DM1 patients.

  1. The chicken-wing morphology: an anatomical challenge for left atrial appendage occlusion.

    PubMed

    Freixa, Xavier; Tzikas, Apostolos; Basmadjian, Arsène; Garceau, Patrick; Ibrahim, Rèda

    2013-10-01

    To describe the particular assessment and closure strategy that was followed in patients with left atrial appendages (LAA) with an early and severe bend. The presence of a chicken-wing morphology with an early and severe bend constitutes one of the most difficult anatomical settings for transcatheter LAA occlusion. Between November 2009 and December 2012, patients who presented chicken-wing LAA with an early (<20 mm from the ostium) and severe bend (<180°) were identified and included in the analysis. A particular implanting strategy consisting of deploying the distal lobe of the device inside the chicken-wing bend was used in all cases. Among 42 patients who underwent LAA occlusion during the study period, 5 (12%) presented the pre-specified anatomy. Following the mentioned implanting strategy, all patients underwent successful LAA occlusion using the Amplatzer Cardiac Plug (n = 2) and the Amplatzer Amulet (n = 3). Successful occlusion was achieved in all patients. None of them presented any procedural complication. Follow-up transesophageal echocardiography at 3 months showed successful LAA sealing in all patients and no device embolization or thrombosis. According to our results, the pre-specified closing implantation technique for chicken-wing LAAs with an early and severe bend might be a valid strategy for this challenging anatomical setting. Further cases will be necessary to confirm the results. © 2013, Wiley Periodicals, Inc.

  2. Concentrations of teicoplanin in serum and atrial appendages of patients undergoing cardiac surgery.

    PubMed Central

    Bergeron, M G; Saginur, R; Desaulniers, D; Trottier, S; Goldstein, W; Foucault, P; Lessard, C

    1990-01-01

    The concentrations of teicoplanin in sera and heart tissues of 49 patients undergoing coronary bypass were measured. Each patient received a 6- or 12-mg/kg dose of teicoplanin administered in a slow intravenous bolus injection over 3 to 5 min beginning at the time of induction of anesthesia. Mean +/- standard error of the mean concentrations in serum were, for the two doses, respectively, 58.1 +/- 1.7 and 123.3 +/- 7.4 micrograms/ml 5 min after administration and 22.2 +/- 0.7 and 56.5 +/- 2.8 micrograms/ml at the time of removal of atrial appendages. Mean +/- standard error of the mean concentrations in tissue were 70.6 +/- 1.7 and 139.8 +/- 2.2 micrograms/g, respectively, giving mean tissue/serum ratios of 3.7 +/- 0.3 and 2.8 +/- 0.2, respectively. Teicoplanin penetrates heart tissue readily and reaches levels in the serum far in excess of the MICs for most pathogens that have been found to cause infections following open heart surgery. PMID:2149493

  3. Predictors of Early (1-Week) Outcomes Following Left Atrial Appendage Closure With Amplatzer Devices.

    PubMed

    Koskinas, Konstantinos C; Shakir, Samera; Fankhauser, Máté; Nietlispach, Fabian; Attinger-Toller, Adrian; Moschovitis, Aris; Wenaweser, Peter; Pilgrim, Thomas; Stortecky, Stefan; Praz, Fabien; Räber, Lorenz; Windecker, Stephan; Meier, Bernhard; Gloekler, Steffen

    2016-07-11

    The aim of this study was to assess predictors of adverse 1-week outcomes and determine the effect of left atrial appendage (LAA) morphology following LAA closure (LAAC) with Amplatzer devices. Percutaneous LAAC is a valuable treatment option for stroke prevention in patients with atrial fibrillation. Determinants of procedural safety events with Amplatzer occluders are not well established, and the possibly interrelating effect of LAA anatomy is unknown. Between 2009 and 2014, 500 consecutive patients with atrial fibrillation ineligible or at high risk for oral anticoagulation underwent LAAC using Amplatzer devices. Procedure- and device-related major adverse events (MAEs) were defined as the composite of death, stroke, major or life-threatening bleeding, serious pericardial effusion, device embolization, major access-site vascular complication, or need for cardiovascular surgery within 7 days following the intervention. Patients (mean age 73.9 ± 10.1 years) were treated with Amplatzer Cardiac Plug (n = 408 [82%]) or Amulet (n = 92 [18%]) devices. Early procedural success was 97.8%, and MAEs occurred in 29 patients (5.8%). Independent predictors of MAEs included device repositioning (odds ratio: 9.13; 95% confidence interval: 2.85 to 33.54; p < 0.001) and left ventricular ejection fraction <30% (odds ratio: 4.08; 95% confidence interval: 1.49 to 11.20; p = 0.006), with no effect of device type or size. Angiographic LAA morphology, characterized as cauliflower (33%), cactus (32%), windsock (20%), or chicken wing (15%), was not associated with procedural success (p = 0.51) or the occurrence of MAEs (p = 0.78). In this nonrandomized study, procedural success of LAAC using Amplatzer devices was high. MAEs within 7 days were predicted by patient- and procedure-related factors. Although LAA morphology displayed substantial heterogeneity, outcomes were comparable across the spectrum of LAA anatomies. Copyright © 2016 American College of Cardiology Foundation

  4. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure.

    PubMed

    Saw, Jacqueline; Fahmy, Peter; DeJong, Peggy; Lempereur, Mathieu; Spencer, Ryan; Tsang, Michael; Gin, Kenneth; Jue, John; Mayo, John; McLaughlin, Patrick; Nicolaou, Savvas

    2015-11-01

    Left atrial appendage (LAA) device imaging after endovascular closure is important to assess for device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion. Cardiac CT angiography (CCTA) is well suited to assess these non-invasively. We report our consecutive series of non-valvular atrial fibrillation patients who underwent CCTA post-LAA closure with Amplatzer Cardiac Plug (ACP), Amulet (second generation ACP), or WATCHMAN devices. Patients underwent CCTA typically 1-6 months post-implantation. Prospective cardiac-gated CCTA was performed with Toshiba 320-detector or Siemens 2nd generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation™. GFR <30 mL/min/1.73 m(2) was an exclusion. We assessed for device thrombus, residual LAA leak, device embolization, position, pericardial effusion, optimal implantation, and device lobe dimensions. Forty-five patients underwent CCTA at median 97 days post-LAA closure (18 ACP, 9 Amulet, 18 WATCHMAN). Average age was 75.5 ± 8.9 years, mean CHADS2 score 3.1 ± 1.3, and CHADS-VASc score 4.9 ± 1.6. All had contraindications to oral anticoagulation. Post-procedure, 41 (91.1%) were discharged on DAPT. There was one device embolization (ACP, successfully retrieved percutaneously) and one thrombus (WATCHMAN, resolved with 3 months of warfarin). There were two pericardial effusions, both pre-existing and not requiring intervention. Residual leak (patency) was seen in 28/44 (63.6%), and the mechanisms of leak were readily identified by CCTA (off-axis device, gaps at orifice, or fabric leak). Mean follow-up was 1.2 ± 1.1year, with no death, stroke, or systemic embolism. CCTA appears to be a feasible alternative to transoesophageal echocardiography for post-LAA device surveillance to evaluate for device thrombus, residual leak, embolization, position, and pericardial effusion. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015

  5. Early Canadian Multicenter Experience With WATCHMAN for Percutaneous Left Atrial Appendage Closure.

    PubMed

    Saw, Jacqueline; Fahmy, Peter; Azzalini, Lorenzo; Marquis, Jean-Francois; Hibbert, Benjamin; Morillo, Carlos; Carrizo, Aldo; Ibrahim, Reda

    2017-04-01

    There are limited data with WATCHMAN (Boston Scientific Corporation, Natick, MA, USA) for left atrial appendage (LAA) closure in patients with nonvalvular atrial fibrillation (AF) and contraindications to anticoagulation. The purpose of this study was to evaluate the safety and efficacy of WATCHMAN in our early Canadian experience. We report our pooled consecutive series of patients who underwent WATCHMAN implantation at four major Canadian centers. Indications for LAA closure were CHADS2 ≥ 1 or CHA2 DS2 -VASc ≥ 2, and contraindication/intolerance to or failure on anticoagulation. Follow-up imaging was typically performed 1-6 months postprocedure. One hundred and six patients underwent LAA closure with WATCHMAN from May 2013 to October 2015. The mean age was 74.8 ± 7.7, mean CHADS2 score was 2.8 ± 1.2, CHA2 DS2 -VASc score was 4.3 ± 1.5, and HASBLED score was 3.2 ± 1.2. Permanent AF was present in 67.9% and paroxysmal AF in 32.1%. Indications for LAA closure were prior bleeding 89.6% (87 major bleeding and 8 minor bleeding), 9.4% were deemed high risk for bleeding, and 0.9% with recurrent strokes on warfarin. Procedural success was 97.2% (103 of 106), with one device embolization (snared percutaneously), one implant failure due to inadequate LAA depth, and one cardiac perforation requiring surgical repair before WATCHMAN implantation. The composite major safety event-rate was 1.9% (1 death and 1 device embolization). Mean hospital stay was 1.8 ± 4.7 days. Antithrombotic therapy postimplant included dual antiplatelet therapy in 76 of 103 (73.8%). Mean follow-up was 210 ± 182 days; there were two transient ischemic attacks, with estimated 66% reduction in thromboembolic events relative to CHADS2 predicted risk. In our early Canadian experience, WATCHMAN for LAA closure in patients contraindicated to anticoagulation appeared safe and effective. © 2017 Wiley Periodicals, Inc.

  6. Percutaneous left atrial appendage occlusion procedures in patients with heart failure.

    PubMed

    Szymała, Magdalena; Streb, Witold; Mitręga, Katarzyna; Podolecki, Tomasz; Mencel, Grzegorz; Kukulski, Tomasz; Kalarus, Zbigniew

    2017-01-01

    Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia. Percutaneous left atrial appendage occlusion (LAAO) may be considered for stroke prophylaxis in patients with nonvalvular AF (NVAF), especially in contraindications for oral anticoagulants (OAC) or high risk of bleeding. The data about implantation, safety, efficacy, and follow-up are limited. Moreover, there are no studies on patients with NVAF and heart failure with severe left ventricular systolic dysfunction (left ventricular ejection fraction [LVEF] ≤ 35%). To assess the safety, efficacy, and mid-term outcomes of LAAO procedures with Amplatzer Cardiac Plug (ACP) and Amplatzer Amulet device in patients with NVAF and heart failure with LVEF ≤ 35% (group I) and to perform a comparative analysis of the patients who had LAAO with NVAF and LVEF > 35%. The analysis included 80 patients (group I: 19, group II: 61) with NVAF. The patients were enrolled for the study if they had: CHA2DS2VASc ≥ 2 and high risk of bleeding assessed in HAS-BLED (≥ 3) or less points in HAS-BLED but coexisting contraindications for OAC, or thromboembolic complications while using OAC. Time of follow-up was six months. In the studied population, the median CHA2DS2VASc score was 4 and the average HAS-BLED score was 3.2. Device implantation was successful in all patients from group I and in 59/61 patients from group II. The periprocedural clinical ef-ficacy (no thromboembolic complications) was 100% in group I and 98.4% in group II. Serious periprocedural complications (cardiac tamponade: 2.5%, device embolisation: 1.25%, unexplained death: 1.25%) occurred only in patients from group II (p = NS). The mid-term clinical efficacy was 100% in group I and 98.3% in group II (p = NS). During follow-up, one transient ischaemic attack and three deaths not related to the procedure occurred. Percutaneous LAAO is an effective and safe procedure in patients with NVAF and severe systolic heart failure. No significant

  7. Interventional left atrial appendage occlusion: added value of 3D transesophageal echocardiography for device sizing.

    PubMed

    Goebel, Björn; Wieg, Stephanie; Hamadanchi, Ali; Otto, Sylvia; Jung, Christian; Kretzschmar, Daniel; Figulla, Hans R; Christian Schulze, P; Poerner, Tudor C

    2016-09-01

    Aim of this study was the assessment of left atrial appendage (LAA) dimensions comparing 2D- to 3D-TEE measurements in patients with nonvalvular atrial fibrillation undergoing percutaneous LAA occlusion. Patients underwent transesophageal echocardiography (TEE) before, during and 45 days after intervention. The maximal LAA orifice diameters in 2D-TEE (LODmax 2D) were obtained from multiple views. Test-retest reliability (screening vs. implantation), inter- and intra-observer variability for echocardiographic parameters were assessed by two independent examiners. Overall, 74 patients underwent percutaneous LAA occlusion. 2D-TEE significantly underestimated the maximal LAA orifice diameter compared with 3D-TEE (screening LODmax 2D 21.11 ± 2.75 mm vs. 22.52 ± 3.45 mm for LODmax 3D, p < 0.001; during implantation LODmax 2D 21.56 ± 3.48 mm vs. 22.99 ± 3.24 mm for LODmax 3D, p < 0.001). The intraobserver and interobserver variability calculated as coefficient of variation (CV) were both lower for the 3D-TEE quantification of the maximal orifice diameter (intraobserver CV for 3D-TEE 6.07 % vs. 9.31 % for 2D-TEE; interobserver CV for 3D-TEE 6.73 % vs. 9.69 % for 2D-TEE). Compared to 3D-TEE the test-retest reliability of 2D-TEE showed a lower intraclass correlation coefficient calculated as average of raters (0.92 for 3D-TEE vs. for 2D-TEE 0.78). Firstly, 2D-TEE significantly underestimates the maximal LAA orifice diameter compared to 3D-TEE. Secondly, 3D-TEE measurements are associated with a lower observer variability and higher reliability than 2D-TEE.

  8. Cardiac CT Angiography (CCTA) predicts left atrial appendage occluder device size and procedure outcome.

    PubMed

    Goitein, Orly; Fink, Noam; Hay, Ilan; Di Segni, Elio; Guetta, Victor; Goitein, David; Brodov, Yafim; Konen, Eli; Glikson, Michael

    2017-05-01

    To investigate the role of cardiac CT angiography (CCTA) in predicting optimal left atrial appendage (LAA) occluder size and procedure outcome. Thirty-six patients underwent pre-procedural CCTA. CCTA and TEE LAA orifice diameters and perimeters were compared with the implanted device size. CCTA 3D configuration was correlated with procedure outcome. Watchman™ device (N = 18): diameters were 21 ± 4, 26 ± 5 and 25 ± 3 mm for TEE, CCTA and inserted device, respectively. Average perimeters were 61 ± 10, 74 ± 8 and 78 ± 11 mm for TEE, CCTA and inserted device, respectively. Better agreement with the device size was found for CCTA compared to TEE (Bland-Altman). ACP™ device (N = 15): diameters were 20 ± 5, 25 ± 4 and 23 ± 4 for TEE, CCTA and inserted device, respectively. Average perimeters were 58 ± 11, 72 ± 15 and 72 ± 13 mm for TEE, CCTA and inserted device, respectively. Excellent correlation and agreement with the device size was found for CCTA compared to TEE. CCTA perimeter >100 mm and "cactus" 3D configuration had a specificity of 96 and 81% respectively for procedure failure. CCTA LAA ostial perimeter predicted better the optimal occluder size as compared with the currently used LAA TEE diameter. Moreover, CCTA 3D data may help in predicting potential complications.

  9. Echocardiographic guidance and monitoring of left atrial appendage closure with AtriClip during open-chest cardiac surgery.

    PubMed

    Contri, Rachele; Clivio, Sara; Torre, Tiziano; Cassina, Tiziano

    2017-09-12

    Left atrial appendage (LAA) closure prevents thromboembolic risk and avoids lifelong anticoagulation due to atrial fibrillation (AF). Nowadays, AtriClip, a modern epicardial device approved in June 2010, allows external and safe closure of LAA in patients undergoing cardiac surgery during other open-chest cardiac surgical procedures. Such a surgical approach and its epicardial deployment differentiates LAA closure with AtriClip from percutaneous closure techniques such as Watchman (Boston Scientific, Marlborough, MA, USA), Lariat (SentreHEART Inc., Redwood City, CA, USA), and Amplatzer Amulet (St. Jude Medical, St. Paul, MN, USA) device procedures. AtriClip positioning must consider perioperative transesophageal echocardiography (TEE) to confirm LAA anatomical features, to explore the links with neighboring structures, and finally to assess its successful closure. We report a sequence of images to document the role of intraoperative TEE during an elective aortic valve replacement and LAA external closure with AtriClip. © 2017, Wiley Periodicals, Inc.

  10. Intracardiac versus transesophageal echocardiography for left atrial appendage occlusion with watchman.

    PubMed

    Frangieh, Antonio H; Alibegovic, Jasmina; Templin, Christian; Gaemperli, Oliver; Obeid, Slayman; Manka, Robert; Holy, Erik W; Maier, Willibald; Lüscher, Thomas F; Binder, Ronald K

    2017-08-01

    Left atrial appendage occlusion (LAAO) is mostly performed by transesophageal echocardiography (TEE) guidance. Intracardiac echocardiography (ICE) may be an alternative imaging modality for LAAO that precludes the need for general anesthesia or sedation. All consecutive single center, single operator LAAO candidates were analyzed. Baseline clinical and procedural characteristics and in-hospital outcomes were compared between patients in whom a Watchman was implanted with ICE vs. TEE guidance. In 76 consecutive patients the Watchman device was deployed under ICE in 32 patients (42%) and under TEE guidance in 44 patients (58%). Baseline characteristics were comparable between groups, except that patients in the TEE group were older (81 [75-85] years vs. 75 [68-80] years, P = 0.007). Total injected contrast media as well as fluoroscopy time were comparable between groups (90 ml [54-140] vs. 85 ml [80-110], P = 0.86 and 7.9 min [6.4-15.5] vs. 9.8 min [7.0-13.2], P = 0.51, for TEE vs. ICE, respectively). However, time from femoral venous puncture to transseptal puncture and to closure was longer in the ICE group (14 min [7.3-20] vs. 6 min [3.3-11], P = 0.007 and 48 min [40-60] vs. 34.5 min [27-44], P = 0.003, respectively). In the TEE group one patient suffered esophageal erosion with bleeding, which was managed conservatively and one non-LAAO related in-hospital mortality occurred in an 88-year-old patient. Device implantation success rate was 100% in both groups. No device embolization, no significant peri-device leak, no tamponade, no stroke, and no access site bleeding occurred in any patient. Total hospital stay for stand-alone LAAO was comparable between groups (2 days [2-2] vs. 2 days [2-3.3], P = 0.17, in ICE vs. TEE, respectively). ICE guidance for LAAO with the Watchman device is feasible and comparable to TEE and may become the preferred imaging modality for LAAO. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Comparing Measurements of CT Angiography, TEE, and Fluoroscopy of the Left Atrial Appendage for Percutaneous Closure.

    PubMed

    Saw, Jacqueline; Fahmy, Peter; Spencer, Ryan; Prakash, Roshan; McLaughlin, Patrick; Nicolaou, Savvas; Tsang, Michael

    2016-04-01

    Left atrial appendage (LAA) closure requires accurate preprocedural measurements, and trans-esophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) and fluoroscopy can be utilized. However, correlations between these measurements remain inadequately assessed. Patients who underwent LAA closure at Vancouver General Hospital who had baseline LAA measurements by CCTA, TEE, and fluoroscopy were included in this analysis. CCTAs were performed with prospective-ECG-gating with Toshiba 320-detector or Siemens second generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation.™ LAA maximal dimensions were obtained for all patients at: (1) Amplatzer Cardiac Plug (ACP)/Amulet landing zone 10 mm within orifice, (2) WATCHMAN ostium, and (3) WATCHMAN depth measurements. Correlations and agreements were compared. We report 50 consecutive patients who underwent LAA closure (8 ACP, 10 Amulet, 32 WATCHMAN). Average age was 75.2 ± 8.7 years, mean CHADS2 score 3.0 ± 1.3, and CHA2 DS2 -VASc 4.7 ± 1.5. Procedural device implantation success was 100%. For ACP landing zone, mean maximal measurements were 24.1 ± 4.7 mm with CCTA, 22.3 ± 4.9 mm TEE, and 19.9 ± 5.6 mm fluoroscopy (P < 0.001); R value 0.81 fluoroscopy/CTA, 0.67 fluoroscopy/TEE, and 0.80 CTA/TEE. For WATCHMAN ostium, mean maximal measurements were 25.8 ± 4.7 mm CCTA (P < 0.001 vs. fluoroscopy, P = 0.16 vs. TEE), 25.1 ± 4.4 mm TEE (P = 0.016 vs. fluoroscopy), and 23.8 ± 4.9 mm fluoroscopy; R value 0.71 fluoroscopy/CTA, 0.65 fluoroscopy/TEE, and 0.74 CTA/TEE. Depth measurements were 34.3 ± 5.7 mm with CCTA, 31.1 ± 6.5 mm TEE, and 27.8 ± 7.1 mm fluoroscopy (all P < 0.01); and correlations with R value 0.28 fluoroscopy/CTA, 0.22 fluoroscopy/TEE, and 0.56 CTA/TEE. All 3 imaging modalities correlated with ACP landing zone and WATCHMAN ostium measurements, with CCTA providing the largest measurements, followed by TEE and fluoroscopy. © 2016 Wiley Periodicals, Inc.

  12. Resolution of massive left atrial appendage thrombi with rivaroxaban before balloon mitral commissurotomy in severe mitral stenosis

    PubMed Central

    Li, Yuechun; Lin, Jiafeng; Peng, Chen

    2016-01-01

    Abstract Rationale: Data on nonvitamin K antagonist oral anticoagulant being used for the treatment of LAA thrombi are limited only in nonvalvular atrial fibrillation. There are no data on the antithrombotic efficacy and safety of nonvitamin K antagonist oral anticoagulant in the resolution of left atrial appendage (LAA) thrombi in patients with rheumatic mitral stenosis. Patient concerns: A 49-year-old woman with known rheumatic mitral stenosis and atrial fibrillation was referred for percutaneous transvenous mitral commissurotomy because of progressive dyspnea on exertion over a period of 3 months. Diagnoses: Transesophageal echocardiography (TEE) demonstrated a large LAA thrombus protruding into left atria cavity before the procedure. Interventions: Direct factor Xa (FXa) inhibitor rivaroxaban (20 mg/d) was started for the patient. After 3 weeks of rivaroxaban treatment TEE showed a relevantly decreased thrombus size, and a complete thrombus resolution was achieved after 5 weeks of anticoagulant therapy with the FXa inhibitor. Outcomes: To the best of our knowledge, this is the first documented case of large LAA thrombus resolution with nonvitamin K antagonist oral anticoagulant in severe mitral stenosis, and in which percutaneous transvenous mitral commissurotomy was performed subsequently. Lessons: The report indicated that rivaroxaban could be a therapeutic option for mitral stenosis patients with LAA thrombus. Further study is required before the routine use of rivaroxaban in patients with rheumatic mitral stenosis and atrial fibrillation. PMID:27930571

  13. Left atrial appendage occlusion with the AMPLATZER Amulet device: an expert consensus step-by-step approach.

    PubMed

    Tzikas, Apostolos; Gafoor, Sameer; Meerkin, David; Freixa, Xavier; Cruz-Gonzalez, Ignacio; Lewalter, Thorsten; Saw, Jacqueline; Berti, Sergio; Nielsen-Kudsk, Jens Erik; Ibrahim, Reda; Lakkireddy, Dhanunjaya; Paul, Vincent; Arzamendi, Dabit; Nietlispach, Fabian; Worthley, Stephen G; Hildick-Smith, David; Thambo, Jean Benoit; Tondo, Claudio; Aminian, Adel; Kalarus, Zbigniew; Schmidt, Boris; Sondergaard, Lars; Kefer, Joelle; Meier, Bernhard; Park, Jai-Wun; Sievert, Horst; Omran, Heyder

    2016-04-20

    This document aims to describe a standardised methodology for performing left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device, and to provide useful tips and tricks for operators with different levels of experience. Physicians who are experts in LAAO and had personal clinical experience with the AMPLATZER Amulet device were asked to contribute in the preparation of this consensus document. Twenty-seven physicians (20 interventional cardiologists and 7 electrophysiologists) from 14 different countries reviewed the manuscript. A step-by-step approach, simulating a real case, was followed. Starting with patient selection and planning, related cardiac imaging is discussed, followed by vascular access - transseptal puncture optimisation. Then, angiographic calibration/sizing and the required fluoroscopy views are explained and a device sizing strategy is proposed. Device preparation and de-airing is briefly described, followed by sheath exchange, device deployment steps, evaluation of device stability and decision for final release. The way to recapture and change a device is then shown, together with some additional tips on how to deal with challenging anatomies like "chicken wing" left atrial appendage. Finally, for operators who are switching from AMPLATZER Cardiac Plug to Amulet, the main differences between the two devices with respect to implantation technique are presented. In conclusion, this document reflects a consensus approach by expert implanters on the steps of LAAO technique and best practices for implantation of the AMPLATZER Amulet device, along with some practical tips to minimise the complication rate.

  14. Potential uselessness and futility of left atrial appendage occlusion and patent foramen ovale closure in cardioembolic stroke.

    PubMed

    Nicolosi, Gian L

    2017-02-16

    International guidelines indicate that interventional closure of left atrial appendage and patent foramen ovale may be considered in selected patients for stroke prevention. These procedures appear, however, from the published literature, at high risk of uselessness and futility in the single case, if not even capable to induce harm and adverse events. In fact, all reported systematic reviews and meta-analyses have not shown in a convincing manner the superiority of these procedures in stroke prevention, taking into account the occurrence of possible complications also, as compared with alternative medical treatment. On the basis of these considerations, it becomes very difficult to define always and unequivocally how adequate and complete was the information when given to each single candidate patient before the procedure by the Heart Team, the left atrial appendage occlusion Team or patent foramen ovale closure Team, potentially involved in conflict of interest. Before indicating these procedures, a complete diagnostic work-up should then be planned for each single patient to identify and treat not only one, but all concomitant risk factors and potential different cardioembolic sources. It could also be suggested to have, for each single candidate patient, a second independent opinion from physicians not involved in the procedure and possibly not operating in the same institution. This prudential approach could reduce in each single case the risk of uselessness, futility and even potential harm and adverse events of those procedures.

  15. Differences in atrial fibrillation-associated proteins between the left and right atrial appendages from patients with rheumatic mitral valve disease: A comparative proteomic analysis

    PubMed Central

    Liu, Hai; Chen, Guangxian; Zheng, Hongsheng; Qin, Han; Liang, Mengya; Feng, Kangni; Wu, Zhongkai

    2016-01-01

    The majority of proteomic studies have focused on identifying atrial fibrillation (AF)-associated proteins in the right atrium (RA), thus potential differences in AF-associated proteins between the RA and left atrium (LA) remain unknown. The aim of the present study was to perform proteomic analysis to compare the potential differences in AF-associated proteins between the right atrial appendage (RAA) and left atrial appendage (LAA) in patients with rheumatic mitral valve disease (RMVD). RAA and LAA tissues were obtained from 18 patients with RMVD (10 with AF) during mitral valve replacement surgery. Two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) proteomics analysis was performed using these tissues to identify AF-associated proteins in RAA and LAA. Subsequently, the proteomics data was validated using western blot analysis of nine selected proteins. In RAA, 32 AF-associated proteins were significantly dysregulated (15 upregulated and 17 downregulated). In LAA, 31 AF-associated proteins were significantly dysregulated (13 upregulated and 18 downregulated). Among these AF-associated proteins, 17 were AF-associated in both RAA and LAA, 15 were AF-associated only in RAA, and 14 were AF-associated only in LAA. Amongst the differentially expressed proteins, western blot analysis validated the results for 6 AF-associated proteins, and demonstrated similar distributions in RAA and LAA compared with the 2-D DIGE results. Of these proteins, 2 proteins were AF-associated in both RAA and LAA, 2 were AF-associated only in RAA, and 2 were AF-associated only in LAA. Additionally, the different distributions of AF-associated proteins in the RAA and LAA of patients with RMVD was analyzed, which may reflect the different regulatory mechanisms of the RA and LA in AF. These findings may provide new insights into the underlying molecular mechanisms of AF in patients with RMVD. PMID:27667121

  16. Limb ischemia, an alarm signal to a thromboembolic cascade - renal infarction and nephrectomy followed by surgical suppression of the left atrial appendage.

    PubMed

    Caraşca, Cosmin; Borda, Angela; Incze, Alexandru; Caraşca, Emilian; Frigy, Attila; Suciu, HoraŢiu

    2016-01-01

    We present the case of a 55-year-old male with mild hypertension and brief episodes of paroxysmal self-limiting atrial fibrillation (AF) since 2010. Despite a small cardioembolic risk score, CHA2DS2-Vasc=1 (Congestive heart failure, Hypertension, Age=75, Diabetes melitus, prior Stroke), the patient is effectively anticoagulated using acenocumarol. In December 2014, he showed signs of plantar transitory ischemia, for which he did not address the doctor. In early January 2015, he urgently presented at the hospital with left renal pain, caused by a renal infarction, diagnosed by computed tomography (CT) angiography. Left nephrectomy was performed with pathological confirmation. He was discharged with effective anticoagulation treatment. Within the next two weeks, he suffered a transitory ischemic event and a stroke, associated with right sided hemiparesis. On admission, AF was found and converted to sinus rhythm with effective anticoagulation - international normalized ratio (INR) of 2.12. Transthoracic echocardiography detected no pathological findings. Transesophageal echocardiography showed an expended left atrial appendage (LAA) with a slow blood flow (0.2 m÷s) and spontaneous echocontrast. Considering these clinical circumstances, surgical LAA suppression was decided on as a last therapeutic resort. Postoperative evolution was favorable; the patient is still free of ischemic events, one year post-intervention. Some morphological and hemodynamic characteristics of LAA may add additional thromboembolic risk factors, not included in scores. Removing them by surgical LAA suppression may decrease the risk of cardioembolic events. Intraoperative presence of thrombus makes it an indisputable proof.

  17. Histopathological characteristics and oxidative injury secondary to atrial fibrillation in the left atrial appendages of patients with different forms of mitral valve disease.

    PubMed

    Yongjun, Qian; Huanzhang, Shao; Wenxia, Zhou; Hong, Tang; Xijun, Xiao

    2013-01-01

    The prevalence of atrial fibrillation (AF) and the frequency cardioversion of AF postoperatively are different in different forms of mitral valve disease. We hypothesized that these differences would relate to different extent of histopathological characteristics and oxidative injury in different forms of mitral valve diseases. Left atrial appendages were obtained from 24 patients of mitral valve disease with or without AF undergoing mitral valve surgery. Control data were obtained from left appendages of 4 persons in normal sinus rhythm (SR) died of traffic accident. Histopathology, immunohistochemistry, Western blotting and enzyme kinetics examination were performed to assess the extent of histopathological characteristics and oxidative injury. The average cross-sectional diameter of atrial myocyte of mitral stenosis (MS)+AF, MS+SR, mitral regurgitation (MR)+AF, MR+SR and control was 25.62±7.56 μm, 20.20±9.34 μm, 21.69±7.00 μm, 13.93±4.32 μm and 9.81±2.34 μm, respectively. Significantly statistical difference was found between each group (P<.05). Increased degree of atrial interstitial fibrosis was seen both in MS and MR with AF patients compared to other groups (P<.05), and the extent of fibrosis was more remarkable in MR patients compared to MS patients (P<.05). The extent of 3-nitrotyrosine (3-NT) immunoreactivity significantly increased in the patients with MS and AF compared to those of MR and AF (P<.05), and the immunoprevalence of 3-NT was significantly increased in patients of MS and SR compared to those of MR and SR (P<.05). Correlation analysis demonstrated a negative correlation between creatine kinase (CK) activity and extent of 3-NT immunoreactivity in atrial tissues (r=-0.382, P<.05). Significant decreases in CK activity were observed in myocardium from all patients of mitral valve disease with or without AF compared to controls (P<.05). Western blotting demonstrating an increased prevalence of 3-NT formation in CK-MM was detected compared

  18. Percutaneous closure of the left atrial appendage for prevention of thromboembolism in atrial fibrillation for patients with contraindication to or failure of oral anticoagulation: a single-center experience.

    PubMed

    Faustino, Ana; Paiva, Luís; Providência, Rui; Trigo, Joana; Botelho, Ana; Costa, Marco; Leitão-Marques, António

    2013-06-01

    In non-valvular atrial fibrillation 90% of thrombi originate in the left atrial appendage (LAA). Percutaneous LAA closure has been shown to be non-inferior to warfarin for prevention of thromboembolism. To evaluate the initial experience of a single center in percutaneous LAA closure in patients with high thromboembolic risk and in whom oral anticoagulation was impractical or contraindicated or had failed. Patients with non-valvular atrial fibrillation and CHADS2 score ≥2 in whom oral anticoagulation was impractical or contraindicated or had failed underwent percutaneous LAA closure according to the standard technique. After the procedure, dual antiplatelet therapy was maintained for one month, followed by single antiplatelet therapy indefinitely. Patients were followed by clinical assessment and transthoracic and transesophageal echocardiography. The procedure was performed in 22 of the 23 selected patients (95.7%), mean age 70±9 years, CHADS2 score 3.2±0.9 and CHA2DS2-VASC score 4.7±1.4. Intraprocedural device replacement was necessary only in the first patient, due to oversizing. The following periprocedural complications were observed: one femoral pseudoaneurysm, three femoral hematomas and two minor oropharyngeal bleeds, resolved by local hemostatic measures. During a 12±8 month follow-up a mild peri-device flow and a thrombus adhering to the device, resolved under with enoxaparin therapy, were identified. The rate of transient ischemic attack (TIA)/stroke was lower than expected according to the CHADS2 score (0 vs. 6.7±2.2%). In our initial experience, this procedure proved to be a feasible, safe and effective alternative for atrial fibrillation patients in whom oral anticoagulation is not an option. Only relatively minor complications were observed, with a lower than expected TIA/stroke rate. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  19. Pulmonary artery perforation and coronary air embolism-two fatal outcomes in percutaneous left atrial appendage occlusion.

    PubMed

    Zwirner, J; Bayer, R; Hädrich, C; Bollmann, A; Klein, N; Dreßler, J; Ondruschka, B

    2017-01-01

    Percutaneous left atrial appendage (LAA) closure is a routinely performed method to reduce the risk of stroke in patients suffering from atrial fibrillation, when an oral anticoagulation is no longer indicated due to relevant bleeding complications. Currently, the Amplatzer Amulet and the Watchman system are two equally used systems. While there is an acute success rate of more than 95 per cent for this intervention, several minor and major complications such as pericardial effusions, air embolism, vascular lesions in proximity to the heart or even death can occur. Here, we report two cases of very rare fatal outcomes in percutaneous LAA occlusion. Eight hours after deployment of an Amplatzer Amulet a patient died, after the pulmonary trunk was perforated by a hook of the occluder device causing pericardial tamponade. In the second case during final radiological position control of the deployed Watchman occluder air was injected accidentally. The patient immediately died due to coronary air embolism. Forensic autopsies are necessary to solve the cause and manner of death, to evaluate and develop medical devices and to rule out medical malpractice. Thus, a close collaboration of legal medicine and the various cardiologic departments is proposed.

  20. Percutaneous balloon mitral valvuloplasty and closure of the left atrial appendage: Synergy of two procedures in one percutaneous intervention.

    PubMed

    Gemma, Daniele; Moreno Gómez, Raúl; Fernández de Bobadilla, Jaime; Galeote García, Guillermo; López Fernandez, Teresa; López-Mínguez, Jose R; López-Sendón, José L

    2016-11-01

    Mitral stenosis (MS) is frequently associated with the development of atrial fibrillation (AF) as a consequence of hemodynamic and inflammatory changes in the left atrium. Both conditions predispose to thrombus formation, with frequent involvement of the left atrial appendage (LAA), and consequent increase in the incidence of systemic thromboembolic events. Percutaneous mitral valvuloplasty (PMV) reduces the risk of thromboembolism in patients with significant mitral stenosis. Percutaneous LAA closure is also associated with a reduction in thromboembolic risk in patients with AF, but there are no data regarding the use of this technique in patients with significant mitral valve disease. We report the case of a 57-year-old-woman with significant MS and permanent AF, in New York Heart Association functional class II, who despite adequate oral anticoagulation with acenocoumarol, presented several clinical episodes of systemic thromboembolism in the last four years. It was decided to perform a combined percutaneous procedure, including both PMV and percutaneous LAA closure with the Amplatzer Cardiac Plug device. No significant acute complications occurred and the patient was discharged on indefinite treatment with acenocoumarol associated with aspirin 100 mg/d for three months. After a one-year follow-up, there have been no new embolic episodes or other complications. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Left atrial appendage occlusion versus standard medical care in patients with atrial fibrillation and intracerebral haemorrhage: a propensity score-matched follow-up study.

    PubMed

    Nielsen-Kudsk, Jens Erik; Johnsen, Søren Paaske; Wester, Per; Damgaard, Dorte; Airaksinen, Juhani; Lund, Juha; De Backer, Ole; Pakarinen, Sami; Odenstedt, Jacob; Vikman, Saila; Settergren, Magnus; Kongstad, Ole; Rosenqvist, Mårten; Krieger, Derk W

    2017-06-20

    The aim of this study was to investigate the prognosis in patients with atrial fibrillation (AF) and intracerebral haemorrhage (ICH) having a left atrial appendage occlusion (LAAO) versus patients receiving standard medical therapy. A total of 151 patients from the Nordic countries with AF and previous ICH who underwent LAAO using the AMPLATZER Cardiac Plug or the AMPLATZER AMULET were compared to a propensity score-matched group of 151 patients receiving standard medical therapy. The two groups were matched so that their risks for stroke and bleeding were similar (CHA2DS2-VASc and HAS-BLED scores). The standard care patients were identified from the Danish Stroke Registry among 787 patients with AF and ICH. The primary endpoint was a composite of all-cause mortality, ischaemic stroke and major bleeding. Patients with AF and a prior ICH treated with LAAO had a lower risk of the composite outcome as compared to patients treated with standard medical care (events/1,000 years [95% confidence interval]: 53.3 [44.3-64.1] vs. 366.7 [298.2-450.9]; hazard ratio 0.16 [0.07-0.37]). LAAO is suggested to be of major clinical benefit in AF patients having sustained an ICH. These results have to be confirmed in a randomised clinical trial.

  2. Percutaneous left atrial appendage occlusion – treatment outcomes and 6 months of follow-up – a single-center experience

    PubMed Central

    Karczewski, Michał; Skowronek, Radomir; Burysz, Marian; Fischer, Marcin; Anisimowicz, Lech; Demkow, Marcin; Konka, Marek; Ogorzeja, Wojciech

    2016-01-01

    Aim To present the results of treatment and evaluate 6 months of follow-up in a group of patients with non-valvular atrial fibrillation, who underwent the procedure of percutaneous left atrial appendage occlusion (PLAAO). Material and methods Percutaneous left atrial appendage occlusion was performed in 34 patients with non-valvular atrial fibrillation and contraindications for oral anticoagulation therapy. The risk of thromboembolic and bleeding complications was determined based on the CHA2DS2VASc and HAS-BLED scales. The Amplatzer Amulet system from St. Jude Medical was used. On the first postoperative day, all patients were started on double antiplatelet therapy with 75 mg/day of acetylsalicylic acid (ASA) and 75 mg/day of clopidogrel (CLO). On the 30th postoperative day, the efficacy of the antiplatelet therapy was assessed with impedance aggregometry using a Multiplate analyzer (Roche). Echocardiographic examinations were performed intraoperatively and on the first postoperative day; subsequently, follow-up examinations were conducted 1 and 6 months after the implantation. Results In all patients, proper occluder position was observed throughout the follow-up. No leakage or thrombi around the implants were found. No strokes or bleeding complications associated with the antiplatelet therapy were observed. Multiplate assessment of platelet activity was conducted in 20 out of 34 patients. The efficacy of ASA treatment was demonstrated in all patients; no response to clopidogrel treatment was observed in 5 out of 20 patients. One patient suffered from cardiac tamponade, which required the performance of full sternotomy. Local complications (hematomas of the inguinal region) were observed in 3 patients. One of the patients died for reasons unrelated to the procedure. Conclusions Percutaneous left atrial appendage occlusion is an effective procedure in patients with non-valvular atrial fibrillation and contraindications for chronic anticoagulation therapy. Further

  3. Light and electron microscopic features of surgically excised left atrial appendage in rheumatic heart disease patients with atrial fibrillation and sinus rhythm.

    PubMed

    Sharma, Shruti; Sharma, Gautam; Hote, Milind; Devagourou, V; Kesari, Vikas; Arava, Sudhir; Airan, Balram; Ray, Ruma

    2014-01-01

    There are few studies comparing the pathology of the remodeled substrate in patients of rheumatic heart disease with atrial fibrillation (AF) and normal sinus rhythm (NSR). The study group comprised 30 patients with rheumatic heart disease undergoing mitral valve replacement. Excised left atrial appendages of these patients [17 with persistent AF and 13 NSR (control group)] were subjected to light and electron microscopic examination. The histopathological findings of the myocardium were characterized by cardiomyocyte hypertrophy (CH), nuclear enlargement (NE), perinuclear clearing (PC), sarcoplasmic vacuolation (SV), fibrosis, and inflammation in the patients with AF and NSR. NE (17/17 vs. 4/13; P=.004), PC (17/17 vs. 4/13; P=.004), SV (17/17 vs. 9/13; P=.06), and fibrosis (15/17 vs. 3/13; P=.001) were all significantly more common in patients with AF. Inflammatory cells were observed in 9/17 patients of AF as compared to 1 in NSR patients (9/17 vs. 1/13; P=.02). CH was common in the patients with AF as compared with those in NSR (17/17 vs. 10/13; P=.103). In AF patients, electron microscopy revealed cardiomyocytes with depletion of the contractile elements (Z-bands), glycogen particle accumulation, and an increase in mitochondria. Cells severely affected by AF showed loss of contractile elements with extensive areas of SV, presence of myelin figures, and mitochondrial aggregates. Majority of AF cases showed extensive fibrosis in the form of collagen bundles in the interstitium. The left atrial substrate in AF as compared with NSR, in rheumatic heart disease patients, is associated with significant degenerative remodeling and ongoing inflammation that is associated with extensive fibrosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a randomised non-inferiority trial.

    PubMed

    Holmes, David R; Reddy, Vivek Y; Turi, Zoltan G; Doshi, Shephal K; Sievert, Horst; Buchbinder, Maurice; Mullin, Christopher M; Sick, Peter

    2009-08-15

    In patients with non-valvular atrial fibrillation, embolic stroke is thought to be associated with left atrial appendage (LAA) thrombi. We assessed the efficacy and safety of percutaneous closure of the LAA for prevention of stroke compared with warfarin treatment in patients with atrial fibrillation. Adult patients with non-valvular atrial fibrillation were eligible for inclusion in this multicentre, randomised non-inferiority trial if they had at least one of the following: previous stroke or transient ischaemic attack, congestive heart failure, diabetes, hypertension, or were 75 years or older. 707 eligible patients were randomly assigned in a 2:1 ratio by computer-generated randomisation sequence to percutaneous closure of the LAA and subsequent discontinuation of warfarin (intervention; n=463) or to warfarin treatment with a target international normalised ratio between 2.0 and 3.0 (control; n=244). Efficacy was assessed by a primary composite endpoint of stroke, cardiovascular death, and systemic embolism. We selected a one-sided probability criterion of non-inferiority for the intervention of at least 97.5%, by use of a two-fold non-inferiority margin. Serious adverse events that constituted the primary endpoint for safety included major bleeding, pericardial effusion, and device embolisation. Analysis was by intention to treat. This study is registered with Clinicaltrials.gov, number NCT00129545. At 1065 patient-years of follow-up, the primary efficacy event rate was 3.0 per 100 patient-years (95% credible interval [CrI] 1.9-4.5) in the intervention group and 4.9 per 100 patient-years (2.8-7.1) in the control group (rate ratio [RR] 0.62, 95% CrI 0.35-1.25). The probability of non-inferiority of the intervention was more than 99.9%. Primary safety events were more frequent in the intervention group than in the control group (7.4 per 100 patient-years, 95% CrI 5.5-9.7, vs 4.4 per 100 patient-years, 95% CrI 2.5-6.7; RR 1.69, 1.01-3.19). The efficacy of

  5. Anatomically corrected malposition of the great arteries {S, D, L} with left juxtaposition of the atrial appendages in DORV: influence on surgical approach.

    PubMed

    Awasthy, Neeraj; Radhakrishnan, S; Sharma, Rajesh

    2013-04-01

    The case of an infant with double outlet right ventricle with anatomically corrected malposition of the great arteries, bilateral infundibulum, and an echocardiographically routable ventricular septal defect (VSD) is presented. After numerous efforts to visualize the margins of the VSD, the best surgical exposure of the VSD was through the aorta. We believe this to be the first report of this phenomenon, which results from the left-sided position of the aorta and the presence of left juxtaposition of the atrial appendages.

  6. The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine.

    PubMed

    Liu, Peng; Liu, Rijing; Zhang, Yan; Liu, Yingfeng; Tang, Xiaoming; Cheng, Yanzhen

    2016-01-01

    The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to 'Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the

  7. Safety and efficacy of catheter-based left atrial appendage closure in patients with contraindications for long-term anticoagulation.

    PubMed

    Seidel, Adrian; Parwani, Abdul S; Krackhardt, Florian; Huemer, Martin; Attanasio, Philipp; Haverkamp, Wilhelm; Pieske, Burkert; Boldt, Leif-Hendrik

    2017-05-31

    Percutaneous left atrial appendage closure (LAAC) and the role of post interventional anticoagulation often evokes controversy in daily practice. This study aimed to evaluate LAAC in patients with non-rheumatic atrial fibrillation, high thromboembolic risk and contraindications for long-term anticoagulation in a clinical scenario. Between 2010-2015, LAAC was attempted in 118 patients (47 women). Devices were successfully implanted in 95% (Watchman™ device n=97, St. Amplatzer™ Cardiac Plug/Amulet n=14, Amplatzer PFO Occluder n=1). Mean age, HAS-BLED and CHA2DS2VASc score were 75 years (SD 8.35yrs), 4.3 and 4.9, respectively. Median followup was 447 days (P25=183d, P75=789d). The primary safety endpoint was defined as major bleeding according to the International Society on Thrombosis and Haemostasis. The combined efficacy endpoint included ischemic strokes, transitory ischemic attacks (TIA) and systemic embolisms. Procedural complication rate was 3.4%. After successful intervention, either a therapy with anticoagulants (n=62) or dual antiplatelet therapy (DAPT, n=50) was prescribed temporarily. Medication was reduced if implantation proved satisfying in a 6-week follow-up transesophageal echocardiography, which was the case in 79% of these patients. During follow-up, one patient suffered a TIA (0.6%/year). No other efficacy event was observed. 11 major bleedings occurred (6.6%/year): one each under DAPT plus phenprocoumon, DAPT plus rivaroxaban, acetylsalicylic acid (ASA) plus rivaroxaban, two under DAPT, two under ASA plus low molecular weight heparin, and four under ASA only. In our analysis, catheter-based LAA occlusion prevented thromboembolisms with high efficacy. Major bleedings were however common in patients with, but also without anticoagulation, independent from time course.

  8. Does left atrial appendage closure improve the success of pulmonary vein isolation? Results of a randomized clinical trial.

    PubMed

    Romanov, Alexander; Pokushalov, Evgeny; Artemenko, Sergey; Yakubov, Akmal; Stenin, Ilya; Kretov, Evgeny; Krestianinov, Oleg; Grazhdankin, Igor; Risteski, Dejan; Karaskov, Alexander; Steinberg, Jonathan S

    2015-10-01

    The combination of left atrial appendage (LAA) occlusion with pulmonary vein isolation (PVI) potentially represents a comprehensive treatment for atrial fibrillation (AF), controlling symptoms while at the same time reducing the risk of stroke and the need for chronic anticoagulation. The aim of this randomized clinical trial was to assess the impact of LAA closure added to PVI in patients with high-risk AF. Patients with a history of symptomatic paroxysmal or persistent AF refractory to ≥ 2 antiarrhythmic drugs, CHA2DS2-VASc score ≥ 2, and HAS-BLED score ≥ 3 were randomized to PVI-only (n = 44) or PVI with LAA closure (n = 45). Six patients in PVI + LAA closure group crossed over to PVI-only group due to failure of LAA closure device implantation. On-treatment comparisons at the 24 month follow-up revealed that 33 (66%) of the 50 PVI group and 23 (59%) of the 39 PVI with LAA closure group were AF-free on no antiarrhythmic drugs (p = 0.34). The PVI + LAA closure treatment was significantly associated with a higher AF burden during the blanking period: 9.7 ± 10.8 vs 4.2 ± 4.1% (p = 0.004). At the end follow-up, there were no serious complications and no strokes or thromboembolic events in either group. The combination of LAA closure device implantation with PVI was safe but was not observed to influence the success of PVI in patients with symptomatic refractory AF. Early AF after ablation, however, is increased by LAA closure. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01695824.

  9. The effect of different atrioventricular delays on left atrium and left atrial appendage function in patients with DDD pacemaker.

    PubMed

    Kanadaşı, Mehmet; Caylı, Murat; Sahin, Durmuş Yıldıray; Sen, Ömer; Koç, Mevlüt; Usal, Ayhan; Batur, Mustafa Kemal; Demirtaş, Mustafa

    2011-07-01

    Although it has been known that optimization of atrioventricular delay (AVD) has favorable effect on the left ventricular functions in patients with DDD pacemaker, the effect of different AVDs on left atrium (LA) and left atrial appendage (LAA) functions has not been exactly evaluated. The aim of the present study was to assess the effect of different AVDs on LA and LAA functions in DDD pacemaker implanted patients with atrioventricular block. Forty-eight patients with DDD pacemaker were enrolled into the study. Patients were divided into two groups according to the echocardiographic diastolic function: Group I (normal diastolic function) and Group II (diastolic dysfunction). LAA emptying velocity on pulsed wave Doppler and LAA late systolic wave velocity by using tissue Doppler were recorded. Patients were paced for five successive continuous pacing periods of 10 minutes duration using five selective AVDs (80-250 ms). Significant effect on LA and LAA functions has not been observed by the setting of AVD in Group I. However, when the AVD was gradually shortened form 150 ms to 80 ms, LA and LAA functions gradually decreased in Group II patients. When AVD increased to 200 ms, LA and LAA functions were improved. Further increase in AVD resulted in decreased LA and LAA functions. Setting of AVD has not significant effect on the LA and LAA functions in patients with normal diastolic function, but moderate prolongation of AVD in physiological limits improved LA and LAA functions in DDD pacemaker implanted patients with diastolic dysfunction. © 2011, Wiley Periodicals, Inc.

  10. Printed MDCT 3D models for prediction of Left Atrial Appendage (LAA) occluder device size - A feasibility study.

    PubMed

    Goitein, Orly; Fink, Noam; Guetta, Victor; Beinart, Roy; Brodov, Yafim; Konen, Eli; Goitein, David; Di Segni, Elio; Grupper, Avishay; Glikson, Michael

    2017-05-16

    Trans-esophageal echocardiography (TEE) and MDCT currently serve as imaging modalities for left atrial appendage (LAA) occlusion pre-procedural planning. We assessed the feasibility of multi-detector CT (MDCT) based models to predict the correct size of device for LAA occlusion procedures. Patients planned for LAA occlusion underwent MDCT before implantation, which was used for creating and printing 3D LAA models. Three cardiologists evaluated the 3D models and predicted the correct size of the device by manual manipulation, these predictions were compared with the actual device implanted during the procedure. Twenty nine patients were included in this study. Amplatzer™ and Watchman™ devices were deployed in 12 and 17 patients, respectively. Two procedures were aborted due to failure of occlusion, all three physicians predicted it. There was good correlation between the 3D models and the inserted device for Amplatzer™ devices with concordance correlation coefficient 0.778 (P=0.001) and poor agreement for Watchman™ devices - concordance correlation coefficient of 0.315 (P=0.203). Agreement between the three physicians for Amplatzer ™ and Watchman™ devices were excellent with a calculated average intra-class correlation of 0.915 and 0.816 respectively. We found LAA printed 3D models to be accurate for prediction of LAA occluder device size for Amplatzer™ device but not for Watchman™ device.

  11. A Decision Analysis of Percutaneous Left Atrial Appendage Occlusion Relative to Novel and Traditional Oral Anticoagulation for Stroke Prevention in Patients with New-Onset Atrial Fibrillation.

    PubMed

    Micieli, Andrew; Wijeysundera, Harindra C; Qiu, Feng; Atzema, Clare L; Singh, Sheldon M

    2016-04-01

    Percutaneous left atrial appendage occlusion (LAAO) is a nonpharmacologic approach for stroke prevention in nonvalvular atrial fibrillation (NVAF). No direct comparisons to novel oral anticoagulants (OACs) exists, limiting decision making on the optimal strategy for stroke prevention in NVAF patients. Addressing this gap in knowledge is timely given the recent debate by the US Food and Drug Administration regarding the effectiveness of LAAO. To assess the cost-effectiveness of LAAO and novel OACs relative to warfarin in patients with new-onset NVAF without contraindications to OAC. A cost-utility analysis using a patient-level Markov micro-simulation decision analytic model was undertaken to determine the lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of LAAO and all novel OACs relative to warfarin. Effectiveness and utility data were obtained from the published literature and cost from the Ontario Drug Benefits Formulary and Case Costing Initiative. Warfarin had the lowest discounted QALY (5.13 QALYs), followed by dabigatran (5.18 QALYs), rivaroxaban and LAAO (5.21 QALYs), and apixaban (5.25 QALYs). The average discounted lifetime costs were $15 776 for warfarin, $18 280 for rivaroxaban, $19 156 for apixaban, $20 794 for dabigatran, and $21 789 for LAAO. Apixaban dominated dabigatran and LAAO and demonstrated extended dominance over rivaroxaban. The ICER for apixaban relative to warfarin was $28 167/QALY. Apixaban was preferred in 40.2% of simulations at a willingness-to-pay threshold of $50 000/QALY. Assumptions regarding clinical and methodological differences between published studies of each therapy were minimized. Apixaban is the most cost-effective therapy for stroke prevention in patients with new-onset NVAF without contraindications to OAC. Uncertainty around this conclusion exists, highlighting the need for further research. © The Author(s) 2015.

  12. Analysis of real-time three dimensional transesophageal echocardiography in the assessment of left atrial appendage function in patients with atrial fibrillation

    PubMed Central

    Gan, Lin; Yu, Lan; Xie, Manying; Feng, Wei; Yin, Jiabao

    2016-01-01

    The aim of the study was to examine changes in left atrial appendage volume (LAA-V) in patients with non-valvular atrial fibrillation (AF) using real-time three-dimensional transesophageal echocardiography (RT3D-TEE) and evaluate the prediction value on the high risk of thrombosis of LAA. Using RT3D-TEE we measured: i) LAA peak empty velocity (LAA-PEV), ii) LAA-V including LAA end-diastolic volume (LAA-EDV) and end-systolic volume (LAA-ESV). We also calculated LAA ejection fraction (LAA-EF). RT3D-TEE was applied in 20 control cases and 74 patients with non-valvular AF. According to the presence of thrombosis, 74 patients were divided into the no thrombosis group (NTH group, n=52) and thrombosis group (TH group, n=22). Our results showed that there were significant differences in LAA-V and LAA-EF values in different groups (P<0.05). LAA-EDV moderately correlated with LAA-PEV (r=−0.531, P<0.001) while LAA-ESV demonstrated a strong correlation with LAA-PEV (r=−0.741, P<0.001). LAA-EF also showed a strong correlation with LAA-PEV (r=0.693, P<0.001). Through receiver operating characteristic (ROC) curves, the cut-off values of LAA-EDV and LAA-ESV in thrombosis of LAA were 18.45 and 9.69 ml, respectively. RT3D-TEE effectively evaluated the LAA-V, LAA-PEV and LAA-EF parameters, and proved to be valuable in the process of evaluation of thrombosis of LAA. PMID:27882157

  13. Transcatheter left atrial appendage occlusion in patients with atrial fibrillation and a high bleeding risk using aspirin alone for post-implant antithrombotic therapy.

    PubMed

    Korsholm, Kasper; Nielsen, Kirsten Melgaard; Jensen, Jesper Møller; Jensen, Henrik Kjærulf; Andersen, Grethe; Nielsen-Kudsk, Jens Erik

    2017-04-20

    The aim of the study was to evaluate the safety and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) or Amulet using aspirin alone (ASA) as post-implantation antithrombotic treatment. This was a single-centre, prospective, non-randomised study on LAAO with the ACP or Amulet in a consecutive cohort (n=110) treated by ASA alone post implantation. The primary outcome was device-related thrombosis, while secondary outcomes were ischaemic stroke or major bleeding. Clinical follow-up was conducted after six weeks and 12 months with TEE and cardiac CT. One hundred and seven patients were included in the analysis. Three patients were excluded due to a mechanical valve prosthesis. CHA2DS2-VASc score was 4.4±1.6 and HAS-BLED 4.1±1.1. Successful implantation was obtained in all patients with a periprocedural complication rate of 4.6%. Median follow-up was 2.3 years, with a total of 265 patient-years. Device-related thrombosis was detected in 2/107 (1.9%) cases. Stroke occurred in 6/107 patients, with an annualised rate of 2.3%, which is a 61% risk reduction compared to the predicted rate. Annual risk of major bleeding was reduced by 57%. LAAO with the ACP or Amulet was safely performed with ASA monotherapy after implantation without an increased risk of device-related thrombosis or stroke.

  14. A meta-analysis for efficacy and safety evaluation of transcatheter left atrial appendage occlusion in patients with nonvalvular atrial fibrillation

    PubMed Central

    Wei, Zhonghai; Zhang, Xinlin; Wu, Han; Xie, Jun; Dai, Qing; Wang, Lian; Xu, Biao

    2016-01-01

    Abstract Objectives: This meta-analysis was conducted to evaluate the efficacy and safety of transcatheter left atrial appendage (LAA) occlusion in patients with nonvalvular atrial fibrillation. Methods: The randomized controlled trials (RCT) or observational studies with any transcatheter LAA occlusion devices were searched in PubMed, Embase, and Cochrane library from inception to November 2015. The incidence rates from individual studies were combined to evaluate the procedural efficacy and safety, including all-cause death, cardiac/neurological death, stroke, transient ischemic attack (TIA), thrombosis, hemorrhagic complications, and pericardial effusion/tamponade. Results: Thirty-eight studies involving 3585 patients and 6 different occlusion devices were eligible for our inclusion criteria. The procedural failure rate for LAA closure was 0.02 (95% CI: 0.02–0.03). The all-cause mortality was 0.03 (95% CI: 0.02–0.03) and cardiac/neurological mortality was 0 (95% CI: 0.00–0.01). The stroke/TIA rate was estimated only 0.01 (95% CI: 0.01–0.01). The incidence of thrombus on devices was 0.01 (95% CI: 0.01–0.02). The major hemorrhagic complication rate was estimated 0.01 (95% CI: 0.00–0.01). Pericardial effusion/tamponade was estimated 0.02 (95% CI: 0.02–0.03). No heterogeneity was observed for above pooled estimates (I2 = 0). In devices subgroups analysis, the all-cause mortality and cardiac/neurological mortality of PLAATO group were the highest (P = 0.01 and P < 0.01 respectively), whereas the incidence of thrombus on devices in the ACP group was the highest (P < 0.01). In follow-up period subgroups analysis, there were significant differences in all-cause death, stroke/TIA, major hemorrhage, and pericardial effusion/tamponade events between the shorter and longer follow-up period subgroups (P < 0.05). However, the differences among the subgroups were numerically small. Conclusions: the pooled data demonstrated that transcatheter

  15. Left atrial appendage morphology and risk of stroke following pulmonary vein isolation for drug-refractory atrial fibrillation in low CHA2DS2Vasc risk patients.

    PubMed

    Kelly, Faith R; Hull, Robert A; Arrey-Mbi, Takor B; Williams, Michael U; Lee, Joshua S; Slim, Ahmad M; Thomas, Dustin M

    2017-02-28

    Cardiac CT angiography (CCTA) has become an important adjunct in the structural assessment of the pulmonary veins (PV) prior to pulmonary vein isolation (PVI). Published data is conflicting regarding a relationship between left atrial appendage (LAA) and the risk of ischemic stroke (CVA) following PVI. We investigated the associations of volumetric and morphologic left atrial (LA) and LAA measurements for CVA following PVI. We retrospectively reviewed 332 consecutive patients with drug refractory atrial fibrillation who obtained cardiac CT angiogram (CCTA) prior to PVI. Baseline demographic data, procedural and lab details, and outcomes were obtained from abstraction of an electronic medical records system. LA, LAA, and PV volumes were measured using CCTA datasets utilizing a semi-automated 3D workstation application. LAA morphology was assigned utilizing volume rendered images as previously described. The study cohort was 55 ± 13 years-old, 83.7% male, low CVA risk (median CHA2DS2Vasc 1; IQR 1, 3), and 30.4% were treated with novel oral anticoagulants. Chicken wing (CW) was the most common morphology (52%), followed by windsock (WS), cauliflower (CF), and cactus (CS) at 18, 9, and 2%, respectively. CVAs occurred in 4 patients following PVI with median time to CVA of 170.5 days. All CVAs were observed in CW morphology patients. When comparing CW morphology with non-CW morphology, CVAs occurred more frequently with the CW morphology (2.1% vs 0%, p = 0.03). This difference was not significant, though, after adjusting for CHA2DS2Vasc risk factors (p = 0.14). The CW morphology was observed more commonly in patients who experienced post-PVI CVA. After adjusting for CHA2DS2Vasc risk factors, CW morphology was not an independent predictor of post-PVI CVA. These findings should be interpreted in the setting of a low CVA event rate amongst a low risk population that was highly compliant with indicated anticoagulation therapy.

  16. Long-term follow-up after left atrial appendage occlusion with comparison of transesophageal echocardiography versus computed tomography to guide medical therapy and data about postclosure cardioversion.

    PubMed

    Berte, Benjamin; Jost, Christine Attenhofer; Maurer, Dominik; Fäh-Gunz, Anja; Pillois, Xavier; Naegeli, Barbara; Pfyffer, Monica; Sütsch, Gabor; Scharf, Christoph

    2017-07-04

    The use of left atrial appendage (LAA) occluders in atrial fibrillation is increasing. There are few data on the comparison between transesophageal echocardiography (TEE) and computed tomography (MDCT) assessing peridevice flow and outcome of electrical cardioversion (ECV) in these patients. Single-center prospective registry from 2009 to 2015 including all LAA occluders to analyze success and complications during implantation and follow-up. Patients having ≥1 ECV were further analyzed. TEE was performed during implantation and at 6 weeks. In a subgroup of 77 patients, we compared MDCT with TEE at 6 weeks. Overall, 135 patients (69 ± 9 years; 70% male; CHA2 DS2 -VASc score: 3.6 ± 1.4; HAS-BLED score: 2.5 ± 0.6) received a LAA occluder (Watchman, n = 73; ACP-1, n = 59; Amulet, n = 3; PVI + LAA occluder, n = 91; and LAA occluder only, n = 44). Device implantation was successful in 131 (97%). Eight patients (5.9%) had major periprocedural complications (ischemic stroke/transient ischemic attacks, n = 4, tamponade, n = 2, device thrombosis, n = 2, Dressler syndrome, n = 1). The periprocedural complication rate was similar between concomitant procedure and LAA occluder only (8/91 vs. 5/44; P = 0.6). Twelve patients (9%) died (procedure-related, n = 2; 1%) during follow-up of 44 months (IQR: 43). MDCT (n = 77) at 6 weeks showed similar peridevice flow compared to TEE (TEE: 1.5 ± 1.9 mm vs. MDCT: 1.1 ± 2.2 mm, P = 0.25). Thromboembolic events occurred in 3 patients (CVA, n = 1; TIA, n = 2) during follow-up. In total, 41 ECV were performed in 26 patients (1.6 ± 0.9/patient), 13 months (IQR: 24) after implantation (<1 month: n = 8). No ECV-related clinical complications were observed. LAA occlusion is feasible with an acceptable safety profile and few events during long-term follow-up. ECV after LAA occlusion is feasible. MDCT could help to evaluate peridevice flow. © 2017 Wiley Periodicals, Inc.

  17. Roles of real-time three-dimensional transesophageal echocardiography in peri-operation of transcatheter left atrial appendage closure

    PubMed Central

    Zhou, Qing; Song, Hongning; Zhang, Lan; Deng, Qing; Chen, Jinling; Hu, Bo; Wang, Yijia; Guo, Ruiqiang

    2017-01-01

    Abstract Left atrial appendage (LAA) closure is a new treatment option for the prevention of stroke in patients with nonvalvular atrial fibrillation (AF). Conventional 2-dimensional transesophageal echocardiography (2D TEE) has some limitations in the imaging assessment of LAA closure. Real-time 3-dimensional transesophageal echocardiography (RT-3D TEE) allows for detailed morphologic assessment of the LAA. In this study, we aim to determine the clinical values of RT-3D TEE in the periprocedure of LAA closure. Thirty-eight persistent or paroxysmal AF patients with indications for LAA closure were enrolled in this study. RT-3D TEE full volume data of the LAA were recorded before operation to evaluate the anatomic feature, the landing zone dimension, and the depth of the LAA. On this basis, selection of LAA closure device was carried out. During the procedure, RT-3D TEE was applied to guide the interatrial septal puncture, device operation, and evaluate the occlusion effects. The patients were follow-up 1 month and 3 months postclosure. Twenty-eight (73.7%) patients with AF received placement of LAA occlusion device under RT-3D TEE. Eleven cases with single-lobe LAAs were identified using RT-3D TEE, among which 4 showed limited depth. Seventeen cases showed bilobed or multilobed LAA. Seven cases received LAA closure using Lefort and 21 using LAmbre based on the 3D TEE and radiography. The landing zone dimension of the LAA measured by RT-3D TEE Flexi Slice mode was better correlated with the device size used for occlusion (r = 0.90) than 2D TEE (r = 0.88). The interatial septal puncture, the exchange of the sheath, as well as the release of the device were executed under the guidance of RT-3D TEE during the procedure. The average number of closure devices utilized for optimal plugging was (1.11 ± 0.31). There were no clinically unacceptable residual shunts, pericardial effusion, or tamponade right after occlusion. All the patients had the device well

  18. Intracardiac Echocardiography From the Left Atrium for Procedural Guidance of Transcatheter Left Atrial Appendage Occlusion.

    PubMed

    Korsholm, Kasper; Jensen, Jesper Møller; Nielsen-Kudsk, Jens Erik

    2017-08-24

    The aim of this study was to compare the efficacy and safety of intracardiac echocardiography (ICE) from the left atrium (LA) with transesophageal echocardiography (TEE) for procedural guidance of transcatheter left atrial appendage occlusion (LAAO). TEE with general anesthesia is the current gold standard to guide LAAO. By the use of ICE from the LA, LAAO can be performed in local anesthesia and may potentially have advantages over TEE. A single-center, cohort study of patients undergoing LAAO with the Amplatzer Cardiac Plug or Amulet (St. Jude Medical, St. Paul, Minnesota). Procedures were guided by ICE from the LA with local anesthesia (n = 109) or TEE using general anesthesia (n = 107). All patients had pre-procedural cardiac computed tomography. Efficacy outcomes were technical success, procedural success, and peridevice leakage at TEE 8 weeks after LAAO. Safety outcome was a composite of periprocedural complications. Technical success was achieved in 99% of both the TEE and ICE group. Procedural success was similar between groups: 94.4% success rate in the TEE-guided group, and 94.5% in the ICE-guided group. Major periprocedural complications occurred in 4.7% of the TEE group and 1.8% of the ICE group. Rate and degree of peridevice leak did not differ between groups at follow-up. Turnover time in the catheter laboratory, and contrast use were reduced with ICE. LA ICE to guide LAAO as compared with TEE appears to be effective and safe, without increased procedure-related complications. The rate of peridevice leak is low and similar to TEE-guided procedures. Time spent in the catheterization room may decrease substantially. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  19. Left Atrial Appendage Conduction Jump for Real-Time Evaluation of Conduction Block Over the Anterior Mitral Annulus Line.

    PubMed

    Huemer, Martin; Wutzler, Alexander; Parwani, Abdul Shokor; Attanasio, Philipp; Heiderfazel, Salman; Ewertsen, Niels Christian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2015-07-01

    Evaluation of conduction over a linear ablation lesion at the anterior mitral annulus can be time-consuming and difficult during ongoing radiofrequency application. The purpose of this study was to validate conduction time from the beginning of the p wave and from the coronary sinus ostium to the left atrial appendage (LAA) as a new method of conduction block surveillance. Conduction across the anterior mitral annulus line was evaluated using a total of 55 patients. We verified completeness of conduction block by standard techniques including differential pacing, double potential mapping and activation mapping. Those methods were compared to the new method of observing an abrupt prolongation of conduction time into the LAA as well as a conduction sequence change on a circular multipolar mapping catheter placed inside the LAA during sinus rhythm. Bidirectional conduction block across the ablated line was achieved in 51 (92.7%) of the patients. Prior to ablation, mean conduction time across the line was 59 ± 21 milliseconds. This value increased to 163 ± 43 milliseconds after a successful ablation. An abrupt prolongation of conduction time into the LAA of at least 50 milliseconds was observed in all patients at the moment when a complete conduction block was achieved. Additionally, a change of conduction sequence recorded with the multi-electrode catheter placed in the LAA was observed in all of these patients. A sudden jump of p wave and coronary sinus ostium to LAA conduction time together with a change of conduction sequence recorded with a multi-electrode catheter placed inside the LAA during sinus rhythm is a simple and reliable approach for beat-to-beat surveillance of conduction block across the anterior mitral annulus during radiofrequency ablation. © 2015 Wiley Periodicals, Inc.

  20. Contrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: A pilot study

    PubMed Central

    2011-01-01

    Background To evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA) to identify incorrect placement and persistent leaks. Methods 7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP) underwent 2 contrast-enhanced (Gd-DOTA) CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH) to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks. Results All occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion. By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal) than those without a leak (61 ± 22%; p < 0.03). In contrast, the signal increase in LAA proximal to the occluder showed no difference (leak 481 ± 201% vs. no leak 478 ± 125%; p = 0.48). Conclusion This CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types. PMID:21726450

  1. Effects of combined carotid chemoreceptor and atrial receptor stimulation on renal blood flow in anaesthetized dogs.

    PubMed Central

    Kappagoda, C T; Karim, F; Mackay, D

    1983-01-01

    In dogs anaesthetized with chloralose and artificially ventilated, carotid chemoreceptors were stimulated by changing the perfusate of the vascularly isolated carotid bifurcations from arterial to venous blood. Left atrial receptors were stimulated by distending balloons in two pulmonary vein-left atrial junctions and in this left atrial appendage. The left renal blood flow was measured by an electromagnetic flow meter at a constant systemic (renal) arterial pressure in preparations in which heart rate changes were prevented by administration of propranolol hydrochloride (0.5 mg kg-1) and atropine sulphate (0.4 mg kg-1). Muscular movement was prevented by gallamine triethiodide (0.2 mg kg-1). Stimulation of left atrial receptors resulted in a significant increase (P less than 0.001) in renal blood flow of 5.6 +/- 0.88 ml min-1 100 g-1 renal mass from a control of 223 ml min-1 100 g-1 renal mass. The responses were abolished by cooling the cervical vagus nerves to 6-8 degrees C. Stimulation of carotid chemoreceptors, by perfusion of the carotid bifurcations by venous blood, caused a decrease in renal blood flow of 20 +/- 6.9 ml min-1 100 g-1 renal mass from 224 ml min-1 100 g-1 renal mass. Stimulation of left atrial receptors during venous perfusion of carotid chemoreceptors resulted in an increase in renal blood flow of 10.9 +/- 1.82 ml min-1 100 g-1 renal mass from 208 ml min-1 100 g-1 renal mass. These results show that atrial receptors and chemoreceptors can interact in their effects on renal blood flow. PMID:6410054

  2. Preservation of high-energy phosphates in human myocardium. A phosphorus 31-nuclear magnetic resonance study of the effect of temperature on atrial appendages

    SciTech Connect

    Deslauriers, R.; Keon, W.J.; Lareau, S.; Moir, D.; Saunders, J.K.; Smith, I.C.; Whitehead, K.; Mainwood, G.W.

    1989-09-01

    After prolonged exposure to low temperatures (1 and 4{degrees}C), human atrial trabeculae show poor recovery of contraction. At somewhat higher temperatures (12 and 20{degrees}C), recovery is much better. Although better preservation of adenosine triphosphate and therefore improved contractile recovery might be expected after exposure to lower temperatures, it remained possible that, below a certain temperature, adenosine triphosphate-generating mechanisms could be slowed more than adenosine triphosphate utilization. To investigate this phenomenon further, we followed the time course of metabolic changes in human atrial appendages, harvested during cardiac bypass operations, at 1, 4, 12, and 20{degrees}C using high-resolution 31P and 1H nuclear magnetic resonance spectroscopy. The results are quantitated by correlation with data obtained from biochemical assays on quick-frozen tissues. Initial adenosine triphosphate levels in myocytes of human atrial appendages are 3.3 to 4.3 mumol.gm-1 tissue wet weight. At 20{degrees}C, adenosine triphosphate disappears after 6 hours; at 12{degrees}C, about half the initial adenosine triphosphate is still observable at this time; at 4{degrees}C or 1{degree}C, the decline is still slower. Only a small contribution toward adenosine triphosphate maintenance comes from creatine phosphate, since creatine phosphate, inorganic phosphate, and total creatine levels in the appendage are low (less than 2 mumol.gm-1 tissue wet weight). Glycolysis is active at all temperatures; the rate of glycolysis correlates positively with increasing temperature. Adenosine triphosphate generated by glycolysis falls just short of demand at all temperatures, but the difference is small at 1 and 4{degrees}C.

  3. Efficacy and Safety of the WATCHMAN Left Atrial Appendage System for Stroke Prevention in Chinese Patients with Nonvalvular Atrial Fibrillation: A Single-center, Prospective, Observational Study

    PubMed Central

    Huang, Wei-Ping; Zhang, Yong-Hua; He, Lei; Su, Xi; Yang, Xin-Wei; Guo, Zai-Xiong

    2017-01-01

    Background: In patients with nonvalvular atrial fibrillation (NVAF), embolic stroke is thought to be associated with left atrial appendage (LAA) thrombi. The WATCHMAN LAA Occlusion Device has been shown to be noninferior to conventional oral anticoagulation with warfarin for stroke prevention in patients with NVAF. This study aimed to evaluate the procedural feasibility, safety and 12-month outcomes of the WATCHMAN LAA Occlusion Device in NVAF patients with high risk for stroke in China. Methods: The clinical data of 106 NVAF patients, who were consecutively underwent LAA closure with the WATCHMAN Device between April 2014 and May 2015, were collected. Patients were followed up at 1, 3, 6, and 12 months after discharge. A transesophageal echocardiograph was performed at 45 days after implantation and repeated in case of an unexpected event during the follow-up period. Results: This study included 106 NVAF patients with a mean age of 64.2 ± 8.6 years (ranging from 50 to 88 years), and the mean CHA2DS2-VASc score of all patients was 3.6 ± 1.6 (ranging from 2 to 9). Among those 106 NVAF patients, 100 (94.3%) patients were implanted with the device successfully. The procedural success rate was 94.3% (100/106), and the occlusion rate was 100.0% (100/100). There were one tamponade, one ischemic stroke, and eight minor pericardial effusions during hospitalization. During 12-month follow-up period, two patients developed a thrombus layer on the device that resolved with additional anticoagulation: one with visible device-thrombus experienced transient ischemic stroke, and one had a hemorrhagic stroke. There were no deaths in this study. The overall survival rate was 100.0%, and nonmajor adverse event rate was 95.0% (95/100). In this study, the expected annual rate of ischemic stroke risk in these patients according to the CHA2DS2-VASc score was 4.0%, while the observed ischemic stroke rate was 2.0% per year. Conclusions: LAA closure with the WATCHMAN Device was feasible

  4. Cost-Effectiveness of Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation Based on Results from PROTECT AF vs. PREVAIL

    PubMed Central

    Freeman, James V.; Hutton, David W.; Barnes, Geoffrey D.; Zhu, Ruo P.; Owens, Douglas K.; Garber, Alan M.; Go, Alan S.; Hlatky, Mark A.; Heidenreich, Paul A.; Wang, Paul J.; Al-Ahmad, Amin; Turakhia, Mintu P.

    2016-01-01

    Background Randomized trials of left atrial appendage (LAA) closure with the Watchman device have shown varying results, and its cost-effectiveness compared to anticoagulation has not been evaluated using all available contemporary trial data. Methods and Results We used a Markov decision model to estimate lifetime quality-adjusted survival, costs, and cost-effectiveness of LAA closure with Watchman, compared directly with warfarin and indirectly with dabigatran, using data from the long-term (mean 3.8 year) follow-up of PROTECT AF and PREVAIL randomized trials. Using data from PROTECT AF, the incremental cost-effectiveness ratios (ICER) compared to warfarin and dabigatran were $20,486 and $23,422 per quality adjusted life year (QALY), respectively. Using data from PREVAIL, LAA closure was dominated by warfarin and dabigatran, meaning that it was less effective (8.44, 8.54, and 8.59 QALYs, respectively) and more costly. At a willingness-to-pay-threshold of $50,000 per QALY, LAA closure was cost-effective 90% and 9% of the time under PROTECT AF and PREVAIL assumptions, respectively. These results were sensitive to the rates of ischemic stroke and intracranial hemorrhage for LAA closure and medical anticoagulation. Conclusions Using data from the PROTECT AF trial, LAA closure with the Watchman device was cost-effective; using PREVAIL trial data, Watchman was more costly and less effective than warfarin and dabigatran. PROTECT AF enrolled more patients and has substantially longer follow-up time, allowing greater statistical certainty with the cost-effectiveness results. However, longer term trial results and post-marketing surveillance of major adverse events will be vital to determining the value of the Watchman in clinical practice. PMID:27307517

  5. Right atrial appendage tachycardia: A rare cause of tachycardia induced cardiomyopathy with successful radiofrequency ablation using the 3D mapping system

    PubMed Central

    Bokhari, Fayez; AlQurashi, Moayad; Raslan, Omar; Alama, Nabil

    2013-01-01

    We report the case of a 40-year-old patient with incessant supraventricular tachycardia (SVT). As this SVT was resistant to medical therapy and was complicated by severe LV dysfunction and cardiogenic shock, the patient was referred for EPS (electrophysiologic study) and ablation. EPS and successful ablation of the right atrial appendage (RAA) tachycardia were performed by means of a 3D mapping system NavX (St. Jude Medical, St. Paul, MN, USA) with complete resolution of symptoms and normalization of LV function, as evaluated at three-month follow-up examination. PMID:24198452

  6. Investigation of the atrial conduction time measured by tissue Doppler imaging at the left atrial appendage and the actual electrical conduction time: consideration of left atrial remodeling in atrial fibrillation patients.

    PubMed

    Hori, Yuichi; Nakahara, Shiro; Anjo, Naofumi; Nakagawa, Ayako; Nishiyama, Naoki; Yamada, Kouta; Hayashi, Akiko; Komatsu, Takaaki; Kobayashi, Sayuki; Sakai, Yoshihiko; Taguchi, Isao

    2017-01-01

    The atrial conduction time measured by echocardiography using tissue Doppler imaging (TDI) has been reported as a predictive factor of left atrial (LA) remodeling. We investigated the P wave to LA appendage (LAA) conduction time defined by transthoracic echocardiography using TDI (P-LAA TDI), and directly compared the actual LA electrical conduction time determined by the electrophysiological data. Additionally, we confirmed the clinical utility of the P-LAA TDI by examining the relationship to the electroanatomical LA remodeling data. Sixty-three AF patients (22 paroxysmal AF, 41 persistent AF) underwent ablation and electroanatomical LA mapping. The P-LAA TDI was measured after the ablation and was compared with the electrophysiological data during sinus rhythm, including the actual electrical conduction time. A strong linear correlation (r = 0.776, p < 0.001, y = 1.28x + 49) was observed between the P-LAA TDI (161 ± 24 ms) and electrophysiological P-LAA time (87 ± 15 ms). The P-LAA TDI was also strongly correlated with the LA volume (173 ± 52 ml, r = 0.632, p < 0.001) and LA conduction velocity index (1.07 ± 0.19 mm/ms, r = -0.735, p < 0.001), but less to the focal anterior-LVA region surface area (2.2 [0.4-5.0] cm(2), r = 0.380, p = 0.002). Additionally, a stepwise multiple linear regression demonstrated that both the LA volume and LA conduction velocity index were strongly associated with the value of the P-LAA TDI (p < 0.001). The P-LAA TDI was useful for estimating the actual electrophysiological conduction time and represented both electrical and anatomical LA remodeling.

  7. A comparison of two-dimensional and real-time 3D transoesophageal echocardiography and angiography for assessing the left atrial appendage anatomy for sizing a left atrial appendage occlusion system: impact of volume loading.

    PubMed

    Al-Kassou, Baravan; Tzikas, Apostolos; Stock, Friederike; Neikes, Fabian; Völz, Alexander; Omran, Heyder

    2017-04-20

    Correct sizing of a left atrial appendage (LAA) closure system is important to avoid redeployment of the device and peri-device leaks. The aims of this study were to assess the significance of two-dimensional transoesophageal echocardiography (2D-TEE), real-time 3D transoesophageal echocardiography (RT 3D-TEE) and angiography for measuring the size of the LAA landing zone and to determine the impact on sizing an LAA closure device. Furthermore, we investigated the relevance of volume loading on LAA size. In a prospective study, 46 patients underwent 2D-TEE and RT 3D-TEE 24 hours prior to LAA closure, at the beginning of the procedure and just before the procedure after volume loading with an average of 1,035±246 ml. Angiography was performed immediately before the implantation. Maximal diameter (2.2±0.4 versus 2.3±0.4 cm; p<0.01), perimeter (6.5±1.0 versus 6.8±1.0 cm, p<0.01) and area (3.2±1.0 versus 3.5±1.1 cm², p<0.01) of the LAA increased significantly after volume loading. The highest correlation (R) between measurements and LAA device size was found for RT 3D-TEE-derived perimeter (R=0.97) and area (R=0.96), whereas the maximal diameter (R=0.78) measured by 2D-TEE and angiography (R=0.76) correlated less closely. Sizing based on an RT 3D-TEE-measured perimeter resulted only in 4% of undersizing the implanted device. Peri-device leaks occurred in seven cases (15%) and were associated with a lower compression of LAA devices (7±1.3% versus 14±3.2% for patients without leaks, p<0.001). Volume loading before LAA closure increases LAA dimensions significantly. RT 3D-TEE measurements show a closer correlation to LAA closure device size than 2D-TEE or angiographic measurements.

  8. The New 3D Printed Left Atrial Appendage Closure with a Novel Holdfast Device: A Pre-Clinical Feasibility Animal Study

    PubMed Central

    Brzeziński, M.; Bury, K.; Dąbrowski, L.; Holak, P.; Sejda, A.; Pawlak, M.; Jagielak, D.; Adamiak, Z.; Rogowski, J.

    2016-01-01

    Introduction Many patients undergoing cardiac surgery have risk factors for both atrial fibrillation (AF) and stroke. The left atrial appendage (LAA) is the primary site for thrombi formation. The most severe complication of emboli derived from LAA is stroke, which is associated with a 12-month mortality rate of 38% and a 12-month recurrence rate of 17%. The most common form of treatment for atrial fibrillation and stroke prevention is the pharmacological therapy with anticoagulants. Nonetheless this form of therapy is associated with high risk of major bleeding. Therefore LAA occlusion devices should be tested for their ability to reduce future cerebral ischemic events in patients with high-risk of haemorrhage. Aim The aim of this study was to evaluate the safety and feasibility of a novel left atrial appendage exclusion device with a minimally invasive introducer in a swine model. Materials and Methods A completely novel LAA device, which is composed of two tubes connected together using a specially created bail, was designed using finite element modelling (FEM) to obtain an optimal support force of 36 N at the closure line. The monolithic form of the occluder was obtained by using additive manufacturing of granular PA2200 powder with the technology of selective laser sintering (SLS). Fifteen swine were included in the feasibility tests, with 10 animals undergoing fourteen days of follow-up and 5 animals undergoing long-term observation of 3 months. For one animal, the follow-up was further prolonged to 6 months. The device was placed via minithoracotomy. After the observation period, all of the animals were euthanized, and their hearts were tested for LAA closure and local inflammatory and tissue response. Results After the defined observation period, all fifteen hearts were explanted. In all cases the full closure of the LAA was achieved. The macroscopic and microscopic evaluation of the explanted hearts showed that all devices were securely integrated in the

  9. Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures.

    PubMed

    Li, Cai-Ying; Gao, Bu-Lang; Liu, Xiao-Wei; Fan, Qiong-Ying; Zhang, Xue-Jing; Liu, Guo-Chao; Yang, Hai-Qing; Feng, Ping-Yong; Wang, Yong; Song, Peng

    2015-01-01

    To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05) present in women (8.0%) than in men (4.2%). LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01) major axis in men (24.79±3.81) than in women (22.68±4.07). The LAA orifice long axis was significantly (P<0.05) positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05) greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05) positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume. The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation procedures.

  10. ANMCO/AIAC/SICI-GISE/SIC/SICCH Consensus Document: percutaneous occlusion of the left atrial appendage in non-valvular atrial fibrillation patients: indications, patient selection, staff skills, organisation, and training

    PubMed Central

    Gulizia, Michele Massimo; Molon, Giulio; Mazzone, Patrizio; Audo, Andrea; Casolo, Giancarlo; Di Lorenzo, Emilio; Portoghese, Michele; Pristipino, Christian; Ricci, Renato Pietro; Themistoclakis, Sakis; Padeletti, Luigi; Tondo, Claudio; Berti, Sergio; Oreglia, Jacopo Andrea; Gerosa, Gino; Zanobini, Marco; Ussia, Gian Paolo; Musumeci, Giuseppe; Romeo, Francesco; Di Bartolomeo, Roberto

    2017-01-01

    Abstract Atrial fibrillation (AF) is the most common arrhythmia and its prevalence is increasing due to the progressive aging of the population. About 20% of strokes are attributable to AF and AF patients are at five-fold increased risk of stroke. The mainstay of treatment of AF is the prevention of thromboembolic complications with oral anticoagulation therapy. Drug treatment for many years has been based on the use of vitamin K antagonists, but recently newer and safer molecules have been introduced (dabigatran etexilate, rivaroxaban, apixaban, and edoxaban). Despite these advances, many patients still do not receive adequate anticoagulation therapy because of contraindications (relative and absolute) to this treatment. Over the last decade, percutaneous closure of left atrial appendage, main site of thrombus formation during AF, proved effective in reducing thromboembolic complications, thus offering a valid medical treatment especially in patients at increased bleeding risk. The aim of this consensus document is to review the main aspects of left atrial appendage occlusion (selection and multidisciplinary assessment of patients, currently available methods and devices, requirements for centres and operators, associated therapies and follow-up modalities) having as a ground the significant evolution of techniques and the available relevant clinical data. PMID:28751849

  11. Efficacy and safety of left atrial appendage closure versus medical treatment in atrial fibrillation: a network meta-analysis from randomised trials.

    PubMed

    Sahay, Shweta; Nombela-Franco, Luis; Rodes-Cabau, Josep; Jimenez-Quevedo, Pilar; Salinas, Pablo; Biagioni, Corina; Nuñez-Gil, Ivan; Gonzalo, Nieves; de Agustín, Jose Alberto; Del Trigo, Maria; Perez de Isla, Leopoldo; Fernández-Ortiz, Antonio; Escaned, Javier; Macaya, Carlos

    2017-01-15

    The effectiveness of vitamin K antagonist (VKA) versus placebo and antiplatelet therapy (APT) is well established for stroke prevention in atrial fibrillation (AF). Non-vitamin K antagonist oral anticoagulants (NOAC) are mostly superior to VKA in stroke and intracranial bleeding prevention. Recent randomised controlled trials (RCTs) suggested the non-inferiority of percutaneous left atrial appendage closure (LAAC) versus VKA. However, comparisons between LAAC versus placebo, APT or NOAC are lacking. The purpose of this network meta-analysis was to assess the efficacy and safety of LAAC compared with other strategies for stroke prevention in patients with AF. We pooled together all RCTs comparing warfarin with placebo, APT or NOAC in patients with AF using meta-analysis guidelines. Two major trials of LAAC were also included and a network meta-analysis was performed to compare the impact of LAAC on mortality, stroke/systemic embolism (SE) and major bleeding in relation to medical treatment. The network meta-analysis included 19 RCTs with a total of 87 831 patients with AF receiving anticoagulants, APT, placebo or LAAC. Indirect comparison with network meta-analysis using warfarin as the common comparator revealed efficacy benefit favouring LAAC as compared with placebo (mortality: HR 0.38, 95% CI 0.22 to 0.67, p<0.001; stroke/SE: HR 0.24, 95% CI 0.11 to 0.52, p<0.001) and APT (mortality: HR 0.58, 95% CI 0.37 to 0.91, p=0.0018; stroke/SE: HR 0.44, 95% CI 0.23 to 0.86, p=0.017) and similar to NOAC (mortality: HR 0.76, 95% CI 0.50 to 1.16, p=0.211; stroke/SE: HR 1.01, 95% CI 0.53 to 1.92, p=0.969). LAAC showed comparable rates of major bleeding when compared with placebo (HR 2.33, 95% CI 0.67 to 8.09, p=0.183), APT (HR 0.75, 95% CI 0.30 to 1.88, p=0.542) and NOAC (HR 0.80, 95% CI 0.33 to 1.94, p=0.615). The findings of this meta-analysis suggest that LAAC is superior to placebo and APT, and comparable to NOAC for preventing mortality and stroke or SE, with similar

  12. A 64-slice multi-detector CT scan could evaluate the change of the left atrial appendage thrombi of the atrial fibrillation patient, which was reduced by warfarin therapy.

    PubMed

    Takeuchi, Hidekazu

    2011-08-19

    Curable cause of stroke is the left atrial appendage (LAA) thrombi of atrial fibrillation (AF) patients. Some AF patients have the LAA thrombi. It is very important to cure AF patients by warfarin. Transoesophageal echocardiography (TOE) is the usual clinical tool to detect the LAA thrombi. Recently, a 64-slice multi-detector CT (64-MDCT) scan enables us to display the LAA thrombi more easily than TOE. I reported a case that a 64-MDCT scan had been used successfully in displaying the change of the LAA thrombi reduced by warfarin therapy. The size of the LAA thrombi was reduced from 25.2 mm × 19.3 mm (figure 1) to 22.1 mm × 14.8 mm (figure 2) after the 3-month warfarin therapy. It was useful to estimate the LAA thrombi by a 64-MDCT scan to estimate LAA thrombi itself and the change of LAA thrombi to evaluate the effectiveness of warfarin therapy.

  13. Bleeding Outcomes After Left Atrial Appendage Closure Compared With Long-Term Warfarin: A Pooled, Patient-Level Analysis of the WATCHMAN Randomized Trial Experience.

    PubMed

    Price, Matthew J; Reddy, Vivek Y; Valderrábano, Miguel; Halperin, Jonathan L; Gibson, Douglas N; Gordon, Nicole; Huber, Kenneth C; Holmes, David R

    2015-12-28

    The purpose of this study was to compare the relative risk of major bleeding with left atrial appendage (LAA) closure compared with long-term warfarin therapy. LAA closure is an alternative approach to chronic oral anticoagulation for the prevention of thromboembolism in patients with atrial fibrillation (AF). We conducted a pooled, patient-level analysis of the 2 randomized clinical trials that compared WATCHMAN (Boston Scientific, Natick, Massachusetts) LAA closure with long-term warfarin therapy in AF. A total of 1,114 patients were included, with a median follow-up of 3.1 years. The overall rate of major bleeding from randomization to the end of follow-up was similar between treatment groups (3.5 events vs. 3.6 events per 100 patient-years; rate ratio [RR]: 0.96; 95% confidence interval [CI]: 0.66 to 1.40; p = 0.84). LAA closure significantly reduced bleeding >7 days post-randomization (1.8 events vs. 3.6 events per 100 patient-years; RR: 0.49; 95% CI: 0.32 to 0.75; p = 0.001), with the difference emerging 6 months after randomization (1.0 events vs. 3.5 events per 100 patient-years; RR: 0.28; 95% CI: 0.16 to 0.49; p < 0.001), when patients assigned to LAA closure were able to discontinue adjunctive oral anticoagulation and antiplatelet therapy. The reduction in bleeding with LAA closure was directionally consistent across all patient subgroups. There was no difference in the overall rate of major bleeding in patients assigned to LAA closure compared with extended warfarin therapy over 3 years of follow-up. However, LAA closure significantly reduced bleeding beyond the procedural period, particularly once adjunctive pharmacotherapy was discontinued. The favorable effect of LAA closure on long-term bleeding should be considered when selecting a stroke prevention strategy for patients with nonvalvular AF. (WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure

  14. Left atrial appendage occlusion with the AMPLATZER Amulet device: periprocedural and early clinical/echocardiographic data from a global prospective observational study.

    PubMed

    Landmesser, Ulf; Schmidt, Boris; Nielsen-Kudsk, Jens Erik; Lam, Simon Cheung Chi; Park, Jai-Wun; Tarantini, Giuseppe; Cruz-Gonzalez, Ignacio; Geist, Volker; Della Bella, Paolo; Colombo, Antonio; Zeus, Tobias; Omran, Heyder; Piorkowski, Christopher; Lund, Juha; Tondo, Claudio; Hildick-Smith, David

    2017-09-20

    The global, prospective AMPLATZER Amulet observational study documents real-world periprocedural, transoesophageal echocardiographic (TEE) and clinical outcomes from left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device. The aim of this report is to describe the periprocedural and early clinical/TEE results from this study. This multicentre prospective real-world registry included 1,088 patients (75±8.5 years, 64.5% male, CHA2DS2-VASc: 4.2±1.6, HAS-BLED: 3.3±1.1) with non-valvular atrial fibrillation; 82.8% of patients were considered to have an absolute or relative contraindication to long-term anticoagulation and 72.4% had had a previous major bleeding. Periprocedural results, clinical outcomes up to the first three months and the available TEE results from the first scheduled follow-up (one to three months post implant) are reported. Successful device implantation was achieved in 99.0% of patients. During the procedure and index hospitalisation, major adverse events occurred in 3.2% of patients. Patients were discharged on a single antiplatelet agent (23.0%), dual antiplatelets (54.3%) or an oral anticoagulant (18.9%). TEE follow-up 67±23 days post procedure in 673 patients showed adequate (<3 mm jet) occlusion of the appendage in 98.2% of patients and device thrombus in 10 patients (1.5%), as evaluated by core laboratory analysis. This large real-world prospective registry of catheter-based LAAO using the AMPLATZER Amulet device reports a high implant success rate and a low periprocedural complication rate in a population with a high risk of stroke and bleeding. Transoesophageal echo data confirm good closure rates during follow-up and low rates of device-associated thrombus.

  15. Clinical impact of quantitative left atrial vortex flow analysis in patients with atrial fibrillation: a comparison with invasive left atrial voltage mapping.

    PubMed

    Lee, Jung Myung; Hong, Geu-Ru; Pak, Hui-Nam; Shim, Chi Young; Houle, Helene; Vannan, Mani A; Kim, Minji; Chung, Namsik

    2015-08-01

    Recently, left atrial (LA) vortex flow analysis using contrast transesophageal echocardiography (TEE) has been shown to be feasible and has demonstrated significant differences in vortex flow morphology and pulsatility between normal subjects and patients with atrial fibrillation (AF). However, the relationship between LA vortex flow and electrophysiological properties and the clinical significance of LA vortex flow are unknown. The aims of this study were (1) to compare LA vortex flow parameters with LA voltage and (2) to assess the predictive value of LA vortex flow parameters for the recurrence of AF after radiofrequency catheter ablation (RFCA). Thirty-nine patients with symptomatic non-valvular AF underwent contrast TEE before undergoing RFCA for AF. Quantitative LA vortex flow parameters were analyzed by Omega flow (Siemens Medical Solution, Mountain View, CA, USA). The morphology and pulsatility of LA vortex flow were compared with electrophysiologic parameters that were measured invasively. Hemodynamic, electrophysiological, and vortex flow parameters were compared between patients with and without early recurrence of AF after RFCA. Morphologic parameters, including LA vortex depth, length, width, and sphericity index were not associated with LA voltage or hemodynamic parameters. The relative strength (RS), which represents the pulsatility power of LA, was positively correlated with LA voltage (R = 0.53, p = 0.01) and LA appendage flow velocity (R = 0.73, p < 0.001) and negatively correlated with LA volume index (R = -0.56, p < 0.001). Patients with recurrent AF after RFCA showed significantly lower RS (1.7 ± 0.2 vs 1.9 ± 0.4, p = 0.048) and LA voltage (0.9 ± 0.7 vs 1.7 ± 0.8, p = 0.004) than patients without AF recurrence. In the relatively small LA dimension group (LA volume index ≤ 33 ml/m(2)), RS was significantly lower (2.1 ± 0.3 vs 1.7 ± 0.1, p = 0.029) in patients with the recurrent AF. Quantitative LA vortex flow analysis, especially RS

  16. 3D printing for sizing left atrial appendage closure device: Head-to-head comparison with computed tomography and transesophageal echocardiography.

    PubMed

    Hell, Michaela M; Achenbach, Stephan; Yoo, In Seong; Franke, Joerg; Blachutzik, Florian; Roether, Jens; Graf, Verena; Raaz-Schrauder, Dorette; Marwan, Mohamed; Schlundt, Christian

    2017-07-04

    Device sizing for LAA closure using transesophageal echocardiography (TEE) can be challenging due to complex LAA anatomy. We investigated whether the use of 3D-printed left atrial appendage (LAA) models based on pre-procedural computed tomography (CT) permits accurate device sizing. 22 patients (73±8 years, 55% male) with atrial fibrillation requiring anticoagulation at high bleeding risk underwent LAA closure (WatchmanTM device). Pre-procedurally, LAA was sized by TEE and third-generation dual-source CT. Based on CT, 3D printing models of LAA anatomy were created for simulation of device implantation. Device compression was assessed in a CT scan of the 3D model with implanted device. Implantation was successful in all patients. Mean LAA ostium diameter based on TEE was 22±4 mm and based on CT 25±3 mm (p=0.014). Predicted device size based on simulated implantation in the 3D model was equal to the finally implanted device in 21/22 patients (95%). TEE would have undersized the device in 10/22 patients (45%). Device compression determined in the 3D-CT-model corresponded closely with compression upon implantation (16±3% vs. 18±5%, r=0.622, p=0.003). Patient-specific CT-based 3D printing models may assist device selection and prediction of device compression in the context of interventional LAA closure.

  17. The impact of the latest echocardiographic chamber quantification recommendations on the prediction of left atrial appendage thrombus presence by transthoracic echocardiography.

    PubMed

    Kupczynska, Karolina; Kasprzak, Jaroslaw D; Michalski, Blazej W; Miskowiec, Dawid L; Lipiec, Piotr

    2017-08-11

    The latest recommendations for echocardiographic chamber quantification have implemented updated normal values for all cardiac chambers. To evaluate the incidence of normal and abnormal values of routine echocardiographic parameters such as left ventricular ejection fraction (LVEF) and left atrial volume indexed to body surface area (LAVi) in patients with non-valvular atrial fibrillation (AF) and to determine the influence of LVEF and LAVi reclassification on the prediction of LAAT by transthoracic echocardiography. We retrospectively analysed the database of 1674 transesophageal echocardiograms performed between 2012 and 2015 in our echo lab. The study involved patients (mean age 70 ± 7 years, 80% men) with paroxysmal or persistent AF (35 patients with left atrial appendage thrombus [LAAT] and 35 sex- and age-matched controls without LAAT). LVEF and LAVi were categorised in two ways: semi-quantitative using four-degree scale (normal or abnormal graded from mild and moderate to severe) and qualitative (normal vs. abnormal). We reclassified 6 (9%) and 4 (6%) patients with regard to LVEF as well as 38 (54%) and 16 (23%) with regard to LAVi on semi-quantitative and qualitative scale, respectively. After adjustment for effective anticoagulation and approved risk factors in the multivariate models, we identified LVEF categorised in semi-quantitative manner according to both documents, LAVi categorised in a binary manner by new guidelines and semi-quantitative scale by both recommendations as independently associated with LAAT. Differentiation between normal and abnormal value enhanced the diagnostic meaning of LAVi in the aspect of higher LAAT risk. LVEF reclassification had no significant influence.

  18. The impact of surgical left atrial appendage amputation/ligation on stroke prevention in patients undergoing off-pump coronary artery bypass grafting.

    PubMed

    Endo, Daisuke; Kato, Tomoko S; Iwamura, Tai; Oishi, Atsumi; Yokoyama, Yasutaka; Kuwaki, Kenji; Inaba, Hirotaka; Amano, Atsushi

    2016-11-09

    Stroke is a major adverse event in patients developing atrial fibrillation (AF) after cardiac surgery. Surgical left atrial appendage amputation/ligation (LAA-A/L) during off-pump coronary artery bypass grafting (OPCAB) is routinely performed in our institution. We analyzed 578 consecutive patients (mean age 69 years, male 82%) undergoing OPCAB with or without concomitant LAA-A/L from 2011 to 2014 at our institution in a prospective observational manner. The safety and efficacy of the concomitant LAA-A/L on preventing early (<30 days) and overall postoperative stroke were examined. A total of 193 patients (33.4%) underwent LAA-A/L, consisting of amputation in 154 and ligation in 39 patients (80 and 20% of the cases, respectively). Preoperative characteristics, operative time, requirement of blood transfusion, and 30-day mortality were not significantly different between those with and without LAA-A/L. The incidences of postoperative AF and early and overall stroke were not significantly different between the groups in the analysis based on a total cohort. In a subanalysis of patients without LAA-A/L, early and overall stroke occurred more frequently in those developing postoperative AF than those without AF (2.8 vs. 0%; p = 0.005, 6.2 vs. 1.5%; p = 0.017, respectively), while in patients receiving LAA-A/L, stroke incidences did not differ between those with and without AF. Multivariate logistic regression showed postoperative AF without LAA-A/L as the only independent positive predictor of overall stroke (OR 3.69, p = 0.03). Concomitant LAA-A/L with OPCAB can safely prevent postoperative stroke occurrence in case patients develop AF, the most common arrhythmia associated with stroke.

  19. Appraising the safety and efficacy profile of left atrial appendage closure in 2016 and the future clinical perspectives. Results of the EAPCI LAAC survey.

    PubMed

    Santucci, Andrea; Byrne, Robert A; Baumbach, Andreas; Colleran, Roisin; Haude, Michael; Windecker, Stephan; Valgimigli, Marco

    2016-05-17

    The aim of this study was to determine the opinion of the scientific community regarding percutaneous left atrial appendage closure (LAAC). The main focus of the survey was on concerns and expectations regarding the safety and efficacy profile of LAAC in clinical practice and on current and future clinical perspectives. A voluntary web-based survey was distributed by the European Association of Percutaneous Coronary Interventions (EAPCI) to all individuals registered on the EuroIntervention mailing list (n=21,800). A total of 724 physicians responded to the survey, of whom 31.8% had first operator experience with LAAC. Exclusive use of the Amulet (34.4%) or WATCHMAN (30.3%) was similar, but the former was the most frequently used device in Europe. The majority of respondents (59.3%) deemed LAAC to be as effective as, but safer than oral anticoagulants (OAC) in reducing stroke risk. Periprocedural complications (40.3%) and cost (28.8%) were the major concerns. Most practitioners did not consider novel oral anticoagulants (NOACs) to be a deterrent for performing LAAC procedures. Moreover, a history of serious haemorrhage was not deemed necessary to justify LAAC for 59.8% of physicians. The results of this survey reveal a high level of confidence in percutaneous LAAC amongst surveyed interventional cardiologists, with the majority believing it to be as effective as OAC in terms of stroke prevention and safer in terms of bleeding risk.

  20. Digitalis does not improve left atrial mechanical dysfunction after successful electrical cardioversion of chronic atrial fibrillation.

    PubMed

    Yujing, Wang; Congxin, Huang; Shaning, Yang; Lijun, Jin; Xiaojun, Hu; Gang, Wu; Qiang, Xie

    2010-05-01

    This study was designed to investigate whether administration of digitalis could improve mechanical function of left atrial appendage (LAA) and left atrium prospectively in patients with atrial stunning. Fifty-four consecutive patients in whom atrial stunning was observed immediately after cardioversion of chronic atrial fibrillation (AF) were randomized into digitalis or control group for 1 week following cardioversion. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed prior to, immediately following, 1 day after and 1 week after cardioversion to measure transmitral flow velocity and LAA flow velocity. Electrical cardioversion of AF elicited significantly slower left atrial appendage peak emptying velocity (LAA-PEV) and peak filling velocity (LAA-PFV) immediately following cardioversion in both groups. 1 day post cardioversion, there were no significant differences in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or left atrial appendage ejection fraction (LAA-EF) between digitalis and control groups. 1 week post cardioversion, no significant differences were found in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or LAA-EF between the two groups. The occurrence rates of spontaneous echo contrast were not significantly different between digitalis and control groups one day and one week post cardioversion. In conclusion, digitalis did not improve left atrial and appendage mechanical dysfunction following cardioversion of chronic AF. Digitalis did not prevent the development of spontaneous echo contrast in left atrial chamber and appendage. This may be due to the fact that digitalis aggravates intracellular calcium overload induced by chronic AF and has a negative effect on ventricular rate.

  1. EWOLUTION: Design of a registry to evaluate real-world clinical outcomes in patients with AF and high stroke risk-treated with the WATCHMAN left atrial appendage closure technology.

    PubMed

    Boersma, Lucas V A; Schmidt, Boris; Betts, Tim R; Sievert, Horst; Tamburino, Corrado; Teiger, Emmanuel; Stein, Kenneth M; Bergmann, Martin W

    2016-09-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and the rate of ischemic stroke attributed to non-valvular AF is estimated at 5% per year. Several multi-center studies established left atrial appendage closure as a safe and effective alternative to oral anticoagulation, but there is a need for additional real world data. The purpose of this observational, prospective, single-arm, multicenter clinical study is to compile real-world clinical outcome data for WATCHMAN™ LAA (left atrial appendage) Closure Technology. One thousand subjects at up to 70 institutions in Europe, the Middle East, and Russia will be enrolled. Patients will be followed for 2 years after WATCHMAN implantation, according to standard medical practice. Primary endpoints include procedural and long-term data including stroke/embolism, bleeding, and death. This article presents the background of the LAAC device and describes the design of the study. Results for peri-procedural analyses are expected toward the end of 2015; long-term follow-up data are expected in the latter half of 2017. The EWOLUTION study will formally expand knowledge of LAA closure into a broader real world setting. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  2. Device-associated thrombus formation after left atrial appendage occlusion: A systematic review of events reported with the Watchman, the Amplatzer Cardiac Plug and the Amulet.

    PubMed

    Lempereur, Mathieu; Aminian, Adel; Freixa, Xavier; Gafoor, Sameer; Kefer, Joelle; Tzikas, Apostolos; Legrand, Victor; Saw, Jacqueline

    2017-02-01

    This study aimed to provide a systematic review of device-associated thrombosis (DAT) after left atrial appendage occlusion (LAAO) with the Watchman, Amplatzer Cardiac Plug, and Amulet devices. DAT is known as a complication of LAAO but data about its clinical impact is scarce. A systematic review of studies evaluating the incidence, treatment and clinical implications of DAT from January 2008 to September 2015 was conducted. A total of 30 studies describing DAT events were included in the analysis. The overall incidence of DAT was 3.9% (82 DAT for 2118 implanted devices). The median time from procedure to diagnosis of DAT was 1.5 months (IQR: 0-2.9). Most cases were diagnosed with transesophageal echocardiogram (TEE). The treatment consisted of low molecular weight heparin (LMWH) in 45.5% of cases, and oral anticoagulation (OAC) or other treatment modalities in 54.5%. Complete thrombus resolution was achieved in 95.0% of cases (100% with LMWH and 89.5% with OAC). Treatment duration varied greatly with a median treatment duration of 45 days (IQR: 14-135). Clinical events related to DAT consisted of neurologic events namely two transient ischemic attacks (2.4%) and four ischemic strokes (4.9%). DAT is an infrequent complication of percutaneous LAAO. It occurs mainly early after the procedure and is associated with a low rate of neurological complications. In the majority of cases, diagnosis is made during follow-up imaging with TEE. Anticoagulation treatment seems to be safe and highly effective. Further studies are needed to evaluate the optimal management of DAT. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Mesenchymal stem cell secreted platelet derived growth factor exerts a pro-migratory effect on resident Cardiac Atrial appendage Stem Cells.

    PubMed

    Windmolders, Severina; De Boeck, Astrid; Koninckx, Remco; Daniëls, Annick; De Wever, Olivier; Bracke, Marc; Hendrikx, Marc; Hensen, Karen; Rummens, Jean-Luc

    2014-01-01

    Mesenchymal stem cells (MSCs) modulate cardiac healing after myocardial injury through the release of paracrine factors, but the exact mechanisms are still unknown. One possible mechanism is through mobilization of endogenous cardiac stem cells (CSCs). This study aimed to test the pro-migratory effect of MSC conditioned medium (MSC-CM) on endogenous CSCs from human cardiac tissue. By using a three-dimensional collagen assay, we found that MSC-CM improved migration of cells from human cardiac tissue. Cell counts, perimeter and area measurements were utilized to quantify migration effects. To examine whether resident stem cells were among the migrating cells, specific stem cell properties were investigated. The migrating cells displayed strong similarities with resident Cardiac Atrial appendage Stem Cells (CASCs), including a clonogenic potential of ~21.5% and expression of pluripotency associated genes like Oct-4, Nanog, c-Myc and Klf-4. Similar to CASCs, migrating cells demonstrated high aldehyde dehydrogenase activity and were able to differentiate towards cardiomyocytes. Receptor tyrosine kinase analysis and collagen assays performed with recombinant platelet derived growth factor (PDGF)-AA and Imatinib Mesylate, a PDGF receptor inhibitor, suggested a role for the PDGF-AA/PDGF receptor α axis in enhancing the migration process of CASCs. In conclusion, our findings demonstrate that factors present in MSC-CM improve migration of resident stem cells from human cardiac tissue. These data open doors towards future therapies in which MSC secreted factors, like PDGF-AA, can be utilized to enhance the recruitment of CASCs towards the site of myocardial injury. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Incomplete left atrial appendage occlusion and thrombus formation after Watchman implantation treated with anticoagulation followed by further transcatheter closure with a second-generation Amplatzer Cardiac Plug (Amulet device).

    PubMed

    Lam, Simon Cheung Chi; Bertog, Stefan; Sievert, Horst

    2015-02-01

    We report a case of incomplete left atrial appendage (LAA) closure after Watchman device (Atritech, Boston Scientific, Natrick, MA) implantation which subsequently developed a thrombus 3 years after the initial procedure. The thrombus resolved after a short period of anticoagulation with warfarin, and the LAA was successfully occluded with a second-generation Amplatzer Cardiac Plug (Amulet device, AGA, St Jude Medical, Minneapolis, MN). Incomplete LAA closure may be associated with increased risk of thrombus formation and further closure with a second device after a course of anticoagulation may be a reasonable and feasible strategy. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  5. Effect of percutaneous transvenous mitral commissurotomy on left atrial appendage function: an immediate and 6-month follow-up transesophageal Doppler study.

    PubMed

    Vijayvergiya, Rajesh; Sharma, Rajat; Shetty, Ranjan; Subramaniyan, Anand; Karna, Sunil; Chongtham, Dhanraj

    2011-11-01

    The left atrial appendage (LAA) is a common site of thrombus formation and is the source of systemic thromboembolism in patients with rheumatic mitral stenosis. LAA contractile dysfunction is a common finding in these patients. The aim of this study was to assess immediate and 6-month follow-up LAA function by transesophageal Doppler echocardiography in patients who underwent percutaneous transvenous mitral commissurotomy (PTMC). Forty-seven consecutive patients with symptomatic critical mitral stenosis who underwent PTMC were enrolled. All had underwent transthoracic and transesophageal echocardiography before, 24 hours after, and 6 months after PTMC. Pulse Doppler velocities of the LAA were measured, including peak early diastolic (E wave), peak late diastolic (A wave), and peak systolic (S wave). The corresponding tissue Doppler velocities of the LAA, including peak early diastolic (E(LAA)), peak late diastolic (A(LAA)), and peak systolic (S(LAA)), were also measured. LAA ejection fraction was measured using the modified Simpson's method. The mean age of the 47 enrolled patients was 31.7 ± 10.26 years. Thirty-eight patients were in sinus rhythm, and the remaining nine were in atrial fibrillation. PTMC was successful in all patients. The pulse Doppler velocities of the LAA at baseline, after PTMC, and at 6-month follow-up were as follows: for the E wave, 15.29 ± 2.26, 17.02 ± 2.25, and 17.97 ± 2.55 cm/sec, respectively (P < .001); for the A wave 22.45 ± 4.11, 24.19 ± 4.21, and 25.99 ± 4.51 cm/sec, respectively (P < .001); and for the S wave, 28.52 ± 4.37, 31.45 ± 5.37, and 33.06 ± 4.99 cm/sec, respectively (P < .001). The corresponding tissue Doppler velocities of LAA were as follows: for E(LAA), 4.65 ± 0.91, 5.28 ± 0.85, and 5.80 ± 0.84 cm/sec, respectively (P < .001); for A(LAA), 6.67 ± 1.12, 7.33 ± 1.17, and 7.88 ± 1.22 cm/sec, respectively (P < .001); and for S(LAA), 4.67 ± 1.12, 5.52 ± 1.18, 6.07 ± 1.11 cm/sec, respectively (P < .001

  6. Rationale and design of a study exploring the efficacy of once-daily oral rivaroxaban (X-TRA) on the outcome of left atrial/left atrial appendage thrombus in nonvalvular atrial fibrillation or atrial flutter and a retrospective observational registry providing baseline data (CLOT-AF).

    PubMed

    Lip, Gregory Y H; Hammerstingl, Christoph; Marin, Francisco; Cappato, Riccardo; Meng, Isabelle Ling; Kirsch, Bodo; Morandi, Eolo; van Eickels, Martin; Cohen, Ariel

    2015-04-01

    There are still many unresolved issues concerning patient outcomes and prognostic factors in patients with atrial fibrillation (AF) and left atrial/left atrial appendage (LA/LAA) thrombi. Rivaroxaban (Xarelto®), a potent and highly selective oral, direct factor Xa inhibitor, is a new therapeutic option in this setting. The planned study program will consist of a prospective interventional study (X-TRA) and a retrospective observational registry (CLOT-AF). The primary objective of the X-TRA study is to explore the efficacy of rivaroxaban in the treatment of LA/LAA thrombi in patients with nonvalvular AF or atrial flutter, scheduled to undergo cardioversion or AF ablation, in whom an LA/LAA thrombus has been found on transesophageal echocardiography (TEE) before the procedure. The primary end point is the complete LA/LAA thrombus resolution rate at 6 weeks of end of treatment confirmed by TEE. The secondary objectives are to describe categories of thrombus outcome in patients (resolved, reduced, unchanged, larger, or new) confirmed on TEE at the end of treatment (after 6 weeks of treatment), incidence of the composite of stroke and noncentral nervous system systemic embolism at the end of treatment and during follow-up, and incidence of all bleeding at the end of treatment and during follow-up. The objective of the CLOT-AF registry is to provide retrospective thrombus-related patient outcome data after standard-of-care anticoagulant treatment in patients with nonvalvular AF or atrial flutter, who have TEE-documented LA/LAA thrombi. The data will be used as a reference for the prospective X-TRA study. In conclusion, X-TRA and CLOT-AF will provide some answers to the many unresolved issues concerning patient outcomes and prognostic factors in patients with AF and LAA thrombi. Results from this study program would provide the first prospective interventional study (X-TRA) and a large international retrospective observational registry (CLOT-AF) on the prevalence and

  7. Dynamic regulation of atrial coronary blood flow in healthy adult pigs.

    PubMed

    van Bragt, Kelly A; Nasrallah, Hussein M; Kuiper, Marion; van Hunnik, Arne; Kuijpers, Nico H L; Schotten, Ulrich; Verheule, Sander

    2015-05-01

    There are several indications for a mismatch between atrial oxygen supply and demand during atrial fibrillation (AF), but atrial coronary flow regulation has not been investigated extensively. The purpose of this study was to characterize the dynamic regulation of atrial coronary flow in pigs. In anesthetized open-chest pigs, Doppler flow probes were placed around left atrial (LA) and left ventricular (LV) branches of the circumflex artery. Pressures and work indices were measured simultaneously. Systolic and diastolic flow contribution, flow response kinetics, and relationship between pressures, work, and flow were investigated during sinus rhythm, atrial pacing, and acute AF. During atrial systole, LA flow decreased. Only 2% of total LA flow occurred during atrial systole. Pacing with 2:1 AV block and infusion of acetylcholine revealed that atrial contraction itself impeded atrial coronary flow. The response to sudden changes in heart rate was slower in LA compared to LV. Both LA and LV vascular conductance were positively correlated with work. After the cessation of acute AF, the LA showed a more pronounced phase of supranormal vascular conductance than the LV, indicating a period of atrial reactive hyperemia. In healthy adult pigs, atrial coronary flow is impeded by atrial contraction. Although atrial coronary blood flow is positively correlated with atrial external work, it reacts more slowly to changes in rate than ventricular flow. The occurrence of a pronounced hyperemic phase after acute AF supports the notion of a significant supply-demand mismatch during AF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  8. Safety and Procedural Success of Left Atrial Appendage Exclusion With the Lariat Device: A Systematic Review of Published Reports and Analytic Review of the FDA MAUDE Database.

    PubMed

    Chatterjee, Saurav; Herrmann, Howard C; Wilensky, Robert L; Hirshfeld, John; McCormick, Daniel; Frankel, David S; Yeh, Robert W; Armstrong, Ehrin J; Kumbhani, Dharam J; Giri, Jay

    2015-07-01

    The Lariat device has received US Food and Drug Administration (FDA) 510(k) clearance for soft-tissue approximation and is being widely used off-label for left atrial appendage (LAA) exclusion. A comprehensive analysis of safety and effectiveness has not been reported. To perform a systematic review of published literature to assess safety and procedural success, defined as successful closure of the LAA during the index procedure, of the Lariat device. We performed a formal analytic review of the FDA MAUDE (Manufacturer and User Facility Device Experience) database to compile adverse event reports from real-world practice with the Lariat. For the systematic review, PubMed, EMBASE, CINAHL, and the Cochrane Library were searched from January 2007 through August 2014 to identify all studies reporting use of the Lariat device in 3 or more patients. The FDA MAUDE database was queried for adverse events reports related to Lariat use. Data were abstracted in duplicate by 2 physician reviewers. Events from published literature were pooled using a generic inverse variance weighting with a random effects model. Cumulative and individual adverse events were also reported using the FDA MAUDE data set. Procedural adverse events and procedural success. In the systematic review, 5 reports of Lariat device use in 309 participants were identified. Specific complications weighted for inverse of variance of individual studies were urgent need for cardiac surgery (2.3%; 7 of 309 procedures) and death (0.3%; 1 of 309 procedures). Procedural success was 90.3% (279 of 309 procedures). In the FDA MAUDE database, there were 35 unique reports of adverse events with use of the Lariat device. Among these, we identified 5 adverse event reports that noted pericardial effusion and death and an additional 23 reported urgent cardiac surgery without mention of death. This review of published reports and case reports identified risks of adverse events with off-label use of the Lariat device for LAA

  9. Effect of atrial fibrillation on pulmonary venous flow patterns: transoesophageal pulsed Doppler echocardiographic study.

    PubMed

    Ren, W D; Visentin, P; Nicolosi, G L; Canterin, F A; Dall'Aglio, V; Lestuzzi, C; Mimo, R; Pavan, D; Sparacino, L; Cervesato, E

    1993-10-01

    The effect of atrial fibrillation on pulmonary venous flow patterns is still not well known. Twenty-four patients in atrial fibrillation and 21 patients in sinus rhythm were studied by transoesophageal echocardiography. In ninety-five percent (20/21) of sinus rhythm patients, the early systolic wave due to atrial relaxation or reverse wave due to atrial contraction could be distinguished on pulsed Doppler tracings by transoesophageal echocardiography. However, there was no early systolic wave and/or reverse at the end of diastole in any atrial fibrillation patients. In atrial fibrillation patients without mitral regurgitation (n = 14), the onset of systolic flow was delayed (165 +/- 38 vs 50 +/- 46 ms, P < 0.05), and systolic peak velocities, time-velocity integrals and systolic fractions were reduced (31 +/- 13 vs 54 +/- 17 cm.s-1, P < 0.05; 5 +/- 2 vs 13 +/- 6 cm, P < 0.05 and 36 +/- 8 vs 61 +/- 15%, P < 0.05, respectively) as compared to those in sinus rhythm. Significant mitral regurgitation (n = 10) reduced systolic velocity parameters considerably in atrial fibrillation patients but the diastolic flow parameters were not significantly different between sinus rhythm and atrial fibrillation patients. Stepwise multiple regression analysis identified atrial fibrillation as an important independent predictor for changes in systolic flow parameters. The R-R interval is also an important factor for diastolic flow parameters. Thus, the present study demonstrates that atrial fibrillation significantly modifies pulmonary venous flow pattern and is an important factor for systolic flow parameters. Significant mitral regurgitation can further modify systolic flow pattern in atrial fibrillation patients.

  10. Epiploic appendagitis.

    PubMed

    Gandhi, Jamish; Gandhi, Natasha

    2009-01-01

    A 25-year-old female presented to the emergency department (ED) with a 1-day history of crampy left iliac fossa (LIF) abdominal pain. It was associated with both nausea and vomiting. On examination she was tender in the LIF with some guarding. Her observations were satisfactory and she was apyrexial. Urine dipstick and pregnancy stick were negative. The case was a diagnostic quandary. On ultrasound scan (USS) no acute gynaecological problems were found. Computed tomography (CT) of the abdomen showed epiploic appendagitis. This was managed conservatively with analgesia and antibiotics and the patient was discharged home pain free. She was followed up in the general surgical clinic 1 week later where she continued to be symptom free. She was discharged from general surgical care.

  11. Successful Left Atrial Appendage Occlusion with the New Generation Amulet® Device after Late-Occurring Embolization of an Amplatzer® Cardiac Plug in a Patient with Repetitive Strokes

    PubMed Central

    Schillinger, Wolfgang

    2016-01-01

    The Amplatzer Cardiac Plug (ACP) is one of the most commonly used devices for percutaneous left atrial appendage (LAA) closure in order to prevent a stroke in patients with atrial fibrillation and contraindication for long-term oral anticoagulation therapy. We have previously described a patient who had experienced an embolization of the ACP device about 12 months after implantation and the device could be percutaneously retrieved. A few years later, he suffered from a posterior stroke and a stroke located in the brainstem as well as a transischemic attack (TIA). In order to protect him from further cardioembolic events a reocclusion of the LAA with the new generation of ACP device, the Amplatzer Amulet, was performed. A stable position of the device within follow-up period could be confirmed and the patient was free of additional strokes/TIA or bleeding events. This case stresses the importance of proper LAA sizing in order to prevent device embolization and notes that LAA size is not static. Moreover, it demonstrates that repeated implantation of an LAA occlusion device was still possible; one should be aware of undersizing the LAA dimensions and that the modifications of new generation LAA occlusion devices may overcome limitations of first-generation devices in order to prevent a cardioembolic stroke. PMID:27800191

  12. Successful Left Atrial Appendage Occlusion with the New Generation Amulet® Device after Late-Occurring Embolization of an Amplatzer® Cardiac Plug in a Patient with Repetitive Strokes.

    PubMed

    Schroeter, Marco R; Schillinger, Wolfgang

    2016-01-01

    The Amplatzer Cardiac Plug (ACP) is one of the most commonly used devices for percutaneous left atrial appendage (LAA) closure in order to prevent a stroke in patients with atrial fibrillation and contraindication for long-term oral anticoagulation therapy. We have previously described a patient who had experienced an embolization of the ACP device about 12 months after implantation and the device could be percutaneously retrieved. A few years later, he suffered from a posterior stroke and a stroke located in the brainstem as well as a transischemic attack (TIA). In order to protect him from further cardioembolic events a reocclusion of the LAA with the new generation of ACP device, the Amplatzer Amulet, was performed. A stable position of the device within follow-up period could be confirmed and the patient was free of additional strokes/TIA or bleeding events. This case stresses the importance of proper LAA sizing in order to prevent device embolization and notes that LAA size is not static. Moreover, it demonstrates that repeated implantation of an LAA occlusion device was still possible; one should be aware of undersizing the LAA dimensions and that the modifications of new generation LAA occlusion devices may overcome limitations of first-generation devices in order to prevent a cardioembolic stroke.

  13. Can Contrast-Enhanced Multi-Detector Computed Tomography Replace Transesophageal Echocardiography for the Detection of Thrombogenic Milieu and Thrombi in the Left Atrial Appendage: A Prospective Study with 124 Patients.

    PubMed

    Homsi, R; Nath, B; Luetkens, J A; Schwab, J O; Schild, H H; Naehle, C P

    2016-01-01

    To assess the diagnostic value of contrast-enhanced multi-detector computed tomography (MD-CT) for identifying patients with left atrial appendage (LAA) thrombus or circulatory stasis. 124 patients with a history of atrial fibrillation and/or cerebral ischemia (83 men, mean age 58.6 ± 12.4 years) and with a clinical indication for MD-CT of the heart and for transesophageal echocardiography (TEE) were included in the study. LAA thrombus or thrombogenic milieu was visually identified in TEE and MD-CT. In addition, MD-CT was analyzed quantitatively measuring the Hounsfield units (HU) of the left atrium (LA), the LAA and the ascending aorta (AA), and calculating the HU ratios LAA/AA (HU [LAA/AA]) und LAA/LA (HU [LAA/LA]). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated. The prevalence of a thrombus or thrombogenic milieu as assessed by TEE was 21.8 %. The HU ratio was lower in patients with thrombus or thrombogenic milieu (HU [LAA/AA]: 0.590 ± 0.248 vs. 0.909 ± 0.141; p < 0.001 und HU [LAA/LA] 0.689 ± 0.366 vs. 1.082 ± 0.228; p < 0.001). For the diagnosis of thrombus or a thrombogenic milieu, visual analysis yielded a sensitivity of 81.5 %, a specificity of 96.9 %, a PPV of 87.5 % and a NPV of 95.2 %. By combining visual and quantitative analysis with one criterion being positive, the specificity decreased to 91.8 %, the sensitivity to 77.8 %, the PPV to 72.4 %, and the NPV to 94.9 %. Visual analysis of the LAA in the evaluation of thrombus or thrombogenic milieu yields a high NPV of 95.1 % and may especially be useful to rule out LAA thrombi in patients with contraindications for TEE. Additional calculation of HU ratios did not improve the diagnostic performance of MD-CT. • MD-CT can reliably exclude atrial appendage thrombi/thrombogenic milieu. • MD-CT is an alternative method in patients with contraindications to TEE. • Calculation of

  14. Glycoproteomics Reveals Decorin Peptides with Anti-Myostatin Activity in Human Atrial Fibrillation

    PubMed Central

    Barallobre-Barreiro, Javier; Gupta, Shashi K.; Zoccarato, Anna; Kitazume-Taneike, Rika; Fava, Marika; Yin, Xiaoke; Werner, Tessa; Hirt, Marc N; Zampetaki, Anna; Viviano, Alessandro; Chong, Mei; Bern, Marshall; Kourliouros, Antonios; Domenech, Nieves; Willeit, Peter; Shah, Ajay M; Jahangiri, Marjan; Schaefer, Liliana; Fischer, Jens W.; Iozzo, Renato V.; Viner, Rosa; Thum, Thomas; Heineke, Joerg; Kichler, Antoine; Otsu, Kinya; Mayr, Manuel

    2016-01-01

    Background Myocardial fibrosis is a feature of many cardiac diseases. We used proteomics to profile glycoproteins in the human cardiac extracellular matrix (ECM). Methods Atrial specimens were analyzed by mass spectrometry after extraction of ECM proteins and enrichment for glycoproteins or glycopeptides. Results ECM-related glycoproteins were identified in left and right atrial appendages from the same patients. Several known glycosylation sites were confirmed. In addition, putative and novel glycosylation sites were detected. Upon enrichment for glycoproteins, peptides of the small leucine-rich proteoglycan decorin were consistently identified in the flow through. Out of all ECM proteins identified, decorin was found to be most fragmented. Within its protein core, eighteen different cleavage sites were identified. In contrast, no cleavage was observed for biglycan, the most closely related proteoglycan. Decorin processing differed between human ventricles and atria and was altered in disease. The C-terminus of decorin, important for the interaction with connective tissue growth factor, was predominantly detected in ventricles compared to atria. In contrast, atrial appendages from patients in persistent atrial fibrillation had higher levels of full-length decorin but also harbored a cleavage site that was not found in atrial appendages from patients in sinus rhythm. This cleavage site preceded the N-terminal domain of decorin that controls muscle growth by altering the binding capacity for myostatin. Myostatin expression was decreased in atrial appendages of patients with persistent atrial fibrillation and hearts of decorin null mice. A synthetic peptide corresponding to this decorin region dose-dependently inhibited the response to myostatin in cardiomyocytes and in perfused mouse hearts. Conclusions This proteomics study is the first to analyse the human cardiac ECM. Novel processed forms of decorin protein core, uncovered in human atrial appendages can regulate

  15. Hemodynamics of a functional centrifugal-flow total artificial heart with functional atrial contraction in goats.

    PubMed

    Shiga, Takuya; Shiraishi, Yasuyuki; Sano, Kyosuke; Taira, Yasunori; Tsuboko, Yusuke; Yamada, Akihiro; Miura, Hidekazu; Katahira, Shintaro; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yambe, Tomoyuki

    2016-03-01

    Implantation of a total artificial heart (TAH) is one of the therapeutic options for the treatment of patients with end-stage biventricular heart failure. There is no report on the hemodynamics of the functional centrifugal-flow TAH with functional atrial contraction (fCFTAH). We evaluated the effects of pulsatile flow by atrial contraction in acute animal models. The goats received fCFTAH that we created from two centrifugal-flow ventricular assist devices. Some hemodynamic parameters maintained acceptable levels: heart rate 115.5 ± 26.3 bpm, aortic pressure 83.5 ± 10.1 mmHg, left atrial pressure 18.0 ± 5.9 mmHg, pulmonary pressure 28.5 ± 9.7 mmHg, right atrial pressure 13.6 ± 5.2 mmHg, pump flow 4.0 ± 1.1 L/min (left) 3.9 ± 1.1 L/min (right), and cardiac index 2.13 ± 0.14 L/min/m(2). fCFTAH with atrial contraction was able to maintain the TAH circulation by forming a pulsatile flow in acute animal experiments. Taking the left and right flow rate balance using the low internal pressure loss of the VAD pumps may be easier than by other pumps having considerable internal pressure loss. We showed that the remnant atrial contraction effected the flow rate change of the centrifugal pump, and the atrial contraction waves reflected the heart rate. These results indicate that remnant atria had the possibility to preserve autonomic function in fCFTAH. We may control fCFTAH by reflecting the autonomic function, which is estimated with the flow rate change of the centrifugal pump.

  16. Left atrial vascularised thrombus diagnosed by transoesophageal cross sectional echocardiography.

    PubMed Central

    Taams, M A; Gussenhoven, E J; Lancée, C T

    1987-01-01

    This report describes a patient with a Björk-Shiley mitral valve prosthesis in whom transoesophageal cross sectional echocardiography revealed a large vascularised mass within the left atrial appendage with smoke-like opacification of blood flow in the left atrium. Transoesophageal cross sectional echocardiography gave a detailed image of the lesion which was unobtainable with precordial cross sectional echocardiography. Images Fig 1 Fig 2 PMID:3426904

  17. Characteristics of intra-left atrial flow dynamics and factors affecting formation of the vortex flow – analysis with phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging.

    PubMed

    Suwa, Kenichiro; Saitoh, Takeji; Takehara, Yasuo; Sano, Makoto; Nobuhara, Mamoru; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Satoh, Hiroshi; Sugiyama, Masataka; Wakayama, Tetsuya; Alley, Marcus; Sakahara, Harumi; Hayashi, Hideharu

    2015-01-01

    The intra-left atrial (LA) blood flow from pulmonary veins (PVs) to the left ventricle (LV) changes under various conditions and might affect global cardiac function. By using phase-resolved 3-dimensional cine phase contrast magnetic resonance imaging (4D-Flow), the intra-LA vortex formation was visualized and the factors affecting the intra-LA flow dynamics were examined. Thirty-two patients with or without organic heart diseases underwent 4D-Flow and transthoracic echocardiography. The intra-LA velocity vectors from each PV were post-processed to delineate streamline and pathline images. The vector images revealed intra-LA vortex formation in 20 of 32 patients. All the vortices developed during the late systolic and early diastolic phases and were directed counter-clockwise when viewed from the subjects' cranial side. The flow vectors from the right PVs lengthened predominantly toward the mitral valves and partly toward the LA appendage, whereas those from the left PVs directed rightward along the posterior wall and joined the vortex. Patients with vortex had less organic heart diseases, smaller LV and LA volume, and greater peak flow velocity and volume mainly in the left PVs, although the flow directions from each PV or PV areas did not differ. 4D-Flow can clearly visualize the intra-LA vortex formation and analyze its characteristic features. The vortex formation might depend on LV and LA volume and on flow velocity and volume from PVs.

  18. The contribution of classical (beta1/2-) and atypical beta-adrenoceptors to the stimulation of human white adipocyte lipolysis and right atrial appendage contraction by novel beta3-adrenoceptor agonists of differing selectivities.

    PubMed

    Sennitt, M V; Kaumann, A J; Molenaar, P; Beeley, L J; Young, P W; Kelly, J; Chapman, H; Henson, S M; Berge, J M; Dean, D K; Kotecha, N R; Morgan, H K; Rami, H K; Ward, R W; Thompson, M; Wilson, S; Smith, S A; Cawthorne, M A; Stock, M J; Arch, J R

    1998-06-01

    The role of beta3- and other putative atypical beta-adrenoceptors in human white adipocytes and right atrial appendage has been investigated using CGP 12177 and novel phenylethanolamine and aryloxypropanolamine beta3-adrenoceptor (beta3AR) agonists with varying intrinsic activities and selectivities for human cloned betaAR subtypes. The ability to demonstrate beta1/2AR antagonist-insensitive (beta3 or other atypical betaAR-mediated) responses to CGP 12177 was critically dependent on the albumin batch used to prepare and incubate the adipocytes. Four aryloxypropanolamine selective beta3AR agonists (SB-226552, SB-229432, SB-236923, SB-246982) consistently elicited beta1/2AR antagonist-insensitive lipolysis. However, a phenylethanolamine (SB-220646) that was a selective full beta3AR agonist elicited full lipolytic and inotropic responses that were sensitive to beta1/2AR antagonism, despite it having very low efficacies at cloned beta1- and beta2ARs. A component of the response to another phenylethanolamine selective beta3AR agonist (SB-215691) was insensitive to beta1/2AR antagonism in some experiments. Because no [corrected] novel aryloxypropanolamine had a beta1/2AR antagonist-insensitive inotropic effect, these results establish more firmly that beta3ARs mediate lipolysis in human white adipocytes, and suggest that putative 'beta4ARs' mediate inotropic responses to CGP 12177. The results also illustrate the difficulty of predicting from studies on cloned betaARs which betaARs will mediate responses to agonists in tissues that have a high number of beta1- and beta2ARs or a low number of beta3ARs.

  19. Mean corpuscular volume and red cell distribution width as predictors of left atrial stasis in patients with non-valvular atrial fibrillation.

    PubMed

    Providência, Rui; Ferreira, Maria João; Gonçalves, Lino; Faustino, Ana; Paiva, Luís; Fernandes, Andreia; Barra, Sérgio; Pimenta, Joana; Leitão-Marques, António M

    2013-01-01

    The role of erythrocyte indexes for the prediction of left atrial stasis, assessed by transesophageal echocardiography in patients with non-valvular atrial fibrillation, has not been previously clarified. Single center cross-sectional study comprising 247 consecutive patients admitted to the emergency department due to symptomatic atrial fibrillation and undergoing transesophageal echocardiogram evaluation for exclusion of left atrial appendage thrombus (LAAT) before cardioversion. All patients had a complete blood count performed up to 12 hours prior to the transesophageal echocardiogram. Markers of left atrial stasis were sought: LAAT, dense spontaneous echocardiographic contrast (DSEC) and low flow velocities (LFV) in the left atrial appendage. Erythrocyte indexes' accuracy for detecting transesophageal echocardiogram changes was evaluated through receiver operating curve analysis. Binary logistic multivariate analysis, using solely erythrocyte indexes and in combination with other variables (i.e. CHADS2, CHA2DS2VASc classifications and left ventricle ejection fraction), was used for transesophageal echocardiogram endpoints prediction. LAAT was found in 8.5%, DSEC in 26.1% and LFV in 12.1%. Mean corpuscular volume and red cell distribution width were independent predictors of LAAT and DSEC. Despite adding incremental predictive value to each other, when clinical risk factors from CHADS2 and CHA2DS2VASc classifications and left ventricle ejection fraction were added to the models, only mean corpuscular volume remained an independent predictor of LAAT and DSEC. These findings suggest that mean corpuscular volume and red cell distribution width may be linked to left atrial stasis markers.

  20. Rationale and design of a global registry to evaluate real-world clinical outcomes in patients with atrial fibrillation and high risk of stroke treated with left atrial appendage occlusion using the AMPLATZER amulet device-Perspective of available/ongoing registries of catheter-based LAA occlusion.

    PubMed

    Hildick-Smith, David; Diener, Hans-Christoph; Schmidt, Boris; Paul, Vincent; Settergren, Magnus; Teiger, Emmanuel; Camm, John; Tondo, Claudio; Landmesser, Ulf

    2017-09-01

    To describe the rationale and design of a global prospective registry on catheter-based left atrial appendage (LAA) occlusion using the second generation AMPLATZER Amulet LAA occlusion device and to provide a comprehensive perspective on available/ongoing registries for catheter-based LAA occlusion. Given the increasing clinical application of catheter-based LAA occlusion, there is an important need for prospective real-world clinical data regarding this cardiac intervention. The Global Amplatzer Amulet LAA registry aims to provide prospective real-world data from an all-comer population of atrial fibrillation (AF) patients undergoing catheter-based LAA occlusion for stroke prevention. This observational, prospective, multicenter registry will provide peri-procedural and long-term clinical outcome data for catheter-based LAA occlusion using a second generation LAA occlusion device. The global registry will enroll 1,000 patients at up to 75 institutions. Patients will be followed for 2 years after implantation. Primary endpoints will report procedural and long-term data on ischemic stroke, systemic embolism, cardiovascular death and major bleeding. The study will involve independent event adjudication and echocardiographic core laboratory evaluation. Long-term follow-up data are expected in 2018. The Global Amplatzer Amulet LAA registry will collect safety and efficacy information on catheter-based LAA occlusion. Characteristics of available and ongoing catheter-based LAA occlusion registries are described. There is an important need for prospective real-world clinical data of catheter-based LAA occlusion given the increasing application of this intervention. The present global real-world registry will expand our knowledge on peri-procedural and long-term outcome of catheter-based LAA occlusion using a second generation occlusion device. © 2017 Wiley Periodicals, Inc.

  1. Isolated Atrial Amyloidosis in Patients with Various Types of Atrial Fibrillation.

    PubMed

    Sukhacheva, T V; Eremeeva, M V; Ibragimova, A G; Vaskovskii, V A; Serov, R A; Revishvili, A Sh

    2016-04-01

    The myocardium of the right and left atrial appendages (auricles) in patients with paroxysmal, persistent, and permanent forms of atrial fibrillation was examined by histological methods and electron microscopy. Isolated atrial amyloidosis was detected in the left (50.0-56.3% patients) and in the right (45.0-55.6% patients) atrial appendages. In all cases, immunohistochemistry revealed atrial natriuretic peptide in fibrillary amyloid deposits. Ultrastructurally, amyloid masses formed clusters of myofibrils 8-10 nm in diameter. They were chaotically located in the extracellular space along the sarcolemma as well as in membrane invaginations, dilated tubules of cardiomyocyte T-tubular system, and vascular walls. Amyloidosis was predominantly observed in women; its degree positively correlated with age of patients and duration of atrial fibrillation but negatively correlated with atrial fibrosis. The study revealed positive (in permanent atrial fibrillation) and negative (in paroxysmal atrial fibrillation) correlation of amyloidosis with myofibril content in atrial cardiomyocytes.

  2. Passive appendages generate drift through symmetry breaking

    PubMed Central

    Lācis, U.; Brosse, N.; Ingremeau, F.; Mazzino, A.; Lundell, F.; Kellay, H.; Bagheri, S.

    2014-01-01

    Plants and animals use plumes, barbs, tails, feathers, hairs and fins to aid locomotion. Many of these appendages are not actively controlled, instead they have to interact passively with the surrounding fluid to generate motion. Here, we use theory, experiments and numerical simulations to show that an object with a protrusion in a separated flow drifts sideways by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in a fluid flow is unstable and how it stabilizes either to the left or right of the incoming flow direction. It is plausible that organisms with appendages in a separated flow use this newly discovered mechanism for locomotion; examples include the drift of plumed seeds without wind and the passive reorientation of motile animals. PMID:25354545

  3. Increased amount of atrial fibrosis in patients with atrial fibrillation secondary to mitral valve disease.

    PubMed

    Geuzebroek, Guillaume S C; van Amersfoorth, Shirley C M; Hoogendijk, Mark G; Kelder, Johannes C; van Hemel, Norbert M; de Bakker, Jacques M T; Coronel, Ruben

    2012-08-01

    Atrial fibrosis is related to atrial fibrillation but may differ in patients with mitral valve disease or lone atrial fibrillation. Therefore, we studied atrial fibrosis in patients with atrial fibrillation+mitral valve disease or with lone atrial fibrillation and compared it with controls. Left and right atrial appendages amputated during Maze III surgery for lone atrial fibrillation (n=85) or atrial fibrillation+mitral valve disease (n=26) were embedded in paraffin, sectioned, and stained with picrosirius red. Atria from 10 deceased patients without a cardiovascular history served as controls. A total of 1048 images (4-μm sections, 10-fold magnification, 4 images per appendage) were obtained and digitized. The percentage of fibrous tissue was calculated by quantitative morphometry. Irrespective of the presence or absence of atrial fibrillation or mitral valve disease, more fibrous tissue was present in right atrial appendages than in left atrial appendages (12.7%±5.7% vs 8.2%±3.9%; P<.0001). The mean amount of fibrous tissue in the atria was significantly larger in patients with atrial fibrillation+mitral valve disease than in patients with lone AF and controls (13.6%±5.8%, 9.7%±3.2%, and 8.8%±2.4%, respectively; P<.01). No significant differences existed between patients with lone atrial fibrillation and patients without a cardiovascular history (controls). Atria of patients with atrial fibrillation and mitral valve disease have more fibrosis than atria of patients with lone atrial fibrillation. However, patients with lone atrial fibrillation have an equal amount of atrial fibrosis compared with controls. These findings support the notion that fibrosis plays a more important role in the pathogenesis of atrial fibrillation secondary to mitral valve disease than in lone atrial fibrillation and potentially explains the relatively poor success of antiarrhythmic surgery in patients with mitral valve disease. Copyright © 2012 The American Association for

  4. Active Atrial Function and Atrial Scar Burden After Multiple Catheter Ablations of Persistent Atrial Fibrillation.

    PubMed

    Nührich, Jana M; Geisler, Anne C; Steven, Daniel; Hoffmann, Boris A; Schäffer, Benjamin; Lund, Gunnar; Stehning, Christian; Radunski, Ulf K; Sultan, Arian; Schwarzl, Michael; Adam, Gerhard; Willems, Stephan; Muellerleile, Kai

    2017-02-01

    Extensive and repeated substrate modification (SM) is frequently performed as an ablation strategy in persistent atrial fibrillation (persAF). The effect of these extended ablation strategies on atrial function has not been investigated sufficiently so far. The purpose was to assess atrial function by cardiac magnetic resonance (CMR) and its association with left atrial (LA) scar burden by electroanatomical voltage-mapping after multiple persAF ablation procedures. We included 16 persAF patients who had ≥2 SM procedures and a control group (CG) of 21 persAF patients without prior ablation. CMR was performed in sinus rhythm at least 4 weeks after the last cardioversion. Active left and right (RA) atrial emptying fractions (AEF) as well as peak active left atrial appendage (LAA) emptying velocities were obtained by CMR flow measurements. Furthermore, LA scar burden was quantified on electroanatomical voltage maps by the portion of points with local voltage amplitude <0.2 mV. We found median LA-AEF to be lower (13 [9-22] vs 32 [26-36] %, P < 0.001) and median LA scar burden to be higher (40 [20-68] vs nine [3-18] %, P < 0.05) in the SM group compared with the CG. Furthermore, a significant correlation was found between mean LA voltage and LA-AEF (r(2) = 0.62, P < 0.001). No significant differences were detected with respect to median RA-AEF (41 [28-48] vs 47 [35-50] %, P = 0.43) and median peak LAA emptying velocities (30 [16-40] vs 17 [13-28] cm/s, P = 0.07). Active LA function is preserved but significantly impaired and associated with ablation-related LA scar burden after multiple extensive persAF ablations. ©2016 Wiley Periodicals, Inc.

  5. Epiploic appendagitis: color Doppler sonographic findings.

    PubMed

    Danse, E M; Van Beers, B E; Baudrez, V; Pauls, C; Baudrez, Y; Kartheuser, A; Thys, F; Pringot, J

    2001-01-01

    The aim of this study was to analyze the color Doppler sonographic findings in primary epiploic appendagitis. Color Doppler sonographic findings of ten patients with primary epiploic appendagitis were reviewed. The following sonographic features were analyzed: identification of a mass adjacent to the colonic wall; identification of spotty color areas with arterial flow in this mass and detection of abnormalities of the colonic wall adjacent to the infiltrated fatty tissue. A well-delineated hyperechoic mass adjacent to the colonic wall was detected in each patient with sonography. No colonic wall abnormalities were observed nor color Doppler signal in and around the hyperechoic area. Absence of flow at color Doppler sonography is an additional feature of epiploic appendagitis.

  6. Pulmonary artery perforation by plug anchoring system after percutaneous closure of left appendage.

    PubMed

    Bianchi, Giacomo; Solinas, Marco; Gasbarri, Tommaso; Bevilacqua, Stefano; Tiwari, Kaushal Kishore; Berti, Sergio; Glauber, Mattia

    2013-07-01

    Patients receiving oral anticoagulant therapy for atrial fibrillation who are at high risk of bleeding are increasingly referred for percutaneous left atrial appendage exclusion. Although effective, this procedure is not free from risk. We report a case of pericardial tamponade due to pulmonary artery tear caused by a trespassing anchoring hook of an AGA plug. Intraoperatively, no actual bleeding was found from the left appendage, a proof of its complete occlusion by the device. The patient underwent successful surgical repair and radio-frequency ablation of atrial fibrillation was performed by pulmonary veins encircling. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  7. 4D flow MRI assessment of right atrial flow patterns in the normal heart – influence of caval vein arrangement and implications for the patent foramen ovale

    PubMed Central

    Parikh, Jehill D.; Kakarla, Jayant; Keavney, Bernard; O’Sullivan, John J.; Ford, Gary A.; Blamire, Andrew M.; Hollingsworth, Kieren G.

    2017-01-01

    Aim To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO) may be associated with flow pattern. Materials and Methods Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow) was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25–50) and thirteen subjects (6 male, 40 years, range 21–50) with cryptogenic stroke and patent foramen ovale (CS-PFO). Right atrial flow was defined as vortical, helico-vortical, helical and multiple vortices. Time-averaged and peak systolic and diastolic flows in the caval and pulmonary veins and their anatomical arrangement were compared. Results A spectrum of right atrial flow was observed across the four defined categories. The right atrial flow patterns were strongly associated with the relative position of the caval veins. Right atrial flow patterns other than vortical were more common (p = 0.015) and the separation between the superior and inferior vena cava greater (10±5mm versus 3±3mm, p = 0.002) in the CS-PFO group. In the left atrium all subjects except one had counter-clockwise vortical flow. Vortex size varied and was associated with left lower pulmonary vein flow (systolic r = 0.61, p = 0.001, diastolic r = 0.63 p = 0.002). A diastolic vortex was less common and time-averaged left atrial velocity was greater in the CS-PFO group (17±2cm/sec versus 15±1, p = 0.048). One CS-PFO subject demonstrated vortical retrograde flow in the descending aortic arch; all other subjects had laminar descending aortic flow. Conclusion Right atrial flow patterns in the normal heart are heterogeneous and are associated with the relative position of the caval veins. Patterns, other than ‘typical’ vortical flow, are more prevalent in the right atrium of those with cryptogenic stroke in the context of PFO. Left atrial flow patterns are more homogenous in normal hearts and show a

  8. Passive control of a sphere by complex-shaped appendages

    NASA Astrophysics Data System (ADS)

    Bagheri, Shervin; Lacis, Ugis; Olivieri, Stefano; Mazzino, Andrea

    2015-11-01

    Appendages of various shapes and sizes (e.g. plumes, barbs, tails, feathers, hairs, fins) play an important role in dispersion and locomotion. In our previous work (Lacis, U. et al. Passive appendages generate drift through symmetry breaking. Nat. Commun. 5:5310, doi: 10.1038/ncomms6310, 2014), we showed that a free-falling cylinder with a splitter plate turns and drifts due to a symmetry-breaking instability (called inverted-pendulum instability or IPL). In other words, in a separated flow, the straight position of a short splitter plate is unstable and as a consequence a side force and a torque are induced on the cylinder. In this work, we seek the three-dimensional (3D) appendage shape (on a sphere at Re =200) that induces the largest drift of the sphere. We find that highly non-trivial shapes of appendages on a sphere increase the side force significantly compared to trivial shapes (such as an elliptic sheet). We also find that appendages may be designed to generate drift in either direction, that is, a free-falling sphere can drift either in the direction in which appendage is tilted or in the opposite direction depending on the particular geometry of the appendage. We discuss the physical mechanisms behind these optimal appendage shapes in the context of the IPL instability.

  9. Atrial systole enhances intraventricular filling flow propagation during increasing heart rate

    PubMed Central

    Santhanakrishnan, Arvind; Okafor, Ikechukwu; Kumar, Gautam; Yoganathan, Ajit P.

    2016-01-01

    Diastolic fluid dynamics in the left ventricle (LV) has been examined in multiple clinical studies for understanding cardiac function in healthy humans and developing diagnostic measures in disease conditions. The question of how intraventricular filling vortex flow pattern is affected by increasing heart rate (HR) is still unanswered. Previous studies on healthy subjects have shown a correlation between increasing HR and diminished E/A ratio of transmitral peak velocities during early filling (E-wave) to atrial systole (A-wave). We hypothesize that with increasing HR under constant E/A ratio, E-wave contribution to intraventricular vortex propagation is diminished. A physiologic in vitro flow phantom consisting of a LV physical model was used for this study. HR was varied across 70, 100 and 120 beats per minute (bpm) with E/A of 1.1–1.2. Intraventricular flow patterns were characterized using 2D particle image velocimetry measured across three parallel longitudinal (apical-basal) planes in the LV. A pair of counter-rotating vortices was observed during E-wave across all HRs. With increasing HR, diminished vortex propagation occurred during E-wave and atrial systole was found to amplify secondary vorticity production. The diastolic time point where peak vortex circulation occurred was delayed with increasing HR, with peak circulation for 120 bpm occurring as late as 90% into diastole near the end of A-wave. The role of atrial systole is elevated for higher HR due to the limited time available for filling. Our baseline findings and analysis approach can be applied to studies of clinical conditions where impaired exercise tolerance is observed. PMID:26895781

  10. Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow

    NASA Technical Reports Server (NTRS)

    Nakatani, S.; Garcia, M. J.; Firstenberg, M. S.; Rodriguez, L.; Grimm, R. A.; Greenberg, N. L.; McCarthy, P. M.; Vandervoort, P. M.; Thomas, J. D.

    1999-01-01

    OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p < 0.005), confirming the presence of the Frank-Starling mechanism in the LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p < 0.001). Among pulmonary venous flow parameters, no single parameter was sufficient to estimate LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity

  11. Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow

    NASA Technical Reports Server (NTRS)

    Nakatani, S.; Garcia, M. J.; Firstenberg, M. S.; Rodriguez, L.; Grimm, R. A.; Greenberg, N. L.; McCarthy, P. M.; Vandervoort, P. M.; Thomas, J. D.

    1999-01-01

    OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p < 0.005), confirming the presence of the Frank-Starling mechanism in the LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p < 0.001). Among pulmonary venous flow parameters, no single parameter was sufficient to estimate LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity

  12. Left Atrial Ligation Alters Intracardiac Flow Patterns and the Biomechanical Landscape in the Chick Embryo

    PubMed Central

    Kowalski, William J.; Teslovich, Nikola C.; Menon, Prahlad G.; Tinney, Joseph P.; Keller, Bradley B.; Pekkan, Kerem

    2014-01-01

    Background Hypoplastic left heart syndrome (HLHS) is a major human congenital heart defect that results in single ventricle physiology and high mortality. Clinical data indicate that intracardiac blood flow patterns during cardiac morphogenesis are a significant etiology. We used the left atrial ligation (LAL) model in the chick embryo to test the hypothesis that LAL immediately alters intracardiac flow streams and the biomechanical environment, preceding morphologic and structural defects observed in HLHS. Results Using fluorescent dye injections, we found that intracardiac flow patterns from the right common cardinal vein, right vitelline vein, and left vitelline vein were altered immediately following LAL. Furthermore, we quantified a significant ventral shift of the right common cardinal and right vitelline vein flow streams. We developed an in silico model of LAL, which revealed that wall shear stress was reduced at the left atrioventricular canal and left side of the common ventricle. Conclusions Our results demonstrate that intracardiac flow patterns change immediately following LAL, supporting the role of hemodynamics in the progression of HLHS. Sites of reduced WSS revealed by computational modeling are commonly affected in HLHS, suggesting that changes in the biomechanical environment may lead to abnormal growth and remodeling of left heart structures. PMID:24868595

  13. Evaluation of cerebral blood flow in acute ischemic stroke patients with atrial fibrillation: A sonographic study.

    PubMed

    Su, Yu-Chin; Lim, Siew-Na; Yang, Fu-Yi; Lin, Shinn-Kuang

    2017-04-01

    Although cerebral emboli are a frequent cause of cardiogenic stroke, the possibility of a reduction in cerebral perfusion consequent to arrhythmia or impaired cardiac function should be considered in patients with atrial fibrillation (AF). We reviewed sonographic studies and clinical features of patients with acute ischemic stroke. A total of 144 patients with AF and 144 age- and sex-matched patients with small vessel occlusion but without AF were included. Patients with AF had significantly lower peak systolic velocity (PSV), mean velocity, flow volume (p < 0.001), and end-diastolic velocity (p = 0.035) of the internal carotid artery (ICA); significantly lower cerebral blood flow (p < 0.001); and lower flow velocities of the middle cerebral artery (p < 0.01) than patients with small vessel occlusion but without AF. In patients with AF, there was an inverse linear correlation between ICA end-diastolic velocity, mean velocity (p < 0.001), flow volume (p = 0.025), middle cerebral artery flow velocities (p < 0.05), and age. Cardiac ejection fraction had a positive linear correlation with ICA PSV (p = 0.016) but an inverse correlation with the heart rate (p = 0.009). There was a significant decline in PSV (p = 0.002), resistance index (p < 0.001), and flow volume (p = 0.0121) of the ICA as well as cerebral blood flow (p = 0.009) as the heart rate increased. Cerebral blood flow is markedly reduced in ischemic stroke patients with AF as compared with that in patients with small vessel disease but without AF. Copyright © 2016. Published by Elsevier B.V.

  14. Electrical cardioversion for atrial fibrillation improves microvascular flow independent of blood pressure changes.

    PubMed

    Elbers, Paul W G; Prins, Wilhelmina B; Plokker, Herbert W M; van Dongen, Eric P A; van Iterson, Mat; Ince, Can

    2012-10-01

    This study tested the hypothesis that there is a discrepancy between global hemodynamic parameters and microvascular flow in patients before and after successful elective electrical cardioversion (ECV) for atrial fibrillation (AF). Prospective observational study. Preanesthesia holding area in a teaching hospital. Adult patients who underwent successful elective ECV for AF. ECV. Routine measurements of heart rate and noninvasive blood pressure were recorded and the sublingual microcirculation was visualized by sidestream darkfield imaging before and after the conversion of AF to sinus rhythm by elective ECV. The conversion to sinus rhythm significantly improved the microvascular flow index for smaller and larger microvessels. For smaller microvessels, perfused vessel density did not reach significance after conversion to sinus rhythm, whereas the proportion of perfused vessels was significantly larger and indices of heterogeneity for microvascular flow index decreased significantly. No correlation could be identified for the changes in mean blood pressure, perfused vessel density, and microvascular flow index for smaller microvessels. Successful ECV in patients with AF improves indices of sublingual microvascular perfusion. This change has no clear relation to the change in blood pressure and cannot be predicted from it. It may be prudent not to rely solely on global hemodynamic parameters to assess end-organ perfusion in this setting. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Quantification of left and right atrial kinetic energy using four-dimensional intracardiac magnetic resonance imaging flow measurements.

    PubMed

    Arvidsson, Per M; Töger, Johannes; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

    2013-05-15

    Kinetic energy (KE) of atrial blood has been postulated as a possible contributor to ventricular filling. Therefore, we aimed to quantify the left (LA) and right (RA) atrial blood KE using cardiac magnetic resonance (CMR). Fifteen healthy volunteers underwent CMR at 3 T, including a four-dimensional phase-contrast flow sequence. Mean LA KE was lower than RA KE (1.1 ± 0.1 vs. 1.7 ± 0.1 mJ, P < 0.01). Three KE peaks were seen in both atria: one in ventricular systole, one during early ventricular diastole, and one during atrial contraction. The systolic LA peak was significantly smaller than the RA peak (P < 0.001), and the early diastolic LA peak was larger than the RA peak (P < 0.05). Rotational flow contained 46 ± 7% of total KE and conserved energy better than nonrotational flow did. The KE increase in early diastole was higher in the LA (P < 0.001). Systolic KE correlated with the combination of atrial volume and systolic velocity of the atrioventricular plane displacement (r(2) = 0.57 for LA and r(2) = 0.64 for RA). Early diastolic KE of the LA correlated with left ventricle (LV) mass (r(2) = 0.28), however, no such correlation was found in the right heart. This suggests that LA KE increases during early ventricular diastole due to LV elastic recoil, indicating that LV filling is dependent on diastolic suction. Right ventricle (RV) relaxation does not seem to contribute to atrial KE. Instead, RA KE generated during ventricular systole may be conserved in a hydraulic "flywheel" and transferred to the RV through helical flow, which may contribute to RV filling.

  16. 4D phase-contrast flow cardiovascular magnetic resonance: comprehensive quantification and visualization of flow dynamics in atrial septal defect and partial anomalous pulmonary venous return.

    PubMed

    Valverde, Israel; Simpson, John; Schaeffter, Tobias; Beerbaum, Philipp

    2010-11-01

    The case of an 8-year-old girl with atrial septal defect and associated anomalous pulmonary venous return is presented to illustrate the advantages of four dimensional flow (4D flow) over the current two dimensional flow (2D flow) in terms of time efficiency, easy planning, accurate and individual quantification of the blood sources contributing to the left-to-right shunting from one single acquisition, internal validation of flow measurement accuracy, possibility of reanalysis without rescanning in case of unexpected findings during the postprocessing, and comprehensive understanding of flow insight by use of particle tracing visualization.

  17. A prospective randomized study to assess the efficacy of rate and site of atrial pacing on long-term development of atrial fibrillation.

    PubMed

    Lau, Chu-Pak; Wang, Chun-Chieh; Ngarmukos, Tachapong; Kim, You-Ho; Kong, Chi-Woon; Omar, Razali; Sriratanasathavorn, Charn; Munawar, Muhammad; Kam, Ruth; Lee, Kathy Lf; Lau, Elizabeth Oi-Yan; Tse, Hung-Fat

    2009-09-01

    The Septal Pacing for Atrial Fibrillation Suppression Evaluation (SAFE) study is a single-blinded, parallel randomized designed multicenter study in pacemaker indicated patients with paroxysmal atrial fibrillation (AF). The objective is to evaluate whether the site of atrial pacing--conventional right atrial appendage versus low atrial septal--with or without atrial overdrive pacing will influence the development of persistent AF. The study will provide a definitive answer to whether a different atrial pacing site or the use of AF suppression pacing or both can give incremental antiarrhythmic benefit when one is implanting a device for a patient with a history of paroxysmal AF.

  18. Left atrial laceration with epicardial ligation device.

    PubMed

    Keating, Vincent P; Kolibash, Christopher P; Khandheria, Bijoy K; Bajwa, Tanvir; Sra, Jasbir; Kress, David C

    2014-01-01

    Many new devices and techniques are being developed to attempt a reduction in embolic stroke risk for patients with atrial fibrillation who are either unable or unwilling to maintain long-term anticoagulation. One of these new devices (LARIAT®, SentreHEART Inc., Redwood City, California, USA) employs delivery of an epicardial suture to ligate the left atrial appendage after percutaneous pericardial and transseptal access. This series presents three clinical cases that demonstrate a serious and recurrent complication of left atrial laceration and cardiac tamponade shortly following delivery of an epicardial suture ligation to the left atrial appendage. Three clinical cases are described in detail with pre- and postprocedure angiography and echocardiography as well as illustrations reflecting the surgeon's findings on direct visualization of the left atrial lacerations postligation. Potential hypotheses of each injury are examined in light of the case timelines and findings at sternotomy. There was no suggestion that tamponade was related to pericardial or transseptal access, but rather a complication with device delivery. These three patients quickly progressed to clinical cardiac tamponade despite attempted drainage, stressing the importance of cardiovascular surgery backup, including a cardiopulmonary bypass pump, when delivering novel, percutaneous ligation devices for the left atrial appendage.

  19. From time-series to complex networks: Application to the cerebrovascular flow patterns in atrial fibrillation

    NASA Astrophysics Data System (ADS)

    Scarsoglio, Stefania; Cazzato, Fabio; Ridolfi, Luca

    2017-09-01

    A network-based approach is presented to investigate the cerebrovascular flow patterns during atrial fibrillation (AF) with respect to normal sinus rhythm (NSR). AF, the most common cardiac arrhythmia with faster and irregular beating, has been recently and independently associated with the increased risk of dementia. However, the underlying hemodynamic mechanisms relating the two pathologies remain mainly undetermined so far; thus, the contribution of modeling and refined statistical tools is valuable. Pressure and flow rate temporal series in NSR and AF are here evaluated along representative cerebral sites (from carotid arteries to capillary brain circulation), exploiting reliable artificially built signals recently obtained from an in silico approach. The complex network analysis evidences, in a synthetic and original way, a dramatic signal variation towards the distal/capillary cerebral regions during AF, which has no counterpart in NSR conditions. At the large artery level, networks obtained from both AF and NSR hemodynamic signals exhibit elongated and chained features, which are typical of pseudo-periodic series. These aspects are almost completely lost towards the microcirculation during AF, where the networks are topologically more circular and present random-like characteristics. As a consequence, all the physiological phenomena at the microcerebral level ruled by periodicity—such as regular perfusion, mean pressure per beat, and average nutrient supply at the cellular level—can be strongly compromised, since the AF hemodynamic signals assume irregular behaviour and random-like features. Through a powerful approach which is complementary to the classical statistical tools, the present findings further strengthen the potential link between AF hemodynamic and cognitive decline.

  20. Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy

    NASA Technical Reports Server (NTRS)

    Yalcin, Fatih; El-Amrousy, Mahmoud; Muderrisoglu, Haldun; Korkmaz, Mehmet; Flachskampf, Frank; Tuzcu, Murat; Garcia, Mario G.; Thomas, James D.

    2002-01-01

    Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (p<0.001). AR peak reverse flow velocity and AR duration decreased from 29 +/- 13 cm/s and 110 =/- 30 msec to 19 +/- 6 cm/s and 80 +/- 29 msec respectively (p<0.001). Transmitral Doppler E wave deceleration time decreased from 327 +/- 85 to 209 +/- 61 s and cardiac output increased from 4.2 +/- 1.0 to 5.2 +/- 1.1 L/minute (p<0.001). The changes in LA pressure were correlated with changes in S/D (r=0.57, p<0.05). The changes in endsystolic LA pressure-volume relationship were also correlated with changes in S/D (r=0.52, p<0.05). Endsystolic LA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.

  1. Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy

    NASA Technical Reports Server (NTRS)

    Yalcin, Fatih; El-Amrousy, Mahmoud; Muderrisoglu, Haldun; Korkmaz, Mehmet; Flachskampf, Frank; Tuzcu, Murat; Garcia, Mario G.; Thomas, James D.

    2002-01-01

    Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (p<0.001). AR peak reverse flow velocity and AR duration decreased from 29 +/- 13 cm/s and 110 =/- 30 msec to 19 +/- 6 cm/s and 80 +/- 29 msec respectively (p<0.001). Transmitral Doppler E wave deceleration time decreased from 327 +/- 85 to 209 +/- 61 s and cardiac output increased from 4.2 +/- 1.0 to 5.2 +/- 1.1 L/minute (p<0.001). The changes in LA pressure were correlated with changes in S/D (r=0.57, p<0.05). The changes in endsystolic LA pressure-volume relationship were also correlated with changes in S/D (r=0.52, p<0.05). Endsystolic LA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.

  2. Left Atrial Ablation for Atrial Fibrillation

    PubMed Central

    Sternik, Leonid; Schaff, Hartzel V.; Luria, David; Glikson, Michael; Kogan, Alexander; Malachy, Ateret; First, Maya; Raanani, Ehud

    2011-01-01

    The maze procedure is the gold standard for the ablation of atrial fibrillation, and the “box lesion” around the pulmonary veins is the most important part of this procedure. We have created this lesion with a bipolar radiofrequency ablator, abandoning the usual use of this device (to achieve bilateral epicardial isolation of the pulmonary veins). From March 2004 through the end of May 2010, we performed surgical ablation of atrial fibrillation in 240 patients. Of this number, 205 underwent operation by a hybrid maze technique and the remaining 35 (our study cohort) underwent the creation of a box lesion around the pulmonary veins by means of a bipolar radiofrequency device. Ablation lines were created by connecting the left atriotomy to the amputated left atrial appendage, with 2 ablation lines made with a bipolar radiofrequency device above and below the pulmonary veins. Lesions were made along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar device. The left atrial isthmus was ablated by bipolar radiofrequency and cryoprobe. No complications were associated with the box lesion: 90% and 89% of patients were in sinus rhythm at 3 and 6 months of follow-up, respectively. By creating a box lesion around the pulmonary veins, we expect to improve transmurality by means of epicardial and endocardial ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. Isolation of the entire posterior wall of the left atrium is better electrophysiologically and renders dissection around the pulmonary veins unnecessary. PMID:21494518

  3. Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation

    NASA Technical Reports Server (NTRS)

    Yang, Hua; Jones, Michael; Shiota, Takahiro; Qin, Jian Xin; Kim, Yong Jin; Popovic, Zoran B.; Pu, Min; Greenberg, Neil L.; Cardon, Lisa A.; Eto, Yoko; Sitges, Marta; Zetts, Arthur D.; Thomas, James D.

    2002-01-01

    BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

  4. Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation

    NASA Technical Reports Server (NTRS)

    Yang, Hua; Jones, Michael; Shiota, Takahiro; Qin, Jian Xin; Kim, Yong Jin; Popovic, Zoran B.; Pu, Min; Greenberg, Neil L.; Cardon, Lisa A.; Eto, Yoko; hide

    2002-01-01

    BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

  5. Surgical Ablation of Atrial Fibrillation.

    PubMed

    Ramlawi, Basel; Abu Saleh, Walid K

    2015-01-01

    The Cox-maze procedure for the restoration of normal sinus rhythm, initially developed by Dr. James Cox, underwent several iterations over the years. The main concept consists of creating a series of transmural lesions in the right and left atria that disrupt re-entrant circuits responsible for propagating the abnormal atrial fibrillation rhythm. The left atrial appendage is excluded as a component of the Maze procedure. For the first three iterations of the Cox- maze procedure, these lesions were performed using a surgical cut-and-sew approach that ensured transmurality. The Cox-Maze IV is the most currently accepted iteration. It achieves the same lesion set of the Cox- maze III but uses alternative energy sources to create the transmural lesions, potentially in a minimally invasive approach on the beating heart. High-frequency ultrasound, microwave, and laser energy have all been used with varying success in the past. Today, bipolar radiofrequency heat or cryotherapy cooling are the most accepted sources for creating linear lesions with consistent safety and transmurality. The robust and reliable nature of these energy delivery methods has yielded a success rate reaching 90% freedom from atrial fibrillation at 12 months. Such approaches offer a significant long-term advantage over catheter-based ablation, especially in patients having longstanding, persistent atrial fibrillation with characteristics such as dilated left atrial dimensions, poor ejection fraction, and failed catheter ablation. Based on these improved results, there currently is significant interest in developing a hybrid ablation strategy that incorporates the superior transmural robust lesions of surgical ablation, the reliable stroke prevention potential of epicardial left atrial appendage exclusion, and sophisticated mapping and confirmatory catheter-based ablation technology. Such a minimally invasive hybrid strategy for ablation may lead to the development of multidisciplinary "Afib teams" to

  6. Passive control of a falling sphere by elliptic-shaped appendages

    NASA Astrophysics Data System (ADS)

    Lācis, Uǧis; Olivieri, Stefano; Mazzino, Andrea; Bagheri, Shervin

    2017-03-01

    The majority of investigations characterizing the motion of single or multiple particles in fluid flows consider canonical body shapes, such as spheres, cylinders, discs, etc. However, protrusions on bodies—either surface imperfections or appendages that serve a function—are ubiquitous in both nature and applications. In this work, we characterize how the dynamics of a sphere with an axis-symmetric wake is modified in the presence of thin three-dimensional elliptic-shaped protrusions. By investigating a wide range of three-dimensional appendages with different aspect ratios and lengths, we clearly show that the sphere with an appendage may robustly undergo an inverted-pendulum-like (IPL) instability. This means that the position of the appendage placed behind the sphere and aligned with the free-stream direction is unstable, similar to how an inverted pendulum is unstable under gravity. Due to this instability, nontrivial forces are generated on the body, leading to turn and drift, if the body is free to fall under gravity. Moreover, we identify the aspect ratio and length of the appendage that induces the largest side force on the sphere, and therefore also the largest drift for a freely falling body. Finally, we explain the physical mechanisms behind these observations in the context of the IPL instability, i.e., the balance between surface area of the appendage exposed to reversed flow in the wake and the surface area of the appendage exposed to fast free-stream flow.

  7. Characterization of the left atrial vortex flow by two-dimensional transesophageal contrast echocardiography using particle image velocimetry.

    PubMed

    Park, Kyu-Hwan; Son, Jang-Won; Park, Won-Jong; Lee, Sang-Hee; Kim, Ung; Park, Jong-Seon; Shin, Dong-Gu; Kim, Young-Jo; Choi, Jung-Hyun; Houle, Helene; Vannan, Mani A; Hong, Geu-Ru

    2013-01-01

    This article is the first clinical investigation of the quantitative left atrial (LA) vortex flow by two-dimensional (2-D) transesophageal contrast echocardiography (2-D-TECE) using vector particle image velocimetry (PIV). The aims of this study were to assess the feasibility of LA vortex flow analysis and to characterize and quantify the LA vortex flow in controls and in patients with atrial fibrillation (AF). Thirty-five controls and 30 patients with AF underwent transesophageal contrast echocardiography. The velocity vector was estimated by particle image velocimetry. The morphology and pulsatility of the LA vortex flow were compared between the control and AF groups. In all patients, quantitative LA vortex flow analysis was feasible. In the control group, multiple, pulsatile, compact and elliptical-shaped vortices were seen in the periphery of the LA. These vortices were persistently maintained and vectors were directed toward the atrioventricular inflow. In the AF group, a large, merged, lower pulsatile and round-shaped vortex was observed in the center of the LA. In comparisons of vortex parameters, the relative strength was significantly lower in the AF group (1.624 ± 0.501 vs. 2.105 ± 0.226, p < 0.001). It is feasible to characterize and quantify the LA vortex flow by transesophageal contrast echocardiography in patients with AF, which offers a new method to obtain additional information on LA hemodynamics. The approach has the potential for early detection of the LA dysfunction and in decisions regarding treatment strategy and guiding anticoagulation treatment in patients with AF. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  8. Specifying spacecraft flexible appendage rigidity

    NASA Technical Reports Server (NTRS)

    Seltzer, S. M.; Shelton, H. L.

    1977-01-01

    As a method for specifying the required degree of rigidity of spacecraft flexible appendages, an analytical technique is proposed for establishing values for the frequency, damping ratio, and modal gain (deflection) of the first several bending modes. The shortcomings of the technique result from the limitations associated with the order of the equations that can be handled practically. An iterative method is prescribed for handling a system whose structural flexibility is described by more than one normal mode. The analytical technique is applied to specifying solar panel rigidity constraints for the NASA Space Telescope. The traditional nonanalytic procedure for specifying the required degree of rigidity of spacecraft flexible appendages has been to set a lower limit below which bending mode frequencies may not lie.

  9. Appendages of the cyanobacterial cell.

    PubMed

    Schuergers, Nils; Wilde, Annegret

    2015-03-04

    Extracellular non-flagellar appendages, called pili or fimbriae, are widespread in gram-negative bacteria. They are involved in many different functions, including motility, adhesion, biofilm formation, and uptake of DNA. Sequencing data for a large number of cyanobacterial genomes revealed that most of them contain genes for pili synthesis. However, only for a very few cyanobacteria structure and function of these appendages have been analyzed. Here, we review the structure and function of type IV pili in Synechocystis sp. PCC 6803 and analyze the distribution of type IV pili associated genes in other cyanobacteria. Further, we discuss the role of the RNA-chaperone Hfq in pilus function and the presence of genes for the chaperone-usher pathway of pilus assembly in cyanobacteria.

  10. Do the left atrial substrate properties correlate with the left atrial mechanical function? A novel insight from the electromechanical study in patients with atrial fibrillation.

    PubMed

    Sung, Shih-Hsien; Chang, Shih-Lin; Hsu, Tsui-Lieh; Yu, Wen-Chung; Tai, Ching-Tai; Lin, Yenn-Jiang; Lo, Li-Wei; Wongcharoen, Wanwarang; Tuan, Ta-Chuan; Hu, Yu-Feng; Udyavar, Ameya; Chen, Shih-Ann

    2008-02-01

    The atrial substrate is the determinant of occurrence and maintenance of atrial fibrillation (AF), which can induce remodeling of atrial function and structure. This study investigated the relationship between the left atrial (LA) substrate properties and LA mechanical function. Forty-four consecutive patients (50.3 +/- 10.7 years old, 33 men) who presented with sinus rhythm during echocardiographic study before receiving catheter ablation for AF were enrolled. The LA diameter, LA volume, ratio of early and late transmitral filling flow velocities (E/A), LA appendage flow velocity, and transmitral velocity-time integral (VTI) were measured by the echocardiography. The LA empty fraction (LAEF), which was obtained via dividing the difference between maximal and minimal LA volume by maximal LA volume, was calculated as a parameter of the global LA contractile function. The LA global contact voltage mapping (NavX system) was performed before pulmonary vein isolation. Mean LA voltage and LA low voltage zone index (LVZ index, area with voltage < 0.5 mV, divided by total LA surface area) showed significant correlation with LA diameter and volume, but only the LA LVZ index showed significant correlation with A-wave velocity, transmitral A-wave VTI, and LAEF (r =-0.340, -0.411, -0.426; P = 0.024, 0.006, 0.005, respectively). We divided the LA LVZ index into three groups (< 10%, 10-20%, > 20%). The LAEF got worse and the transmitral A-wave VTI percentage (divided by transmitral VTI) decreased as LA LVZ index increased. The LA substrate properties showed close correlation with LA size, but only the LA LVZ index correlated with the LA mechanical function.

  11. Minimally Invasive Surgical Therapies for Atrial Fibrillation

    PubMed Central

    Nakamura, Yoshitsugu; Kiaii, Bob; Chu, Michael W. A.

    2012-01-01

    Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablation is an emerging field that aims for the superior results of the traditional Cox-Maze procedure through a less invasive operation with lower morbidity, quicker recovery, and improved patient satisfaction. These novel techniques utilize endoscopic or minithoracotomy approaches with various energy sources to achieve electrical isolation of the pulmonary veins in addition to other ablation lines. We review advancements in minimally invasive techniques for atrial fibrillation surgery, including management of the left atrial appendage. PMID:22666609

  12. Acute atrial tachyarrhythmia induces angiotensin II type 1 receptor-mediated oxidative stress and microvascular flow abnormalities in the ventricles

    PubMed Central

    Goette, Andreas; Bukowska, Alicja; Dobrev, Dobromir; Pfeiffenberger, Jan; Morawietz, Henning; Strugala, Denis; Wiswedel, Ingrid; Röhl, Friedrich-Wilhelm; Wolke, Carmen; Bergmann, Sybille; Bramlage, Peter; Ravens, Ursula; Lendeckel, Uwe

    2009-01-01

    Aims Patients with paroxysmal atrial fibrillation (AF) often present with typical angina pectoris and mildly elevated levels of cardiac troponin (non ST-segment elevation myocardial infarction) during an arrhythmic event. However, in a large proportion of these patients, significant coronary artery disease is excluded by coronary angiography. Here we explored the potential underlying mechanism of these events. Methods and results A total of 14 pigs were studied using a closed chest, rapid atrial pacing (RAP) model. In five pigs RAP was performed for 7 h (600 b.p.m.; n = 5), in five animals RAP was performed in the presence of angiotensin-II type-1-receptor (AT1-receptor) inhibitor irbesartan (RAP+Irb), and four pigs were instrumented without intervention (Sham). One-factor analysis of variance was performed to assess differences between and within the three groups. Simultaneous measurements of fractional flow reserve (FFR) and coronary flow reserve (CFR) before, during, and after RAP demonstrated unchanged FFR (P = 0.327), but decreased CFR during RAP (RAP: 67.7 ± 7.2%, sham: 97.2 ± 2.8%, RAP+Irb: 93.2 ± 3.3; P = 0.0013) indicating abnormal left ventricular (LV) microcirculation. Alterations in microcirculatory blood flow were accompanied by elevated ventricular expression of NADPH oxidase subunit Nox2 (P = 0.039), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1, P = 0.004), and F2-isoprostane levels (P = 0.008) suggesting RAP-related oxidative stress. Plasma concentrations of cardiac troponin-I (cTn-I) increased in RAP (RAP: 613.3 ± 125.8 pmol/L vs. sham: 82.5 ± 12.5 pmol/L; P = 0.013), whereas protein levels of eNOS and LV function remained unchanged. RAP+Irb prevented the increase of Nox2, LOX-1, and F2-isoprostanes, and abolished the impairment of microvascular blood flow. Conclusion Rapid atrial pacing induces AT1-receptor-mediated oxidative stress in LV myocardium that is accompanied by impaired microvascular blood flow and cTn-I release

  13. Potential flow evaluation of the interference effect of strut-through-appendage-tip model mounting technique and reduction of the effect using blowing and suction

    NASA Astrophysics Data System (ADS)

    Mellish, Robert W.; Coder, David W.

    1988-11-01

    A parametric study based on incompressible, irrotational flow theory was conducted to evaluate the effect of strut support interference on the flow field about a model. The use of suction and blowing to correct the support interference is also investigated. Two struts were considered for numerical analysis, a small chord strut of constant cross section and a large chord strut of varying cross section, both attached to the tip of a model submarine sail. For the present study the SS N21 class and SSN 688 class sail geometries are utilized. To assess the level of strut interference, the presence fields on the surface of the sail and a flat representation of the hull were evaluated as follows. The flow field was computed for the model geometry without a strut attached (baseline configuration) and the results are compared with identical calculations for the model-strut combination. The calculated results are presented graphically as contour plots of the pressure coefficient (Cp). Contour plots of delta p (the difference between baseline ad sail-strut results) are utilized to identify regions of principal strut interference. Finally, suction and blowing was applied to minimize strut interference in areas considered important to hull boundary layer and sail flow that would affect wake measurements.

  14. Coefficient of Variation of P-Wave Duration Is a Novel Atrial Heterogeneity Index to Predict Recurrence of Atrial Fibrillation After Catheter Ablation.

    PubMed

    Nakatani, Yosuke; Sakamoto, Tamotsu; Mizumaki, Koichi; Nishida, Kunihiro; Kataoka, Naoya; Tsujino, Yasushi; Yamaguchi, Yoshiaki; Inoue, Hiroshi

    2016-05-01

    Atrial conduction heterogeneity is associated with progression of atrial fibrillation (AF). However, the relationship between P-wave parameters representing atrial conduction heterogeneity and AF recurrence after catheter ablation (ABL) is still unclear. Subjects of the study were 126 consecutive patients with AF (78 paroxysmal and 48 persistent) who had received ABL. Coefficient of variation of P-wave duration (CV-PWD) was determined with all 12 surface electrocardiographic leads as an index of atrial conduction heterogeneity. Rates of freedom from AF recurrence were 78% and 77% in patients with paroxysmal and persistent AF, respectively, over a 12-month follow-up. CV-PWD measured before ABL was smaller in AF-free patients compared with AF-recurrent patients (0.089 ± 0.019 vs. 0.129 ± 0.042, P < 0.001). CV-PWD significantly decreased after ABL in AF-free patients, but did not change in AF-recurrent patients. CV-PWD after ABL was also smaller in AF-free patients compared with AF-recurrent patients (0.087 ± 0.025 vs. 0.133 ± 0.035, P < 0.001). In receiver operating curve analysis, CV-PWD before and after ABL achieved area under the curve of 0.829 and 0.854, respectively, for the ability to predict AF recurrence. CV-PWD correlated positively with left atrial (LA) diameter and negatively with LA appendage flow velocity. CV-PWD is a useful index to predict AF recurrence after ABL for both patients with paroxysmal and persistent AF. ABL may suppress AF by decreasing atrial conduction heterogeneity. © 2016 Wiley Periodicals, Inc.

  15. Hemolymph circulation in insect flight appendages: physiology of the wing heart and circulatory flow in the wings of the mosquito Anopheles gambiae.

    PubMed

    Chintapalli, Ravi Theja V; Hillyer, Julián F

    2016-12-15

    The wings of insects are composed of membranes supported by interconnected veins. Within these veins are epithelial cells, nerves and tracheae, and their maintenance requires the flow of hemolymph. For this purpose, insects employ accessory pulsatile organs (auxiliary hearts) that circulate hemolymph throughout the wings. Here, we used correlative approaches to determine the functional mechanics of hemolymph circulation in the wings of the malaria mosquito Anopheles gambiae Examination of sectioned tissues and intravital videos showed that the wing heart is located underneath the scutellum and is separate from the dorsal vessel. It is composed of a single pulsatile diaphragm (indicating that it is unpaired) that contracts at 3 Hz and circulates hemolymph throughout both wings. The wing heart contracts significantly faster than the dorsal vessel, and there is no correlation between the contractions of these two pulsatile organs. The wing heart functions by aspirating hemolymph out of the posterior wing veins, which forces hemolymph into the wings via anterior veins. By tracking the movement of fluorescent microspheres, we show that the flow diameter of the wing circulatory circuit is less than 1 µm, and we present a spatial map detailing the flow of hemolymph across all the wing veins, including the costa, sub-costa, ambient costa, radius, media, cubitus anterior, anal vein and crossveins. We also quantified the movement of hemolymph within the radius and within the ambient costa, and show that hemolymph velocity and maximum acceleration are higher when hemolymph is exiting the wing.

  16. Atrial supply-demand balance in healthy adult pigs: coronary blood flow, oxygen extraction, and lactate production during acute atrial fibrillation.

    PubMed

    van Bragt, Kelly A; Nasrallah, Hussein M; Kuiper, Marion; Luiken, Joost J; Schotten, Ulrich; Verheule, Sander

    2014-01-01

    Little is known about how atrial oxygen supply responds to increased demand, and under which conditions it falls short (supply-demand mismatch). Here, we have investigated the vasodilator response, oxygen extraction, and lactate production of the left atrium (LA) and left ventricle (LV) in response to atrial pacing and atrial fibrillation (AF). Series A (n = 9 Dutch landrace pigs) was instrumented to measure LA and LV vascular conductance in branches of the circumflex artery. Coronary conductance reserve (CCR) was calculated as the ratio between conductance during adenosine infusion and baseline. Series B (n = 7) was instrumented with sampling catheters in LA and LV veins for determination of blood gases and lactate levels. LA CCR (1.76 ± 0.14) was significantly lower than LV CCR (3.16 ± 0.27, P = 0.002). However, basal oxygen extraction was lower in LA (27 ± 3%) than that in the LV (58 ± 6%, P = 0.0006), indicating a larger extraction reserve in the LA than that in the LV (4.68 ± 0.84 vs. 1.88 ± 0.26, P = 0.01). Atrial pacing caused an increase in LA conductance (Series A) and oxygen extraction (Series B). AF increased LA vascular conductance to 177 ± 14% at 1 min, 168 ± 14 at 5 min, and 164 ± 31% at 10 min of AF (P < 0.05 vs. baseline). Atrial oxygen extraction also increased from 26 ± 3% at baseline to 63 ± 5% (P < 0.01) at 5 min and 60 ± 11% (P < 0.01) at 10 min of AF. Arterio-venous lactate difference increased significantly (P = 0.02) during AF. In healthy pigs, the LA has a lower CCR, but a higher extraction reserve compared with the LV. Although both reserves were recruited during AF, atrial lactate production increased significantly.

  17. Collateral flow measurement by phase-contrast magnetic resonance imaging for the assessment of systemic venous baffle patency after atrial switch repair for transposition of the great arteries.

    PubMed

    Muzzarelli, Stefano; Ordovas, Karen Gomes; Higgins, Charles B; Meadows, Alison Knauth

    2012-05-01

    We aimed to describe and compare azygos vein flow patterns of patients with obstructed and unobstructed systemic venous baffle after atrial switch repair for d-transposition of the great arteries (TGA). We hypothesized that phase-contrast magnetic resonance imaging would enable characterization of retrograde collateral flow across the azygos vein in cases of systemic venous baffle obstruction. This is a retrospective, cross-sectional study. Twelve patients with atrial switch repair for TGA were examined. Azygos flow index was measured with phase-contrast magnetic resonance imaging; comparison was made between patients with documented systemic venous baffle obstruction (n=3) and a control group of patients without baffle obstruction (n=9). Patients with systemic venous baffle obstruction had a distinctive azygos flow pattern that was retrograde and an increased amount of azygos flow compared with patients without obstruction [median (range), -436 (-455/-399) vs. 103 (51/125) mL/min/m2; P=0.01]. Patients with systemic venous baffle obstruction have a characteristic collateral flow across the azygos vein. Azygos vein flow measurement may be used for the assessment of baffle patency in patients after atrial switch repair for TGA. However, diagnostic accuracy needs to be tested in a larger population.

  18. Primary epiploic appendagitis: CT diagnosis.

    PubMed

    Sandrasegaran, Kumaresan; Maglinte, Dean D; Rajesh, Arumugam; Akisik, Fatih M

    2004-08-01

    The purpose of this study was to analyze the CT signs of primary epiploic appendagitis. A retrospective search of the CT database over 12 months for this diagnosis revealed 11 cases. The clinical findings were recorded. Softcopy CT images were reviewed by two experienced abdominal radiologists (KS, DM) for location of lesion, size, shape, presence of central hyperdense focus, degree of bowel wall thickening, mass effect, and ancillary signs. Abdominal pain was the primary symptom in all patients. Preliminary diagnoses were appendicitis (n=2), diverticulitis (n=5), pancreatitis (n=1), ovarian lesion (n=1), or unknown (n=2). Abdominal examination and white blood cell count were uninformative. CT examination revealed a solitary (n=11), ovoid (n=9) fatty lesion with some soft tissue stranding adjacent to the left colon (n=6), transverse colon (n=3), or right colon (n=2). Central hyperdensity (n=5), mild bowel wall thickening (n=2), and parietal peritoneal thickening (n=4) were also seen. In 4 patients the lesions were not visible on follow-up CT examination performed 23-184 days later. Primary epiploic appendagitis can clinically mimic other, more serious inflammatory conditions. Knowledge of its findings on CT would help the radiologist make the diagnosis and allow a more conservative approach to patient care.

  19. The effects of hypoxemia on myocardial blood flow during exercise.

    PubMed

    Paridon, S M; Bricker, J T; Dreyer, W J; Reardon, M; Smith, E O; Porter, C B; Michael, L; Fisher, D J

    1989-03-01

    We evaluated the adequacy of regional and transmural blood flow during exercise and rapid pacing after 1 wk of hypoxemia. Seven mature mongrel dogs were made hypoxemic (mean O2 saturation = 72.4%) by anastomosis of left pulmonary artery to left atrial appendage. Catheters were placed in the left atrium, right atrium, pulmonary artery, and aorta. Atrial and ventricular pacing wires were placed. An aortic flow probe was placed to measure cardiac output. Ten nonshunted dogs, similarly instrumented, served as controls. Recovery time was approximately 1 wk. Cardiac output, mean aortic pressure, and oxygen saturation were measured at rest, with ventricular pacing, atrial pacing, and with treadmill exercise. Ventricular and atrial pace and exercise were at a heart rate of 200. Right ventricular free wall, left ventricular free wall, and septal blood flow were measured with radionuclide-labeled microspheres. Cardiac output, left atrial blood pressure, and aortic blood pressure were similar between the two groups of dogs in all testing states. Myocardial blood flow was significantly higher in the right and left ventricular free wall in the hypoxemic animals during resting and exercise testing states. Myocardial oxygen delivery was similar between the two groups of animals. Pacing resulted in an increase in myocardial blood flow in the control animals but not the hypoxemic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Appendage mountable electronic devices conformable to surfaces

    DOEpatents

    Rogers, John; Ying, Ming; Bonifas, Andrew; Lu, Nanshu

    2017-01-24

    Disclosed are appendage mountable electronic systems and related methods for covering and conforming to an appendage surface. A flexible or stretchable substrate has an inner surface for receiving an appendage, including an appendage having a curved surface, and an opposed outer surface that is accessible to external surfaces. A stretchable or flexible electronic device is supported by the substrate inner and/or outer surface, depending on the application of interest. The electronic device in combination with the substrate provides a net bending stiffness to facilitate conformal contact between the inner surface and a surface of the appendage provided within the enclosure. In an aspect, the system is capable of surface flipping without adversely impacting electronic device functionality, such as electronic devices comprising arrays of sensors, actuators, or both sensors and actuators.

  1. [Atrial fibrillation].

    PubMed

    Cárdenas, Manuel

    2007-01-01

    Atrial fibrillation is an arrhythmia characterized by no-coordinated atrial contraction that results in an inefficient atrial systole. The clinical classification of atrial fibrillation includes: ocassional, paroxysmal, persistent, and permanent. Multiple mechanisms have been described and accounts for a single ECG manifestation. Treatment should be individualized and has to considered several aspects including age, associated heart disease, and symptoms. Treatment strategies are: rhythm control, rate control, and thromboprophylaxis.

  2. Concept of left atrial pressure estimation using its pulsatile amplitude in the helical flow total artificial heart.

    PubMed

    Wu, Sheng-Yuan; Saito, Itsuro; Isoyama, Takashi; Inoue, Yusuke; Sato, Masami; Hara, Shintaro; Li, Xin-Yang; Yurimoto, Terumi; Murakami, Haruka; Kawase, Yukino; Ono, Toshiya; Abe, Yusuke

    2014-12-01

    The total artificial heart (TAH) requires physiological control to respond to the metabolic demand of the body. To date, 1/R control is a single physiological control method that can control venous pressure. To realize an implantable 1/R control system, we are developing a new pressure measuring method using absolute pressure sensor. To find a method for absolute pressure sensor, which went well without calibration, concept of left atrial pressure (LAP) estimation using its pulsatile amplitude was proposed. Its possibility was investigated with two long-term survived goats whose hearts were replaced with the helical flow TAHs. In manual control condition, there existed a positive relation between mean LAP (mLAP) and normalized pulsatile amplitude (NPA). Percent systole revealed not to affect the relationship between mLAP and NPA. Dispersion was observed between different pulse rates. As for cardiac output difference (QLD) that is the difference of flow rate between systolic and diastolic phases, similar results were obtained except in low QLDs. In the 1/R control condition, relatively high correlation between mLAP and NPA could be obtained. In estimation of mLAP using the correlating function of individual goat, fairly good correlation was obtained between measured mLAP and estimated mLAP. Despite that further studies are necessary, it was demonstrated that the concept of the LAP estimation could be possible.

  3. Quantifying right atrial filling and emptying: A 4D-flow MRI study.

    PubMed

    Callaghan, Fraser M; Arnott, Clare; Figtree, Gemma A; Kutty, Shelby; Celermajer, David S; Grieve, Stuart M

    2017-04-01

    To quantitatively characterize the central role of vortex formation on the flow patterns and energy transfer within the right atrium (RA). 4D-flow magnetic resonance imaging (MRI) data with multiple encoding velocities was acquired in 12 healthy subjects at 3T. Particles entering the RA were classified according to the origin of entry. Vortex membership was numerically derived by assessing the location of pathline center of curvature relative to the vortex core, defined by Q-criteria. Flow dynamics and energetics were assessed using paired t-tests. The majority of flow (74%) passes through the RA in a single beat, with a very small volume fraction retained longer than two beats (<1%). RA flow was dominated by a governing vortex, comprising 79% of total flow, and acting to preserve kinetic energy. Flow comprising the vortex enters the RA significantly earlier than nonvortex flow (P < 0.01). The majority of nonvortex flow enters the RA during systole, traversing the RA via a direct path with a significantly shorter residence time and distance traveled (both P < 0.01). Blood flow momentum is preserved during systole within a dominant vortex, which we are able to characterize numerically using a semiautomated approach. Our analytical approach has potential for application to understanding right heart function in health and disease. 1 J. Magn. Reson. Imaging 2017;45:1046-1054. © 2016 International Society for Magnetic Resonance in Medicine.

  4. Acute epiploic appendagitis and its mimics.

    PubMed

    Singh, Ajay K; Gervais, Debra A; Hahn, Peter F; Sagar, Pallavi; Mueller, Peter R; Novelline, Robert A

    2005-01-01

    Acute epiploic appendagitis most commonly manifests with acute lower quadrant pain. Its clinical features are similar to those of acute diverticulitis or, less commonly, acute appendicitis. The conditions that may mimic acute epiploic appendagitis at computed tomography (CT) include acute omental infarction, mesenteric panniculitis, fat-containing tumor, and primary and secondary acute inflammatory processes in the large bowel (eg, diverticulitis and appendicitis). Whereas the location of acute epiploic appendagitis is most commonly adjacent to the sigmoid colon, acute omental infarction is typically located in the right lower quadrant and often is mistaken for acute appendicitis. It is important to correctly diagnose acute epiploic appendagitis and acute omental infarction on CT images because these conditions may be mistaken for acute abdomen, and the mistake may lead to unnecessary surgery. The CT features of acute epiploic appendagitis include an oval lesion 1.5-3.5 cm in diameter, with attenuation similar to that of fat and with surrounding inflammatory changes, that abuts the anterior sigmoid colon wall. The CT features of acute omental infarction include a well-circumscribed triangular or oval heterogeneous fatty mass with a whorled pattern of concentric linear fat stranding between the anterior abdominal wall and the transverse or ascending colon. As CT increasingly is used for the evaluation of acute abdomen, radiologists are likely to see acute epiploic appendagitis and its mimics more often. Recognition of these conditions on CT images will allow appropriate management of acute abdominal pain and may help to prevent unnecessary surgery. RSNA, 2005.

  5. Sympathetic nerves in the mediation of renal response to localized stimulation of atrial receptors in anaesthetized dogs.

    PubMed Central

    Karim, F; Majid, D S; Summerill, R A

    1989-01-01

    1. Dogs were anaesthetized with chloralose and artificially ventilated. Localized stimulation of left atrial receptors for 23-25 min was achieved by distension of three small balloons at the pulmonary vein-atrial junctions and one in atrial appendage. Renal blood flows were measured by electromagnetic flow probes, glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and solute excretion by osmometry. The mean aortic pressure was held constant at 92.2 +/- 2.4 mmHg (mean +/- S.E.M., n = 27) by means of a pressure bottle connected to the aorta and beta-adrenergic receptor activity was blocked by continuous infusion of propranolol (17 micrograms kg-1 min-1, I.V.). 2. In twelve dogs stimulation of left atrial receptors resulted in significant increases of 11.8 +/- 2.4% (P less than 0.001) in renal blood flow; 32.5 +/- 7.2% (P less than 0.001) in glomerular filtration rate; 19.5 +/- 5.0% (P less than 0.005) in filtration fraction: 36.3 +/- 9.0% (P less than 0.001) in urine flow: 32.7 +/- 9.2% (P less than 0.005) in sodium excretion: 36.6 +/- 9.9% (P less than 0.005) in osmolar excretion and a decrease of 31.3 +/- 11.2% (P less than 0.025) in free water clearance. Left atrial pressure and heart rate did not change significantly. In eight of the dogs ligation of the renal nerves resulted in similar changes in all of the renal variables; subsequent stimulation of atrial receptors did not cause significant changes in the renal variables. 3. In five additional dogs, in which heart rate and aortic pressure were allowed to change, stimulation of left atrial receptors for the same period resulted in significant increases in heart rate (4.3 +/- 0.7%. P less than 0.001) and mean aortic pressure (2.0 +/- 0.6%, P less than 0.025). Under this condition both the intact right kidneys and the denervated left kidneys showed significant responses in urine flow, sodium excretion, osmolar excretion and free water clearance. 4. The results show

  6. Relations of Arterial Stiffness and Brachial Flow-Mediated Dilation With New-Onset Atrial Fibrillation: The Framingham Heart Study.

    PubMed

    Shaikh, Amir Y; Wang, Na; Yin, Xiaoyan; Larson, Martin G; Vasan, Ramachandran S; Hamburg, Naomi M; Magnani, Jared W; Ellinor, Patrick T; Lubitz, Steven A; Mitchell, Gary F; Benjamin, Emelia J; McManus, David D

    2016-09-01

    The relations of measures of arterial stiffness, pulsatile hemodynamic load, and endothelial dysfunction to atrial fibrillation (AF) remain poorly understood. To better understand the pathophysiology of AF, we examined associations between noninvasive measures of vascular function and new-onset AF. The study sample included participants aged ≥45 years from the Framingham Heart Study offspring and third-generation cohorts. Using Cox proportional hazards regression models, we examined relations between incident AF and tonometry measures of arterial stiffness (carotid-femoral pulse wave velocity), wave reflection (augmentation index), pressure pulsatility (central pulse pressure), endothelial function (flow-mediated dilation), resting brachial arterial diameter, and hyperemic flow. AF developed in 407/5797 participants in the tonometry sample and 270/3921 participants in the endothelial function sample during follow-up (median 7.1 years, maximum 10 years). Higher augmentation index (hazard ratio, 1.16; 95% confidence interval, 1.02-1.32; P=0.02), baseline brachial artery diameter (hazard ratio, 1.20; 95% confidence interval, 1.01-1.43; P=0.04), and lower flow-mediated dilation (hazard ratio, 0.79; 95% confidence interval, 0.63-0.99; P=0.04) were associated with increased risk of incident AF. Central pulse pressure, when adjusted for age, sex, and hypertension (hazard ratio, 1.14; 95% confidence interval, 1.02-1.28; P=0.02) was associated with incident AF. Higher pulsatile load assessed by central pulse pressure and greater apparent wave reflection measured by augmentation index were associated with increased risk of incident AF. Vascular endothelial dysfunction may precede development of AF. These measures may be additional risk factors or markers of subclinical cardiovascular disease associated with increased risk of incident AF. © 2016 American Heart Association, Inc.

  7. Galectin-3 as a marker of interstitial atrial remodelling involved in atrial fibrillation

    PubMed Central

    Hernández-Romero, Diana; Vílchez, Juan Antonio; Lahoz, Álvaro; Romero-Aniorte, Ana I.; Jover, Eva; García-Alberola, Arcadio; Jara-Rubio, Rubén; Martínez, Carlos M.; Valdés, Mariano; Marín, Francisco

    2017-01-01

    Remodelling in the atria could appear as a result of hypertension, diabetes or ischaemic heart disease. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and a potential biomarker of cardiac remodelling. We prospectively recruited consecutive patients undergoing elective cardiac surgery. Preoperative Gal-3 levels were determined from serum samples, and the presence of fibrosis was assessed from atrial appendage tissue samples obtained during cardiac surgery. We included 100 patients with aortic valve or ischaemic heart diseases and 15 controls with permanent AF. Gal-3 levels were associated with sex, left atrial volume, previous cardiac disease, diabetes mellitus, hypertension, NYHA and NT-proBNP. We observed differences in serum Gal-3 concentrations between patients and controls with permanent AF (p = 0.020). We performed ROC curves related to fibrosis and established a cutoff point for Gal-3 >13.65 ng/ml. Multivariate analyses showed previous cardiac disease, NYHA scale and high Gal-3 to be independent predictors of fibrosis. After adjustment for confounding factors, atrial fibrosis remained the only independent factor for the development of AF (p = 0.022). High Gal-3 serum levels predict fibrosis of the atrial appendage. NYHA scale and previous cardiac disease were also associated with tissue fibrosis in patients undergoing surgery. Atrial fibrosis was the only independent predictor for post-operative AF occurrence in our model after correcting for confounding factors. PMID:28079145

  8. Atrial tissue expression of receptor for advanced glycation end-products (RAGE) and atrial fibrosis in patients with mitral valve disease.

    PubMed

    Yang, Pil-Sung; Lee, Seung Hyun; Park, Junbeom; Kim, Tae-Hoon; Uhm, Jae-Sun; Joung, Boyoung; Lee, Moon-Hyoung; Chang, Byung-Chul; Pak, Hui-Nam

    2016-10-01

    It has been reported that receptor for advanced glycation end-products (RAGE) plays a significant role in cardiac fibrosis. Nonetheless, the precise relationship between the RAGE and atrial fibrosis has never been studied in humans. The aim of this study was to determine whether degree of atrial fibrosis was associated with atrial tissue expression of RAGE in patients with mitral valve disease (MVD). We collected human left atrial (LA) appendage tissue from 25 patients who underwent mitral valve surgery. We quantified the expression of RAGE and other protein markers by Western blotting and compared these levels with histological evaluations. RAGE expression in the LA appendage tissue was significantly correlated with atrial fibrosis (r=0.681, p=0.001). RAGE expression (regression coefficient [B] 9.49, 95% confidence interval [CI] 4.76-14.2, p<0.001) and LA diameter (B 0.43, 95% CI 0.13-0.74, p=0.008) were independently associated with degree of atrial fibrosis in multiple linear regression analysis. RAGE expression was significantly correlated with protein expression of von Willebrand factor (r=0.659, p<0.001), vascular endothelial cadherin (r=0.757, p<0.001), ICAM-1 (r=0.568, p=0.003), and PECAM-1 (r=0.423, p=0.035) in the LA appendage tissue. In addition, patients with severe mitral stenosis (MS) had higher atrial RAGE expression than those with no, mild, or moderate MS (p=0.013). Patients with MVD and atrial fibrillation (AF) had more severe atrial fibrosis (p=0.024) and higher RAGE expression (p=0.047) than those who remained in sinus rhythm. Atrial tissue expression of RAGE was significantly associated with atrial fibrosis, severe MS, and AF rhythm in patients with MVD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Atrial fibrillation and hyperthyroidism: relation between transoesophageal markers of a thrombogenic milieu and clinical risk factors for thromboembolism.

    PubMed

    Souza, Marcus Vinicius Leitão de; Duarte, Martha Maria Turano; Coeli, Claudia Medina; Vaisman, Mario

    2012-03-01

    Hyperthyroidism is a questionable risk factor for thromboembolism among patients with atrial fibrillation.   To correlate clinical risk factors for thromboembolism from a group of patients with atrial fibrillation related to hyperthyroidism with transoesophageal echocardiography (TOE) markers of a thrombogenic milieu.   Clinical risk factors for thromboembolism, thyroid hormonal status, time since diagnosis of hyperthyroidism and TOE markers of a thrombogenic milieu were assessed in consecutive patients with atrial fibrillation related to hyperthyroidism. The following TOE parameters were assessed to define the presence of thrombogenic milieu: dense spontaneous echo contrast, thrombi or left atrial appendage blood flow velocities <0·20 m/s. Clinical risk factors for thromboembolism were based on CHADS(2) (Cardiac failure, Hypertension, Age, Diabetes and Stroke) classification.   This study included 31 consecutive patients aged between 18 and 65 years with atrial fibrillation related to hyperthyroidism scheduled for TOE.   Thrombogenic milieu was present in 14 of 31 (45·2%) patients. The thyroid status could not predict the presence of a thrombogenic milieu. Despite low CHADS(2) score of 0/1, 6 of 13 (46·1%) patients had a thrombogenic milieu, whereas 10 of 18 (55·6%) patients with score ≥2 had none. The probability of having a thrombogenic milieu did not correlate with the number of clinical risk factors.   Among patients younger than 65 years of age with atrial fibrillation related to hyperthyroidism, there is no association between clinical risk factors with TOE markers of a thrombogenic milieu. TOE adds useful information that may affect antithrombotic therapy guided by clinical risk classification. © 2012 Blackwell Publishing Ltd.

  10. Right versus left atrial pacing in patients with sick sinus syndrome and paroxysmal atrial fibrillation (Riverleft study): study protocol for randomized controlled trial.

    PubMed

    Ramdjan, Tanwier T T K; van der Does, Lisette J M E; Knops, Paul; Res, Jan C J; de Groot, Natasja M S

    2014-11-17

    The incidence of sick sinus syndrome will increase due to population ageing. Consequently, this will result in an increase in the number of pacemaker implantations. The atrial lead is usually implanted in the right atrial appendage, but this position may be ineffective for prevention of atrial fibrillation. It has been suggested that pacing distally in the coronary sinus might be more successful in preventing atrial fibrillation episodes. The aim of this trial is to study the efficacy of distal coronary sinus versus right atrial appendage pacing in preventing atrial fibrillation episodes in patients with sick sinus syndrome. This study is designed as a multicenter, randomized controlled trial. Patients with sick sinus syndrome and at least one atrial fibrillation episode of 30 seconds or more in the six months before recruitment will be eligible for participation in this study.All participants will be randomized between pacing distally in the coronary sinus and right atrial appendage. Randomization is stratified for all participating centers. Conventional dual-chamber pacemakers with advanced home monitoring functionality will be implanted. The ventricular lead will be implanted in the right ventricular apex. The first three months of the 36-month follow-up period are considered as run-in time. During the pre-randomization visit and follow-up, an interview, electrocardiogram and pacemaker assessment will be performed, prescribed antiarrhythmic medication will be reviewed and patients will be asked to complete an SF-36 questionnaire. An echocardiographic examination will be conducted in the pre-randomization phase and at the end of each follow-up year. Home monitoring will be used to send daily reports in case of atrial fibrillation episodes. This randomized controlled trial is the first in which home monitoring will be used to compare atrial fibrillation recurrences between pacing in the distal coronary sinus or right atrial appendage. Home monitoring gives the

  11. Heterogeneous atrial wall thickness and stretch promote scroll waves anchoring during atrial fibrillation

    PubMed Central

    Yamazaki, Masatoshi; Mironov, Sergey; Taravant, Clément; Brec, Julien; Vaquero, Luis M.; Bandaru, Krishna; Avula, Uma Mahesh R; Honjo, Haruo; Kodama, Itsuo; Berenfeld, Omer; Kalifa, Jérôme

    2012-01-01

    Aims Atrial dilatation and myocardial stretch are strongly associated with atrial fibrillation (AF). However, the mechanisms by which the three-dimensional (3D) atrial architecture and heterogeneous stretch contribute to AF perpetuation are incompletely understood. We compared AF dynamics during stretch-related AF (pressure: 12cmH2O) in normal sheep hearts (n = 5) and in persistent AF (PtAF, n = 8)-remodelled hearts subjected to prolonged atrial tachypacing. We hypothesized that, in the presence of stretch, meandering 3D atrial scroll waves (ASWs) anchor in regions of large spatial gradients in wall thickness. Methods and results We implemented a high-resolution optical mapping set-up that enabled simultaneous epicardial- and endoscopy-guided endocardial recordings of the intact atria in Langendorff-perfused normal and PtAF (AF duration: 21.3 ± 11.9 days) hearts. The numbers and lifespan of long-lasting ASWs (>3 rotations) were greater in PtAF than normal (lifespan 0.9 ± 0.5 vs. 0.4 ± 0.2 s/(3 s of AF), P< 0.05). Than normal hearts, focal breakthroughs interacted with ASWs at the posterior left atrium and left atrial appendage to maintain AF. In PtAF hearts, ASW filaments seemed to span the atrial wall from endocardium to epicardium. Numerical simulations using 3D atrial geometries (Courtemanche-Ramirez-Nattel human atrial model) predicted that, similar to experiments, filaments of meandering ASWs stabilized at locations with large gradients in myocardial thickness. Moreover, simulations predicted that ionic remodelling and heterogeneous distribution of stretch-activated channel conductances contributed to filament stabilization. Conclusion The heterogeneous atrial wall thickness and atrial stretch, together with ionic and anatomic remodelling caused by AF, are the main factors allowing ASW and AF maintenance. PMID:22227155

  12. Epiploic appendagitis of caecum: a diagnostic dilemma

    PubMed Central

    Rashid, Arshad; Nazir, Saima; Hakim, Suhail Yaqoob; Chalkoo, Manzoor Ahamad

    2012-01-01

    Epiploic appendagitis is a rare cause of acute abdomen. Depending on the site of occurrence, it can mimic any cause of acute abdomen or disease of the colon and caecal appendix; making its preoperative diagnosis very difficult. We present here a case of a 7-year-old boy misdiagnosed preoperatively as acute appendicitis and later on, upon surgical exploration, found to have caecal appendagitis. The affected epiploic appendage was removed and the patient had an uneventful recovery. We also review the relevant literature and discuss the measures to overcome this diagnostic dilemma. General surgeons should be aware of this self-limiting disease and consider it as a differential diagnosis of acute abdomen. PMID:23255877

  13. Procollagen propeptides: serum markers for atrial fibrosis?

    PubMed

    Neuberger, Hans-Ruprecht; Cacciatore, Angela; Reil, Jan-Christian; Gräber, Stefan; Schäfers, Hans-Joachim; Ukena, Christian; Böhm, Michael; Mewis, Christian

    2012-08-01

    Atrial fibrosis and its spatial heterogeneity are regarded as a substrate for the perpetuation of atrial arrhythmias. During collagen synthesis and degradation, collagen propeptides and telopeptides are released into the blood. This study tested the hypothesis that serum markers of collagen turnover correlate with atrial fibrosis. We prospectively included 28 patients in sinus rhythm undergoing cardiac surgery. Plasma concentrations of the carboxy- and amino-terminal propeptide of procollagen type-I (PICP and PINP) and type-III (PIIINP), and the C-terminal telopeptide of type-I collagen (ICTP) were determined. Interstitial fibrosis of left (n = 10) and right atrial appendages (n = 28) was analyzed histologically. We found a correlation between left and right atrial fibrosis (r (s) = 0.79, p < 0.01). Interestingly, the higher the interstitial collagen content, the higher was the spatial heterogeneity of fibrosis (r (s) = 0.90, p < 0.001). However, PICP, PIIINP, and ICTP were not correlated to left or right atrial collagen content, or to the spatial heterogeneity of atrial fibrosis. There was a weak and even negative correlation between the serum PINP concentration and the degree of fibrosis in both the left and the right atrium (r (s) = -0.65 (p = 0.04) and r (s) = -0.42 (p = 0.03), respectively). A high degree of interstitial atrial fibrosis indicates a high degree of spatial heterogeneity of interstitial collagen. Although serum PICP is known to be correlated with ventricular fibrosis, this and other serum markers of collagen turnover (PINP, PIIINP, and ICTP) do not directly reflect atrial fibrosis in patients with severe cardiac disease.

  14. Recurrent epiploic appendagitis mimicking appendicitis and cholecystitis

    PubMed Central

    Hearne, Christopher B.; Taboada, Jorge

    2017-01-01

    Epiploic appendagitis (EA) is a rare cause of acute abdominal pain caused by inflammation of an epiploic appendage. It has a nonspecific clinical presentation that may mimic other acute abdominal pathologies on physical exam, such as appendicitis, diverticulitis, or cholecystitis. However, EA is usually benign and self-limiting and can be treated conservatively. We present the case of a patient with two episodes of EA, the first mimicking acute appendicitis and the second mimicking acute cholecystitis. Although recurrence of EA is rare, it should be part of the differential diagnosis of acute, localized abdominal pain. A correct diagnosis of EA will prevent unnecessary hospitalization, antibiotic use, and surgical procedures. PMID:28127129

  15. Dynamics of spacecraft with deploying flexible appendages

    NASA Technical Reports Server (NTRS)

    Downer, Janice D.; Park, K. C.

    1992-01-01

    A computational formulation for the dynamic analysis of spacecraft with deploying appendages is presented. The appendage model is based on a geometrically nonlinear beam formulation which accurately accounts for large rotational and large deformation motions. A moving finite element reference grid is incorporated within the nonlinear beam formulation to model the deployment motion. Hamilton's Law is used to formulate the general equations of motion, and a transient integration solution procedure is derived from a space-time finite element discretization of the Hamiltonian variational statement. Computational results of the methodology are presented for a classical gravity gradient stabilized satellite configuration.

  16. TRIF promotes angiotensin II-induced cross-talk between fibroblasts and macrophages in atrial fibrosis

    SciTech Connect

    Chen, Xiao-Qing; Zhang, Dao-Liang; Zhang, Ming-Jian; Guo, Meng; Zhan, Yang-Yang; Liu, Fang; Jiang, Wei-Feng; Zhou, Li; Zhao, Liang; Wang, Quan-Xing; Liu, Xu

    2015-08-14

    Aims: Atrial fibroblasts and macrophages have long been thought to participate in atrial fibrillation (AF). However, which specific mediator may regulate the interaction between them remains unclear. Methods and results: We provided the evidence for the involvement of Toll/IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF), an important inflammation-related molecule, in the pathophysiology of AF. Patients with AF showed higher levels of angiotensin II (AngII) and TRIF expression and larger number of macrophages infiltration in left atria appendage than individuals with sinus rhythm (SR). In the cell study, AngII induced chemokines expressions in mouse atrial fibroblasts and AngII-stimulated atrial fibroblasts induced the chemotaxis of macrophages, which were reduced by losartan and TRIF siRNA. Meanwhile, AngII-stimulated atrial fibroblasts proliferation was enhanced by macrophages. Conclusions: Our data demonstrated that TRIF may be a crucial factor promoting the interaction between atrial fibroblasts and macrophages, leading to atrial fibrosis. - Highlights: • Compared with SR, AF showed higher TRIF expression in left atrial appendage. • TRIF siRNA reversed macrophage chemotaxis induced by AngII-treated fibroblast. • TRIF siRNA reversed chemokines expressions induced by AngII in fibroblast. • AngII-stimulated atrial fibroblast proliferation was enhanced by macrophage.

  17. Protein analysis of atrial fibrosis via label-free proteomics in chronic atrial fibrillation patients with mitral valve disease.

    PubMed

    Zhang, Peide; Wang, Wei; Wang, Xin; Wang, Xu; Song, Yunhu; Han, Yong; Zhang, Jing; Zhao, Hui

    2013-01-01

    Atrial fibrosis, as a hallmark of atrial structure remodeling, plays an important role in maintenance of chronic atrial fibrillation, but interrelationship of atrial fibrosis and atrial fibrillation is uncertain. Label-free proteomics can implement high throughput screening for finding and analyzing pivotal proteins related to the disease.. Therefore, we used label-free proteomics to explore and analyze differentially proteins in chronic atrial fibrillation patients with mitral valve disease. Left and right atrial appendages obtained from patients with mitral valve disease were both in chronic atrial fibrillation (CAF, AF≥6 months, n = 6) and in sinus rhythm (SR, n = 6). One part of the sample was used for histological analysis and fibrosis quantification; other part were analyzed by label-free proteomic combining liquid chromatography with mass spectrometry (LC-MS), we utilized bioinformatics analysis to identify differential proteins. Degree of atrial fibrosis was higher in CAF patients than that of SR patients. 223 differential proteins were detected between two groups. These proteins mainly had vital functions such as cell proliferation, stress response, focal adhesion apoptosis. We evaluated that serine/threonine protein kinase N2 (PKN2), dermatopontin (DP), S100 calcium binding protein B (S100B), protein tyrosine kinase 2 (PTK2) and discoidin domain receptor tyrosine kinase 2 (DDR2) played important roles in fibrotic process related to atrial fibrillation. The study presented differential proteins responsible for atrial fibrosis in chronic atrial fibrillation patients through label-free proteomic analysis. We assessed some vital proteins including their characters and roles. These findings may open up new realm for mechanism research of atrial fibrillation.

  18. Association of left atrial endothelin-1 with atrial rhythm, size, and fibrosis in patients with structural heart disease.

    PubMed

    Mayyas, Fadia; Niebauer, Mark; Zurick, Andrew; Barnard, John; Gillinov, A Marc; Chung, Mina K; Van Wagoner, David R

    2010-08-01

    Atrial fibrillation (AF) promotes atrial remodeling and can develop secondary to heart failure or mitral valve disease. Cardiac endothelin-1 (ET-1) expression responds to wall stress and can promote myocyte hypertrophy and interstitial fibrosis. We tested the hypothesis that atrial ET-1 is elevated in AF and is associated with AF persistence. Left atrial appendage tissue was studied from coronary artery bypass graft, valve repair, and/or Maze procedure in patients in sinus rhythm with no history of AF (SR, n=21), with history of AF but in SR at surgery (AF/SR, n=23), and in AF at surgery (AF/AF, n=32). The correlation of LA size with atrial protein and mRNA expression of ET-1 and ET-1 receptors (ETAR and ETBR) was evaluated. LA appendage ET-1 content was higher in AF/AF than in SR, but receptor levels were similar. Immunostaining revealed that ET-1 and its receptors were present both in atrial myocytes and in fibroblasts. ET-1 content was positively correlated with LA size, heart failure, AF persistence, and severity of mitral regurgitation. Multivariate analysis confirmed associations of ET-1 with AF, hypertension, and LA size. LA size was associated with ET-1 and MR severity. ET-1 mRNA levels were correlated with genes involved in cardiac dilatation, hypertrophy, and fibrosis. Elevated atrial ET-1 content is associated with increased LA size, AF rhythm, hypertension, and heart failure. ET-1 is associated with atrial dilatation, fibrosis, and hypertrophy and probably contributes to AF persistence. Interventions that reduce atrial ET-1 expression and/or block its receptors may slow AF progression.

  19. Remodeling of atrial ATP-sensitive K+ channels in a model of salt-induced elevated blood pressure

    PubMed Central

    Lader, Joshua M.; Vasquez, Carolina; Bao, Li; Maass, Karen; Qu, Jiaxiang; Kefalogianni, Eirini; Fishman, Glenn I.; Coetzee, William A.

    2011-01-01

    Hypertension is associated with the development of atrial fibrillation; however, the electrophysiological consequences of this condition remain poorly understood. ATP-sensitive K+ (KATP) channels, which contribute to ventricular arrhythmias, are also expressed in the atria. We hypothesized that salt-induced elevated blood pressure (BP) leads to atrial KATP channel activation and increased arrhythmia inducibility. Elevated BP was induced in mice with a high-salt diet (HS) for 4 wk. High-resolution optical mapping was used to measure atrial arrhythmia inducibility, effective refractory period (ERP), and action potential duration at 90% repolarization (APD90). Excised patch clamping was performed to quantify KATP channel properties and density. KATP channel protein expression was also evaluated. Atrial arrhythmia inducibility was 22% higher in HS hearts compared with control hearts. ERP and APD90 were significantly shorter in the right atrial appendage and left atrial appendage of HS hearts compared with control hearts. Perfusion with 1 μM glibenclamide or 300 μM tolbutamide significantly decreased arrhythmia inducibility and prolonged APD90 in HS hearts compared with untreated HS hearts. KATP channel density was 156% higher in myocytes isolated from HS animals compared with control animals. Sulfonylurea receptor 1 protein expression was increased in the left atrial appendage and right atrial appendage of HS animals (415% and 372% of NS animals, respectively). In conclusion, KATP channel activation provides a mechanistic link between salt-induced elevated BP and increased atrial arrhythmia inducibility. The findings of this study have important implications for the treatment and prevention of atrial arrhythmias in the setting of hypertensive heart disease and may lead to new therapeutic approaches. PMID:21724863

  20. Atrial Fibrillation

    MedlinePlus

    ... information about the heart's electrical system and detailed animations, go to the Diseases and Conditions Index How ... can't restore a normal heart rhythm. The animation below shows atrial fibrillation. Click the "start" button ...

  1. Role of the MAPKs/TGF-β1/TRAF6 signaling pathway in atrial fibrosis of patients with chronic atrial fibrillation and rheumatic mitral valve disease.

    PubMed

    Zhang, Daoliang; Liu, Xu; Chen, Xiaoqing; Gu, Jun; Li, Feng; Zhang, Wei; Zheng, Yue

    2014-01-01

    Atrial remodeling is involved in atrial fibrillation (AF), and atrial fibrosis is an important marker of atrial remodeling. On the basis of our previous animal studies of the mitogen-activated protein kinases (MAPKs)/transforming growth factor β1 (TGF-β1)/tumor necrosis factor pathway in atrial fibrosis, we undertook investigation of this signaling pathway in atrial fibrosis of patients with chronic AF (CAF) and rheumatic mitral valve disease. Fifty-six rheumatic mitral valve disease patients were divided into CAF (course of AF >12 months) and sinus rhythm (SR) groups. Left atrial appendage tissue was collected during heart surgery, and pathological examination was done to evaluate atrial fibrosis. Protein and mRNA expression of TGF-β1, TRAF6 and connective tissue growth factor (CTGF) and protein expression of phosphorylated MAPKs and TGF-β-activated kinase 1 (TAK1) were measured. Histological examination revealed that the severity of atrial fibrosis in CAF patients was significantly higher, mRNA and protein expression of TGF-β1, TRAF6 and CTGF in CAF were significantly increased, and the protein expression of phosphorylated MAPKs and TAK1 was significantly increased in CAF compared to SR patients. The MAPKs/TGF-β1/TRAF6 signaling pathway is involved in atrial fibrosis of CAF patients, and TRAF6 may become a new target for the treatment of atrial fibrosis.

  2. Premature senescence of cardiac fibroblasts and atrial fibrosis in patients with atrial fibrillation.

    PubMed

    Xie, Jun; Chen, Yuhan; Hu, Chuanxian; Pan, Quanhua; Wang, Bingjian; Li, Xueling; Geng, Jin; Xu, Biao

    2017-08-29

    Premature senescence is associated with atrial fibrosis and has an antifibrotic effect in mice. However, the role of senescence in atrial fibrillation (AF) remains unclear. Here, we investigated the association of premature senescence with fibrosis and also determined the role of senescence in the recurrence of AF after surgery ablation. Western blot, Sirius red staining, SA-β-gal staining and immunohistochemistry were performed to detect the degree of atrial fibrosis ,the expression of TGF-β and collagens, and also the senescence markers in 72 tissue specimens of left atrial appendage in this study. Then the patients undergoing successful surgical ablation were followed up for 12 months. The expression of collagens and TGF-β was paralleled by a high level of atrial fibrosis and were increased in AF group, especially in the persistent AF group. Western blotting of P16 and SA-β-gal staining showed an increased premature senescence in the sinus rhythm, paroxysmal AF and persistent AF groups. In addition, positive area of senescence markers, SA-β-gal and P16, was correlated positively with fibrotic lesions. We also found a lower ratio of P16/TGF-β in patients with recurrence of AF than in patients without recurrent AF. In conclusion, premature senescence is associated with atrial fibrosis in AF, and may have an antifibrotic role in AF.

  3. The Incidence of Audible Steam Pops Is Increased and Unpredictable With the ThermoCool® Surround Flow Catheter During Left Atrial Catheter Ablation: A Prospective Observational Study.

    PubMed

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

    2015-06-08

    Open irrigated radiofrequency (RF) ablation catheters with a porous tip (56 holes, TC-SF) permit delivering RF energy in a temperature-controlled mode without temperature rise. This prospective observational study investigated the association of different catheter parameters on the occurrence of audible steam pops during left atrial (LA) ablation. A total of 226 patients underwent TC-SF catheter ablation for atrial fibrillation. RF power delivery, impedance and catheter tip temperature were continually recorded throughout the ablation. Pulmonary vein isolation was performed with a maximum of 27 W and LA electrogram-guided or linear ablation with a maximum of 30 W. A total of 59 audible steam pops occurred, 2 of them resulting in pericardial tamponade. In the initial 89 patients, with an irrigation flow rate of 10 mL/min, 18 steam pops with one tamponade occurred in 12 (14%) patients. Subsequently, the irrigation flow rate was increased to 20 mL/min in the following 137 patients, resulting in the occurrence of 41 steam pops including one case of tamponade in a total of 30 (22%) patients. The maximal power was significantly higher in RF applications associated with a pop than those that did not. In only 12 (20%) steam pops, a significant impedance change occurred immediately before pop occurrence (4 [7%] impedance rise >10 ohm, 8 [13%] impedance drop >15 ohm). The TC-SF catheter does not provide sufficient feedback from the ablated tissue to prevent steam popping. © 2015 Wiley Periodicals, Inc.

  4. Inhibition of atrial receptor-induced renal responses by stimulation of carotid baroreceptors in anaesthetized dogs.

    PubMed Central

    Karim, F; Majid, D S

    1991-01-01

    1. Dogs were anaesthetized with chloralose and artificially ventilated. The receptors at three pulmonary vein-atrial junctions and in the left atrial appendage were stimulated by distension of small balloons. The carotid sinuses were vascularly isolated and perfused with arterial blood. A volume reservoir was connected to the aorta via the common carotid and femoral arteries to keep the mean aortic pressure constant (78.8 +/- 2.9 mmHg at low and 87.1 +/- 4.3 mmHg at high carotid sinus pressure, CSP). Propranolol and atropine were infused (i.v.) at 17 and 13 micrograms kg-1 min-1 respectively in order to block beta-adrenergic and cholinergic receptor activities. The renal blood flow was measured by an electromagnetic flow meter (wrap-round probe), glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and osmolar excretion by osmometry. 2. In twelve tests in eight dogs, stimulation of the left atrial receptors for 13 min, at a mean CSP of 68.6 +/- 2.3 mmHg, resulted in significant increases in renal blood flow from 216 +/- 20.0 to 230 +/- 22.1 ml min-1 (100 g renal mass)-1 (P less than 0.005), glomerular filtration rate from 33.9 +/- 3.2 to 42.1 +/- 4.1 ml min-1 100 g-1 (P less than 0.005), filtration fraction from 0.23 +/- 0.02 to 0.26 +/- 0.02 (P less than 0.005), urine flow rate from 0.21 +/- 0.03 to 0.26 +/- 0.03 ml min-1 100 g-1 (P less than 0.001), sodium excretion from 12.9 +/- 4.0 to 16.4 +/- 4.8 mumol min-1 100 g-1 (P less than 0.01), osmolar excretion from 196 +/- 27.8 to 246 +/- 32.9 muosmol min-1 100 g-1 (P less than 0.005), whilst free water clearance decreased from -0.39 +/- 0.07 to -0.50 +/- 0.09 ml min-1 100 g-1 (P less than 0.005). However, the fractional excretion of sodium did not change. 3. In nine tests in seven dogs, stimulation of the left atrial receptors at a constantly high CSP (161 +/- 11.3 mmHg) did not produce significant change in any of the renal variables. 4. The results show that high level

  5. Primary epiploic appendagitis and fructose malabsorption.

    PubMed

    Schnedl, W J; Lipp, R W; Wallner-Liebmann, S J; Kalmar, P; Szolar, D H; Mangge, H

    2014-12-01

    Primary epiploic appendagitis (PEA) is a rare cause of abdominal acute or subacute complaints. Diagnosis of PEA is made when computed tomography (CT) reveals a characteristic lesion. We report on contrast-enhanced CT images of a patient with PEA and regression of inflammation and the reduction in size of the inflamed appendage over the time period of 4 months. Patients with PEA usually recover without medication or surgical treatment within a few weeks. However, due to continuing bloating and irregular bowel movements we investigated carbohydrate malabsorption and diagnosed a fructose malabsorption. Bloating and irregular bowel movements in this patient with PEA were correlated to carbohydrate malabsorption and were treated successfully with a diet free of culprit carbohydrates.

  6. Evaluating the Atrial Myopathy Underlying Atrial Fibrillation: Identifying the Arrhythmogenic and Thrombogenic Substrate

    PubMed Central

    Goldberger, Jeffrey J.; Arora, Rishi; Green, David; Greenland, Philip; Lee, Daniel C.; Lloyd-Jones, Donald M.; Markl, Michael; Ng, Jason; Shah, Sanjiv J.

    2015-01-01

    Atrial disease or myopathy forms the substrate for atrial fibrillation (AF) and underlies the potential for atrial thrombus formation and subsequent stroke. Current diagnostic approaches in patients with AF focus on identifying clinical predictors with evaluation of left atrial size by echocardiography serving as the sole measure specifically evaluating the atrium. Although the atrial substrate underlying AF is likely developing for years prior to the onset of AF, there is no current evaluation to identify the pre-clinical atrial myopathy. Atrial fibrosis is one component of the atrial substrate that has garnered recent attention based on newer MRI techniques that have been applied to visualize atrial fibrosis in humans with prognostic implications regarding success of treatment. Advanced ECG signal processing, echocardiographic techniques, and MRI imaging of fibrosis and flow provide up-to-date approaches to evaluate the atrial myopathy underlying AF. While thromboembolic risk is currently defined by clinical scores, their predictive value is mediocre. Evaluation of stasis via imaging and biomarkers associated with thrombogenesis may provide enhanced approaches to assess risk for stroke in patients with AF. Better delineation of the atrial myopathy that serves as the substrate for AF and thromboembolic complications might improve treatment outcomes. Furthermore, better delineation of the pathophysiologic mechanisms underlying the development of the atrial substrate for AF, particularly in its earlier stages, could help identify blood and imaging biomarkers that could be useful to assess risk for developing new onset AF and suggest specific pathways that could be targeted for prevention. PMID:26216085

  7. Behavior of tethered debris with flexible appendages

    NASA Astrophysics Data System (ADS)

    Aslanov, Vladimir S.; Yudintsev, Vadim V.

    2014-11-01

    Active exploration of the space leads to growth of a near-Earth space pollution. The frequency of the registered collisions of space debris with functional satellites highly increased during last 10 years. As a rule a large space debris can be observed from the Earth and catalogued, then it is possible to avoid collision with the active spacecraft. However every large debris is a potential source of a numerous small debris particles. To reduce debris population in the near Earth space the large debris should be removed from working orbits. The active debris removal technique is considered that intend to use a tethered orbital transfer vehicle, or a space tug attached by a tether to the space debris. This paper focuses on the dynamics of the space debris with flexible appendages. Mathematical model of the system is derived using the Lagrange formalism. Several numerical examples are presented to illustrate the mutual influence of the oscillations of flexible appendages and the oscillations of a tether. It is shown that flexible appendages can have a significant influence on the attitude motion of the space debris and the safety of the transportation process.

  8. Active damping of spacecraft structural appendage vibrations

    NASA Technical Reports Server (NTRS)

    Fedor, Joseph V. (Inventor)

    1990-01-01

    An active vibration damper system, for bending in two orthogonal directions and torsion, in each of three mutually perpendicular axes is located at the extremities of the flexible appendages of a space platform. The system components for each axis includes: an accelerometer, filtering and signal processing apparatus, and a DC motor-inertia wheel torquer. The motor torquer, when driven by a voltage proportional to the relative vibration tip velocity, produces a reaction torque for opposing and therefore damping a specific modal velocity of vibration. The relative tip velocity is obtained by integrating the difference between the signal output from the accelerometer located at the end of the appendage with the output of a usually carried accelerometer located on a relatively rigid body portion of the space platform. A selector switch, with sequential stepping logic or highest modal vibration energy logic, steps to another modal tip velocity channel and receives a signal voltage to damp another vibration mode. In this manner, several vibration modes can be damped with a single sensor/actuator pair. When a three axis damper is located on each of the major appendages of the platform, then all of the system vibration modes can be effectively damped.

  9. Primary Cardiac Sarcoidosis with Syncope and Refractory Atrial Arrhythmia: A Case Report and Review of the Literature.

    PubMed

    Thangam, Manoj; Nathan, Sriram; Kar, Biswajit; Petrovic, Marija; Patel, Manish; Loyalka, Pranav; Buja, L Maximilian; Gregoric, Igor D

    2016-06-01

    We discuss the case of a 38-year-old black man who presented at our hospital with his first episode of syncope, recently developed atrial arrhythmias refractory to pharmacologic therapy, and a left atrial thrombus. He was diagnosed with primary cardiac sarcoidosis characterized by predominant involvement of the epicardium that caused atrial fibrillation and atrial flutter. Histologic analysis of his epicardial lesions yielded a diagnosis of sarcoidosis. This patient's atrial arrhythmia was successfully treated with a hybrid operation that involved resection of his atrial appendage, an Epicor maze procedure, and radiofrequency ablation during a catheter-based electrophysiologic study. The cardiac sarcoidosis was successfully managed with corticosteroid therapy. Our case report shows that sarcoidosis can initially manifest itself as syncope with new-onset atrial arrhythmia. Sarcoidosis is important in the differential diagnosis because of its progressive nature and its potential for treatment with pharmacologic, surgical, and catheter-based interventions.

  10. Primary Cardiac Sarcoidosis with Syncope and Refractory Atrial Arrhythmia: A Case Report and Review of the Literature

    PubMed Central

    Thangam, Manoj; Nathan, Sriram; Kar, Biswajit; Petrovic, Marija; Patel, Manish; Loyalka, Pranav; Buja, L. Maximilian

    2016-01-01

    We discuss the case of a 38-year-old black man who presented at our hospital with his first episode of syncope, recently developed atrial arrhythmias refractory to pharmacologic therapy, and a left atrial thrombus. He was diagnosed with primary cardiac sarcoidosis characterized by predominant involvement of the epicardium that caused atrial fibrillation and atrial flutter. Histologic analysis of his epicardial lesions yielded a diagnosis of sarcoidosis. This patient's atrial arrhythmia was successfully treated with a hybrid operation that involved resection of his atrial appendage, an Epicor maze procedure, and radiofrequency ablation during a catheter-based electrophysiologic study. The cardiac sarcoidosis was successfully managed with corticosteroid therapy. Our case report shows that sarcoidosis can initially manifest itself as syncope with new-onset atrial arrhythmia. Sarcoidosis is important in the differential diagnosis because of its progressive nature and its potential for treatment with pharmacologic, surgical, and catheter-based interventions. PMID:27303240

  11. [Successful treatment of atrial fibrillation by resection of a congenital aneurysm of the left heart atrium].

    PubMed

    Heigl, F; Steinbeck, G; Rienmüller, R; Kemkes, B M; Klinner, W

    1992-10-01

    Atrial fibrillation occurred in a 27-year-old patient with a history of globular cardiac enlargement since childhood. Because of the probable causal relationship between the preexisting heart disease-which was supposed to be an enlargement of the left atrium-and the rhythm disturbance, we recommended a surgical intervention. Cardiac surgery revealed a congenital aneurysm of the left atrial appendage which could be resected without any complication. Postoperatively, atrial fibrillation had returned to regular sinus rhythm. The bad prognosis with a high risk of systemic embolism is the reason why early cardiac surgery should be performed after diagnosis of this rare anomaly (20 reported cases) of the left atrium.

  12. Neonatal repair of left atrial diverticulum with gigantic thrombus without cardiopulmonary bypass.

    PubMed

    Higashida, Akihiko; Hoashi, Takaya; Sakaguchi, Heima; Ichikawa, Hajime

    2017-04-08

    A 5-day-old neonate with coarctation of the aorta, hypoplastic aortic arch, large apical muscular ventricular septal defect, and patent ductus arteriosus developed pulmonary over-circulation and systemic hypoperfusion underwent bilateral pulmonary artery banding through median sternotomy as a part of hybrid stage I palliation. At operation, left atrial diverticulum with gigantic thrombus formation at the base of the left atrial appendage was incidentally detected by intraoperative direct echocardiography, and therefore, was successfully resected with the whole thrombus inside it without use of cardiopulmonary bypass. Histopathological finding was compatible with diverticulum. The patient was free from atrial arrhythmia and recurrent thrombus formation.

  13. Prevalence of auricular thrombosis before atrial flutter cardioversion: a 17-year transoesophageal echocardiographic study.

    PubMed

    Cresti, Alberto; García-Fernández, Miguel Angel; De Sensi, Francesco; Miracapillo, Gennaro; Picchi, Andrea; Scalese, Marco; Severi, Silva

    2016-03-01

    Prevalence of left appendage thrombosis ranges from 6 to 18% in persistent atrial fibrillation (AF). Few and low sample size studies have assessed left and right atrial thrombosis in persistent atrial flutter (AFL) and a wide variety of frequencies, from 1 to 21%, has been reported. The aim of this study was to evaluate the prevalence of atrial appendage thrombosis in a large population of patients undergoing transoesophageal echocardiography (TEE)-guided cardioversion (CV) for recent AFL onset and compare it with AF. From 1999 to September 2014, we collected data of 1081 patients to CV: 877 affected by AF (81.1%) and 204 by AFL (18.9%). The presence of auricular thrombosis was evaluated by TEE in AF or AFL persisting for more than 48 h. The presence of appendage thrombosis, Doppler emptying velocities, and severe spontaneous echo contrast (SEC) was studied. The overall prevalence of atrial thrombosis was 9.62% (104/1081). Frequency of atrial thrombosis in AFL patients was 6.4% (13/204) vs. 10.5% among AF (92/877), P = 0.074. Comparing the two appendages, frequency of left atrial appendage thrombosis was in AFL 5.9% (12/204) vs. 9.9% (87/877) in the AF group, P = 0.07. Right atrial appendage thrombosis was present in 0.5% (1/204) in the AFL group vs. 0.8% (7/877) in the AF group, P = 0.64. Moderate to severe SEC (3+/4+) was present in 28% of AFL patients (57/204) vs. 35% of AF patients (307/877), P = 0.05. Auricular thrombosis is not an infrequent finding in AFL before CV. Our study suggests the use of TEE screening in AFL, as well as in AF, when patients arrive to clinical attention after more than 48 h from arrhythmia onset. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  14. Dynamic and dual-site atrial pacing in the prevention of atrial fibrillation: The STimolazione Atrial DInamica Multisito (STADIM) Study.

    PubMed

    De Simone, Antonio; Senatore, Gaetano; Donnici, Giovanni; Turco, Pietro; Romano, Enrico; Gazzola, Carlo; Stabile, G

    2007-01-01

    The impact of new algorithms to consistently pace the atrium on the prevention of atrial fibrillation (AF) remains unclear. Our randomized, crossover study compared the efficacy of single- and dual-site atrial pacing, with versus without dynamic atrial overdrive pacing in preventing AF. We studied 72 patients (mean age = 69.6 +/- 6.5 years, 34 men) with sick sinus syndrome (SSS) and paroxysmal or persistent AF, who received dual-chamber pacemakers (PM) equipped with an AF prevention algorithm and two atrial leads placed in the right atrial appendage (RAA), by passive fixation, and in the coronary sinus ostium (CS), by active fixation, respectively. At implant, the patients were randomly assigned to unipolar CS versus RAA pacing. The PM was programmed in DDDR mode 1 month after implant. Each patient underwent four study phases of equal duration: (1) unipolar, single site (CS or RAA) pacing with the AF algorithm ON (atrial lower rate = 0 ppm); (2) unipolar, single site pacing with the AF algorithm OFF (atrial lower rate = 70 bpm); (3) bipolar, dual-site pacing with AF algorithm ON; (4) bipolar, dual-site pacing with the AF algorithm OFF. Among 40 patients (56%), who completed the follow-up (15 +/- 4 months) no difference was observed in the mean number of automatic mode switch (AMS) corrected for the duration of follow-up, in unipolar (5.6 +/- 22.8 vs 2.6 +/- 5.5) or bipolar mode (3.3 +/- 12.7 vs 2.1 +/- 4.9) with, respectively, the algorithm OFF or ON. With the AF prevention algorithm ON, the percentage of atrial pacing increased significantly from 78.7 +/- 22.1% to 92.4 +/- 4.9% (P < 0.001), while the average ventricular heart rate was significantly lower with the algorithm ON (62.4 +/- 17.5 vs 79.9 +/- 3 bpm (P < 0.001). The AF prevention algorithm increased the percentage of atrial pacing significantly, regardless of the atrial pulse configuration and pacing site, while maintaining a slower ventricular heart rate. It had no impact on the number of AMS in the

  15. Dynamics modeling and simulation of autonomous underwater vehicles with appendages

    NASA Astrophysics Data System (ADS)

    Su, Yumin; Zhao, Jinxin; Cao, Jian; Zhang, Guocheng

    2013-03-01

    To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle's (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV's motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.

  16. Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

    PubMed Central

    Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

    2011-01-01

    Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

  17. Atrial Fibrillation: Complications

    MedlinePlus

    ... this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Complications Past Issues / Winter 2015 Table of Contents ... two major complications—stroke and heart failure. Atrial Fibrillation and Stroke Click to enlarge image This illustration ...

  18. Atrial Fibrillation: Treatment

    MedlinePlus

    ... this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Treatment Past Issues / Winter 2015 Table of Contents Treatment for atrial fibrillation depends on how often you have symptoms, how ...

  19. Noninvasive pacing study via pacemakers and implantable cardioverter-defibrillators for differentiating right from left atrial flutter.

    PubMed

    Burri, Haran; Zimmermann, Marc; Sunthorn, Henri; Al-Jefairi, Nora; Trentaz, Florence; Stettler, Carine; Gentil-Baron, Pascale; Shah, Dipen

    2015-06-01

    Patients with atrial flutter who are implanted with a pacemaker (PM) or implantable cardioverter-defibrillator (ICD) present with the opportunity to perform a noninvasive pacing study (NIPS) using the right atrial pacing lead to differentiate right from left atrial flutter. The purpose of this study was to study the feasibility and accuracy of NIPS to distinguish right from left atrial flutter. We enrolled consecutive patients scheduled for an electrophysiological study or ablation procedure who were in atrial flutter and who were implanted with a PM or ICD with a functional atrial lead in the right atrial appendage. Flutter tachycardia cycle lengths (TCLs) and postpacing intervals (PPIs) were measured noninvasively via the device during the procedure. A total of 48 (67%) patients were studied. Right atrial flutter was present in 32 patients (of whom 29 had typical cavotricuspid isthmus-dependent flutter) and 16 (33%) patients had left atrial flutter. A PPI-TCL interval of >100 ms was 100% specific and 81% sensitive to identify left atrial flutter, with an overall accuracy of 94% and a c statistic of 0.94 (95% confidence interval 0.87-1.00). A PPI-TCL interval of ≤100 ms had a positive predictive value of 86% for diagnosing typical flutter. NIPS via PMs and ICDs with a PPI-TCL interval of >100 ms can reliably identify left atrial flutter (although we have only validated this cutoff for leads implanted in the right atrial appendage). This simple maneuver may allow planning for left-sided access and may avoid an unnecessary invasive electrophysiological study if left atrial flutter ablation is not to be considered. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  20. Primary prevention of atrial fibrillation: does the atrial lead position influence the incidence of atrial arrhythmias in patients with sinus node dysfunction? Results from the PASTA Trial.

    PubMed

    Spitzer, Stefan G; Wacker, Petra; Gazarek, Steffen; Malinowski, Klaus; Schibgilla, Volker

    2009-12-01

    PASTA (pacing of the atria in sinus node disease) is a prospective and randomized trial, assessing the effect of different atrial lead positions on the atrial fibrillation (AF) incidence in patients with sinus node disease (SND). The atrial lead position is randomized to: (a) free right atrial wall, (b) right atrial appendage (RAA), (c) coronary sinus ostium (CS-Os), or (d) dual site right atrial pacing (CS-Os + RAA). The pacemakers (Vitatron Selection 9000 or Prevent AF, Vitatron B.V., Arnhem, The Netherlands) are programmed in DDDR 70 mode and the total follow-up duration is 24 months. To describe the atrial rhythm state, pacemaker-derived data (arrhythmia counter) were assessed for AF episodes. AF was considered as evident, if the AF burden (time in AF related to follow-up interval) was >1% (i.e., 15 min/d). Follow-up data after 24 months were evaluated. The analysis evaluates 142 patients (77 male, 74.5 +/- 7.8 years). There was no statistical significant difference with respect to the occurrence of AF between the four groups after 24 months (A: 36%; B: 38%, C: 32%, D: 48%). The percentage of atrial/ventricular pacing was in A: 78/76%, in B: 84/81%, in C: 70/65%, and in D: 79/69%. These differences were not significant. The evaluation of the AF burden >1% and the total AF burden after 24 months did not show differences in the incidence of AF in patients with dual chamber pacemaker therapy for SND. We were not able to demonstrate a significant influence of right atrial lead position on the incidence of AF recurrence.

  1. Atrial fibrillation pacing decreases intravascular shear stress in a New Zealand white rabbit model: implications in endothelial function.

    PubMed

    Jen, Nelson; Yu, Fei; Lee, Juhyun; Wasmund, Steve; Dai, Xiaohu; Chen, Christina; Chawareeyawong, Pai; Yang, Yongmo; Li, Rongsong; Hamdan, Mohamed H; Hsiai, Tzung K

    2013-08-01

    Atrial fibrillation (AF) is characterized by multiple rapid and irregular atrial depolarization, leading to rapid ventricular responses exceeding 100 beats per minute (bpm). We hypothesized that rapid and irregular pacing reduced intravascular shear stress (ISS) with implication to modulating endothelial responses. To simulate AF, we paced the left atrial appendage of New Zealand White rabbits (n = 4) at rapid and irregular intervals. Surface electrical cardiograms were recorded for atrial and ventricular rhythm, and intravascular convective heat transfer was measured by microthermal sensors, from which ISS was inferred. Rapid and irregular pacing decreased arterial systolic and diastolic pressures (baseline, 99/75 mmHg; rapid regular pacing, 92/73; rapid irregular pacing, 90/68; p < 0.001, n = 4), temporal gradients ([Formula: see text] from 1,275 ± 80 to 1,056 ± 180 dyne/cm(2) s), and reduced ISS (from baseline at 32.0 ± 2.4 to 22.7 ± 3.5 dyne/cm(2)). Computational fluid dynamics code demonstrated that experimentally inferred ISS provided a close approximation to the computed wall shear stress at a given catheter to vessel diameter ratio, shear stress range, and catheter position. In an in vitro flow system in which time-averaged shear stress was maintained at [Formula: see text] , we further demonstrated that rapid pulse rates at 150 bpm down-regulated endothelial nitric oxide, promoted superoxide (O 2 (.-) ) production, and increased monocyte binding to endothelial cells. These findings suggest that rapid pacing reduces ISS and [Formula: see text] , and rapid pulse rates modulate endothelial responses.

  2. Atrial Fibrillation Pacing Decreases Intravascular Shear Stress in a New Zealand White Rabbit Model: Implications in Endothelial Function

    PubMed Central

    Jen, Nelson; Yu, Fei; Lee, Juhyun; Wasmund, Steve; Dai, Xiaohu; Chen, Christina; Chawareeyawong, Pai; Yang, Yongmo; Li, Rongsong; Hamdan, Mohamed H.; Hsiai, Tzung

    2012-01-01

    Atrial fibrillation (AF) is characterized by multiple rapid and irregular atrial depolarization leading to rapid ventricular responses exceeding 100 beats per minute (bpm). We hypothesized that rapid and irregular pacing reduced intravascular shear stress (ISS) with implication to modulating endothelial responses. To simulate AF, we paced the left atrial appendage of New Zealand White (NZW) rabbits (n=4) at rapid and irregular intervals. Surface electrical cardiograms (ECG) were recorded for atrial and ventricular rhythm, and intravascular convective heat transfer was measured by micro thermal sensors, from which ISS was inferred. Rapid and irregular pacing decreased arterial systolic and diastolic pressures (baseline: 99/75 mmHg; rapid regular pacing: 92/73; rapid irregular pacing: 90/68; P < 0.001, n=4), temporal gradients (∂τ/∂t from 1275 ± 80 to 1056 ± 180 dyne/cm2·s), and reduced ISS (from baseline at 32.0 ± 2.4 to 22.7 ± 3.5 dyne/cm2). Computational fluid dynamics (CFD) code demonstrated that experimentally inferred ISS provided a close approximation to the computed wall shear stress (WSS) at a given catheter to vessel diameter ratio, shear stress range, and catheter position. In an in vitro flow system in which time-averaged shear stress was maintained at τavg=23 ±4 dyn·cm−2·s−1, we further demonstrated that rapid pulse rates at 150 bpm down-regulated endothelial nitric oxide (NO), promoted superoxide (O2·−) production, and increased monocyte binding to endothelial cells. These findings suggest that rapid pacing reduces ISS and ∂τ/∂t, and rapid pulse rates modulate endothelial responses. PMID:22983703

  3. Fibroblast growth factor-21 is positively associated with atrial fibrosis in atrial fibrillation patients with rheumatic heart disease.

    PubMed

    Wang, Rui; Yi, Xin; Li, Xiaoyan; Jiang, Xuejun

    2015-01-01

    Fibroblast growth factor-21 (FGF-21) has been discovered as a strong hormone, plays an important role in lipid metabolism, glucose metabolism, associated with several diseases such as obesity, metabolic syndrome, diabetes mellitus, and cardiovascular events; however, no evidence is available concerning the relationship of FGF-21 and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD). Twenty-four rheumatic heart disease patients were divided into two groups, 12 cases with AF and 12 cases with sinus rhythm (SR). Clinical characteristics and blood samples were collected before surgery; right atrial appendage samples were taken in the surgery of valve replacement. HE staining was performed to determine cross-sectional area of atrial myocytes; Masson stained sections and mRNA levels of cardiac fibrosis biomarkers were used to evaluate the degree of cardiac fibrosis; the level of FGF-21 was evaluated via enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and real-time polymerase chain reaction (PCR). Compared with SR group, cross-sectional area of atrial myocytes and collagen volume fraction were significantly increased in the atrial tissue of AF group. The distribution of FGF-21 in the AF group was remarkably higher than SR group. In addition, plasma and mRNA levels of FGF-21 in atrial tissue of AF showed the same trend as the result of immunohistochemistry. Using linear correlation analysis, the expression level of FGF-21 was found to be positively related to the degree of atrial fibrosis. FGF-21 might involve in the development and maintenance of atrial fibrosis in atrial fibrillation with rheumatic heart disease, and FGF-21 could be used as a novel biomarker to evaluate myocardial fibrosis in the future.

  4. Efficacy of adjunctive measures used to assist pulmonary vein isolation for atrial fibrillation: a systematic review.

    PubMed

    Nair, Girish M; Raut, Roshan; Bami, Karan; Nery, Pablo B; Redpath, Calum J; Sadek, Mouhannad M; Green, Martin S; Birnie, David H

    2017-01-01

    Pulmonary vein reconnection leading to recurrence of atrial arrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation remains a significant challenge. A number of adjunctive measures during PVI have been used to attempt to reduce pulmonary vein reconnection and recurrence of atrial arrhythmias. We performed a systematic review of the literature and meta-analysis of studies evaluating the efficacy of adjunctive measures used during PVI in reducing recurrent atrial arrhythmias. Our literature search found four interventions that met the prespecified definition of adjunctive measure: adenosine testing post-PVI, contact force-guided PVI, pacing inexcitability of the ablation line during PVI and additional ablation based on the computed tomography thickness of the pulmonary vein-left atrial appendage ridge. Sixteen studies enrolling 3507 patients met all inclusion and exclusion criteria. PVI performed with adjunctive measures was shown to reduce the 1-year recurrence rate of atrial arrhythmias. The point estimate for the combined relative risk of atrial arrhythmia recurrence was 0.56 [95% confidence interval (CI): 0.43-0.73; P value <0.001] in the PVI with adjunctive measures group. PVI for atrial fibrillation assisted by adjunctive measures results in clinically significant reduction of recurrent atrial arrhythmias. Additional research is required to assess the relative efficacy of individual or combined adjunctive strategies used during PVI for atrial fibrillation.

  5. The Photogrammetric Appendage Structural Dynamics Experiment

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.; Welch, Sharon S.; Moore, Christopher L.

    1995-01-01

    The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) is a Hitchhiker payload scheduled to fly as part of the International Space Station (ISS) Phase-1 flight program to the Russian Space Station Mir. The objective of the first flight of PASDE on STS-74 is to obtain video images of the Mir Kvant-2 solar array response to various structural dynamic excitation events. This experiment will demonstrate the use of photogrammetric techniques for on-orbit structural dynamics measurements. Photogrammetric measurements will provide a low cost alternative to appendage mounted accelerometers to the ISS program. The PASDE experiment hardware consists of three instruments each containing two video cameras, two video tape recorders, a modified video signal time inserter, and associated avionics boxes. The instruments were designed and built at the NASA Langley Research Center, and are integrated into standard Hitchhiker canisters at the NASA Goddard Space Flight Center. The Hitchhiker canisters are then installed into the Space Shuttle cargo bay in locations selected to achieve good video coverage and photogrammetric geometry. The measurement resolution of the instruments is expected to be on the order of 0.25 cm (0.1 in.).

  6. Hedgehog Signaling during Appendage Development and Regeneration

    PubMed Central

    Singh, Bhairab N.; Koyano-Nakagawa, Naoko; Donaldson, Andrew; Weaver, Cyprian V.; Garry, Mary G.; Garry, Daniel J.

    2015-01-01

    Regulatory networks that govern embryonic development have been well defined. While a common hypothesis supports the notion that the embryonic regulatory cascades are reexpressed following injury and tissue regeneration, the mechanistic regulatory pathways that mediate the regenerative response in higher organisms remain undefined. Relative to mammals, lower vertebrates, including zebrafish and newts, have a tremendous regenerative capacity to repair and regenerate a number of organs including: appendages, retina, heart, jaw and nervous system. Elucidation of the pathways that govern regeneration in these lower organisms may provide cues that will enhance the capacity for the regeneration of mammalian organs. Signaling pathways, such as the hedgehog pathway, have been shown to play critical functions during development and during regeneration in lower organisms. These signaling pathways have been shown to modulate multiple processes including cellular origin, positional identity and cellular maturation. The present review will focus on the cellular and molecular regulation of the hedgehog (HH) signaling pathway and its interaction with other signaling factors during appendage development and regeneration. PMID:26110318

  7. The Photogrammetric Appendage Structural Dynamics Experiment

    NASA Astrophysics Data System (ADS)

    Gilbert, Michael G.; Welch, Sharon S.; Moore, Christopher L.

    1995-09-01

    The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) is a Hitchhiker payload scheduled to fly as part of the International Space Station (ISS) Phase-1 flight program to the Russian Space Station Mir. The objective of the first flight of PASDE on STS-74 is to obtain video images of the Mir Kvant-2 solar array response to various structural dynamic excitation events. This experiment will demonstrate the use of photogrammetric techniques for on-orbit structural dynamics measurements. Photogrammetric measurements will provide a low cost alternative to appendage mounted accelerometers to the ISS program. The PASDE experiment hardware consists of three instruments each containing two video cameras, two video tape recorders, a modified video signal time inserter, and associated avionics boxes. The instruments were designed and built at the NASA Langley Research Center, and are integrated into standard Hitchhiker canisters at the NASA Goddard Space Flight Center. The Hitchhiker canisters are then installed into the Space Shuttle cargo bay in locations selected to achieve good video coverage and photogrammetric geometry. The measurement resolution of the instruments is expected to be on the order of 0.25 cm (0.1 in.).

  8. The influence of cardiac autonomic nerve plexus on the electrophysiological properties in canines with atrial fibrillation

    PubMed Central

    Sun, Juan; Lu, Yanmei; Wugeti, Najina; Aikemu, Ainiwaer

    2015-01-01

    Background: This study sought to examine the effect of the cardiac autonomic nerve plexus, which originates from the vagus nerve trunk, on atrial vulnerability. Methods: Dogs in group I (n = 6) underwent ganglionated plexi (GP) sequential ablation following six hours of left atrial appendage rapid atrial pacing (RAP). The monophasic action potential duration at 90% of repolarization (APD90), effective refractory period (ERP), and the atrial fibrillation inducing rate of bilateral atria and pulmonary veins were recorded at baseline, l h, 3 h and 6 h after pacing, as well as after sequential ablation (RAGP + RIGP ablation, LSGP + RIGP ablation). Dogs in group II (n = 6) received vagus nerve stimulation following six hours of left atrial appendage RAP. APD90, ERP and atrial fibrillation inducing rate of bilateral atria and pulmonary veins were recorded at baseline, 1 h, 3 h and 6 h after pacing, as well as after GP sequential ablation (RAGP + RIGP ablation, LSGP + RIGP ablation). Results: In group I, APD90 and ERP progressively shortened and atrial fibrillation inducing rate increased in various sites l h, 3 h and 6 h after RAP (P < 0.05). APD90 and ERP shortened significantly and atrial fibrillation inducing rate was significantly higher in the left atrial appendage and bilateral pulmonary veins than in other sites (P < 0.05). Following GP sequential ablation, APD90, ERP and atrial fibrillation inducing rate were not significantly different from baseline levels (P > 0.05). In group II, APD90 and ERP progressively shortened in various sites over pacing time period, and the atrial fibrillation inducing rate increased l h, 3 h and 6 h after RAP + VNS (P < 0.05). APD90 and ERP shortened significantly and atrial fibrillation inducing rate was significantly higher in the left atrial appendage and right superior/inferior pulmonary veins when compared with other sites (P < 0.05). After GP sequential ablation, APD90, ERP and atrial fibrillation inducing rate were not

  9. Atrial Fibrillation.

    PubMed

    Zimetbaum, Peter

    2017-03-07

    This issue provides a clinical overview of atrial fibrillation, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  10. Some Practical Design Aspects of Appendages for Passenger Vessels

    NASA Astrophysics Data System (ADS)

    Jang, Hag Soo; Lee, Hwa Joon; Joo, Young Ryeol; Kim, Jung Joong; Chun, Ho Hwan

    2009-09-01

    The hydrodynamic effect of appendages for high-speed passenger vessels, such as Ro-Pax, Ro-Ro and cruiser vessels, is very severe and, therefore, it is essential to carry out the design of appendages for high-speed passenger vessels from the preliminary design stage to the final detail design stage through a full survey of the reference vessels together with sufficient technical investigation. Otherwise, many problems would be caused by mismatches between the appendages and the hull form. This paper investigates the design characteristics of some appendages, such as the side thruster, the shaft-strut, and the stern wedge, based on the design experience accumulated at Samsung, on CFD, and on model test results for high-speed passenger vessels. Further to this investigation, some practical and valuable design guidelines for such appendages are suggested.

  11. Relationship between Doppler transmitral flow velocity pattern and plasma atrial and brain natriuretic peptide concentrations in anuric patients on maintenance hemodialysis.

    PubMed

    Ito, Shigenori; Murai, Sumiko; Takada, Norio; Ozasa, Atsushi; Hanada, Mayumi; Sugiyama, Masaya; Suzuki, Kaoru; Nagae, Yuji; Inagaki, Toshiaki; Takeda, Yutaka; Fukutomi, Tatsuya; Joh, Takashi

    2006-05-01

    Plasma atrial (ANP) and brain (BNP) natriuretic peptide levels were compared to determine if transmitral flow velocity pattern is an instantaneous marker of body fluid balance in anuric patients on hemodialysis (HD). We measured plasma ANP and BNP levels and performed Doppler echocardiography in 38 anuric patients before and after HD. Patients with valvular disease, left ventricular systolic dysfunction having a fractional shortening < 0.3, arrhythmia, or left ventricular hypertrophy were excluded. The relationships between plasma ANP or BNP levels and the transmitral flow velocity pattern were evaluated. We also determined if the magnitude of the decrease in plasma ANP level was related to that in the early peak of transmitral flow velocity (peak E). The mean age of the subjects was 61.1 +/- 9.7 years. The ANP level of 213.6 +/- 146.1 pg/mL was related to peak E of 61 +/- 15 cm/s before HD (R = 0.504, P < 0.001), but not after HD. Plasma ANP level was not related to peak late transmitral flow velocity (peak A) or peak E/peak A before or after HD. BNP level was not related to the transmitral flow velocity pattern. The magnitude of decrease in hANP level during HD was significantly related to that in peak E (R = 0.342, P < 0.05). Before HD, peak E was related to the plasma ANP level, reflecting volume overload. Change in peak E showed a weak relationship with that of plasma ANP level in the same HD patient. The measurement of peak E during a HD session may potentially enable the assessment of hydration status during HD.

  12. [Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation].

    PubMed

    Ben Khalfallah, A; Sanaa, I

    2007-09-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, p<0.0001; Mean PicV: 44 +/- 15.8 vs. 31.4 +/- 13,7 cm/s, p<0.0001). This difference was maintained on multivariate analysis (p=0.002 for SOG and p=0.005 for PicV). In patients with recent atrial fibrillation, only left atrial area can predict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re

  13. Comparison of diverse platelet activation markers as indicators for left atrial thrombus in atrial fibrillation.

    PubMed

    Tarnowski, Daniel; Poitz, David M; Plichta, Lina; Heidrich, Felix M; Wiedemann, Stephan; Ruf, Tobias; Mierke, Johannes; Löhn, Tobias; Jellinghaus, Stefanie; Strasser, Ruth H; Ibrahim, Karim; Pfluecke, Christian

    2017-03-13

    Atrial fibrillation (AF) is well known for being a major risk factor of thromboembolic stroke. We could recently demonstrate an association of monocyte-platelet aggregates (MPAs) with the degree of thrombogenicity in patients with AF. This study investigated platelet activation markers, as potential biomarkers for the presence of left atrial (LA) thrombus in patients with AF. One hundred and eight patients with symptomatic AF underwent transesophageal echocardiography (TEE) before scheduled cardioversion or pulmonary vein isolation. In order to determine the content of MPAs by flow-cytometric quantification analyses, blood was drawn on the day of TEE. The soluble CD40 Ligand (sCD40L) and soluble P-selectin (sP-selectin) were obtained by Cytometric Bead Arrays (CBA). D-dimer levels were detected by quantitative immunological determination of fibrin degradation products. Clinical, laboratory, and echocardiographic standard parameters were obtained from all patients, including the determination of the flow in the left atrial appendage (LAA). Patients with detected LA thrombus (n = 28) compared with patients without thrombus (n = 80) showed an increased number of common risk factors, such as age, diabetes, heart failure, and coronary artery disease (CAD). The presence of LA thrombus was associated with significantly increased levels of MPAs (147 ± 12 vs. 304 ± 29 per µl; p < 0.00), sCD40L (106.3 ± 31.0 vs. 33.5 ± 2.1 pg/ml, p = 0.027), and D-dimer (0.13 ± 0.02 vs. 0.69 ± 0.21 mg FEU/l, p = 0.015). In contrast, sP-selectin showed no association with LA thrombus. A multivariate regression analysis showed that MPAs, sCD40L as well as D-dimers were independent indicators for the existence of LA thrombus. MPAs above 170 cells/µl indicated LA thrombus with a high sensitivity of 93% and a specificity of 73% (OR 62, 95% CI. 6.9-557.2, p < 0.001) in patients with AF, whereas the D-dimer lost their quality as independent indicator by using the conventional cut-off of 0

  14. Advanced left-atrial fibrosis is associated with unsuccessful maze operation for valvular atrial fibrillation.

    PubMed

    Kainuma, Satoshi; Masai, Takafumi; Yoshitatsu, Masao; Miyagawa, Shigeru; Yamauchi, Takashi; Takeda, Koji; Morii, Eiichi; Sawa, Yoshiki

    2011-07-01

    Atrial dilatation and fibrosis are considered to be important factors in the occurrence and maintenance of atrial fibrillation (AF). However, the relationship between those structural remodeling and postoperative sinus conversions after a maze operation has been rarely studied. The purpose of this study was to determine whether pathological evaluation of atrial tissues was useful for predicting an unsuccessful maze operation in patients with valvular AF. Between March 2006 and June 2007, left-atrial tissues in the posterior wall and right-atrial appendage were obtained from 47 consecutive patients (24 patients with chronic AF, and 23 with sinus rhythm) undergoing mitral valve surgery (MVS). A concomitant maze operation was performed for all patients with chronic AF. Atrial cell diameters were measured using hematoxylin and eosin staining, and quantitative assessment of atrial fibrosis was performed with Masson trichrome staining using an image analyzer (Image Processor for Analytical Pathology, Sumika Technoservice Co., Hyogo, Japan). Successful MVS was performed for all patients and there were no complications associated with tissue sampling. Patients with chronic AF had more advanced histological features in both atria as compared with those with sinus rhythm. Sixteen of 24 patients, who underwent a maze operation, had successfully restored sinus rhythm (successful maze group), while that in the remaining eight was not restored (unsuccessful maze group). Patients in the unsuccessful maze group had a larger left-atrial dimension and cardiothoracic ratio as compared with those in the successful group, whereas the duration of AF was not significantly different. Patients in the unsuccessful maze group also had greater hypertrophy of cardiomyocytes and more extensive intercellular fibrosis in the left atrium, while there were no differences for right-atrial pathological features between the groups. Multivariate logistic analysis confirmed that a larger amount of left-atrial

  15. Mosaic trisomy 13 and a sacral appendage.

    PubMed

    Pachajoa, Harry; Meza Escobar, Luis Enrique

    2013-07-31

    Mosaic trisomy 13 occurs when there is a percentage of trisomic cells for an entire chromosome 13, while the remaining percentage of cells is euploid. The prevalence of this syndrome ranges from 1 in 10 000 to 1 in 20 000 births. Complete, partial or mosaic forms of this disorder can occur. The phenotype of mosaic trisomy 13 patients varies widely. Patients with mosaic trisomy 13 usually have a longer survival and a less severe phenotype compared to patients with complete trisomy 13. Genetic counselling is difficult due to the wide variation among the clinical manifestations of these patients. There have been 49 cases of mosaic trisomy 13 reported in the literature. We report the case of a patient with mosaic trisomy 13, a sacral appendage and a cleft lip and palate.

  16. Mosaic trisomy 13 and a sacral appendage

    PubMed Central

    Pachajoa, Harry; Meza Escobar, Luis Enrique

    2013-01-01

    Mosaic trisomy 13 occurs when there is a percentage of trisomic cells for an entire chromosome 13, while the remaining percentage of cells is euploid. The prevalence of this syndrome ranges from 1 in 10 000 to 1 in 20 000 births. Complete, partial or mosaic forms of this disorder can occur. The phenotype of mosaic trisomy 13 patients varies widely. Patients with mosaic trisomy 13 usually have a longer survival and a less severe phenotype compared to patients with complete trisomy 13. Genetic counselling is difficult due to the wide variation among the clinical manifestations of these patients. There have been 49 cases of mosaic trisomy 13 reported in the literature. We report the case of a patient with mosaic trisomy 13, a sacral appendage and a cleft lip and palate. PMID:23904413

  17. Epiploic appendagitis: the emergency department presentation.

    PubMed

    Legome, Eric L; Belton, Austin L; Murray, Robert E; Rao, Pat M; Novelline, Robert A

    2002-01-01

    We performed a structured retrospective chart review to describe clinical characteristics of Emergency Department (ED) patients diagnosed by history, physical examination, and abdominal computed tomography (CT) scan with epiploic appendagitis (EA). EA is a disease caused by inflammation of the appendix epiploica, subserosal adipose tissue along the colon. It may mimic surgical causes of acute abdominal pain, but is treated conservatively with pain management. There were 19 patients diagnosed with EA, with follow-up performed on 85%. All had focal, nonmigratory symptoms. Common findings included left lower quadrant pain and guarding, and a normal temperature and white cell count. No patient required operation. This preliminary work characterizes some common clinical features of ED patients diagnosed with EA. As use of emergency CT scan for abdominal pain increases, clinicians will encounter this more often. These features should also prompt the clinician to consider CT scan in patients with similar signs and symptoms. Accurate diagnosis may avoid unnecessary surgery.

  18. Atrial fibrillation

    PubMed Central

    Munger, Thomas M.; Wu, Li-Qun; Shen, Win K.

    2014-01-01

    Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years. PMID:24474959

  19. Brain structure resolves the segmental affinity of anomalocaridid appendages.

    PubMed

    Cong, Peiyun; Ma, Xiaoya; Hou, Xianguang; Edgecombe, Gregory D; Strausfeld, Nicholas J

    2014-09-25

    Despite being among the most celebrated taxa from Cambrian biotas, anomalocaridids (order Radiodonta) have provoked intense debate about their affinities within the moulting-animal clade that includes Arthropoda. Current alternatives identify anomalocaridids as either stem-group euarthropods, crown-group euarthropods near the ancestry of chelicerates, or a segmented ecdysozoan lineage with convergent similarity to arthropods in appendage construction. Determining unambiguous affinities has been impeded by uncertainties about the segmental affiliation of anomalocaridid frontal appendages. These structures are variably homologized with jointed appendages of the second (deutocerebral) head segment, including antennae and 'great appendages' of Cambrian arthropods, or with the paired antenniform frontal appendages of living Onychophora and some Cambrian lobopodians. Here we describe Lyrarapax unguispinus, a new anomalocaridid from the early Cambrian Chengjiang biota, southwest China, nearly complete specimens of which preserve traces of muscles, digestive tract and brain. The traces of brain provide the first direct evidence for the segmental composition of the anomalocaridid head and its appendicular organization. Carbon-rich areas in the head resolve paired pre-protocerebral ganglia at the origin of paired frontal appendages. The ganglia connect to areas indicative of a bilateral pre-oral brain that receives projections from the eyestalk neuropils and compound retina. The dorsal, segmented brain of L. unguispinus reinforces an alliance between anomalocaridids and arthropods rather than cycloneuralians. Correspondences in brain organization between anomalocaridids and Onychophora resolve pre-protocerebral ganglia, associated with pre-ocular frontal appendages, as characters of the last common ancestor of euarthropods and onychophorans. A position of Radiodonta on the euarthropod stem-lineage implies the transformation of frontal appendages to another structure in crown

  20. Caudal appendage derived from a vestigial remnant of the tailgut.

    PubMed

    Tatekawa, Yukihiro; Yamanaka, Hiroaki; Hasegawa, Toshimichi; Sonobe, Hiroshi

    2013-10-01

    The presence of smooth muscle at the basal portion of a caudal appendage is very rare. We report a 3-month-old girl in which a caudal appendage is associated with smooth muscle bundles at the perianal region. Immunohistochemistry was performed for NCAM (neural cell adhesion molecule) to identify smooth muscle. NCAM immunoreactivity was observed within the presumptive circular and/or longitudinal muscle layers of the muscularis propria. NCAM is expressed by smooth muscle during the early stages of human embryonic gut development, suggesting that the caudal appendage in the present case may be derived from a tailgut remnant.

  1. Ablation for Atrial Fibrillation

    PubMed Central

    2006-01-01

    Executive Summary Objective To review the effectiveness, safety, and costing of ablation methods to manage atrial fibrillation (AF). The ablation methods reviewed were catheter ablation and surgical ablation. Clinical Need Atrial fibrillation is characterized by an irregular, usually rapid, heart rate that limits the ability of the atria to pump blood effectively to the ventricles. Atrial fibrillation can be a primary diagnosis or it may be associated with other diseases, such as high blood pressure, abnormal heart muscle function, chronic lung diseases, and coronary heart disease. The most common symptom of AF is palpitations. Symptoms caused by decreased blood flow include dizziness, fatigue, and shortness of breath. Some patients with AF do not experience any symptoms. According to United States data, the incidence of AF increases with age, with a prevalence of 1 per 200 people aged between 50 and 60 years, and 1 per 10 people aged over 80 years. In 2004, the Institute for Clinical Evaluative Sciences (ICES) estimated that the rate of hospitalization for AF in Canada was 582.7 per 100,000 population. They also reported that of the patients discharged alive, 2.7% were readmitted within 1 year for stroke. One United States prevalence study of AF indicated that the overall prevalence of AF was 0.95%. When the results of this study were extrapolated to the population of Ontario, the prevalence of AF in Ontario is 98,758 for residents aged over 20 years. Currently, the first-line therapy for AF is medical therapy with antiarrhythmic drugs (AADs). There are several AADs available, because there is no one AAD that is effective for all patients. The AADs have critical adverse effects that can aggravate existing arrhythmias. The drug selection process frequently involves trial and error until the patient’s symptoms subside. The Technology Ablation has been frequently described as a “cure” for AF, compared with drug therapy, which controls AF but does not cure it

  2. [Use of P-wave polarity during atrial tachycardia to predict site of origin in children].

    PubMed

    Ge, H Y; Li, X M; Jiang, H; Li, Y H; Liu, H J; Zhang, Y

    2016-07-01

    To perform a detailed analysis of the P-wave polarity in focal atrial tachycardia (FAT) on the basis of surface electrocardiograms (ECGs) and construct an algorithm for identification of the anatomic site of origin in children. P-wave polarities for 40 consecutive children(14 boys and 26 girls, mean age of(8±3)years) with FAT undergoing successful radiofrequency ablation of a single atrial focus at First Hospital of Tsinghua University (2009-2014) were analyzed retrospectively from 12-lead ECGs during tachycardia.P waves were classified as positive, negative, isoelectric, or biphasic.The relations between P-wave and anatomic site of origin were analyzed using a chi-square test. The P-wave polarities in leads V1(χ(2)=23.509, P=0.000) andⅠ(χ(2)=14.315, P=0.001) were significantly helpful in distinguishing left from right atrial origin of the tachycardia focus.The P-wave in lead V1 of a left atrial tachycardia was always positive or isoelectric in tachycardia.The P-wave in leadⅠof a right atrial tachycardia was always positive or isoelectric during tachycardia.The P-wave polarities in leads Ⅱ, Ⅲ, aVR and aVF(χ(2)=26.447, 23.974, 19.613, 17.415, all P=0.000)distinguished superior from inferior atrial foci significantly.Tachycardia arising from the superior foci (n=22) had positive P waves in leads Ⅱ, Ⅲ and aVF ( 95% (n=21), 86% (n=19), 95% (n=21), respectively) and negative P wave in lead aVR (73%, n=16). The P-wave was frequently negative in leads Ⅱ, Ⅲ and aVF(n=12) and positive in lead aVR (n=11) for a tachycardia arising from the inferior foci (n=18). The anatomic sites of FAT in children located mainly at right atrial appendage (23%, n=9), coronary sinus (18%, n=7), left atrial appendage (15%, n=6) and right superior pulmonary vein (10%, n=4). The anatomic sites of FAT in children are located mainly at right and left atrial appendage, coronary sinus and right superior pulmonary vein.P-waves in leads V1 andⅠprove to be significantly useful in

  3. The comparative hydrodynamics of rapid rotation by predatory appendages.

    PubMed

    McHenry, M J; Anderson, P S L; Van Wassenbergh, S; Matthews, D G; Summers, A P; Patek, S N

    2016-11-01

    Countless aquatic animals rotate appendages through the water, yet fluid forces are typically modeled with translational motion. To elucidate the hydrodynamics of rotation, we analyzed the raptorial appendages of mantis shrimp (Stomatopoda) using a combination of flume experiments, mathematical modeling and phylogenetic comparative analyses. We found that computationally efficient blade-element models offered an accurate first-order approximation of drag, when compared with a more elaborate computational fluid-dynamic model. Taking advantage of this efficiency, we compared the hydrodynamics of the raptorial appendage in different species, including a newly measured spearing species, Coronis scolopendra The ultrafast appendages of a smasher species (Odontodactylus scyllarus) were an order of magnitude smaller, yet experienced values of drag-induced torque similar to those of a spearing species (Lysiosquillina maculata). The dactyl, a stabbing segment that can be opened at the distal end of the appendage, generated substantial additional drag in the smasher, but not in the spearer, which uses the segment to capture evasive prey. Phylogenetic comparative analyses revealed that larger mantis shrimp species strike more slowly, regardless of whether they smash or spear their prey. In summary, drag was minimally affected by shape, whereas size, speed and dactyl orientation dominated and differentiated the hydrodynamic forces across species and sizes. This study demonstrates the utility of simple mathematical modeling for comparative analyses and illustrates the multi-faceted consequences of drag during the evolutionary diversification of rotating appendages. © 2016. Published by The Company of Biologists Ltd.

  4. Epiploic appendagitis in a 27-year-old man

    PubMed Central

    Uehara, Ryohei; Isomoto, Hajime; Yamaguchi, Naoyuki; Ohnita, Ken; Fujita, Fumihiko; Ichikawa, Tatsuki; Takeshima, Fuminao; Yamaguchi, Tetsuji; Uetani, Masataka; Nakao, Kazuhiko

    2011-01-01

    Summary Background Epiploic appendagitis is an ischemic infarction of an epiploic appendage caused by torsion or spontaneous thrombosis of the central draining vein. Epiploic appendagitis is self-limited without surgery, and it is imperative for clinicians to be familiar with this entity. Case Report A healthy 27-year-old man was admitted due to acute right lower quadrant abdominal pain. Physical examination showed focal abdominal tenderness with slight rebound tenderness. Laboratory tests showed leukocytosis and an increased serum C-reactive protein level. Computed tomography (CT) showed a fatty ovoid pericolonic mass measuring 12 mm in diameter, with a circumferential hyperdense ring that abutted on the ascending colon and was surrounded by ill-defined fat stranding with a hyperdense ring. These findings were diagnostic of primary epiploic appendagitis. The patient was given high-dose antibiotics due to the secondary inflammation involving the parietal peritoneum. Conclusions Epiploic appendagitis presents with an abrupt onset of focal abdominal pain and tenderness without significant guarding or rigidity; it is an uncommon and difficult diagnosis. With awareness of this condition, however, evaluation by CT can provide an accurate diagnosis of epiploic appendagitis, distinguishing it from conditions with clinically overlapping manifestations. PMID:21959616

  5. Angiotensin II activates signal transducers and activators of transcription 3 via Rac1 in the atrial tissue in permanent atrial fibrillation patients with rheumatic heart disease.

    PubMed

    Xue, Xiao-Dong; Huang, Jian-Hua; Wang, Hui-Shan

    2015-01-01

    Patients with rheumatic heart disease (RHD) often experience persistent atrial fibrillation (AF) associated with adverse atrial structural remodeling (ASR) manifested by atrial fibrosis and left atrial enlargement. The aim of this study was to explore the potential molecular signaling mechanisms for atrial fibrosis and ASR. Twenty RHD patients with persistent AF and 10 RHD patients with sinus rhythm (Group A) were recruited in our study, which all underwent transthoracic echocardiography. Right atrial appendage (RAA) tissue samples were obtained from these patients during mitral/aortic valve replacement operation. The AF patients were further divided into two groups according to left atrial diameter (LAD): Group B with LAD ranging 50-65 mm and Group C with LAD >65 mm. Histological examinations were performed with hematoxylin-eosin staining and Masson's trichrome staining. Atrial angiotensin II (AngII) content was measured by ELISA. Rac1 and STAT3 protein levels were determined by Western blot analysis. Hematoxylin-eosin staining demonstrated highly organized arrangement of atrial muscles in control Group A and significant derangement in both Group B and C AF patients with reduced cell density and increased cell size. Moreover, Masson's trichrome staining showed that atrial myocytes were surrounded by large trunks of collagen fibers in both Group B and C, but not in Group A. There was a positive correlation between atrial tissue fibrosis and LAD. AngII content was markedly higher in Group C than in Group B than in Group A, which was positively correlated with LAD. Similarly, Rac1 and STAT3 protein levels were found considerably higher in Group C and B than in Group A with excellent correlation to LAD. Our study unraveled for the first time the AngII/Rac1/STAT3 signaling as a mechanism for ASR thereby AF in a particular clinical setting-RHD patients with persistent AF and indicated inhibition of this pathway may help ameliorating adverse ASR.

  6. Relation of hs-CRP and BNP levels with the atrial spontaneous echo contrast and thrombi in permanent atrial fibrillation patients with different etiologies

    PubMed Central

    Sahin, Tayfun; Acar, Eser; Celikyurt, Umut; Kilic, Teoman; Kozdag, Guliz; Yilmaz, Irem; Agacdiken, Aysen; Ural, Dilek

    2012-01-01

    Summary Background Thromboembolic risk in permanent atrial fibrillation (AF) is strongly associated with the underlying etiology, and inflammatory parameters may contribute. The present study aimed to investigate the relationship of hs-CRP and BNP levels with left and right atrial appendage (LAA and RAA) function, presence of spontaneous echo contrast (SEC) and thrombus. Material/Methods Eighty-four permanent AF patients with different etiologies (20 mitral stenosis, 44 hypertension and 20 hyperthyroidism) and 23 patients with sinus rhythm were included. LAA and RAA flow velocities were measured by pulsed-wave Doppler and wall motion velocities with tissue Doppler imaging (TDI) in transesophageal echocardiography. Results Hs-CRP and BNP levels significantly differed among the 3 AF groups: levels were highest in mitral stenosis patients (8.6±5.3 mg/L and 98.0±125.7 pg/mL, respectively), the lowest hs-CRP was in hyperthyroidism patients (4.3±3.8 mg/L), and the lowest BNP was in hypertensive patients (64.8±44.3 pg/mL). There were also significant differences between the AF group and controls regarding hs-CRP and BNP levels. In the correlation analysis, BNP level was not significantly correlated with LAA and RAA functions, whereas hs-CRP level was significantly correlated with some LAA and RAA functions. On the other hand, hs-CRP level was significantly related to the presence of mild-moderate SEC and thrombi, mainly in mitral stenosis patients. Moreover, hs-CRP was the most important determinant of RAA thrombus formation, followed by RAA ejection fraction. In contrast, no positive or negative correlation was found between BNP levels and RAA and LAA thrombi. Conclusions Higher hs-CRP levels in AF patients may be a predictor for the presence of SEC and thrombi in the atria. PMID:22293881

  7. A Silurian short-great-appendage arthropod

    PubMed Central

    Siveter, Derek J.; Briggs, Derek E. G.; Siveter, David J.; Sutton, Mark D.; Legg, David; Joomun, Sarah

    2014-01-01

    A new arthropod, Enalikter aphson gen. et sp. nov., is described from the Silurian (Wenlock Series) Herefordshire Lagerstätte of the UK. It belongs to the Megacheira (=short-great-appendage group), which is recognized here, for the first time, in strata younger than mid-Cambrian age. Discovery of this new Silurian taxon allows us to identify a Devonian megacheiran representative, Bundenbachiellus giganteus from the Hunsrück Slate of Germany. The phylogenetic position of megacheirans is controversial: they have been interpreted as stem chelicerates, or stem euarthropods, but when Enalikter and Bundenbachiellus are added to the most comprehensive morphological database available, a stem euarthropod position is supported. Enalikter represents the only fully three-dimensionally preserved stem-group euarthropod, it falls in the sister clade to the crown-group euarthropods, and it provides new insights surrounding the origin and early evolution of the euarthropods. Recognition of Enalikter and Bundenbachiellus as megacheirans indicates that this major arthropod group survived for nearly 100 Myr beyond the mid-Cambrian. PMID:24452026

  8. Managing atrial fibrillation in the very elderly patient: challenges and solutions

    PubMed Central

    Karamichalakis, Nikolaos; Letsas, Konstantinos P; Vlachos, Konstantinos; Georgopoulos, Stamatis; Bakalakos, Athanasios; Efremidis, Michael; Sideris, Antonios

    2015-01-01

    Atrial fibrillation (AF) is the most common arrhythmia affecting elderly patients. Management and treatment of AF in this rapidly growing population of older patients involve a comprehensive assessment that includes comorbidities, functional, and social status. The cornerstone in therapy of AF is thromboembolic protection. Anticoagulation therapy has evolved, using conventional or newer medications. Percutaneous left atrial appendage closure is a new invasive procedure evolving as an alternative to systematic anticoagulation therapy. Rate or rhythm control leads to relief in symptoms, fewer hospitalizations, and an improvement in quality of life. Invasive methods, such as catheter ablation, are the new frontier of treatment in maintaining an even sinus rhythm in this particular population. PMID:26604772

  9. What Is Atrial Fibrillation?

    MedlinePlus

    ANSWERS by heart Cardiovascular Conditions What Is Atrial Fibrillation? Your heart has a natural pacemaker, called the “ ... if the electric signals are normal. In atrial fibrillation (AFib), the heart’s two small upper chambers (atria) ...

  10. Atrial fibrillation or flutter

    MedlinePlus

    ... atrial fibrillation include: Alcohol use (especially binge drinking) Coronary artery disease Heart attack or heart bypass surgery Heart failure ... low. An ECG (a test that records the electrical activity of the heart) may show atrial fibrillation ...

  11. Relationship between local production of microRNA-328 and atrial substrate remodeling in atrial fibrillation.

    PubMed

    Soeki, Takeshi; Matsuura, Tomomi; Bando, Sachiko; Tobiume, Takeshi; Uematsu, Etsuko; Ise, Takayuki; Kusunose, Kenya; Yamaguchi, Koji; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Wakatsuki, Tetsuzo; Shimabukuro, Michio; Sata, Masataka

    2016-12-01

    The underlying mechanism of atrial substrate remodeling in atrial fibrillation (AF) remains unknown. In this study, we investigated whether local and systemic levels of microRNA (miR) might be associated with the presence of AF and with left atrial (LA) substrate properties. Blood from the periphery, pulmonary vein (PV), and left atrial appendage (LAA) was sampled from 30 patients with AF undergoing PV isolation, and from 10 control subjects with Wolff-Parkinson-White syndrome and without AF. We measured peripheral, PV, and LAA plasma levels of miR-1, -26, -133a, -328, and -590 by reverse transcription-polymerase chain reaction. LA global contact mapping during sinus rhythm was performed before PV isolation. Plasma levels of miR-328 were higher in patients with AF than in control subjects. Plasma miR-328 levels were significantly higher in the LAA than in the periphery and PV in patients with AF, but not in control subjects. Plasma miR-1 levels were also higher in the LAA than in the PV in AF patients. Interestingly, LAA plasma levels of miR-328 showed a positive correlation with the LA voltage zone index (area with voltage <0.5mV divided by total LA surface area) and a weak correlation with LA volume. Local production of miR-328 in the left atrium may be involved in the process of atrial remodeling in patients with AF. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  12. Growth differentiation factor-15 (GDF-15), novel biomarker for assessing atrial fibrosis in patients with atrial fibrillation and rheumatic heart disease.

    PubMed

    Zhou, Yong-Ming; Li, Ming-Jiang; Zhou, Yan-Li; Ma, Le-Le; Yi, Xin

    2015-01-01

    Growth differentiation factor-15 (GDF-15) has been identified as a strong biomarker of cardiovascular diseases; however, no evidence are available concerning the relationship of GDF-15 and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD). Twenty patients with rheumatic heart disease were divided into two groups, 10 cases with AF and 10 cases with sinus rhythm (SR). Clinical data and blood samples were collected; left atrial appendage was taken by the surgeon in the process of valve replacement. Masson stained sections and mRNA levels of cardiac fibrosis biomarkers were used to determine the level of cardiac fibrosis, the expression level of GDF-15 was evaluated via immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Compared with SR group, more collagen deposited in the atrial tissue of AF group. The distribution of GDF-15 in the AF group was significantly higher than SR group (P<0.05). In addition, plasma GDF-15 level and mRNA level of GDF-15 in atrial tissue of AF showed the same trend as the result of immunohistochemistry. After linear correlation analysis, the expression level of GDF-15 was found to be positively related to the degree of cardiac fibrosis. GDF-15 might involve in the development and maintenance of atrial fibrosis in patients with atrial fibrillation and rheumatic heart disease, and GDF-15 could be used as a novel biomarker to evaluate myocardial fibrosis in the future.

  13. [Atrial fibrillation].

    PubMed

    Colín Lizalde, L J

    2001-01-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia. AF has now been exhaustively studied: more is known about its mechanism and research is moving towards new forms of treatment. For chronic AF, basically the control of ventricular rate and the brain protection are the main issues. It is well known that with the identification of high risk group for embolism, oral anticoagulation should be administered. Ventricular rate control can be achieved by using betablockers or calcium channel blockers, unless these are contraindicated for the elderly. Oral anticoagulation prevents the stroke. The main mechanism of AF is the re-entry of multiple wavelets, but now it is more frequently found on patients with focal AF. Therapies are employed to bring the patient to a sinusal rhythm as soon as possible with antiarryhthmics or electric cardioversion externally or internally. The internal procedure includes 1 to 15 J and the success rate is of 91% vs 67% in relation to the external one. The introduction of the catheter ablation has opened new frontiers for the treatment of AF, first as the ablate-and-pace technique and now trying to mimic the maze procedure or with the ablation of the focal tachycardia. The stimulation for prevention of AF under research, as well as the implantable dysfibrillation for selected patients. On going studies will show the possible benefit of this type of benefits.

  14. Focal adhesion kinase mediates atrial fibrosis via the AKT/S6K signaling pathway in chronic atrial fibrillation patients with rheumatic mitral valve disease.

    PubMed

    Zhang, Peide; Wang, Wei; Wang, Xin; Wang, Xu; Song, Yunhu; Zhang, Jing; Zhao, Hui

    2013-10-09

    Atrial fibrosis, as a hallmark of atrial structural remodeling, plays a critical role in the maintenance of chronic atrial fibrillation (AF), but the mechanisms responsible for atrial fibrosis are still uncertain. Fibrogenesis represents a complex process in which focal adhesion kinase (FAK) plays an important role. Therefore, we investigated the role of FAK-mediated signaling in atrial fibrosis in patients with chronic AF related to rheumatic mitral valve disease (RMVD). Atrial appendages were excised from 45 patients with RMVD and either chronic AF (n=25, AF >6 months) or sinus rhythm (n=20). Fibrosis was assessed by histology, and FAK and its two downstream pathways (AKT/S6K and ERK1/2) were evaluated by western blotting. We further evaluated the role of FAK in fibrogenesis by culturing neonatal rat cardiac fibroblasts to determine the importance of FAK-regulated signaling in cardiac myofibroblast differentiation induced by transforming growth factor-β1 (TGFβ1). Our study revealed that FAK can regulate its downstream signaling to cause fibrosis in atrial tissue and activate isolated fibroblasts. Histology revealed a significant increase in atrial fibrosis in AF patients. The phosphorylation of FAK and its downstream AKT/S6K signaling was increased secondary to TGFβ1-induced high expression of α-SMA, a marker of myofibroblast activity. FAK and AKT inhibitors suppressed α-SMA expression in TGFβ1-induced fibroblasts. However, ERK1/2 signaling seemed to be unrelated to the fibrotic process in AF patients. The FAK-mediated AKT/S6K signaling pathway participated in atrial fibrogenesis and this finding may contribute to the prevention of atrial fibrosis associated with chronic AF in patients with underlying cardiac disease. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Management of atrial fibrillation.

    PubMed

    Moukabary, Talal; Gonzalez, Mario D

    2015-07-01

    Atrial fibrillation is a very common clinical problem with a high prevalence that is expected to rise over time because of increasing risk factors (eg, age, obesity, hypertension). This high prevalence is also associated with high cost, because atrial fibrillation represents about 1% of overall health care spending. The management of atrial fibrillation involves multiple facets: (1) management of underlying disease if present and the management of atrial fibrillation risk factors, (2) prevention of thromboembolism, (3) control of the ventricular rate during atrial fibrillation, and (4) restoration and maintenance of normal sinus rhythm.

  16. Box lesion in the open left atrium for surgical ablation of atrial fibrillation.

    PubMed

    Sternik, Leonid; Kogan, Alexander; Luria, David; Glikson, Michael; Malachy, Ateret; Levin, Shany; Raanani, Ehud

    2014-03-01

    Cut-and-sew maze with a box lesion around the pulmonary veins is currently the criterion standard procedure for surgical ablation of atrial fibrillation. Recently, we changed our technique from standard bilateral epicardial pulmonary vein isolation with interconnecting lesions to a box lesion procedure with a bipolar radiofrequency ablation device. Our study describes this technique. Between March 2009 and June 2012, we performed 90 ablations by the box technique with a bipolar radiofrequency device. Fifty-five patients (61%) had persistent atrial fibrillation, and 21 (23%) had long-standing persistent atrial fibrillation. The left atriotomy was performed along the interatrial septum and the left atrial appendage amputated. The box was made by connecting the left atriotomy to the base of the amputated appendage with lines along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar radiofrequency ablation device. The left atrial isthmus was ablated by cryoprobe. There were no ablation-related complications. The box was easy to perform, with no dissection around the pulmonary veins. At 6-month, 1-year, and 2-year follow-ups, 80 (94%), 69 (93%), and 47 (91%) patients, respectively, were in sinus rhythm. Freedoms from antiarrhythmic medications in patients in sinus rhythm at 6 months, 1 year, and 2 years were 78%, 88%, and 85%, respectively. The box lesion provided excellent freedom from atrial fibrillation and may improve transmurality through ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. With the box lesion, dissection around the pulmonary veins is unnecessary. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  17. Atrial Strain and Strain Rate: A Novel Method for the Evaluation of Atrial Stunning

    PubMed Central

    Ozkan, Hakan; Binici, Suleyman; Tenekecioglu, Erhan; Ari, Hasan; Bozat, Tahsin

    2016-01-01

    Background Atrial fibrillation (AF) is the most common arrhythmia seen in adults. Atrial stunning is defined as the temporary mechanical dysfunction of the atrial appendage developing after AF has returned to sinus rhythm (SR). Objectives We aimed to evaluate atrial contractile functions by strain and strain rate in patients with AF, following pharmacological and electrical cardioversion and to compare it with conventional methods. Methods This study included 41 patients with persistent AF and 35 age-matched control cases with SR. All the AF patients included in the study had transthoracic and transesophageal echocardiography performed before and after. Septum (SEPsSR), left atrium (LAsSR) and right atrium peak systolic strain rate (RAsSR) were defined as the maximum negative value during atrial contraction and septum (SEPε), left atrium (LAε) and right atrium peak systolic strain (RAε) was defined as the percentage of change. Parameters of two groups were compared. Results In the AF group, 1st hour and 24th hour LAε, RAε, SEPε, LAsSR, RAsSR, SEPsSR found to be significantly lower than in the control group (LAε: 2.61%±0.13, 3.06%±0.19 vs 6.45%±0.27, p<0.0001; RAε: 4.03%±0.38, 4.50%±0.47 vs 10.12%±0.64, p<0.0001; SEPε: 3.0%±0.22, 3.19%±0.15 vs 6.23%±0.49, p<0.0001; LAsSR: 0.61±0.04s-1, 0.75±0.04s-1 vs 1.35±0.04s-1, p<0.0001; RAsSR: 1.13±0.06s-1, 1.23±0.07s-1 vs 2.10±0.08s- 1, p<0.0001; SEPsSR: 0.76±0.04s- 1, 0.78±0.04s- 1 vs 1.42±0.06 s- 1, p<0.0001). Conclusion Atrial strain and strain rate parameters are superior to conventional echocardiographic parameters for the evaluation of atrial stunning in AF cases where SR has been achieved. PMID:27627221

  18. Atrial Strain and Strain Rate: A Novel Method for the Evaluation of Atrial Stunning.

    PubMed

    Ozkan, Hakan; Binici, Suleyman; Tenekecioglu, Erhan; Ari, Hasan; Bozat, Tahsin

    2016-10-01

    Atrial fibrillation (AF) is the most common arrhythmia seen in adults. Atrial stunning is defined as the temporary mechanical dysfunction of the atrial appendage developing after AF has returned to sinus rhythm (SR). We aimed to evaluate atrial contractile functions by strain and strain rate in patients with AF, following pharmacological and electrical cardioversion and to compare it with conventional methods. This study included 41 patients with persistent AF and 35 age-matched control cases with SR. All the AF patients included in the study had transthoracic and transesophageal echocardiography performed before and after. Septum (SEPsSR), left atrium (LAsSR) and right atrium peak systolic strain rate (RAsSR) were defined as the maximum negative value during atrial contraction and septum (SEPε), left atrium (LAε) and right atrium peak systolic strain (RAε) was defined as the percentage of change. Parameters of two groups were compared. In the AF group, 1st hour and 24th hour LAε, RAε, SEPε, LAsSR, RAsSR, SEPsSR found to be significantly lower than in the control group (LAε: 2.61%±0.13, 3.06%±0.19 vs 6.45%±0.27, p<0.0001; RAε: 4.03%±0.38, 4.50%±0.47 vs 10.12%±0.64, p<0.0001; SEPε: 3.0%±0.22, 3.19%±0.15 vs 6.23%±0.49, p<0.0001; LAsSR: 0.61±0.04s-1, 0.75±0.04s- 1 vs 1.35±0.04s-1, p<0.0001; RAsSR: 1.13±0.06s-1, 1.23±0.07s-1 vs 2.10±0.08s- 1, p<0.0001; SEPsSR: 0.76±0.04s- 1, 0.78±0.04s- 1 vs 1.42±0.06 s- 1, p<0.0001). Atrial strain and strain rate parameters are superior to conventional echocardiographic parameters for the evaluation of atrial stunning in AF cases where SR has been achieved.

  19. Dynamic analysis of satellites with deployable hinged appendages

    NASA Technical Reports Server (NTRS)

    Oakes, Kevin F.

    1987-01-01

    The nonlinear equations of motion determining the planar dynamical behavior of an orbiting satellite deploying both one and two rigid appendages have been formulated using Lagrange's equations. The analysis accounts for large angle rotations, Coriolis effects, and the gravitational gradient, and the resulting coupled governing equations are integrated numerically. The analysis is applied to the Space Shuttle based deployment of rigid truss-like members, and results show that spacecraft inertia parameters, appendage mass and length, deployment velocity, and initial conditions all influence the system response. It is found that the resulting librational movement is related to the size of the deployment payload, and that gravitational forces lead to vehicle stabilization.

  20. Surgical ablation of atrial fibrillation during mitral-valve surgery.

    PubMed

    Gillinov, A Marc; Gelijns, Annetine C; Parides, Michael K; DeRose, Joseph J; Moskowitz, Alan J; Voisine, Pierre; Ailawadi, Gorav; Bouchard, Denis; Smith, Peter K; Mack, Michael J; Acker, Michael A; Mullen, John C; Rose, Eric A; Chang, Helena L; Puskas, John D; Couderc, Jean-Philippe; Gardner, Timothy J; Varghese, Robin; Horvath, Keith A; Bolling, Steven F; Michler, Robert E; Geller, Nancy L; Ascheim, Deborah D; Miller, Marissa A; Bagiella, Emilia; Moquete, Ellen G; Williams, Paula; Taddei-Peters, Wendy C; O'Gara, Patrick T; Blackstone, Eugene H; Argenziano, Michael

    2015-04-09

    Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited. We randomly assigned 260 patients with persistent or long-standing persistent atrial fibrillation who required mitral-valve surgery to undergo either surgical ablation (ablation group) or no ablation (control group) during the mitral-valve operation. Patients in the ablation group underwent further randomization to pulmonary-vein isolation or a biatrial maze procedure. All patients underwent closure of the left atrial appendage. The primary end point was freedom from atrial fibrillation at both 6 months and 12 months (as assessed by means of 3-day Holter monitoring). More patients in the ablation group than in the control group were free from atrial fibrillation at both 6 and 12 months (63.2% vs. 29.4%, P<0.001). There was no significant difference in the rate of freedom from atrial fibrillation between patients who underwent pulmonary-vein isolation and those who underwent the biatrial maze procedure (61.0% and 66.0%, respectively; P=0.60). One-year mortality was 6.8% in the ablation group and 8.7% in the control group (hazard ratio with ablation, 0.76; 95% confidence interval, 0.32 to 1.84; P=0.55). Ablation was associated with more implantations of a permanent pacemaker than was no ablation (21.5 vs. 8.1 per 100 patient-years, P=0.01). There were no significant between-group differences in major cardiac or cerebrovascular adverse events, overall serious adverse events, or hospital readmissions. The addition of atrial fibrillation ablation to mitral-valve surgery significantly increased the rate of freedom from atrial fibrillation at 1 year among patients with persistent or long-standing persistent atrial fibrillation, but the risk of implantation of a permanent pacemaker

  1. Surgical Ablation of Atrial Fibrillation during Mitral-Valve Surgery

    PubMed Central

    Gillinov, A. Marc; Gelijns, Annetine C.; Parides, Michael K.; DeRose, Joseph J.; Moskowitz, Alan J.; Voisine, Pierre; Ailawadi, Gorav; Bouchard, Denis; Smith, Peter K.; Mack, Michael J.; Acker, Michael A.; Mullen, John C.; Rose, Eric A.; Chang, Helena L.; Puskas, John D.; Couderc, Jean-Philippe; Gardner, Timothy J.; Varghese, Robin; Horvath, Keith A.; Bolling, Steven F.; Michler, Robert E.; Geller, Nancy L.; Ascheim, Deborah D.; Miller, Marissa A.; Bagiella, Emilia; Moquete, Ellen G.; Williams, Paula; Taddei-Peters, Wendy C.; O’Gara, Patrick T.; Blackstone, Eugene H.; Argenziano, Michael

    2015-01-01

    Background Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited. Methods We randomly assigned 260 patients with persistent or long-standing persistent atrial fibrillation who required mitral-valve surgery to undergo either surgical ablation (ablation group) or no ablation (control group) during the mitral-valve operation. Patients in the ablation group underwent further randomization to pulmonary-vein isolation or a biatrial maze procedure. All patients underwent closure of the left atrial appendage. The primary end point was freedom from atrial fibrillation at both 6 months and 12 months (as assessed by means of 3-day Holter monitoring). Results More patients in the ablation group than in the control group were free from atrial fibrillation at both 6 and 12 months (63.2% vs. 29.4%, P<0.001). There was no significant difference in the rate of freedom from atrial fibrillation between patients who underwent pulmonary-vein isolation and those who underwent the biatrial maze procedure (61.0% and 66.0%, respectively; P = 0.60). One-year mortality was 6.8% in the ablation group and 8.7% in the control group (hazard ratio with ablation, 0.76; 95% confidence interval, 0.32 to 1.84; P = 0.55). Ablation was associated with more implantations of a permanent pacemaker than was no ablation (21.5 vs. 8.1 per 100 patient-years, P = 0.01). There were no significant between-group differences in major cardiac or cerebrovascular adverse events, overall serious adverse events, or hospital readmissions. Conclusions The addition of atrial fibrillation ablation to mitral-valve surgery significantly increased the rate of freedom from atrial fibrillation at 1 year among patients with persistent or long-standing persistent atrial fibrillation, but the

  2. How Is Atrial Fibrillation Treated?

    MedlinePlus

    ... from the NHLBI on Twitter. How Is Atrial Fibrillation Treated? Treatment for atrial fibrillation (AF) depends on ... much thyroid hormone). Who Needs Treatment for Atrial Fibrillation? People who have AF but don't have ...

  3. Deglutition induced atrial tachycardia and atrial fibrillation.

    PubMed

    Kanjwal, Yousuf; Imran, Naser; Grubb, Blair

    2007-12-01

    Deglutition induced supraventricular tachycardia is an uncommon condition postulated to be a vagally mediated phenomenon due to mechanical stimulation. Patients usually present with mild symptoms or may have severe debilitating symptoms. Treatment with Class I agents, beta blockers, calcium channel blockers, amiodarone and radiofrquency catheter ablation has shown to be successful in the majority of reported cases. We report the case of a 46-year-old healthy woman presenting with palpitations on swallowing that was documented to be transient atrial tachycardia with aberrant ventricular conduction as well as transient atrial fibrillation. She was successfully treated with propafenone with no induction of swallowing-induced tachycardia after treatment. This is also the first case to show swallowing-induced atrial tachycardia and atrial fibrillation in the same patient.

  4. 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.

  5. Restoration of Atrial Mechanical Function after Successful Radio-Frequency Catheter Ablation of Atrial Flutter

    PubMed Central

    Rhee, Kyoung-Suk; Kang, Duk-Hyun; Song, Jae-Kwan; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2001-01-01

    Background: Atrial mechanical dysfunction and its recovery time course after successful radiofrequency ablation of chronic atrial flutter (AFL) has been largely unknown. We serially evaluated left atrial function by echocardiography after successful ablation of chronic atrial flutter. Methods: In 13 patients with chronic AFL, mitral E wave A wave, and the ratio of A/E velocity were measured at 1 day, 1 month, 3 months and 6–12 months after successful radiofrequency (RF) ablation. Doppler tissue imaging (DTI) technique was also used to avoid load-dependent variation in the flow velocity pattern. Results: Left atrial mechanical function, assessed by A wave velocity and the annular motion, was depressed at 1 day, but improved significantly at 1 month and maintained through 6–12 months after the ablation. Left atrial size did not change significantly. Conclusion: Left atrial mechanical function was depressed immediately after successful RF ablation of chronic AFL, but it improved significantly after 1 month and was maintained over one year. PMID:11590904

  6. Heat loss regulation: role of appendages and torso in the deer mouse and the white rabbit

    SciTech Connect

    Conley, K.E.; Porter, W.P.

    1985-01-01

    Thermal conductance was subdivided into the component conductances of the appendages and torso using a heat transfer analysis for the deer mouse, Peromyscus maniculatus, and the white rabbit, Oryctolagus cuniculus. The authors analysis was based on laboratory measurements of skin temperature and respiratory gas exchange made between air temperatures of 8 and 34/sup 0/C for the deer mouse, and from published data for the white rabbit. Two series conductances to heat transfer for each appendage and torso were evaluated: (1) internal (h/sub in/), for blood flow and tissue conduction to the skin surface, and (2) external (h/sub ex/), for heat loss from the skin surface to the environment. These two series conductances were represented in a single, total conductance (h/sub tot/). The limit to h/sub tot/ was set by h/sub ex/ and was reached by the torso h/sub tot/ of both animals. The increase in torso h/sub tot/ observed with air temperature for the mouse suggests that a pilomotor change in fur depth occurred. A control of h/sub tot/ below the limit set by h/sub ex/ was achieved by the h/sub in/ of each appendage. Elevation of mouse thermal conductance (C) resulted from increases in feet, tail, and torso h/sub tot/. In contrast, the rabbit showed no change in torso h/sub tot/ between 5 and 30/sup 0/C and ear h/sub tot/ exclusively increased C over these air temperatures. They suggest that the hyperthermia reported for the rabbit at 35/sup 0/C resulted from C reaching the physical limit set by torso and near h/sub ex/. Thus the ear alone adjusted rabbit C, whereas the feet, tail, and the torso contributed to the adjustment of mouse C.

  7. Organized Atrial Tachycardias after Atrial Fibrillation Ablation

    PubMed Central

    Castrejón-Castrejón, Sergio; Ortega, Marta; Pérez-Silva, Armando; Doiny, David; Estrada, Alejandro; Filgueiras, David; López-Sendón, José L.; Merino, José L.

    2011-01-01

    The efficacy of catheter-based ablation techniques to treat atrial fibrillation is limited not only by recurrences of this arrhythmia but also, and not less importantly, by new-onset organized atrial tachycardias. The incidence of such tachycardias depends on the type and duration of the baseline atrial fibrillation and specially on the ablation technique which was used during the index procedure. It has been repeatedly reported that the more extensive the left atrial surface ablated, the higher the incidence of organized atrial tachycardias. The exact origin of the pathologic substrate of these trachycardias is not fully understood and may result from the interaction between preexistent regions with abnormal electrical properties and the new ones resultant from radiofrequency delivery. From a clinical point of view these atrial tachycardias tend to remit after a variable time but in some cases are responsible for significant symptoms. A precise knowledge of the most frequent types of these arrhythmias, of their mechanisms and components is necessary for a thorough electrophysiologic characterization if a new ablation procedure is required. PMID:21941669

  8. Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.

    PubMed

    Vary, Jay C

    2015-11-01

    This article reviewed some of the more common diseases of the skin appendages that are encountered in medicine: hyperhidrosis, acne, AA, FPHL, AGA, and TE. The pathophysiology behind the conditions and their treatments were discussed so that the clinician can make logical therapeutic choices for their affected patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. [Contribution of imaging in the diagnosis of epiploic appendagitis].

    PubMed

    Daghfous, A; Bouzaïdi, K; Ayari, H; Yahmadi, A; Zoghlemi, A; Rezgui Marhoul, L

    2014-09-01

    Primary epiploic appendagitis is known to be a rare finding among causes of acute abdomen. Depending on location, it may mimic several disorders such as colonic diverticulitis and acute appendicitis. Diagnosis is sometimes performed during surgery. This is a retrospective descriptive study. The authors report the contribution of imaging for the diagnosis of appendagitis in seven patients investigated between July 2010 and April 2013 by abdominal and pelvic ultrasound or computed tomography (CT). CT scan confirmed the diagnosis in six patients avoiding unnecessary surgery and hospitalization. The seventh patient was a pregnant woman in whom the diagnosis of appendagitis was made during surgery for appendicitis. Appendagitis is a rare cause of acute abdominal pain. Outcome is favorable with medical treatment only. Abdominal ultrasound and CT are helpful diagnostic tests avoiding useless surgical procedure. Copyright © 2013 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  10. Enhanced expression of ROCK in left atrial myocytes of mitral regurgitation: a potential mechanism of myolysis.

    PubMed

    Chen, Huang-Chung; Chang, Jen-Ping; Chang, Tzu-Hao; Lin, Yu-Sheng; Huang, Yao-Kuang; Pan, Kuo-Li; Fang, Chih-Yuan; Chen, Chien-Jen; Ho, Wan-Chun; Chen, Mien-Cheng

    2015-05-09

    Severe mitral regurgitation (MR) may cause myolysis in the left atrial myocytes. Myolysis may contribute to atrial enlargement. However, the relationship between Rho-associated kinase (ROCK) and myolysis in the left atrial myocytes of MR patients remain unclear. This study comprised 22 patients with severe MR [12 with atrial fibrillation (AF) and ten in sinus rhythm]. Left atrial appendage tissues were obtained during surgery. Normal left atrial tissues were purchased. Immunofluorescence histochemical and immunoblotting studies were performed. The expression of ROCK2 in the myolytic left atrial myocytes of MR AF patients (p = 0.009) and MR sinus patients (p = 0.011) were significantly higher than that of the normal subjects. Similarly, the expression of ROCK1 in the myolytic left atrial myocytes of MR AF patients was significantly higher than that of the normal subjects (p = 0.010), and the expression of ROCK1 in the myolytic left atrial myocytes of MR sinus patients was higher than that of the normal subjects (p = 0.091). Immunofluorescence study revealed significant co-localization and juxtaposition of ROCK2 and cleaved caspase-3 in the left atrial myocytes both in the MR AF group (Pearson's coefficient = 0.74 ± 0.03) and the MR sinus group (Pearson's coefficient = 0.73 ± 0.02). Similarly, immunofluorescence study revealed significant co-localization and juxtaposition of ROCK1 and cleaved caspase-3 in the left atrial myocytes both in the MR AF group (Pearson's coefficient = 0.65 ± 0.03) and the MR sinus group (Pearson's coefficient = 0.65 ± 0.03). Correlation analysis demonstrated that there was a significant direct relationship between the expression of ROCK2 in the myolytic left atrial myocytes and left atrial diameter in the MR patients (p = 0.041; r = 0.440). Moreover, the ratio of phosphorylated myosin-binding subunit of myosin light chain phosphatase (pMBS)/total MBS of left atrial tissues was significantly higher in the MR AF group (p < 0.04) and the

  11. Atrial fibrillation - discharge

    MedlinePlus

    Auricular fibrillation - discharge; A-fib - discharge; AF - discharge; Afib - discharge ... been in the hospital because you have atrial fibrillation . This condition occurs when your heart beats faster ...

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

    PubMed

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

    2015-01-01

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

  13. Left atrial strain: a new predictor of thrombotic risk and successful electrical cardioversion

    PubMed Central

    González-Alujas, Teresa; Valente, Filipa; Aranda, Carlos; Rodríguez-Palomares, José; Gutierrez, Laura; Maldonado, Giuliana; Galian, Laura; Teixidó, Gisela; Evangelista, Artur

    2016-01-01

    Background Left atrial deformation (LAD) parameters are new markers of atrial structural remodelling that seem to be affected in atrial fibrillation (AF) and atrial flutter (AFL). This study aimed to determine whether LAD can identify patients with a higher risk of thrombosis and unsuccessful electrical cardioversion (ECV). Methods Retrospective study including 56 patients with AF or AFL undergoing ECV, with previous transthoracic (TTE) and transoesophageal echocardiography (TEE) studies. Echocardiographic parameters analysed were as follows: left ventricle function, left atrium (LA) dimensions, LAD parameters (positive and negative strain peaks), left atrial appendage (LAA) filling and emptying velocities and the presence of thrombi. Strain values were analysed according to thrombotic risk and success of ECV. Results Lower mean values of peak-positive strain (PPS) in patients with prothrombotic velocities (<25 cm/s) and a higher incidence of thrombi in LAA were observed compared with those with normal velocities. Multivariate analysis revealed PPS normalised by LA maximum volume indexed by body surface area (BSA) to be associated with prothrombotic risk (odds ratio 0.000 (95% CI: 0.000–0.243), P 0.017), regardless of CHADs2VASC score. Peak-negative strain normalised by LA volumes indexed by BSA were associated with unsuccessful ECV. Conclusions Atrial deformation parameters identify AF and AFL patients with a high risk of thrombosis and unsuccessful ECV. Therefore, these new parameters should be included in anticoagulation management and rhythm vs rate control strategies. PMID:27249551

  14. Effect of Low-level Vagus Nerve Stimulation on Cardiac Remodeling in a Rapid Atrial Pacing-induced Canine Model of Atrial Fibrillation.

    PubMed

    Lu, Yanmei; Sun, Juan; Zhou, Xianhui; Zhang, Ling; Ma, Mei; Tang, Baopeng

    2016-03-01

    The aim of this study was to establish a rapid atrial pacing-induced canine model of atrial fibrillation in studying the effects of low-level vagus nerve stimulation (LLVNS) on atrial fibrillation and the underlying mechanisms for those effects. Adult beagle dogs were randomly assigned to 3 groups: a sham operation group (sham group), a fast left atrial appendage 12-hour pacing group (pacing group), and a 12-hour pacing + LLVNS group (LLVNS group). All dogs underwent tests for their left and right atrial effective refractory period at various time points, after which they were killed, and samples of atrial and anterior right ganglionated plexi tissue were removed and microscopically examined. As pacing times increased, the mean effective refractory period in the pacing group became significantly shortened. The pacing group and the LLVNS group did show significant differences (P < 0.001). Three groups showed significant differences in their atrial myocardial periodic acid-Schiff-positive area staining densities. Anterior right ganglionated plexi expressions of nerve growth factor and neurturin (NRTN) in the sham group and the LLVNS group were lower than those in the pacing group (nerve growth factor in 3 groups were (36.35 ± 6.18) × 1000, (86.35 ± 5.63) × 1000, and (40.50 ± 7.24) × 1000 μm²/mm², P < 0.001; NRTN in 3 groups were (39.28 ± 7.80) × 1000, (80.24 ± 6.56) × 1000, (40.45 ± 6.97) × 1000 μm²/mm², P < 0.001). Therefore, LLVNS not only reverses the effect of fast pacing-induced atrial electrical remodeling in dogs but also exerts structural effects and stimulates remodeling of autonomic nerves.

  15. Atrial Tachycardias Following Atrial Fibrillation Ablation

    PubMed Central

    Sághy, László; Tutuianu, Cristina; Szilágyi, Judith

    2015-01-01

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

  16. Left ventricular diastolic function is closely associated with mechanical function of the left atrium in patients with paroxysmal atrial fibrillation.

    PubMed

    Lee, Jihei Sara; Shim, Chi Young; Wi, Jin; Joung, Boyoung; Ha, Jong-Won; Lee, Moon Hyoung; Pak, Hui-Nam

    2013-01-01

    Left ventricular (LV) diastolic dysfunction may be a mechanism of left atrial (LA) electroanatomical remodeling in atrial fibrillation (AF). We evaluated the association between LV diastolic function and LA mechanical function in non-valvular paroxysmal AF (PAF). In 286 patients with PAF (males 73%, 57 ± 11 years), LA size, indexed LA volume, LV diastolic function, and LA appendage flow velocity (LAA-FV) in sinus rhythm were measured using transthoracic echocardiography, transesophageal echocardiography and cardiac computed tomography. The LA voltage map was obtained using NavX contact mapping. Patients with impaired LA mechanical function (LAA-FV <58 cm/s, n=142) showed a higher E/Em ratio (10.3 vs. 9.2, P=0.034) and lower Em velocity (6.8 vs. 7.7 cm/s, P=0.004) than those with preserved function (LAA-FV ≥ 58 cm/s, n=144). The patient population displayed weak correlations of E/Em with LAA-FV (r=-0.19, P=0.003) and LA voltage (r=-0.23, P=0.004), but more significant association of E/Em and LAA-FV (r=-0.39, P<0.001) for age ≥ 55 years and LA diameter ≥ 40 mm. E/Em was an independent predictor of LAA mechanical function (β=-0.20, P=0.013) even after age, sex, LA size and comorbidities were controlled for. In patients with non-valvular PAF, LA mechanical function is closely related to the degree of LA remodeling and LV diastolic function. Impaired LV diastolic function significantly contributes to LA electoanatomical remodeling in older patients with a larger LA.

  17. Electrophysiological Mechanisms of Atrial Flutter

    PubMed Central

    Tai, Ching- Tai; Chen, Shin-Ann

    2006-01-01

    Atrial flutter (AFL) is a common arrhythmia in clinical practice. Several experimental models such as tricuspid regurgitation model, tricuspid ring model, sterile pericarditis model and atrial crush injury model have provided important information about reentrant circuit and can test the effect of antiarrhythmic drugs. Human atrial flutter has typical and atypical forms. Typical atrial flutter rotates around tricuspid annulus and uses the crista terminalis and sometimes sinus venosa as the boundary. The IVC-tricuspid isthmus is a slow conduction zone and the target of radiofrequency ablation. Atypical atrial flutter may arise from the right or left atrium. Right atrial flutter includes upper loop reentry, free wall reentry and figure of eight reentry. Left atrial flutter includes mitral annular atrial flutter, pulmonary vein-related atrial flutter and left septal atrial flutter. Radiofrequency ablation of the isthmus between the boundaries can eliminate these arrhythmias. PMID:16943903

  18. Simulation of the photogrammetric appendage structural dynamics experiment

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Gilbert, Michael G.; Welch, Sharon S.

    1995-01-01

    The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) uses six video cameras in the Space Shuttle cargo bay to measure vibration of the Russian Mir space station Kvant-ll solar array. It occurs on Shuttle/Mir docking mission STS-74 scheduled for launch in November 1995. The objective of PASDE is to demonstrate photogrammetric technology for measuring 'untargeted' spacecraft appendage structural dynamics. This paper discusses a pre-flight simulation test conducted in July 1995, focusing on the image processing aspects. The flight camera system recorded vibrations of a full-scale structural test article having grids of white lines on black background, similar in appearance to the Mir solar array. Using image correlation analysis, line intersections on the structure are tracked in the video recordings to resolutions of less than 0.1 pixel. Calibration and merging of multiple camera views generated 3-dimensional displacements from which structural modal parameters are then obtained.

  19. Radiofrequency ablation of atrial fibrillation during concomitant cardiac surgery.

    PubMed

    Pinho-Gomes, Ana C; Amorim, Mário J; Oliveira, Sílvia M; Azevedo, Luís; Almeida, Jorge; Monteiro, Vítor; Maciel, Maria Júlia; Pinho, Paulo; Leite-Moreira, Adelino F

    2014-01-01

    We present the experience of our centre with radiofrequency ablation of atrial fibrillation concomitantly with cardiac surgery Methods: 170 patients underwent atrial fibrillation ablation with uni/bipolar-radiofrequency. They were followed for 3-months and then as appropriate for the cardiac disease. In 2013, patients still alive underwent rhythm monitoring with ECG and 24-hour tape if in sinus rhythm Mean age was 65 years old and 42% of the patients were male. Paroxysmal AF was rare (7%). Most patients had preserved ejection fraction and dilated left atria (diameter 53.2±7.5 mm). The most common indication for cardiac surgery was valve disease. More than 75% of the patients underwent prophylactic closure of the left atrial appendage. Pulmonary vein isolation was performed in all patients, followed by other left atrial ablation lines. Overall, surgical complications were rare, being the most frequent pacemaker implantation (15%). Median length of stay was 9 days (p25-p75:7-14). At discharge, 69% of the patients were in sinus rhythm, being 90% on anticoagulation and 69% on amiodarone. In-hospital mortality was less than 3% (5 patients), none of them related to the ablation procedure. At 3 months, 50% of the patients were in sinus rhythm, being 92% on anticoagulation and 75% on antiarrhythmic drugs. Direct current cardioversion was successful in 8 of 12 patients. In the multivariate analysis, being in sinus rhythm at discharge was the single independent predictor of maintaining sinus rhythm at 3 months. In 2013 (469 patients-year), 40% of the patients were in sinus rhythm, being 80% on anticoagulation and 45% on antiarrhythmic drugs. Concurrent atrial fibrillation ablation with radiofrequency achieves satisfactory and stable recovery of sinu rhythm without adding significant operative risk and post-operative complications.

  20. In search of the Golden Fleece: unraveling principles of morphogenesis by studying the integrative biology of skin appendages.

    PubMed

    Hughes, Michael W; Wu, Ping; Jiang, Ting-Xin; Lin, Sung-Jan; Dong, Chen-Yuan; Li, Ang; Hsieh, Fon-Jou; Widelitz, Randall B; Chuong, Cheng Ming

    2011-04-01

    The mythological story of the Golden Fleece symbolizes the magical regenerative power of skin appendages. Similar to the adventurous pursuit of the Golden Fleece by the multi-talented Argonauts, today we also need an integrated multi-disciplined approach to understand the cellular and molecular processes during development, regeneration and evolution of skin appendages. To this end, we have explored several aspects of skin appendage biology that contribute to the Turing activator/inhibitor model in feather pattern formation, the topo-biological arrangement of stem cells in organ shape determination, the macro-environmental regulation of stem cells in regenerative hair waves, and potential novel molecular pathways in the morphological evolution of feathers. Here we show our current integrative biology efforts to unravel the complex cellular behavior in patterning stem cells and the control of regional specificity in skin appendages. We use feather/scale tissue recombination to demonstrate the timing control of competence and inducibility. Feathers from different body regions are used to study skin regional specificity. Bioinformatic analyses of transcriptome microarrays show the potential involvement of candidate molecular pathways. We further show Hox genes exhibit some region specific expression patterns. To visualize real time events, we applied time-lapse movies, confocal microscopy and multiphoton microscopy to analyze the morphogenesis of cultured embryonic chicken skin explants. These modern imaging technologies reveal unexpectedly complex cellular flow and organization of extracellular matrix molecules in three dimensions. While these approaches are in preliminary stages, this perspective highlights the challenges we face and new integrative tools we will use. Future work will follow these leads to develop a systems biology view and understanding in the morphogenetic principles that govern the development and regeneration of ectodermal organs.

  1. In search of the Golden Fleece: Unraveling principles of morphogenesis by studying the integrative biology of skin appendages

    PubMed Central

    Hughes, Michael W.; Wu, Ping; Jiang, Ting-Xin; Lin, Sung-Jan; Dong, Chen-Yuan; Li, Ang; Hsieh, Fon-Jou; Widelitz, Randall B.; Choung, Cheng Ming

    2013-01-01

    Summary The mythological story of the Golden Fleece symbolizes the magical regenerative power of skin appendages. Similar to the adventurous pursuit of the Golden Fleece by the multi-talented Argonauts, today we also need an integrated multi-disciplined approach to understand the cellular and molecular processes during development, regeneration and evolution of skin appendages. To this end, we have explored several aspects of skin appendage biology that contribute to the Turing activator / inhibitor model in feather pattern formation, the topo-biological arrangement of stem cells in organ shape determination, the macro-environmental regulation of stem cells in regenerative hair waves, and potential novel molecular pathways in the morphological evolution of feathers. Here we show our current integrative biology efforts to unravel the complex cellular behavior in patterning stem cells and the control of regional specificity in skin appendages. We use feather / scale tissue recombination to demonstrate the timing control of competence and inducibility. Feathers from different body regions are used to study skin regional specificity. Bioinformatic analyses of transcriptome microarrays show the potential involvement of candidate molecular pathways. We further show Hox genes exhibit some region specific expression patterns. To visualize real time events, we applied time-lapse movies, confocal microscopy and multiphoton microscopy to analyze the morphogenesis of cultured embryonic chicken skin explants. These modern imaging technologies reveal unexpectedly complex cellular flow and organization of extracellular matrix molecules in three dimensions. While these approaches are in preliminary stages, this perspective highlights the challenges we face and new integrative tools we will use. Future work will follow these leads to develop a systems biology view and understanding in the morphogenetic principles that govern the development and regeneration of ectodermal organs

  2. Attitude dynamic of spin-stabilized satellites with flexible appendages

    NASA Technical Reports Server (NTRS)

    Renard, M. L.

    1973-01-01

    Equations of motion and computer programs have been developed for analyzing the motion of a spin-stabilized spacecraft having long, flexible appendages. Stability charts were derived, or can be redrawn with the desired accuracy for any particular set of design parameters. Simulation graphs of variables of interest are readily obtainable on line using program FLEXAT. Finally, applications to actual satellites, such as UK-4 and IMP-1 have been considered.

  3. Subdistal Appendages Stabilize the Ups and Downs of Ciliary Life.

    PubMed

    Galati, Domenico F; Mitchell, Brian J; Pearson, Chad G

    2016-11-21

    Centrioles acquire subdistal appendages (sDAPs) during primary cilium formation. In this issue of Developmental Cell, Mazo et al. (2016) demonstrate that sDAPs keep cilia submerged within deep membrane invaginations. When sDAPs and centrosome cohesion are disrupted, cilia surface to the plasma membrane, which may alter mechanical and chemical signal transduction. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Magnetic resonance imaging of epiploic appendagitis in children.

    PubMed

    Boscarelli, Alessandro; Frediani, Simone; Ceccanti, Silvia; Falconi, Ilaria; Masselli, Gabriele; Casciani, Emanuele; Cozzi, Denis A

    2016-12-01

    In children, epiploic appendagitis has been seldom reported. We describe two children with clinical presentations mimicking appendicitis. A correct diagnosis was eventually achieved by magnetic resonance imaging (MRI) and confirmed at laparoscopy in the initial case. Our preliminary experience suggests that MRI is a valid and non-invasive alternative to computed tomography for characterization of unusual causes of pediatric abdominal pain in the acute hospital care setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Notch signaling and the determination of appendage identity

    PubMed Central

    Kurata, Shoichiro; Go, Masahiro J.; Artavanis-Tsakonas, Spyros; Gehring, Walter J.

    2000-01-01

    The Notch signaling pathway defines an evolutionarily conserved cell–cell interaction mechanism that throughout development controls the ability of precursor cells to respond to developmental signals. Here we show that Notch signaling regulates the expression of the master control genes eyeless, vestigial, and Distal-less, which in combination with homeotic genes induce the formation of eyes, wings, antennae, and legs. Therefore, Notch is involved in a common regulatory pathway for the determination of the various Drosophila appendages. PMID:10681430

  6. [Secondary pulmonary embolism to right atrial myxoma].

    PubMed

    Vico Besó, L; Zúñiga Cedó, E

    2013-10-01

    A case of pulmonary thromboembolism secondary to atrial myxoma right. The myxoma is a primary cardiac tumor, namely, has his origin in the cardiac tissue. Primary cardiac tumors are rare, including myxomas, the most common type. Have a predilection for females and the most useful tool for diagnosis is echocardiography. About 75% of myxomas occur in the left atrium of the heart and rest are in the right atrium. Right atrial myxomas in some sometimes associated with tricuspid stenosis and atrial fibrillation. The most common clinical manifestations include symptoms of this neoplasm constitutional, and embolic phenomena resulting from the obstruction to the flow intracavitary. The treatment of this condition is surgical. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  7. Kodymirus and the case for convergence of raptorial appendages in Cambrian arthropods.

    PubMed

    Lamsdell, James C; Stein, Martin; Selden, Paul A

    2013-09-01

    Kodymirus vagans Chlupáč and Havlíček in Sb Geol Ved Paleontol 6:7-20, 1965 is redescribed as an aglaspidid-like arthropod bearing a single pair of enlarged raptorial appendages, which are shown to be the second cephalic appendage. A number of early Palaeozoic arthropods, recognized from predominantly Cambrian Konservat-Lagerstätten, are known to have borne single pairs of large raptorial appendages. They are well established for the iconic yet problematic anomalocarids, the common megacheirans, and the ubiquitous bivalved Isoxys. Further taxa, such as fuxianhuiids and Branchiocaris, have been reported to have single pairs of specialized cephalic appendages, i.e., appendages differentiated from a largely homonomous limbs series, members of which act in metachronal motion. The homology of these raptorial appendages across these Cambrian arthropods has often been assumed, despite differences in morphology. Thus, anomalocaridids, for instance, have long multiarticulate "frontal appendages" consisting of many articles bearing an armature of paired serial spines, while megacheirans and Isoxys have short "great appendages" consisting of few articles with well-developed endites or elongate fingers. Homology of these appendages would require them to belong to the same cephalic segment. We argue based on morphological evidence that, to the contrary, the raptorial appendages of some of these taxa can be shown to belong to different cephalic segments and are the result of convergence in life habits. K. vagans is yet another important example for this, representing an instance for this morphology from a marginal marine environment.

  8. [Epiploic appendagitis: a rare cause of abdominal pain].

    PubMed

    García-Marín, Andrés; Nofuentes-Riera, Carmen; Mella-Laborde, Mario; Pérez-López, Mercedes; Pérez-Bru, Susana; Rubio-Cerdido, José María

    2014-01-01

    Epiploic appendagitis is an atypical cause of abdominal pain whose knowledge could avoid diagnostic or treatment errors. Diagnosis has been performed with abdominal ultrasound or tomography with the only treatment being nonsteroidal anti-inflammatory drugs. To analyze patients diagnosed in our hospital. We performed a 4-year retrospective and descriptive study (March 2009-March 2013) of patients diagnosed with epiploic appendagitis in our hospital. Seventeen patients were included, 14 females and three males with a median age of 57 years. Symptom delay was 72 h. Abdominal pains were located in the left lower quadrant in 64.7% and right lower quadrant in 35.3% of patients. Blood test demonstrated leukocytes 6,300 (5,000-9,500), neutrophils 61.6% (57-65.8), and C reactive protein 1.5 (0.85-2.92). Diagnosis was confirmed with abdominal ultrasound or tomography in 88.2% and intraoperatively in 11.8%. Epiploic appendagitis was more frequent in women. Abdominal pain was located in the lower quadrant, more predominant in left than right. Blood tests were normal except for increased levels of C-reactive protein. Diagnosis was made mostly preoperatively due to imaging tests, avoiding unnecessary surgical intervention.

  9. STS-74/Mir photogrammetric appendage structural dynamics experiment

    NASA Technical Reports Server (NTRS)

    Welch, Sharon S.; Gilbert, Michael G.

    1996-01-01

    The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) is an International Space Station (ISS) Phase-1 risk mitigation experiment. Phase-1 experiments are performed during docking missions of the U.S. Space Shuttle to the Russian Space Station Mir. The purpose of the experiment is to demonstrate the use of photogrammetric techniques for determination of structural dynamic mode parameters of solar arrays and other spacecraft appendages. Photogrammetric techniques are a low cost alternative to appendage mounted accelerometers for the ISS program. The objective of the first flight of PASDE, on STS-74 in November 1995, was to obtain video images of Mir Kvant-2 solar array response to various structural dynamic excitation events. More than 113 minutes of high quality structural response video data was collected during the mission. The PASDE experiment hardware consisted of three instruments each containing two video cameras, two video tape recorders, a modified video signal time inserter, and associated avionics boxes. The instruments were designed, fabricated, and tested at the NASA Langley Research Center in eight months. The flight hardware was integrated into standard Hitchhiker canisters at the NASA Goddard Space Flight Center and then installed into the Space Shuttle cargo bay in locations selected to achieve good video coverage and photogrammetric geometry.

  10. Surgery for Atrial Fibrillation.

    PubMed

    Lawrance, Christopher P; Henn, Matthew C; Damiano, Ralph J

    2016-04-01

    Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its fourth iteration (Cox-Maze IV). This article reviews the indications and preoperative planning for performing a Cox-Maze IV procedure. This article also reviews the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous cut-and-sew method.

  11. Surgery for atrial fibrillation.

    PubMed

    Lawrance, Christopher P; Henn, Matthew C; Damiano, Ralph J

    2014-11-01

    Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its fourth iteration (Cox-Maze IV). This article reviews the indications and preoperative planning for performing a Cox-Maze IV procedure. This article also reviews the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous cut-and-sew method.

  12. Induction of Atrial Fibrillation by Neutrophils Critically Depends on CD11b/CD18 Integrins

    PubMed Central

    Remane, Lisa; Mollenhauer, Martin; Rudolph, Volker; Rudolph, Tanja K.; Andrié, René P.; Stöckigt, Florian; Schrickel, Jan W.; Ravekes, Thorben; Deuschl, Florian; Nickenig, Georg; Willems, Stephan; Baldus, Stephan; Klinke, Anna

    2014-01-01

    Background Recent observational clinical and ex-vivo studies suggest that inflammation and in particular leukocyte activation predisposes to atrial fibrillation (AF). However, whether local binding and extravasation of leukocytes into atrial myocardium is an essential prerequisite for the initiation and propagation of AF remains elusive. Here we investigated the role of atrial CD11b/CD18 mediated infiltration of polymorphonuclear neutrophils (PMN) for the susceptibility to AF. Methods and Results C57bl/6J wildtype (WT) and CD11b/CD18 knock-out (CD11b−/−) mice were treated for 14 days with subcutaneous infusion of angiotensin II (Ang II), a known stimulus for PMN activation. Atria of Ang II-treated WT mice were characterized by increased PMN infiltration assessed in immunohistochemically stained sections. In contrast, atrial sections of CD11b−/− mice lacked a significant increase in PMN infiltration upon Ang II infusion. PMN infiltration was accompanied by profoundly enhanced atrial fibrosis in Ang II treated WT as compared to CD11b−/− mice. Upon in-vivo electrophysiological investigation, Ang II treatment significantly elevated the susceptibility for AF in WT mice if compared to vehicle treated animals given an increased number and increased duration of AF episodes. In contrast, animals deficient of CD11b/CD18 were entirely protected from AF induction. Likewise, epicardial activation mapping revealed decreased electrical conduction velocity in atria of Ang II treated WT mice, which was preserved in CD11b−/− mice. In addition, atrial PMN infiltration was enhanced in atrial appendage sections of patients with persistent AF as compared to patients without AF. Conclusions The current data critically link CD11b-integrin mediated atrial PMN infiltration to the formation of fibrosis, which promotes the initiation and propagation of AF. These findings not only reveal a mechanistic role of leukocytes in AF but also point towards a potential novel avenue of

  13. Atrial Fibrillation in Children

    MedlinePlus

    ... attribute childhood AF to congenital heart abnormalities or post-surgical complications. Learn more about children and arrhythmia. This content was last reviewed July 2016. Atrial Fibrillation • Introduction • What is ...

  14. Atrial Fibrillation Medications

    MedlinePlus

    ... think you are pregnant If you notice red, dark brown or black urine or stools If you ... Fibrillation • Introduction • What is Atrial Fibrillation? • Why AFib Matters • Understand your Risk for AFib Children • Symptoms of ...

  15. Atrial Fibrillation - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Atrial Fibrillation URL of this page: https://medlineplus.gov/languages/atrialfibrillation.html Other topics A-Z Expand Section ...

  16. Principles of appendage design in robots and animals determining terradynamic performance on flowable ground.

    PubMed

    Qian, Feifei; Zhang, Tingnan; Korff, Wyatt; Umbanhowar, Paul B; Full, Robert J; Goldman, Daniel I

    2015-10-08

    Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device consisting of an air fluidized bed trackway in which a gentle upward flow of air through the granular material resulted in a decreased penetration resistance. As the volumetric air flow, Q, increased to the fluidization transition, the penetration resistance decreased to zero. Using a bio-inspired hexapedal robot as a physical model, we systematically studied how locomotor performance (average forward speed, v(x)) varied with ground penetration resistance and robot leg frequency. Average robot speed decreased with increasing Q, and decreased more rapidly for increasing leg frequency, ω. A universal scaling model revealed that the leg penetration ratio (foot pressure relative to penetration force per unit area per depth and leg length) determined v(x) for all ground penetration resistances and robot leg frequencies. To extend our result to include continuous variation of locomotor foot pressure, we used a resistive force theory based terradynamic approach to perform numerical simulations. The terradynamic model successfully predicted locomotor performance for low resistance granular states. Despite variation in morphology and gait, the performance of running lizards, geckos and crabs on flowable ground was also influenced by the leg penetration ratio. In summary, appendage designs which reduce foot pressure can passively maintain minimal leg penetration ratio as the ground weakens, and consequently permits maintenance of effective locomotion over a range of terradynamically challenging surfaces.

  17. Right coronary artery perforation by an active-fixation atrial pacing lead resulting in life-threatening tamponade.

    PubMed

    Nakagawa, Eiichiro; Abe, Yukio; Komatsu, Ryushi; Naruko, Takahiko; Itoh, Akira

    2015-10-01

    Cardiac tamponade resulting from perforation of a cardiac chamber is a relatively rare complication of pacemaker implantation. We report the first case of perforation of the right coronary artery related to the implantation of a screw-in atrial pacing lead, presenting as life-threatening cardiac tamponade. We report the case of a 72-year-old woman with complete atrioventricular block and dyspnea on exertion. A permanent pacemaker was implanted with bipolar Medtronic active-fixation leads positioned in the right atrial appendage and at the right ventricular basal septum without any difficulty. Approximately 3.5 h after the procedure, the patient complained of nausea, and the systolic blood pressure decreased to less than 60 mmHg. Echocardiography revealed a large pericardial effusion. Because the effects of pericardiocentesis lasted for less than an hour, the patient underwent a thoracotomy. After evacuation of a massive hemopericardium, bright red blood was seen gushing out from the right coronary artery, which was located on the opposite site of the right atrial appendage where a small portion of the screw tip was observed to be penetrating the atrial wall. The right coronary artery perforation was repaired using autologous pericardium-reinforced 7-0 prolene mattress sutures. Perforation of the right coronary artery is a potential complication and should be part of the differential diagnosis of cardiac tamponade after pacemaker implantation.

  18. Right coronary artery perforation by an active-fixation atrial pacing lead resulting in life-threatening tamponade

    PubMed Central

    Nakagawa, Eiichiro; Abe, Yukio; Komatsu, Ryushi; Naruko, Takahiko; Itoh, Akira

    2015-01-01

    Cardiac tamponade resulting from perforation of a cardiac chamber is a relatively rare complication of pacemaker implantation. We report the first case of perforation of the right coronary artery related to the implantation of a screw-in atrial pacing lead, presenting as life-threatening cardiac tamponade. We report the case of a 72-year-old woman with complete atrioventricular block and dyspnea on exertion. A permanent pacemaker was implanted with bipolar Medtronic active-fixation leads positioned in the right atrial appendage and at the right ventricular basal septum without any difficulty. Approximately 3.5 h after the procedure, the patient complained of nausea, and the systolic blood pressure decreased to less than 60 mmHg. Echocardiography revealed a large pericardial effusion. Because the effects of pericardiocentesis lasted for less than an hour, the patient underwent a thoracotomy. After evacuation of a massive hemopericardium, bright red blood was seen gushing out from the right coronary artery, which was located on the opposite site of the right atrial appendage where a small portion of the screw tip was observed to be penetrating the atrial wall. The right coronary artery perforation was repaired using autologous pericardium-reinforced 7-0 prolene mattress sutures. Perforation of the right coronary artery is a potential complication and should be part of the differential diagnosis of cardiac tamponade after pacemaker implantation. PMID:26550089

  19. Autonomic mechanism for complex fractionated atrial electrograms: evidence by fast fourier transform analysis.

    PubMed

    Lu, Zhibing; Scherlag, Benjamin J; Lin, Jiaxiong; Niu, Guodong; Ghias, Muhammad; Jackman, Warren M; Lazzara, Ralph; Jiang, Hong; Po, Sunny S

    2008-08-01

    The mechanism(s) underlying complex fractionated atrial electrograms (CFAE) is not well understood. We hypothesized that CFAE may be caused by enhanced activity of the intrinsic cardiac autonomic nervous system. In 35 anesthetized dogs, via a right or left thoracotomy, sustained atrial fibrillation was induced by local application of acetylcholine (ACh; 10, 100 mM) to the surface of the atrial appendage (AA) or by injection of ACh (10 mM) into the ganglionated plexi (GP). Fast Fourier transform analysis was performed from recordings at AA, atrial sites near the AA, mid portion of the atrium, atrial sites near the GP, and the pulmonary veins. After AF was induced with ACh either by topical application to the AA or by direct injection into the GP, CFAE exhibited a significant gradient of progressively decreasing dominant frequency and incidence of CFAE (CFAE%) from the GP toward distant sites, while regularity index progressively decreased in the opposite direction. Ablation of GP markedly attenuated CFAE and eliminated these gradients. These results suggest CFAE may result from activation of the intrinsic cardiac autonomic nervous system in these animal models of sustained AF. Ablation of GP attenuates CFAE and eliminates the DF gradient.

  20. Recovery of atrial systolic function after pharmacological conversion of chronic atrial fibrillation to sinus rhythm: a Doppler echocardiographic study.

    PubMed Central

    Jović, A.; Troskot, R.

    1997-01-01

    OBJECTIVE: To evaluate the time course of the recovery of atrial mechanical function after pharmacological cardioversion of chronic atrial fibrillation to sinus rhythm. PATIENTS AND METHODS: 21 patients (12 male, 9 female, aged 37-77 years) with chronic atrial fibrillation (< 6 months) were followed up by serial transmitral pulsed Doppler echocardiography. Echocardiographic studies were performed within the first 24 hours and on day 8, 15, and 30 after cardioversion. RESULTS: There was a significant increase (mean (SD)) in the peak A-wave velocity (from 0.35 (0.10) on day 1 to 0.50 (1.73) on day 8, and thereafter a gradual increase to 0.61 (0.14) m/s on day 30). Similarly, integrated late atrial velocities increased from 4.50 (1.46) on day 1 to 5.61 (1.73) on day 8 and 5.97 (1.47) cm/s2 on day 30. The atrial contribution to total transmitral flow increased significantly from 26 (7)% immediately after conversion of atrial fibrillation to sinus rhythm to 34 (7)% on day 30, indicating the haemodynamic benefit of the restoration of sinus rhythm. Left atrial diameter decreased but not significantly, from 4.11 (0.37) to 3.98 (0.34) cm (P < 0.005). CONCLUSIONS: These results suggest that restoration of atrial mechanical function after pharmacological cardioversion in patients with chronic atrial fibrillation is slow and gradual, as it is after electrical DC restoration of sinus rhythm. This time course may have important implications for determining how long treatment with anticoagulants and antiarrhythmic agents needs to continue in individual patients. It will also influence the clinical assessment of the haemodynamic benefit of restoring sinus rhythm in patients with chronic atrial fibrillation. Images PMID:9038694

  1. Artificial helical microswimmers with mastigoneme-inspired appendages

    PubMed Central

    Tottori, Soichiro; Nelson, Bradley J.

    2013-01-01

    A smooth flagellum moves in the opposite direction of the propagation of flagellar waves. Conversely, a flagellum covered with appendages perpendicular to the main flagellum, called mastigonemes, moves in the same direction as the propagation of flagellar waves. Inspired by mastigoneme structures in nature, we report the reversal of the swimming direction of magnetically actuated artificial helical microswimmers. The main flagella and mastigonemes of these microswimmers are fabricated together using three-dimensional lithography and electron beam evaporation of ferromagnetic thin films. The results show that the swimming speed and direction can be controlled by changing the length/spacing ratio of the mastigonemes. PMID:24396533

  2. Atrial fibrillation (acute onset)

    PubMed Central

    2014-01-01

    Introduction Acute atrial fibrillation is rapid, irregular, and chaotic atrial activity of recent onset. Various definitions of acute atrial fibrillation have been used in the literature, but for the purposes of this review we have included studies where atrial fibrillation may have occurred up to 7 days previously. Risk factors for acute atrial fibrillation include increasing age, cardiovascular disease, alcohol, diabetes, and lung disease. Acute atrial fibrillation increases the risk of stroke and heart failure. The condition resolves spontaneously within 24 to 48 hours in more than 50% of people; however, many people will require interventions to control heart rate or restore sinus rhythm. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent embolism, for conversion to sinus rhythm, and to control heart rate in people with recent-onset atrial fibrillation (within 7 days) who are haemodynamically stable? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 26 studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: amiodarone, antithrombotic treatment before cardioversion, atenolol, bisoprolol, carvedilol, digoxin, diltiazem, direct current cardioversion, flecainide, metoprolol, nebivolol, propafenone, sotalol, timolol, and verapamil. PMID:25430048

  3. Can Atrial Fibrillation Be Prevented?

    MedlinePlus

    ... from the NHLBI on Twitter. How Can Atrial Fibrillation Be Prevented? Following a healthy lifestyle and taking ... for heart disease may help you prevent atrial fibrillation (AF). These steps include: Following a heart healthy ...

  4. Cellular and Molecular Mechanisms of Atrial Arrhythmogenesis in Patients with Paroxysmal Atrial Fibrillation

    PubMed Central

    Wang, Qiongling; Chiang, David Y.; Li, Na; Karck, Matthias; Wehrens, Xander H.T.; Nattel, Stanley; Dobrev, Dobromir

    2015-01-01

    Background Electrical, structural and Ca2+-handling remodeling contribute to the perpetuation/progression of atrial fibrillation (AF). Recent evidence has suggested a role for spontaneous sarcoplasmic-reticulum Ca2+-release events (SCaEs) in longstanding persistent AF, but the occurrence and mechanisms of SCaEs in paroxysmal AF (pAF) are unknown. Method and Results Right-atrial appendages from control sinus-rhythm patients (Ctl) or patients with pAF (last episode median 10-20 days preoperatively) were analyzed with simultaneous measurements of [Ca2+]i (Fluo-3) and membrane-currents/action potentials (patch-clamp) in isolated atrial cardiomyocytes, as well as Western blot. Action potential duration, L-type Ca2+-current and Na+/Ca2+-exchange current were unaltered in pAF, indicating absence of AF-induced electrical remodeling. In contrast, there was an increased incidence of delayed afterdepolarizations (DADs) in pAF. Ca2+-transient (CaT)-amplitude and sarcoplasmic-reticulum Ca2+-load (caffeine-induced CaT-amplitude, integrated membrane current) were larger in pAF. CaT-decay was faster in pAF but decay of caffeine-induced CaT was unaltered, suggesting increased Serca2a function. In agreement, phosphorylation (inactivation) of the Serca2a-inhibitor protein phospholamban was increased in pAF. Ryanodine-receptor (RyR2) fractional phosphorylation was unaltered in pAF, whereas RyR2-expression and single-channel open probability were increased. A novel computational model of the human atrial cardiomyocyte indicated that both RyR2 dysregulation and enhanced Serca2a activity promote increased sarcoplasmic-reticulum Ca2+-leak and SCaEs, causing DADs/triggered activity in pAF. Conclusions Increased diastolic sarcoplasmic-reticulum Ca2+-leak and related DADs/triggered activity promote cellular arrhythmogenesis in pAF-patients. Biochemical, functional and modeling studies point to a combination of increased sarcoplasmic-reticulum Ca2+-load related to phospholamban

  5. Atrial selectivity of antiarrhythmic drugs

    PubMed Central

    Ravens, Ursula; Poulet, Claire; Wettwer, Erich; Knaut, Michael

    2013-01-01

    New antiarrhythmic drugs for treatment of atrial fibrillation should ideally be atrial selective in order to avoid pro-arrhythmic effects in the ventricles. Currently recognized atrial selective targets include atrial Nav1.5 channels, Kv1.5 channels and constitutively active Kir3.1/3.4 channels, each of which confers atrial selectivity by different mechanisms. Na+ channel blockers with potential- and frequency-dependent action preferentially suppress atrial fibrillation because of the high excitation rate and less negative atrial resting potential, which promote drug binding in atria. Kv1.5 channels are truly atrial selective because they do not conduct repolarizing current IKur in ventricles. Constitutively active IK,ACh is predominantly observed in remodelled atria from patients in permanent atrial fibrillation (AF). A lot of effort has been invested to detect compounds which will selectively block Kir3.1/Kir3.4 in their remodelled constitutively active form. Novel drugs which have been and are being developed aim at atrial-selective targets. Vernakalant and ranolazine which mainly block atrial Na+ channels are clinically effective. Newly designed selective IKur blockers and IK,ACh blockers are effective in animal models; however, clinical benefit in converting AF into sinus rhythm (SR) or reducing AF burden remains to be demonstrated. In conclusion, atrial-selective antiarrhythmic agents have a lot of potential, but a long way to go. PMID:23732646

  6. Co-occurrence of carbohydrate malabsorption and primary epiploic appendagitis

    PubMed Central

    Schnedl, Wolfgang J; Kalmar, Peter; Mangge, Harald; Krause, Robert; Wallner-Liebmann, Sandra J

    2015-01-01

    Unspecific abdominal complaints including bloating and irregular bowel movements may be caused by carbohydrate malabsorption syndromes, e.g., lactose and fructose malabsorption. These symptoms were investigated with hydrogen (H2) breath tests and correlated to carbohydrate malabsorption. During performing these H2-breath tests the patient presented with an acute, localized, non-migratory pain in the left lower abdominal quadrant. Primary epiploic appendagitis is a rare cause of abdominal acute or subacute complaints and diagnosis of primary epiploic appendagitis (PEA) is made when computed tomography reveals a characteristic lesion. We report on a patient with co-occurrence of lactose and fructose malabsorption, which was treated successfully with a diet free of culprit carbohydrates, with PEA recovering without medication or surgical treatment within few days. Since the abdominal unspecific symptoms had been present for months, they appeared not to be correlated to the acute localized abdominal pain, therefore we speculate on a random co-occurrence of combined carbohydrate malabsorption and PEA. PMID:26401090

  7. Co-occurrence of carbohydrate malabsorption and primary epiploic appendagitis.

    PubMed

    Schnedl, Wolfgang J; Kalmar, Peter; Mangge, Harald; Krause, Robert; Wallner-Liebmann, Sandra J

    2015-09-21

    Unspecific abdominal complaints including bloating and irregular bowel movements may be caused by carbohydrate malabsorption syndromes, e.g., lactose and fructose malabsorption. These symptoms were investigated with hydrogen (H2) breath tests and correlated to carbohydrate malabsorption. During performing these H2-breath tests the patient presented with an acute, localized, non-migratory pain in the left lower abdominal quadrant. Primary epiploic appendagitis is a rare cause of abdominal acute or subacute complaints and diagnosis of primary epiploic appendagitis (PEA) is made when computed tomography reveals a characteristic lesion. We report on a patient with co-occurrence of lactose and fructose malabsorption, which was treated successfully with a diet free of culprit carbohydrates, with PEA recovering without medication or surgical treatment within few days. Since the abdominal unspecific symptoms had been present for months, they appeared not to be correlated to the acute localized abdominal pain, therefore we speculate on a random co-occurrence of combined carbohydrate malabsorption and PEA.

  8. Evo-Devo of amniote integuments and appendages.

    PubMed

    Wu, Ping; Hou, Lianhai; Plikus, Maksim; Hughes, Michael; Scehnet, Jeffrey; Suksaweang, Sanong; Widelitz, Randall; Jiang, Ting-Xin; Chuong, Cheng-Ming

    2004-01-01

    Integuments form the boundary between an organism and the environment. The evolution of novel developmental mechanisms in integuments and appendages allows animals to live in diverse ecological environments. Here we focus on amniotes. The major achievement for reptile skin is an adaptation to the land with the formation of a successful barrier. The stratum corneum enables this barrier to prevent water loss from the skin and allowed amphibian / reptile ancestors to go onto the land. Overlapping scales and production of beta-keratins provide strong protection. Epidermal invagination led to the formation of avian feather and mammalian hair follicles in the dermis. Both adopted a proximal - distal growth mode which maintains endothermy. Feathers form hierarchical branches which produce the vane that makes flight possible. Recent discoveries of feathered dinosaurs in China inspire new thinking on the origin of feathers. In the laboratory, epithelial - mesenchymal recombinations and molecular mis-expressions were carried out to test the plasticity of epithelial organ formation. We review the work on the transformation of scales into feathers, conversion between barbs and rachis and the production of "chicken teeth". In mammals, tilting the balance of the BMP pathway in K14 noggin transgenic mice alters the number, size and phenotypes of different ectodermal organs, making investigators rethink the distinction between morpho-regulation and pathological changes. Models on the evolution of feathers and hairs from reptile integuments are discussed. A hypothetical Evo-Devo space where diverse integument appendages can be placed according to complex phenotypes and novel developmental mechanisms is presented.

  9. Simultaneous right atrioventricular pacing: a novel model to study atrial remodeling and fibrillation in the setting of heart failure.

    PubMed

    Laurent, Gabriel; Moe, Gordon W; Hu, Xudong; Pui-Sze So, Petsy; Ramadeen, Andrew; Leong-Poi, Howard; Doumanovskaia, Liia; Konig, Andrea; Trogadis, Judy; Courtman, David; Strauss, Bradley H; Dorian, Paul

    2008-04-01

    Atrial fibrillation (AF) is a common arrhythmia which contributes to morbidity and mortality in patients with heart failure (HF). Atrial remodeling is a key substrate for the development of AF in HF. However, experimental models that study AF in the setting of HF have important limitations. We evaluated a new dog model of atrial remodeling and AF. Twenty-two mongrel dogs were randomized into 2 groups: 14 dogs with simultaneous atrioventricular pacing (SAVP) for 2 weeks (220 beats/min, no AV delay) and 8 control dogs with no pacing. SAVP for 2 weeks induced marked changes in atrial mechanical function and conduction. Left atrial area fractional shortening decreased 61 +/- 17%, whereas left ventricular area fractional shortening decreased by 38 +/- 18% from baseline (both P < .05). Conduction slowed and conduction heterogeneity increased. AF was induced in 83% of SAVP dogs, lasting a median of 1600 seconds, versus no dogs with induced AF in the controls. SAVP significantly increased nonfibrillar collagen in the mid-myocardium of both atrial appendages and matrix metalloproteinase-9 activity. SAVP in dogs induces structural and electrical remodelling that form the substrate for reproducibly inducible AF. This novel model may be useful for studies of the pathophysiology and treatment of AF in heart failure.

  10. Attitude dynamics simulation subroutines for systems of hinge-connected rigid bodies with nonrigid appendages

    NASA Technical Reports Server (NTRS)

    Fleischer, G. E.; Likins, P. W.

    1975-01-01

    Three computer subroutines designed to solve the vector-dyadic differential equations of rotational motion for systems that may be idealized as a collection of hinge-connected rigid bodies assembled in a tree topology, with an optional flexible appendage attached to each body are reported. Deformations of the appendages are mathematically represented by modal coordinates and are assumed small. Within these constraints, the subroutines provide equation solutions for (1) the most general case of unrestricted hinge rotations, with appendage base bodies nominally rotating at a constant speed, (2) the case of unrestricted hinge rotations between rigid bodies, with the restriction that those rigid bodies carrying appendages are nominally nonspinning, and (3) the case of small hinge rotations and nominally nonrotating appendages. Sample problems and their solutions are presented to illustrate the utility of the computer programs.

  11. The controversial origin of the abdominal appendage-like processes in immature insects: are they true segmental appendages or secondary outgrowths? (Arthropoda Hexapoda).

    PubMed

    Bitsch, Jacques

    2012-08-01

    In this article, I review the major characteristics of different types of appendage-like processes that develop at the abdominal segments of many immature insects, and I discuss their controversial morphological value. The main question is whether the abdominal processes are derived from segmental appendages serially homologous to thoracic legs, or whether they are "secondary" outgrowths not homologous with true appendages. Morphological and embryological data, in particular, a comparison with the structure and development of the abdominal appendages in primitive apterygote hexapods, and data from developmental genetics, support the hypothesis of appendicular origin of many of the abdominal processes present in the juvenile stages of various pterygote orders. For example, the lateral processes, such as the tracheal gills in aquatic nymphs of exopterygote insects, are regarded as derived from lateral portions of appendage primordia, homologous with the abdominal styli of apterygotan insects; these processes correspond either to rudimentary telopodites or to coxal exites. The ventrolateral processes, such as the prolegs of different endopterygote insect larvae, appear to be derived from medial portions of the appendicular primordia; they correspond to coxal endites. These views lead to the rejection of Hinton's hypothesis (Hinton [1955] Trans R Entomol Soc Lond 106:455-545) according to which all the abdominal processes of insect larvae are secondary outgrowths not derived from true appendage anlagen. Copyright © 2012 Wiley Periodicals, Inc.

  12. High-resolution two-dimensional gel electrophoresis analysis of atrial tissue proteome reveals down-regulation of fibulin-1 in atrial fibrillation.

    PubMed

    García, Angel; Eiras, Sonia; Parguiña, Andrés F; Alonso, Jana; Rosa, Isaac; Salgado-Somoza, Antonio; Rico, Trinidad Yolanda; Teijeira-Fernández, Elvis; González-Juanatey, José Ramón

    2011-08-04

    Atrial fibrillation (AF) is the most common cardiac arrhythmia found in clinical practice. We combined high-resolution two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to compare the atrial proteome of subjects with AF versus controls with sinus rhythm (SR). Our aim was to identify novel differentially regulated proteins that could be related to the development of the arrhythmia. Human atrial appendage tissue samples from patients undergoing heart surgery with AF or SR were analyzed by high-resolution 2-DE. Proteins of interest were identified by MS and validated by western blotting and inmunohistochemistry. Our analysis allowed the detection of over 2300 protein spots per gel. Following differential image analysis, we found 22 spot differences between the AF and SR groups in the 4-7 isoelectric point range, leading to the identification of 15 differentially regulated proteins. The main group of proteins identified was that of heat shock proteins (HSPs), including TRAP-1, HspB3, HspΒ6 and AHA1. Some of the differences detected between AF and SR for the above proteins were due to post-translational modifications. In addition, we identified the structural protein fibulin-1 as down-regulated in atrial tissue from AF patients. High-resolution 2-DE analysis of human atrial tissue revealed that AF is associated with changes in structural proteins and an important number of HSPs. The lower expression of the structural protein fibulin-1 in atrial tissue from AF patients might reflect the myocardial structural changes that take place in the arrhythmia. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Rivaroxaban in atrial fibrillation

    PubMed Central

    Giorgi, Mariano A; Miguel, Lucas San

    2012-01-01

    Warfarin is the traditional therapeutic option available to manage thromboembolic risk in atrial fibrillation. The hemorrhagic risk with warfarin depends mainly on the international normalized ratio (INR). Data from randomized controlled trials show that patients have a therapeutic INR (2.00–3.00) only 61%–68% of the time while taking warfarin, and this target is sometimes hard to establish. Many compounds have been developed in order to optimize the profile of oral anticoagulants. We focus on one of them, rivaroxaban, comparing it with novel alternatives, ie, dabigatran and apixaban. The indication for rivaroxaban in nonvalvular atrial fibrillation was evaluated in ROCKET-AF (Rivaroxaban-once daily, Oral, direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation). In this trial, rivaroxaban was associated with a 12% reduction in the incidence of the primary endpoint compared with warfarin (hazard ratio 0.88; 95% confidence interval [CI] 0.74–1.03; P < 0.001 for noninferiority and P = 0.12 for superiority). However, patients remained in the therapeutic range for INR only 55% of the time, which is less than that in RE-LY (the Randomized Evaluation of Long-Term Anticoagulation Therapy, 64%) and in the ARISTOTLE trial (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation, 66%). This shorter time spent in the therapeutic range has been one of the main criticisms of the ROCKET-AF trial, but could actually reflect what happens in real life. In addition, rivaroxaban exhibits good pharmacokinetic and pharmacoeconomic properties. Novel anticoagulants are a viable and commercially available alternative to vitamin K antagonists nowadays for the prevention of thromboembolic complications in atrial fibrillation. Rivaroxaban is an attractive alternative, but the true picture of this novel compound in atrial fibrillation will only become available with more widespread

  14. Right atrial spleen.

    PubMed Central

    Kuijer, P; Dion, R; van Merrienboer, F

    1985-01-01

    A large cardiac tumour occupying most of the right atrium and the right ventricle and causing inflow obstruction to the right heart was confirmed by cross sectional echocardiography in a 41 year old man. After surgical resection histological examination showed that the atrial tumour had the characteristics of splenic tissue. Possible mechanisms for the development of such a tumour include an origin analogous to that of an accessory spleen or the implantation and subsequent growth of lymphoid tissue in a pre-existing superior vena caval or high right atrial angioma. Images PMID:4041304

  15. A conserved genetic mechanism specifies deutocerebral appendage identity in insects and arachnids

    PubMed Central

    Sharma, Prashant P.; Tarazona, Oscar A.; Lopez, Davys H.; Schwager, Evelyn E.; Cohn, Martin J.; Wheeler, Ward C.; Extavour, Cassandra G.

    2015-01-01

    The segmental architecture of the arthropod head is one of the most controversial topics in the evolutionary developmental biology of arthropods. The deutocerebral (second) segment of the head is putatively homologous across Arthropoda, as inferred from the segmental distribution of the tripartite brain and the absence of Hox gene expression of this anterior-most, appendage-bearing segment. While this homology statement implies a putative common mechanism for differentiation of deutocerebral appendages across arthropods, experimental data for deutocerebral appendage fate specification are limited to winged insects. Mandibulates (hexapods, crustaceans and myriapods) bear a characteristic pair of antennae on the deutocerebral segment, whereas chelicerates (e.g. spiders, scorpions, harvestmen) bear the eponymous chelicerae. In such hexapods as the fruit fly, Drosophila melanogaster, and the cricket, Gryllus bimaculatus, cephalic appendages are differentiated from the thoracic appendages (legs) by the activity of the appendage patterning gene homothorax (hth). Here we show that embryonic RNA interference against hth in the harvestman Phalangium opilio results in homeonotic chelicera-to-leg transformations, and also in some cases pedipalp-to-leg transformations. In more strongly affected embryos, adjacent appendages undergo fusion and/or truncation, and legs display proximal defects, suggesting conservation of additional functions of hth in patterning the antero-posterior and proximo-distal appendage axes. Expression signal of anterior Hox genes labial, proboscipedia and Deformed is diminished, but not absent, in hth RNAi embryos, consistent with results previously obtained with the insect G. bimaculatus. Our results substantiate a deep homology across arthropods of the mechanism whereby cephalic appendages are differentiated from locomotory appendages. PMID:25948691

  16. A conserved genetic mechanism specifies deutocerebral appendage identity in insects and arachnids.

    PubMed

    Sharma, Prashant P; Tarazona, Oscar A; Lopez, Davys H; Schwager, Evelyn E; Cohn, Martin J; Wheeler, Ward C; Extavour, Cassandra G

    2015-06-07

    The segmental architecture of the arthropod head is one of the most controversial topics in the evolutionary developmental biology of arthropods. The deutocerebral (second) segment of the head is putatively homologous across Arthropoda, as inferred from the segmental distribution of the tripartite brain and the absence of Hox gene expression of this anterior-most, appendage-bearing segment. While this homology statement implies a putative common mechanism for differentiation of deutocerebral appendages across arthropods, experimental data for deutocerebral appendage fate specification are limited to winged insects. Mandibulates (hexapods, crustaceans and myriapods) bear a characteristic pair of antennae on the deutocerebral segment, whereas chelicerates (e.g. spiders, scorpions, harvestmen) bear the eponymous chelicerae. In such hexapods as the fruit fly, Drosophila melanogaster, and the cricket, Gryllus bimaculatus, cephalic appendages are differentiated from the thoracic appendages (legs) by the activity of the appendage patterning gene homothorax (hth). Here we show that embryonic RNA interference against hth in the harvestman Phalangium opilio results in homeonotic chelicera-to-leg transformations, and also in some cases pedipalp-to-leg transformations. In more strongly affected embryos, adjacent appendages undergo fusion and/or truncation, and legs display proximal defects, suggesting conservation of additional functions of hth in patterning the antero-posterior and proximo-distal appendage axes. Expression signal of anterior Hox genes labial, proboscipedia and Deformed is diminished, but not absent, in hth RNAi embryos, consistent with results previously obtained with the insect G. bimaculatus. Our results substantiate a deep homology across arthropods of the mechanism whereby cephalic appendages are differentiated from locomotory appendages.

  17. Phrenic nerve injury after atrial fibrillation catheter ablation: characterization and outcome in a multicenter study.

    PubMed

    Sacher, Frédéric; Monahan, Kristi H; Thomas, Stuart P; Davidson, Neil; Adragao, Pedro; Sanders, Prashanthan; Hocini, Mélèze; Takahashi, Yoshihide; Rotter, Martin; Rostock, Thomas; Hsu, Li-Fern; Clémenty, Jacques; Haïssaguerre, Michel; Ross, David L; Packer, Douglas L; Jaïs, Pierre

    2006-06-20

    The purpose of this study was to characterize the occurrence of phrenic nerve injury (PNI) and its outcome after radiofrequency (RF) ablation of atrial fibrillation (AF). It is recognized that extra-myocardial damage may develop owing to penetration of ablative energy. Between 1997 and 2004, 3,755 consecutive patients underwent AF ablation at five centers. Among them, 18 patients (0.48%; 9 male, 54 +/- 10 years) had PNI (16 right, 2 left). The procedure consisted of pulmonary vein (PV) isolation in 15 patients and anatomic circumferential ablation in 3 patients, with additional left atrial lesions (n = 11) and/or superior vena cava (SVC) disconnection (n = 4). Right PNI occurred during ablation of right superior PV (n = 12) or SVC disconnection (n = 3). Left PNI occurred during ablation at the left atrial appendage. Immediate features were dyspnea, cough, hiccup, and/or sudden diaphragmatic elevation in 9, and in the remaining the diagnosis was made after ablation owing to dyspnea (n = 7) or on routine radiographic evaluation (n = 2). Four patients (22%) were asymptomatic. Complete recovery occurred in 12 patients (66%). Recovery occurred within 24 h in the two patients with left PNI and in one patient with right PNI occurring with SVC disconnection. In the other nine patients, right PNI recovery occurred after 4 +/- 5 months (1 to 12 months) with respiratory rehabilitation. After a mean follow-up of 36 +/- 33 months, six patients have persistent PNI (three with partial and three with no recovery). In this multicenter experience, PNI was a rare complication (0.48%) of AF ablation. Ablation of the right superior PV, SVC, and left atrial appendage were associated with PNI. Complete (66%) or partial (17%) recovery was observed in the majority.

  18. Leaf epidermal appendages of desert plant: an ecological perspective

    NASA Astrophysics Data System (ADS)

    Liu, Yubing; Li, Xinrong; Li, Mengmeng

    2014-05-01

    Desert plant often have few, tiny or no leaves, which reduces transpiration. The epidermis of their leaves is often ornamented outgrowths called trichomes or hairs and a thick waxy cuticle. Hairs on the leaf surface trap humidity in dry climates and waxy leaf surfaces reduce water loss. Our present study is to investigate the characteristics of trichomes and waxy cuticle in leaf surface of desert plant, which in the long term acclimation in semi-humid, semi-arid and arid ecosystems of Northern China, from east (Zhangwu county, Liaoning province) to west (Korla city, Xinjiang Uygur Autonomous Region), passing through several provinces including the Inner Mongolia Autonomous Region, Shanxi province, the Ningxia Hui Autonomous Region and Gansu province. 68 shrubs and 7 trees were selected in the natural habitats which were artificial sand fixing vegetation and the adjacent natural vegetation in sandy areas. The leaf epidermis was observed by scanning electron microscopy (SEM) and the cuticle thickness was calculated in the leaf cross-section by transmission electron microscopy (TEM). The results indicated that the epidermis of selected materials was divided into five categories: (1) Trichomes with different forms covered completely on the adaxial and abaxial surfaces of leaf, and any other epidermal appendages could not been observed. (2) Epicuticular wax crystals with different forms almost completely covered in the epistomatal chambers as well as on the surrounding epidermis, and there were no other appendages on the leaf surface. (3) A lot of warty hairs arranged neatly on the surface and the stomatal index was too low. (4) Several or even dozens of papillary epidermal cells covered with waxy crystals enclosed a sunken stomata chamber, therefore the stomatal density is very low. (5) Like ordinary terrestrial plants, epidermal cells and cell outline are clear, with epidermal hairs or not, and the stomata and waxy crystals are visible. TEM showed that desert plants

  19. Skin and dermal appendages stem cells exposure to tobacco smoke.

    PubMed

    Kolanko, Emanuel; Czekaj, Piotr

    2013-01-01

    Stem cells are thought to persist throughout human life possessing enormous capacity for proliferation and differentiation. These cells and their microenvironment are potential targets for environmental pollutions, for example tobacco smoke. Tobacco smoke consists of thousands of substances which can disturb stem cell homeostasis by evoking, in particular, oxidative stress and hypoxia. It causes also deep, irreversible changes in the affected tissues. It is strongly linked with carcinogenesis. Skin is one of the most exposed tissues to tobacco smoke. Self-renewal dermal tissues, such as epidermis and its appendages, are composed of various stem cell populations. The tissue of the skin that is richest in SC is the hair follicle. In wound healing are involved: epidermal KSC population and stem populations from hair follicle, such as CD34+ and Lrig6+ cells. Some skin cancers, i.e., squamous cell carcinoma, originate from skin stem cells and are considered to be most associated with long-term smoking. Dermal stem cells can be affected by tobacco smoke components in two ways: internal, where xenobiotics are delivered with blood stream, and external, where the tissues are directly exposed to environmental tobacco smoke, as well as to third-hand smoke. Assessment of the dose- and time-response of the skin and dermal appendages to tobacco smoke exposure can allow to estimate the adverse health effects risk. Usually, to assess tobacco smoke exposure time, hairs and toenails are used. This is because they have a unique ability to store xenobiotics for longer periods of time in respect to their temporal appearance in the blood. Current scientific and medical problem is searching for more adequate biomarkers for TS exposure assessment. The unresolved question is, if stem cells isolated from the skin and its appendages might be good biomarkers for tobacco smoke exposure. We should take into consideration stem cell biology (proliferation vs. differentiation), expression of

  20. Exploiting periodicity to extract the atrial activity in atrial arrhythmias

    NASA Astrophysics Data System (ADS)

    Llinares, Raul; Igual, Jorge

    2011-12-01

    Atrial fibrillation disorders are one of the main arrhythmias of the elderly. The atrial and ventricular activities are decoupled during an atrial fibrillation episode, and very rapid and irregular waves replace the usual atrial P-wave in a normal sinus rhythm electrocardiogram (ECG). The estimation of these wavelets is a must for clinical analysis. We propose a new approach to this problem focused on the quasiperiodicity of these wavelets. Atrial activity is characterized by a main atrial rhythm in the interval 3-12 Hz. It enables us to establish the problem as the separation of the original sources from the instantaneous linear combination of them recorded in the ECG or the extraction of only the atrial component exploiting the quasiperiodic feature of the atrial signal. This methodology implies the previous estimation of such main atrial period. We present two algorithms that separate and extract the atrial rhythm starting from a prior estimation of the main atrial frequency. The first one is an algebraic method based on the maximization of a cost function that measures the periodicity. The other one is an adaptive algorithm that exploits the decorrelation of the atrial and other signals diagonalizing the correlation matrices at multiple lags of the period of atrial activity. The algorithms are applied successfully to synthetic and real data. In simulated ECGs, the average correlation index obtained was 0.811 and 0.847, respectively. In real ECGs, the accuracy of the results was validated using spectral and temporal parameters. The average peak frequency and spectral concentration obtained were 5.550 and 5.554 Hz and 56.3 and 54.4%, respectively, and the kurtosis was 0.266 and 0.695. For validation purposes, we compared the proposed algorithms with established methods, obtaining better results for simulated and real registers.

  1. Surgery for Atrial Fibrillation

    PubMed Central

    Lawrance, Christopher P.; Henn, Matthew C.; Damiano, Ralph J.

    2015-01-01

    Synopsis Atrial fibrillation is the most common cardiac arrhythmia and its treatment options include drug therapy or, catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure which was developed by James Cox in 1987 is a procedure where multiple surgical incisions are created along the atria to interrupt the electrical pathways thought to allow atrial fibrillation to persist. This procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its 4th iteration called the Cox-Maze IV. The Cox-Maze IV replaced the previous “cut-and-sew” method with a combination of cryoablation and bipolar RF ablation. The adaption of ablation technologies allowed the Cox-Maze IV procedure to be performed through a less invasive right minithoracotomy instead of a traditional sternotomy approach. The aim of this article is to review the indications and preoperative planning for performing a Cox-Maze IV procedure. A description of the operative techniques for both a sternotomy and right mini-thoracotomy approach will be discussed in addition to specific postoperative considerations. Finally, this article will review the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous “cut-and-sew” method. PMID:25443237

  2. Centriole distal appendages promote membrane docking, leading to cilia initiation

    PubMed Central

    Tanos, Barbara E.; Yang, Hui-Ju; Soni, Rajesh; Wang, Won-Jing; Macaluso, Frank P.; Asara, John M.; Tsou, Meng-Fu Bryan

    2013-01-01

    The distal appendages (DAPs) of centrioles have been proposed to anchor cilia to the plasma membrane, but their molecular composition, assembly, and exact function in ciliogenesis remain poorly understood. Using quantitative centrosome proteomics and superresolution microscopy, we identified five DAP components, including one previously described (CEP164), one partially characterized (CEP89 [ccdc123]), and three novel (CEP83 [ccdc41], SCLT1, and FBF1) DAP proteins. Analyses of DAP assembly revealed a hierarchy. CEP83 recruits both SCLT1 and CEP89 to centrioles. Subsequent recruitment of FBF1 and CEP164 is independent of CEP89 but mediated by SCLT1. All five DAP components are essential for ciliogenesis; loss of CEP83 specifically blocks centriole-to-membrane docking. Undocked centrioles fail to recruit TTBK2 or release CP110, the two earliest modifications found on centrioles prior to cilia assembly, revealing centriole-to-membrane docking as a temporal and spatial cue promoting cilia initiation. PMID:23348840

  3. Dissimilar Pain of Primary Epiploic Appendagitis and Malabsorption

    PubMed Central

    Enko, Dietmar; Wallner-Liebmann, Sandra J; Lackner, Sonja; Mangge, Harald

    2017-01-01

    Primary Epiploic Appendagitis (PEA) is a rare cause of acute or subacute abdominal complaints and non-migratory pain. Usually the diagnosis of PEA is made when Computed Tomography (CT) reveals characteristic figures. Nonspecific abdominal complaints including diffuse abdominal pain may be caused by carbohydrate and/or protein malabsorption. We report a case of a patient with PEA who recovered without medication or surgical treatment within a few days. Eight months later, he was diagnosed with lactose- and histamine malabsorption and Helicobacter pylori infection. The malabsorption was treated successfully with an individually-tailored diet free of culprit triggers and the Helicobacter pylori infection was eradicated. A localized non-migratory abdominal pain caused by PEA needs to be differentiated from nonspecific abdominal complaints due to malabsorption and Helicobacter pylori infection. PMID:28384920

  4. Evo-Devo of Amniote Integuments and Appendages

    PubMed Central

    Wu, Ping; Hou, Lianhai; Plikus, Maksim; Hughes, Michael; Scehnet, Jeffrey; Suksaweang, Sanong; Widelitz, Randall B.; Jiang, Ting-Xin; Chuong, Cheng-Ming

    2015-01-01

    Integuments form the boundary between an organism and the environment. The evolution of novel developmental mechanisms in integuments and appendages allows animals to live in diverse ecological environments. Here we focus on amniotes. The major achievement for reptile skin is an adaptation to the land with the formation of a successful barrier. The stratum corneum enables this barrier to prevent water loss from the skin and allowed amphibian/reptile ancestors to go onto the land. Overlapping scales and production of β-keratins provide strong protection. Epidermal invagination led to the formation of avian feather and mammalian hair follicles in the dermis. Both adopted a proximal - distal growth mode that maintains endothermy. Feathers form hierarchical branches which produce the vane that makes flight possible. Recent discoveries of feathered dinosaurs in China inspire new thinking on the origin of feathers. In the laboratory, epithelial - mesenchymal recombinations and molecular mis-expressions were carried out to test the plasticity of epithelial organ formation. We review the work on the transformation of scales into feathers, conversion between barbs and rachis, and the production of “chicken teeth”. In mammals, tilting the balance of the BMP pathway in K14 noggin transgenic mice alters the number, size and phenotypes of different ectodermal organs, making investigators rethink the distinction between morpho-regulation and pathological changes. Models on the evolution of feathers and hairs from reptile integuments are discussed. A hypothetical Evo-Devo space where diverse integument appendages can be placed according to complex phenotypes and novel developmental mechanisms is presented. PMID:15272390

  5. Association between the N-terminal plasma brain natriuretic peptide levels or elevated left ventricular filling pressure and thromboembolic risk in patients with non-valvular atrial fibrillation.

    PubMed

    Yu, Ga-In; Cho, Kyoung-Im; Kim, Hyun-Su; Heo, Jung-Ho; Cha, Tae-Joon

    2016-08-01

    We aimed to investigate the role of brain natriuretic peptide (BNP) levels and left ventricular (LV) filling pressures in thromboembolic risk in patients with non-valvular atrial fibrillation (AF). Among 327 patients with non-valvular AF, the ratio of peak early filling velocity to mitral annulus velocity (E/Ea) and N-terminal proBNP (NT-proBNP) was compared according to the presence of left atrial appendage (LAA) dysfunction [presence of spontaneous echo contrast (SEC)≥grade 3 and/or reduced LAA emptying flow velocity <20cm/s]. Compared to patients without LAA dysfunction, patients with LAA dysfunction presented with significantly higher CHADS2 scores (1.24±1.14 vs. 1.68±1.31, p=0.005), high-sensitivity C-reactive protein (0.36±1.18mg/dl vs. 0.66±1.32mg/dl, p=0.043), and NT-proBNP (765.3±2534.8pg/ml vs. 2266.9±6117.4pg/ml, p=0.002). Furthermore, patients with LAA dysfunction showed significantly higher left atrial volume index (LAVI, 25.1±10.9 vs. 43.1±22.1, p<0.001) and E/Ea (10.8±7.27 vs. 7.97±2.50mg/dl, p<0.001). Plasma logNT-proBNP levels were significantly correlated with the presence of SEC (r=0.276, p<0.001), LAA emptying flow velocity (r=-0.492, p<0.001), LAVI (r=0.405, p<0.001), and E/Ea (r=0.353, p<0.001). Binary logistic regression analysis showed that high NT-proBNP level >249.7pg/ml (odds ratio, OR 6.79, 95% confidence interval, CI 3.16-15.55, p<0.001) and E/Ea >10 (OR 4.41, 95% CI 2.39-8.15, p<0.001) were independent predictors of LAA dysfunction after adjustment of known thromboembolic risk factors. Elevated plasma NT-proBNP concentrations and LV filling pressures represented by LAA dysfunction may be reliable surrogate markers for predicting thromboembolic risk in patients with AF. Copyright © 2016. Published by Elsevier Ltd.

  6. Homology of arthropod anterior appendages revealed by Hox gene expression in a sea spider.

    PubMed

    Jager, Muriel; Murienne, Jérôme; Clabaut, Céline; Deutsch, Jean; Le Guyader, Hervé; Manuel, Michaël

    2006-05-25

    Arthropod head segments offer a paradigm for understanding the diversification of form during evolution, as a variety of morphologically diverse appendages have arisen from them. There has been long-running controversy, however, concerning which head appendages are homologous among arthropods, and from which ancestral arrangement they have been derived. This controversy has recently been rekindled by the proposition that the probable ancestral arrangement, with appendages on the first head segment, has not been lost in all extant arthropods as previously thought, but has been retained in the pycnogonids, or sea spiders. This proposal was based on the neuroanatomical analysis of larvae from the sea spider Anoplodactylus sp., and suggested that the most anterior pair of appendages, the chelifores, are innervated from the first part of the brain, the protocerebrum. Our examination of Hox gene expression in another sea spider, Endeis spinosa, refutes this hypothesis. The anterior boundaries of Hox gene expression domains place the chelifore appendages as clearly belonging to the second head segment, innervated from the second part of the brain, the deutocerebrum. The deutocerebrum must have been secondarily displaced towards the protocerebrum in pycnogonid ancestors. As anterior-most appendages are also deutocerebral in the other two arthropod groups, the Euchelicerata and the Mandibulata, we conclude that the protocerebral appendages have been lost in all extant arthropods.

  7. Characterization of a novel Bacillus thuringiensis phenotype possessing multiple appendages attached to a parasporal body.

    PubMed

    Ventura-Suárez, Antonio; Cruz-Camarillo, Ramón; Rampersad, Joanne; Ammons, David R; López-Villegas, Edgar O; Ibarra, Jorge E; Rojas-Avelizapa, Luz I

    2011-01-01

    Bacillus thuringiensis is a bacterium best known for its production of crystal-like bodies comprised of one or more Cry-proteins, which can be toxic to insects, nematodes or cancer cells. Although strains of B. thuringiensis have occasionally been observed with filamentous appendages attached to their spores, appendages in association with their parasporal bodies are extremely rare. Herein we report the characterization of Bt1-88, a bacterial strain isolated from the Caribbean that produces a spore-crystal complex containing six long appendages, each comprised of numerous thinner filaments approximately 10 nm in diameter and 2.5 μm in length. Each of the multi-filament appendages was attached to a single, small parasporal body located at one end of the bacterial spore. Biochemical tests, 16S rDNA gene sequencing, and the identification of two Cry proteins by partial protein sequencing (putatively Cry1A and Cry2A), unambiguously identified Bt1-88 as a strain of B. thuringiensis. Bt1-88 represents the second reported strain of B. thuringiensis possessing a parasporal body/appendage phenotype characterized by one or more long appendages, comprised of numerous filaments in association with a parasporal body. This finding suggests that Bt1-88 is a member of a new phenotypic class of B. thuringiensis, in which the parasporal body may perform a novel structural role through its association with multi-filament appendages.

  8. Posterior left atrial wall hematoma mimicking cystic intracavitary atrial mass.

    PubMed

    Bahnacy, Yasser; Suresh, Cheriyil; Dawoud, Hamed; Zubaid, Mohammad

    2010-10-01

    Atrial myxoma is the most common benign primary tumor of the heart most commonly in the left atrium (LA). Cystic or cavitated intracardiac masses are rare. We report the case of a 43-year-old male patient admitted with chest infection, hemoptysis, and severe respiratory distress, who had to be ventilated. Chest computed tomography showed bilateral lung consolidation with large mass occupying the region of the LA. Transthoracic echocardiography and transesophageal echocardiography showed a large intracavitary left atrial cystic mobile mass. Open-heart surgical exploration did not show any mass inside the LA. A posterior left atrial wall hematoma was found and evacuated. Biopsies confirmed the presence of blood clots. Posterior left atrial wall hematoma may appear as left atrial intracavitary cystic mass and should be included in the differential diagnosis of cystic left atrial mass.

  9. Stroke prevention following modified endoscopic ablation and appendectomy for atrial fibrillation.

    PubMed

    Ma, Nan; Jiang, Zhaolei; Chen, Fei; Yin, Hang; Ding, Fangbao; Mei, Ju

    2016-09-01

    We reported the results of stroke prevention following modified endoscopic procedure for atrial fibrillation. 82 patients underwent modified endoscopic procedure for atrial fibrillation (AF), in whom 47 had paroxysmal, 28 had persistent, and 7 had long-standing atrial fibrillation. CHA2DS2VASC median score was 3 (range from 0 to 8). The procedure was performed on the beating heart, through 3 ports on the left chest wall. Pulmonary vein isolation and ablation of the left atrium were achieved by bipolar radiofrequency ablation. Left atrial appendage (LAA) was excluded by stapler. Brain CT, cardiac CT and 24-h Holter monitoring were performed following the procedure. The procedure was successfully completed for all patients. The mean duration was 122 ± 40.1 min. LAA was excluded after appendectomy and checked by intraoperative transesophageal echocardiography. The mean follow-up duration was 24.3 ± 3.5 months. No patients showed signs and symptoms of transient ischemic attack or stroke. No new positive findings were demonstrated by recurring brain CT scan performed after the procedure. Cardiac CT confirmed the absence of LAA and thrombosis in the left atrium. 87.8 % (72/82) of all patients were in sinus rhythm. Our results demonstrate that the modified endoscopic procedure is a safe, effective, and appropriate treatment for AF, which restores sinus rhythm and may be associated with the prevention of AF-related stroke.

  10. Genetics Home Reference: familial atrial fibrillation

    MedlinePlus

    ... Home Health Conditions familial atrial fibrillation familial atrial fibrillation Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Familial atrial fibrillation is an inherited condition that disrupts the heart's ...

  11. Ebstein Anomaly With Right Atrial Clot

    PubMed Central

    Kumar, Prakash; Singhal, Gaurav; Sinha, Santosh Kumar; Pandey, Umeshwar; Thakur, Ramesh; Varma, Chandra Mohan

    2015-01-01

    Ebstein anomaly (EA) is a rare congenital malformation of the tricuspid valve (TV), often associated with other cardiac malformations, especially atrial septal defect/patent foramen ovale (PFO) which is present in 80-90% of patients and predisposes to paradoxical embolization. We describe the case of a 17-year-old female, who presented with worsening exertional dyspnea, fatigue and pedal edema and atrial fibrillation (AF). Transthoracic echocardiography showed EA with severely dilated right atrium (RA), small functional right ventricle (RV), low velocity flow across TV with spontaneous echo contrast and giant clot in RA. Fortunately for the patient, contrast and transesophageal echocardiography revealed an intact interatrial septum with no PFO preventing any paradoxical embolism from large clot in RA, more so in the background of AF. Important differential diagnosis of congenitally unguarded TV orifice was ruled out due to presence of septal and anterior leaflets of TV and associated chordae. PMID:28197250

  12. Ebstein Anomaly With Right Atrial Clot.

    PubMed

    Kumar, Prakash; Singhal, Gaurav; Sinha, Santosh Kumar; Pandey, Umeshwar; Thakur, Ramesh; Varma, Chandra Mohan

    2015-10-01

    Ebstein anomaly (EA) is a rare congenital malformation of the tricuspid valve (TV), often associated with other cardiac malformations, especially atrial septal defect/patent foramen ovale (PFO) which is present in 80-90% of patients and predisposes to paradoxical embolization. We describe the case of a 17-year-old female, who presented with worsening exertional dyspnea, fatigue and pedal edema and atrial fibrillation (AF). Transthoracic echocardiography showed EA with severely dilated right atrium (RA), small functional right ventricle (RV), low velocity flow across TV with spontaneous echo contrast and giant clot in RA. Fortunately for the patient, contrast and transesophageal echocardiography revealed an intact interatrial septum with no PFO preventing any paradoxical embolism from large clot in RA, more so in the background of AF. Important differential diagnosis of congenitally unguarded TV orifice was ruled out due to presence of septal and anterior leaflets of TV and associated chordae.

  13. Phasic Compression of Left Circumflex Coronary Artery during Atrial Systole.

    PubMed

    Roberto, Edward Samuel; Agarwal, Ajay

    2017-04-01

    Phasic coronary artery compression is typically associated with spasm or myocardial bridging. Compression caused by acquired anatomic changes to the surrounding heart chambers has been reported only infrequently. We present a possibly unique case of phasic compression of the proximal left circumflex coronary artery during atrial contraction in association with a dilated left atrium. A 55-year-old man with multiple cardiac risk factors presented with worsening exertional dyspnea. An electrocardiogram and echocardiogram revealed marked left atrial dilation and a left ventricular ejection fraction of 0.15 to 0.20 with elevated filling pressures. Angiograms showed compression of the proximal segment of the left circumflex coronary artery during late ventricular diastole: the compression occurred in phase with atrial systole, whereas good flow without compression was present during atrial diastole. We attributed this phenomenon to ballooning of the lateral region of the atrial wall toward the atrioventricular groove during atrial systole. The patient complied with antihypertensive therapy, and his status improved after one year. To identify coronary artery compression in the presence of abnormal chamber geometry and to guide the treatment of the contributing medical conditions, we recommend careful analysis of angiographic results.

  14. A new atrial septostomy technique.

    PubMed

    Park, S C; Zuberbuhler, J R; Neches, W H; Lenox, C C; Zoltun, R A

    1975-01-01

    Balloon atrial septostomy is usually ineffective if the atrial septum is thickened. A technique for incising the atrial septum is described. A no. 6 French catheter was modified to enclose a tiny surgical blade. The distal end of the blade was pivoted to the catheter tip, and the proximal end was attached to a guide wire in the catheter lumen. Advancing the guide wire protruded the blade through a slit in the long axis of the tip of the catheter. Atrial septostomy was performed in five newborn lambs in vivo and in adult dog hearts and human hearts in vitro by advancing the catheter tip across the atrial septum with the blade retracted and withdrawing it to the right atrium with the blade extended. Eight to 12 mm lacerations of the atrial septum were produced and could be extended by subsequent balloon septostomy. The technique may be useful when balloon septostomy has been ineffective.

  15. α-Adrenoceptor blockade modifies neurally induced atrial arrhythmias

    PubMed Central

    Richer, Louis-Philippe; Vinet, Alain; Kus, Teresa; Cardinal, René; Ardell, Jeffrey L.; Armour, John Andrew

    2008-01-01

    Our objective was to determine whether neuronally induced atrial arrhythmias can be modified by α-adrenergic receptor blockade. In 30 anesthetized dogs, trains of five electrical stimuli (1 mA; 1 ms) were delivered immediately after the P wave of the ECG to mediastinal nerves associated with the superior vena cava. Regional atrial electrical events were monitored with 191 atrial unipolar electrodes. Mediastinal nerve sites were identified that reproducibly initiated atrial arrhythmias. These sites were then restimulated following 1 h (time control, n = 6), or the intravenous administration of naftopidil (α1-adrenergic blocker: 0.2 mg/kg, n = 6), yohimbine (α2-adrenergic blocker: 1 mg/kg, n = 6) or both (n = 8). A ganglionic blocker (hexamethonium: 1 mg/kg) was tested in four dogs. Stimulation of mediastinal nerves sites consistently elicited atrial tachyarrhythmias. Repeat stimulation after 1 h in the time-control group exerted a 19% decrease of the sites still able to induce atrial tachyarrhythmias. Hexamethonium inactivated 78% of the previously active sites. Combined α-adrenoceptor blockade inactivated 72% of the previously active sites. Bradycardia responses induced by mediastinal nerve stimulation were blunted by hexamethonium, but not by α1,2-adrenergic blockade. Naftopidil or yohimbine alone eliminated atrial arrhythmia induction from 31% and 34% of the sites (similar to time control). We conclude that heterogeneous activation of the intrinsic cardiac nervous system results in atrial arrhythmias that involve intrinsic cardiac neuronal α-adrenoceptors. In contrast to the global suppression exerted by hexamethonium, we conclude that α-adrenoceptor blockade targets intrinsic cardiac local circuit neurons involved in arrhythmia formation and not the flow-through efferent projections of the cardiac nervous system. PMID:18716036

  16. Convergent evolutionary reduction of atrial septation in lungless salamanders.

    PubMed

    Lewis, Zachary R; Hanken, James

    2017-01-01

    Nearly two thirds of the approximately 700 species of living salamanders are lungless. These species respire entirely through the skin and buccopharyngeal mucosa. Lung loss dramatically impacts the configuration of the circulatory system but the effects of evolutionary lung loss on cardiac morphology have long been controversial. For example, there is presumably little need for an atrial septum in lungless salamanders due to the absence of pulmonary veins and the presence of a single source of mixed blood flowing into the heart, but whether lungless salamanders possess an atrial septum and whether the sinoatrial aperture is located in the left or right atrium are unresolved; authors have stated opposing claims since the late 1800s. Here, we use micro-computed tomography (μ-CT) imaging, gross dissection and histological reconstruction to compare cardiac morphology among lungless plethodontid salamanders (Plethodontidae), salamanders with lungs, and the convergently lungless species Onychodactylus japonicus (Hynobiidae). Plethodontid salamanders have partial atrial septa and incomplete separation of the atrium into left and right halves. Partial septation is also seen in O. japonicus. Hence, lungless salamanders from two lineages convergently evolved similar morphology of the atrial septum. The partial septum in lungless salamanders can make it appear that the sinoatrial aperture is in the left atrium, but this interpretation is incorrect. Outgroup comparisons demonstrate that the aperture is located in a posterodorsal extension of the right atrium into the left side of the heart. Independent evolutionary losses of the atrial septum may have a similar developmental basis. In mammals, the lungs induce formation of the atrial septum by secreting morphogens to neighboring mesenchyme. We hypothesize that the lungs induce atrial septum development in amphibians in a similar fashion to mammals, and that atrial septum reduction in lungless salamanders is a direct result

  17. Multimodality imaging for patient evaluation and guidance of catheter ablation for atrial fibrillation - current status and future perspective.

    PubMed

    Bhagirath, P; van der Graaf, A W M; Karim, R; van Driel, V J H M; Ramanna, H; Rhode, K S; de Groot, N M S; Götte, M J W

    2014-08-20

    Left atrial catheter ablation is an established non-pharmacological therapy for the treatment of atrial fibrillation. The importance of a noninvasive multimodality imaging approach is emphasized by the current guidelines for the various phases of the ablation work-up e.g. patient identification, therapy guidance and procedural evaluation. Advances in the capabilities of imaging modalities and the increasing cost of healthcare warrant a review of the multimodality approach. This review discusses the application of cardiac imaging for pulmonary vein and left atrial ablation divided into stages: pre-procedural stage (assessment of left atrial dimensions, left atrial appendage thrombus and pulmonary vein anatomy), peri-procedural stage (integration of anatomical and electrical information) and post-procedural stage (evaluation of efficacy by assessment of tissue properties). Each section is dedicated to one of the subtopics of a stage, allowing a thorough comparison to be made between the strengths and weaknesses of the different imaging modalities and the identification of one that exhibits the potential for a single technique approach.

  18. Atrial fibrillation in the elderly

    PubMed Central

    Franken, Roberto A.; Rosa, Ronaldo F.; Santos, Silvio CM

    2012-01-01

    This review discusses atrial fibrillation according to the guidelines of Brazilian Society of Cardiac Arrhythmias and the Brazilian Cardiogeriatrics Guidelines. We stress the thromboembolic burden of atrial fibrillation and discuss how to prevent it as well as the best way to conduct cases of atrial fibrillatios in the elderly, reverting the arrhythmia to sinus rhythm, or the option of heart rate control. The new methods to treat atrial fibrillation, such as radiofrequency ablation, new oral direct thrombin inhibitors and Xa factor inhibitors, as well as new antiarrhythmic drugs, are depicted. PMID:22916053

  19. Racial Differences in Atrial Fibrillation Prevalence and Left Atrial Size

    PubMed Central

    Marcus, Gregory M.; Olgin, Jeffrey E.; Whooley, Mary; Vittinghoff, Eric; Stone, Katie L.; Mehra, Reena; Hulley, Stephen B.; Schiller, Nelson B.

    2010-01-01

    BACKGROUND Previous studies relying on clinical care data have suggested that atrial fibrillation is less common in African Americans than Caucasians, but the mechanism remains unknown. Clinical care may itself vary by race, potentially affecting the accuracy of atrial fibrillation ascertainment in studies relying on clinical data. We sought to examine racial differences in atrial fibrillation prevalence determined by protocol-driven electrocardiograms (ECGs) obtained in prospective cohort studies and to study racial differences in echocardiographic characteristics. METHODS We pooled primary data from 3 cohort studies with atrial fibrillation adjudicated from study protocol ECGs and documentation of potentially important confounders: the Heart and Soul Study (n = 1014), the Heart and Estrogen-Progestin Replacement Study (n = 2673), and The Osteoporotic Fractures in Men Sleep Study (n = 2911). Left atrial anatomic dimensions were compared among races from sinus rhythm echocardiograms in the Heart and Soul Study. RESULTS Of the 6611 participants, 268 (4%) had atrial fibrillation: Caucasians had the highest prevalence (5%), and African Americans had the lowest (1%; P <.001 for each compared with all other races). After adjustment for potential confounders, Caucasians had a 3.8-fold greater odds of having atrial fibrillation than African Americans (95% confidence interval, 1.6–8.8, P = .002). Although ventricular and atrial volumes and function were similar in Caucasians and African Americans, Caucasians had a 2 mm larger anterior-posterior left atrial diameter after adjusting for potential confounders (95% confidence interval, 1–3 mm, P <.001). CONCLUSION ECG confirmed atrial fibrillation is more common in Caucasians than in African Americans, which might be related to the larger left atrial diameter observed in Caucasians. PMID:20227049

  20. Impact of baseline atrial fibrillation cycle length on acute and long-term outcome of persistent atrial fibrillation ablation.

    PubMed

    Ammar, S; Hessling, G; Paulik, M; Reents, T; Dillier, R; Buiatti, A; Semmler, V; Kolb, C; Haller, B; Deisenhofer, I

    2014-12-01

    A short baseline atrial fibrillation (AF) cycle length (CL) has been associated with a worse outcome after catheter ablation for AF, whereas the impact of a long baseline AFCL is unknown. We investigated the influence of AFCL on acute and long-term success in a large series of patients undergoing catheter ablation for persistent AF. Overall, 177 consecutive patients undergoing catheter ablation of persistent AF using a sequential ablation approach were included in the analysis. AFCL was measured in the left atrial appendage (LAA) at baseline and following each ablation step. The primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs (AAD) with a single ablation procedure after 12 months. Mean AFCL was 164 ± 24 ms. A shorter AFCL was associated with longer AF duration, larger LA diameter, and longer procedure duration. Termination to sinus rhythm (SR) was achieved in 57 (32 %) patients. Baseline AFCL was shorter (161 ± 24 ms) in patients without AF termination compared to patients with AF termination (169 ± 23 m, p = 0.03). The primary endpoint was reached less frequently in patients with a short (<155 ms) AFCL (18 vs. 38.5 %, p = 0.006). Patients with an AFCL between 155 and 200 ms had the best outcome compared to patients with AFCL <155 or ≥200 ms (40 vs. 18 %, p = 0.003). Patients with a baseline AFCL between 155 and 200 ms have the best outcome after a single ablation procedure for persistent AF compared to patients with an AFCL of <155 or ≥200 ms.

  1. Canonical Wnt signalling regulates epithelial patterning by modulating levels of laminins in zebrafish appendages.

    PubMed

    Nagendran, Monica; Arora, Prateek; Gori, Payal; Mulay, Aditya; Ray, Shinjini; Jacob, Tressa; Sonawane, Mahendra

    2015-01-15

    The patterning and morphogenesis of body appendages - such as limbs and fins - is orchestrated by the activities of several developmental pathways. Wnt signalling is essential for the induction of limbs. However, it is unclear whether a canonical Wnt signalling gradient exists and regulates the patterning of epithelium in vertebrate appendages. Using an evolutionarily old appendage - the median fin in zebrafish - as a model, we show that the fin epithelium exhibits graded changes in cellular morphology along the proximo-distal axis. This epithelial pattern is strictly correlated with the gradient of canonical Wnt signalling activity. By combining genetic analyses with cellular imaging, we show that canonical Wnt signalling regulates epithelial cell morphology by modulating the levels of laminins, which are extracellular matrix components. We have unravelled a hitherto unknown mechanism involved in epithelial patterning, which is also conserved in the pectoral fins - evolutionarily recent appendages that are homologous to tetrapod limbs.

  2. The dynamics of spin stabilized spacecraft with movable appendages, part 1

    NASA Technical Reports Server (NTRS)

    Bainum, P. M.; Sellappan, R.

    1975-01-01

    The motion and stability of spin stabilized spacecraft with movable external appendages are treated both analytically and numerically. The two basic types of appendages considered are: (1) a telescoping type of varying length and (2) a hinged type of fixed length whose orientation with respect to the main part of the spacecraft can vary. Two classes of telescoping appendages are considered: (a) where an end mass is mounted at the end of an (assumed) massless boom; and (b) where the appendage is assumed to consist of a uniformly distributed homogeneous mass throughout its length. For the telescoping system Eulerian equations of motion are developed. During all deployment sequences it is assumed that the transverse component of angular momentum is much smaller than the component along the major spin axis. Closed form analytical solutions for the time response of the transverse components of angular velocities are obtained when the spacecraft hub has a nearly spherical mass distribution.

  3. The atrial natriuretic factor.

    PubMed Central

    Genest, J

    1986-01-01

    In less than three years since the rapid and potent natriuretic response to intravenous injection of atrial myocardial extract in rats was reported the factor responsible for the diuretic, natriuretic, and vasodilating activity of the atrial homogenates was isolated, its chemical structure elucidated, and its total synthesis achieved. Also the cDNA and the gene encoding for the atrial natriuretic factor in mice, rats, and man have been cloned and the chromosomal site identified. The major effects of this hormone are vasodilatation, prevention and inhibition of the contraction induced by noradrenaline and angiotensin II, diuresis, and natriuresis associated in most instances with a pronounced increase in glomerular filtration rate and filtration fraction, inhibition of aldosterone secretion, and considerable stimulation of particulate guanylate cyclase activity. High density specific binding sites have been demonstrated in the zona glomerulosa of the adrenal cortex, in the renal glomeruli, and in the collecting ducts, and in the brain areas involved in the regulation of blood pressure and of sodium and water (AV3V region, subfornical organ, nucleus tractus solitarius, area postrema). Images Fig 1 Fig 5 PMID:2945572

  4. Reentry and atrial fibrillation.

    PubMed

    Atienza, Felipe; Jalife, José

    2007-03-01

    The mechanisms of human atrial fibrillation (AF) are poorly understood. Experimental studies have demonstrated that cholinergic AF in the sheep heart is maintained by high-frequency reentrant sources (drivers) that result in a consistent left-to-right frequency gradient. More recently, clinical studies have confirmed the existence of a hierarchical organization in the rate of activation of different regions in the atria of patients with paroxysmal and chronic AF. Although maximal dominant-frequency sites were found to play a crucial role in the maintenance of AF in some patients, whether AF drivers in humans are focal or reentrant and whether changes in driver activity alter spatial frequency gradients are unclear. To test the hypothesis that localized functional reentry maintains AF in humans, we determined the effects of adenosine infusion on local dominant frequency at different sites of both atria. In patients with paroxysmal AF, adenosine infusion increases local dominant frequencies, particularly at the pulmonary vein-left atrial junction region, amplifying a left-to-right frequency gradient. In patients with chronic AF, dominant frequency is significantly higher than in patients with paroxysmal AF in all atrial regions surveyed, with the highest adenosine increase of frequencies outside the pulmonary vein region. Adenosine-induced driver acceleration is strongly suggestive of a reentrant mechanism in both groups of AF patients.

  5. Attitude stability of a spinning spacecraft during appendage deployment/retraction

    NASA Technical Reports Server (NTRS)

    Fitz-Coy, Norman; Fullerton, Wayne

    1994-01-01

    The work presented is motivated by the need for a national satellite rescue policy, not the ad hoc policy now in place. In studying different approaches for a national policy, the issue of capture and stabilization of a tumbling spacecraft must be addressed. For a rescue mission involving a tumbling spacecraft, it may be advantageous to have a rescue vehicle which is compact and 'rigid' during the rendezvous/capture phase. After capture, passive stabilization techniques could be utilized as an efficient means of detumbling the resulting system (i.e., both the rescue vehicle and captures spacecraft). Since the rescue vehicle is initially compact and 'rigid,' significant passive stabilization through energy dissipation can only be achieved through the deployment of flexible appendages. Once stabilization is accomplished, retraction of the appendages before maneuvering the system to its final destination may also prove advantageous. It is therefore of paramount interest that we study the effect of appendage deployment/retraction on the attitude stability of a spacecraft. Particular interest should be paid to appendage retraction, since if this process is destabilizing, passive stabilization as proposed may not be useful. Over the past three decades, it has been an 'on-again-off-again affair' with the problem of spacecraft appendage deployment. In most instances, these studies have been numerical simulations of specific spacecraft configurations for which there were specific concerns. The primary focus of these studies was the behavior of the appendage during deployment; the effects of appendage retraction was considered only in one of these studies. What is missing in the literature is a thorough study of the effects of appendage deployment/retraction on the attitude stability of a spacecraft. This paper presents a rigorous analysis of the stability of a spinning spacecraft during the deployment or the retraction of an appendage. The analysis is simplified such that

  6. The eggshell of the almond wasp Eurytoma amygdali (Hymenoptera, Eurytomidae) - 2. The micropylar appendage.

    PubMed

    Zarani, F E; Margaritis, L H

    1994-08-01

    Micropylar apparatuses in insects are specialized regions of the eggshell through which sperm enters the oocyte. This work is an ultrastructural study and deals with the structure and morphogenesis of the micropylar appendage in the hymenopteran Eurytoma amygdali. The micropylar appendage is a 130 microm long cylindrical protrusion located at the posterior pole of the egg, unlike other insects i.e. Diptera. in which the micropylar apparatus is located at the anterior pole. In mature eggs there is a 0.4 microm wide pore (micropyle) at the tip of the appendage leading to a 6 microm wide micropylar canal. The canal contains an electron-lucent substance, it travels along the whole appendage and finally reaches the vitelline membrane of the oocyte. The vitelline membrane is covered by a wax layer and an electron-lucent layer, whereas the chorion surrounding the canal consists of a granular layer (fine and rough) and a columnar layer. The morphogenesis of the appendage starts in immature follicles: four central cells located at the posterior tip of the oocyte near the vitelline membrane, differing morphologically from the adjacent follicle cells. These central cells degenerate during early chorionic stages, thus assisting in the formation of the micropylar canal. The adjacent, peripherally located cells secrete the electron-lucent substance which fills the canal and at the same time, the fine granular layer is formed starting from the base towards the tip of the appendage. The secretion persists at late chorionic stages and results in the formation of the chorion around the micropylar canal. The extremely long (compared to other insects) micropylar appendage seems to facilitate the egg passage through the very thin and long ovipositor. The structure and morphogenesis of this appendage differs significantly from the micropylar apparatuses studied so far in other insects i.e. Diptera, and may reflect adaptational and evolutionary relationships.

  7. Appendage modal coordinate truncation criteria in hybrid coordinate dynamic analysis. [for spacecraft attitude control

    NASA Technical Reports Server (NTRS)

    Likins, P.; Ohkami, Y.; Wong, C.

    1976-01-01

    The paper examines the validity of the assumption that certain appendage-distributed (modal) coordinates can be truncated from a system model without unacceptable degradation of fidelity in hybrid coordinate dynamic analysis for attitude control of spacecraft with flexible appendages. Alternative truncation criteria are proposed and their interrelationships defined. Particular attention is given to truncation criteria based on eigenvalues, eigenvectors, and controllability and observability. No definitive resolution of the problem is advanced, and exhaustive study is required to obtain ultimate truncation criteria.

  8. Clinical Applications of Biomarkers in Atrial Fibrillation.

    PubMed

    Chang, Kay-Won; Hsu, Jonathan C; Toomu, Avinash; Fox, Sutton; Maisel, Alan S

    2017-08-16

    While biomarkers have greatly impacted the diagnosis and management of myocardial infarction and heart failure, the use of biomarkers has been slow to permeate management of atrial fibrillation. Guideline recommendations on the use of biomarkers in atrial fibrillation were virtually non-existent until the 2016 European Society of Cardiology guidelines on atrial fibrillation offered a class IIb recommendation to consider using biomarkers such as high sensitivity troponin and natriuretic peptide to further refine stroke and bleeding risk in atrial fibrillation patients. Biomarker levels have been associated with incident atrial fibrillation, post-operative atrial fibrillation, acute atrial fibrillation, diagnosis of myocardial infarction and heart failure in atrial fibrillation, and prognosis in atrial fibrillation. This review will offer an in-depth survey of current evidence on the use of biomarkers in atrial fibrillation and propose clinical algorithms to aid the internist in using biomarkers in atrial fibrillation management. Copyright © 2017. Published by Elsevier Inc.

  9. Quantitative proteomics of changes in energy metabolism-related proteins in atrial tissue from valvular disease patients with permanent atrial fibrillation.

    PubMed

    Tu, Tao; Zhou, Shenghua; Liu, Zhenjiang; Li, Xuping; Liu, Qiming

    2014-01-01

     The modification of cardiac energy metabolism during atrial fibrillation (AF) has been demonstrated in previous studies, indicating a close association between these 2 processes. The aim of the present study was to identify the underlying mechanisms via profiling of the expression of energy metabolism-related proteins in the left atrial appendage (LAA) of patients with AF.  Isobaric tag for relative and absolute quantification-coupled 2-D liquid chromatography-tandem mass spectrometry (iTRAQ-coupled 2-D LC-MS/MS) was used to profile the expression of energy metabolism-related proteins in the LAA from valvular disease patients with sinus rhythm (SR; n=6) and AF (n=8). Using ProteinPilot 4.0, 122 energy metabolism-related proteins, consisting of 39 carbohydrate metabolism-related proteins, 22 proteins involved in lipid metabolism, 49 biological oxidation-related proteins and 12 other kinds of proteins, were identified. Most of them were key enzymes involved in energy metabolism. Moreover, most of the proteins that were expressed differently in the LAA between the AF and SR patients, and which were related to energy metabolism, were downregulated. These results were further validated on western blot.  Atrial myocardium energy production in valvular disease patients is impaired during permanent AF, and this impairment in energy production may be involved in the matrix of AF formation. 

  10. [Catheter ablation of atrial flutter and paroxysmal atrial fibrillation].

    PubMed

    Márquez, Manlio F

    2003-01-01

    Radiofrequency catheter ablation has emerged as a curative therapy for atrial flutter based on studies demonstrating the role of the cavotricuspid isthmus. With a high rate of success and minimal complications, catheter ablation is the therapy of choice for patients with the common type of atrial flutter. Left atrial flutter, non-cavotricuspid isthmus dependent, and those associated with heart disease have a worst outcome with catheter ablation. Radiofrequency catheter ablation has also emerged as a curative therapy for paroxysmal atrial fibrillation based on studies demonstrating the role of triggering foci in the pulmonary veins for the initiation of atrial fibrillation. Catheter ablation is performed by a transseptal approach using radiofrequency energy at the ostium of each pulmonary vein. Mapping is guided by special catheters. Sequential radiofrequency applications eliminates or dissociates pulmonary vein muscle activity. Although complications exists, this is the only curative method for these patients.

  11. Regeneration versus scarring in vertebrate appendages and heart.

    PubMed

    Jaźwińska, Anna; Sallin, Pauline

    2016-01-01

    Injuries to complex human organs, such as the limbs and the heart, result in pathological conditions, for which we often lack adequate treatments. While modern regenerative approaches are based on the transplantation of stem cell-derived cells, natural regeneration in lower vertebrates, such as zebrafish and newts, relies predominantly on the intrinsic plasticity of mature tissues. This property involves local activation of the remaining material at the site of injury to promote cell division, cell migration and complete reproduction of the missing structure. It remains an unresolved question why adult mammals are not equally competent to reactivate morphogenetic programmes. Although organ regeneration depends strongly on the proliferative properties of cells in the injured tissue, it is apparent that various organismic factors, such as innervation, vascularization, hormones, metabolism and the immune system, can affect this process. Here, we focus on a correlation between the regenerative capacity and cellular specialization in the context of functional demands, as illustrated by appendages and heart in diverse vertebrates. Elucidation of the differences between homologous regenerative and non-regenerative tissues from various animal models is essential for understanding the applicability of lessons learned from the study of regenerative biology to clinical strategies for the treatment of injured human organs.

  12. Photodynamic Therapy and Skin Appendage Disorders: A Review

    PubMed Central

    Megna, Matteo; Fabbrocini, Gabriella; Marasca, Claudio; Monfrecola, Giuseppe

    2017-01-01

    Photodynamic therapy (PDT) is a noninvasive treatment that utilizes light treatment along with application of a photosensitizing agent. In dermatology, PDT is commonly used and approved for the treatment of oncological conditions such as actinic keratosis, Bowen disease and superficial basal cell carcinoma. In the last 2 decades however, PDT has also been used for the treatment of several nonneoplastic dermatological diseases. The present review summarizes published data on PDT application in skin appendage disorders. Our literature review shows that: (a) PDT may be a suitable treatment for acne, folliculitis decalvans, hidradenitis suppurativa, nail diseases, and sebaceous hyperplasia; (b) there is a lack of agreement on PDT features (type, concentrations and incubation period of used substances, number and frequency of PDT sessions, optimal parameters of light sources, and patient characteristics [e.g., failure to previous treatments, disease severity, body surface area involved, etc.] which should guide PDT use in these diseases); (c) further research is needed to establish international guidelines helping dermatologists to choose PDT for the right patient at the right time. PMID:28232927

  13. Regulated deployment mechanism for a panel like appendage

    NASA Astrophysics Data System (ADS)

    Bueno, José Ignacio; Vázquez, Javier; Gavira, José Manuel; Migliorero, Gerard

    2001-09-01

    The definition of a cost effective deployment mechanism to deploy 180° panel like appendages in a safe way and with minimum end stroke deployment shock has been a challenge that led the design to achieve a low cost, light, compact, simple, flexible, modular, and low power demanding configuration. This mechanism is composed of an active hinge, that includes an optimised helical torsion spring with a deployment regulator in parallel, and a passive hinge, that includes the end stop and the monitorisation. The main functions of the mechanisms are decoupled in order to make the mechanism as flexible as possible to be adapted to very different needs such as different deployment torque, deployment angle, stiffness, interfaces, monitorisation, etc. The deployment mechanism is provided with a very compact novel deployment regulator based on the progressive melting of a band made of a low melting temperature metal alloy, that is cylindrically disposed. The deployment mechanism has been subject to a qualification test campaign including an extensive characterisation of the deployment regulator.

  14. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... Dictionary of Medical Words En Español What Other Kids Are Reading 7 Videos: Kids Talk About Life Video: Am I Normal? (Girls ... Train Your Temper Atrial Septal Defect KidsHealth > For Kids > Atrial Septal Defect Print A A A What's ...

  15. The effect on the efferent vagal nerves to the heart of stimulating atrial receptors in the dog.

    PubMed

    Walters, G E; Mary, D A

    1986-10-01

    In chloralose-anaesthetized dogs, distension of small balloons at the pulmonary vein-atrial junctions to stimulate atrial receptors with myelinated vagal afferent nerves causes an increase in heart rate but does not influence the activity in efferent vagal cardiac nerves. However, distension of these small balloons also stimulates atrial receptors with non-myelinated vagal and sympathetic afferent nerves, which are thought to affect the heart rate and activity in efferent vagal cardiac nerves. In the present investigation, seven dogs anaesthetized with chloralose were studied by distension of small balloons at the pulmonary vein-atrial junctions and in the left atrial appendage, and by graded cooling of the vagal nerves in the neck; cooling to 9 degrees C was used to prevent the increase in activity in myelinated vagal afferent nerves to distension of the small balloons and cooling to 0 degree C was used to prevent responses to the distension in all vagal afferent nerves. Eleven vagal efferent nerve fibers were studied which responded to stimulation of carotid baroreceptors and chemoreceptors. Distension of the small balloons did not affect the activity in these eleven efferent vagal nerve fibres, with the vagi at 37 degrees C or during vagal cooling to 9 degrees C or to 0 degree C. The results indicate that upon distension of the small balloons, none of the three types of atrial receptor influence the activity in efferent vagal cardiac nerves. The results support the conclusion that stimulation of atrial receptors with myelinated vagal afferent nerves, responsible for the reflex increase in heart rate, does not influence the activity in efferent vagal cardiac nerves.

  16. The Left Atrio-Vertebral Ratio: a new simple means for assessing left atrial enlargement on Computed Tomography.

    PubMed

    Montillet, Marie; Baqué-Juston, Marie; Tasu, Jean-Pierre; Bertrand, Sandra; Berthier, Frédéric; Zarqane, Naïma; Brunner, Philippe

    2017-09-27

    The purpose of this study is to describe a new method to quickly estimate left atrial enlargement (LAE) on Computed Tomography. Left atrial (LA) volume was assessed with a 3D-threshold Hounsfield unit detection technique, including left atrial appendage and excluding pulmonary venous confluence, in 201 patients with ECG-gated 128-slice dual-source CT and indexed to body surface area. LA and vertebral axial diameter and area were measured at the bottom level of the right inferior pulmonary vein ostium. Ratio of LA diameter and surface on vertebra (LAVD and LAVA) were compared to LA volume. In accordance with the literature, a cutoff value of 78 ml/m(2) was chosen for maximal normal LA volume. 18% of LA was enlarged. The best cutoff values for LAE assessment were 2.5 for LAVD (AUC: 0.65; 95% CI: 0.58-0.73; sensitivity: 57%; specificity: 71%), and 3 for LAVA (AUC: 0.78; 95% CI: 0.72-0.84; sensitivity: 67%; specificity: 79%), with higher accuracy for LAVA (P=0.015). Inter-observer and intra-observer variability were either good or excellent for LAVD and LAVA (respective intraclass coefficients: 0.792 and 0.910; 0.912 and 0.937). A left atrium area superior to three times the vertebral area indicates LAE with high specificity. • Left atrial enlargement is a frequent condition associated with poor cardiac outcome. • Left atrial enlargement is highly time-consuming to diagnose on CT. • The left atrio-vertebral ratio quickly assesses left atrial enlargement. • A left atrial area > three times vertebral area is highly specific.

  17. Non-Pharmacologic Approach to Prevent Embolization in Patients with Atrial Fibrillation in Whom Anticoagulation is Contraindicated

    PubMed Central

    Sharma, Munish; Khalighi, Koroush

    2017-01-01

    Ischemic stroke is the most common complication of atrial fibrillation (AF). Anticoagulation therapy reduces the risk of systemic embolization in almost all patients with AF irrespective of the type of AF (paroxysmal, persistent or permanent). But, all patients are not suitable candidates for systemic anticoagulation mainly due to the risk of bleeding. Left atrial appendage closure (LAAC) devices have been found to be very effective non-pharmacologic alternative therapy for such patients. There are various types of LAAC devices but United States Food and Drug Administration (US-FDA) have approved only Watchman device. Initially, bigger medical centers in the US had started the insertion of Watchman device but with improving procedural techniques and exciting outcomes, even the community-based hospitals have started to embrace this therapy. We have presented the first three cases of Watchman device placement performed in our hospital and discussed about the indications for placement of LAAC devices. We have also reviewed their efficacy individually. PMID:28243428

  18. Five years of keeping a watch on the left atrial appendage—how has the WATCHMAN fared?

    PubMed Central

    Jazayeri, Mohammad-Ali; Vuddanda, Venkat; Parikh, Valay; Lavu, Madhav; Atkins, Donita; Reddy, Y. Madhu; Nath, Jayant

    2016-01-01

    Left atrial appendage closure (LAAC) is a promising site-directed therapy for stroke prevention in patients with non-valvular atrial fibrillation (AF) who are ineligible or contraindicated for long-term oral anticoagulation. A variety of LAAC modalities are available, including percutaneous endocardial occluder devices such as WATCHMANTM (Boston Scientific Corp., Marlborough, MA, USA), and an ever-increasing body of evidence is helping to define the optimal use of each technique. Similarly increased experience with LAAC has revealed challenges such as device-related thrombi and peri-device leaks for which the long-term significance and appropriate management are areas of active investigation. We review the evolution and long-term outcomes with the WATCHMANTM device with particular emphasis on the nuances of its use and its role in the broader landscape of appendageology. PMID:28149625

  19. The polyuria of paroxysmal atrial tachycardia

    NASA Technical Reports Server (NTRS)

    Kinney, M. J.; Stein, R. M.; Discala, V. A.

    1974-01-01

    Two patients with paroxysmal atrial fibrillation and an associated polyuria were studied to delineate the mechanism of the increase in urine flow. A striking saluresis was noted in both patients. The increased sodium excretion was probably due to decreased sodium reabsorption, perhaps at proximal tubular nephron sites. This inhibition of sodium reabsorption could explain both the saluresis and some part or all of the polyuria. Re-evaluation of earlier case reports reveals patterns of concomitant salt and water excretion consistent with this mechanism. The saluresis cannot be explained by the previously favored hypothesis of antidiuretic hormone inhibition.

  20. The polyuria of paroxysmal atrial tachycardia

    NASA Technical Reports Server (NTRS)

    Kinney, M. J.; Stein, R. M.; Discala, V. A.

    1974-01-01

    Two patients with paroxysmal atrial fibrillation and an associated polyuria were studied to delineate the mechanism of the increase in urine flow. A striking saluresis was noted in both patients. The increased sodium excretion was probably due to decreased sodium reabsorption, perhaps at proximal tubular nephron sites. This inhibition of sodium reabsorption could explain both the saluresis and some part or all of the polyuria. Re-evaluation of earlier case reports reveals patterns of concomitant salt and water excretion consistent with this mechanism. The saluresis cannot be explained by the previously favored hypothesis of antidiuretic hormone inhibition.

  1. [Stroke. are there any difference between patients with or without patent foramen ovale in left atrial appendage systolic function?].

    PubMed

    Contreras, Alejandro E; Perrote, Federico; Concari, Ignacio; Brenna, Eduardo J; Lucero, Cecilia

    2012-01-01

    Introducción: El objetivo del presente trabajo fue comparar la función sistólica de la orejuela de la aurícula izquierda (OAI) en un grupo de pacientes con y sin foramen oval permeable (FOP) quienes sufrieron eventos cerebrovasculares isquémicos. Material y métodos: Entre septiembre de 2010 y octubre de 2011, 17 pacientes fueron enviados para la realización de un ecocardiograma transesofágico (ETE) por haber sufrido un accidente cerebrovascular (ACV). Se definió FOP al pasaje de al menos una burbuja a través del septum interauricular con test de burbujas. Se comparó la velocidad sistólica en la orejuela entre los pacientes con y sin FOP y con un grupo control. Resultados: Fueron 8 mujeres y 9 hombres, con una edad media de 54,1 ± 19,5 años. Todos los pacientes habían sufrido un evento cerebrovascular isquémico, el 41,2% habían tenido ACV, el 52,9% crisis isquémica transitoria y el 5,9% amaurosis fugaz. En la evaluación con ETE, el 11,8% tuvo aneurisma del septum interauricular y el 35,3% FOP. La velocidad sistólica media de la OAI fue 66,3 ± 20,3 cm/seg. No hubo diferencia en la velocidad sistólica de la OAI entre pacientes con o sin FOP (67,5 ± 11,8 cm/seg vs 65,7 ± 24,3 cm/seg respectivamente, p= 0,87). El grupo control compuesto por 8 pacientes, 5 mujeres y 3 hombres, con una edad media de 39,5 ± 18 años, tuvo una velocidad sistólica de la OAI de 77,6 ± 28,9 cm/seg, sin diferencias significativas con los pacientes isquémicos. Conclusión: No hubo diferencias en la función sistólica de la OAI entre pacientes con y sin FOP con eventos cerebrovasculares isquemicos.

  2. Atrial Cardiopathy: A Broadened Concept of Left Atrial Thromboembolism Beyond Atrial Fibrillation

    PubMed Central

    Kamel, Hooman; Okin, Peter M.; Longstreth, W. T.; Elkind, Mitchell S.V.; Soliman, Elsayed Z.

    2016-01-01

    Atrial fibrillation (AF) has long been associated with a heightened risk of ischemic stroke and systemic thromboembolism, but recent data require a re-evaluation of our understanding of the nature of this relationship. New findings about the temporal connection between AF and stroke, alongside evidence linking markers of left atrial abnormalities with stroke in the absence of apparent AF, suggest that left atrial thromboembolism may occur even without AF. These observations undermine the hypothesis that the dysrhythmia that defines AF is necessary and sufficient to cause thromboembolism. In this commentary, we instead suggest that the substrate for thromboembolism may often be the anatomic and physiological atrial derangements associated with AF. Therefore, our understanding of cardioembolic stroke may be more complete if we shift our representation of its origin from AF to the concept of atrial cardiopathy. PMID:26021638

  3. Left Atrial Epicardial Adiposity and Atrial Fibrillation

    PubMed Central

    Batal, Omar; Schoenhagen, Paul; Shao, Mingyuan; Ayyad, Ala Eddin; Van Wagoner, David R.; Halliburton, Sandra S.; Tchou, Patrick J.; Chung, Mina K.

    2010-01-01

    Background Atrial fibrillation (AF) has been linked to inflammatory factors and obesity. Epicardial fat is a source of several inflammatory mediators related to the development of coronary artery disease. We hypothesized that periatrial fat may have a similar role in the development of AF. Methods and Results Left atrium (LA) epicardial fat pad thickness was measured in consecutive cardiac CT angiograms performed for coronary artery disease or AF. Patients were grouped by AF burden: no (n=73), paroxysmal (n=60), or persistent (n=36) AF. In a short-axis view at the mid LA, periatrial epicardial fat thickness was measured at the esophagus (LA-ESO), main pulmonary artery, and thoracic aorta; retrosternal fat was measured in axial view (right coronary ostium level). LA area was determined in the 4-chamber view. LA-ESO fat was thicker in patients with persistent AF versus paroxysmal AF (P=0.011) or no AF (P=0.003). LA area was larger in patients with persistent AF than paroxysmal AF (P=0.004) or without AF (P<0.001). LA-ESO was a significant predictor of AF burden even after adjusting for age, body mass index, and LA area (odds ratio, 5.30; 95% confidence interval, 1.39 to 20.24; P=0.015). A propensity score–adjusted multivariable logistic regression that included age, body mass index, LA area, and comorbidities was also performed and the relationship remained statistically significant (P=0.008). Conclusions Increased posterior LA fat thickness appears to be associated with AF burden independent of age, body mass index, or LA area. Further studies are necessary to examine cause and effect, and if inflammatory, paracrine mediators explain this association. PMID:20504944

  4. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages.

    PubMed

    Turchyn, Nataliya; Chesebro, John; Hrycaj, Steven; Couso, Juan P; Popadić, Aleksandar

    2011-09-01

    Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila melanogaster (fruit fly). While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages

    PubMed Central

    Turchyn, Nataliya; Chesebro, John; Hrycaj, Steven; Couso, Juan P.; Popadić, Aleksandar

    2011-01-01

    Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila. While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects. PMID:21708143

  6. Microelectrode array measurement of potassium ion channel remodeling on the field action potential duration in rapid atrial pacing rabbits model.

    PubMed

    Sun, Juan; Yan, Huang; Wugeti, Najina; Guo, Yujun; Zhang, Ling; Ma, Mei; Guo, Xingui; Jiao, Changan; Xu, Wenli; Li, Tianqi

    2015-01-01

    Atrial fibrillation (AF) arises from abnormalities in atrial structure and electrical activity. Microelectrode arrays (MEA) is a real-time, nondestructive measurement of the resting and action potential signal, from myocardial cells, to the peripheral circuit of electrophysiological activity. This study examined the field action potential duration (fAPD) of the right atrial appendage (RAA) by MEA in rapid atrial pacing (RAP) in the right atrium of rabbits. In addition, this study also investigated the effect of potassium ion channel blockers on fAPD. 40 New Zealand white rabbits of either sex were randomly divided into 3 groups: 1) the control, 2) potassium ion channel blocker (TEA, 4-Ap and BaCl2), and 3) amiodarone groups. The hearts were quickly removed and right atrial appendage sectioned (slice thickness 500 μm). Each slice was perfused with Tyrode's solution and continuously stimulated for 30 minutes. Sections from the control group were superfused with Tyrode's solution for 10 minutes, while the blocker groups and amiodarone were both treated with their respective compounds for 10 minutes each. The fAPD of RAA and action field action potential morphology were measured using MEA. In non-pace (control) groups, fAPD was 188.33 ± 18.29 ms after Tyrode's solution superfusion, and 173.91 ± 6.83 ms after RAP. In pace/potassium ion channel groups, TEA and BaCl2 superfusion prolonged atrial field action potential (fAPD) (control vs blocker: 176.67 ± 8.66 ms vs 196.11 ± 10.76 ms, 182.22 ± 12.87 ms vs 191.11 ± 13.09 ms with TEA and BaCl2 superfusion, respectively, P < 0.05). 4-AP superfusion significantly prolonged FAPD. In pace/amiodarone groups, 4-Ap superfusion extended fAPD. MEA was a sensitive and stable reporter for the measurement of the tissue action potential in animal heart slices. After superfusing potassium ion channel blockers, fAPD was prolonged. These results suggest that Ito, IKur and IK1 remodel and mediate RAP-induced atrial electrical

  7. Uncontrolled ventricular rate in atrial fibrillation. A manifestation of dissimilar atrial rhythms.

    PubMed Central

    Leier, C V; Johnson, T M; Lewis, R P

    1979-01-01

    A patient with coarse atrial fibrillation and a rapid ventricular response developed periods of high grade atrioventricular block interpersed with periods of rapid ventricular conduction after the administration of digitalis and propranolol. Intracardiac atrial recordings showed similar atrial rhythms of high right atrial flutter and left atrial fibrillation. The low right atrial recordings showed flutter during the periods of fast ventricular rates and fibrillation during periods of slower ventricular rates. Images PMID:475927

  8. Atrial fibrillation in two jet pilots during aircrew periodical medical examination.

    PubMed

    Ozturk, Cengiz; Akin, Ahmet; Metin, Suleyman; Cakmak, Tolga; Sen, Ahmet

    2012-07-01

    Atrial fibrillation (AF) unfavorably affects cardiac output and may cause acute incapacitation in flight due to loss of the atrial systole, which mainly contributes to the diastolic filling of the ventricles. Although it is the most common type of arrhythmia, it is rare in pilots and not compatible with aviation. We present two AF cases incidentally detected in two jet pilots. The first case was a 39-yr-old male jet pilot with a lone AF. Since there was no structural abnormality or thrombus in the left atrial appendage on transesophageal echocardiography (TEE), the patient was converted to sinus rhythm via direct current cardioversion (DCC). The pilot returned to flying duties after a follow-up period without any recurrent arrhythmia. The second case was a 23-yr-old male jet pilot who had suffered six attacks of paroxysmal AF. Conversion to sinus rhythm was provided by DCC at once and the second via pharmacological cardioversion. Also, spontaneous conversion to sinus was observed during two attacks of AF during the follow-up period. There were no abnormalities on physical examination, echocardiography, and laboratory tests. Although the cardiac ablation procedure was applied, the patient couldn't be treated successfully. Thereafter the pilot was treated with sotalol and warfarin and was permanently disqualified from flying duties. Arrhythmia is among the frequent causes for aviators to be disqualified from flying duties. AF particularly should not be overlooked due to its potential for sudden incapacitation during flight via acute hypotension or thromboembolic events.

  9. [Perioperative management of atrial fibrillation].

    PubMed

    Arguis, M J; Navarro, R; Regueiro, A; Arbelo, E; Sierra, P; Sabaté, S; Galán, J; Ruiz, A; Matute, P; Roux, C; Gomar, C; Rovira, I; Mont, L; Fita, G

    2014-05-01

    Atrial fibrillation is a frequent complication in the perioperative period. When it appears there is an increased risk of perioperative morbidity due to stroke, thromboembolism, cardiac arrest, myocardial infarction, anticoagulation haemorrhage, and hospital readmissions. The current article focuses on the recommendations for the management of perioperative atrial fibrillation based on the latest Clinical Practice Guidelines on atrial fibrillation by the European Society of Cardiology and the Spanish Society of Cardiology. This article pays special attention to the preoperative management, as well as to the acute perioperative episode. For this reason, the latest recommendations for the control of cardiac frequency, antiarrhythmic treatment and anticoagulation are included.

  10. Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro.

    PubMed

    Grice, Jeffrey E; Ciotti, Susan; Weiner, Norman; Lockwood, Peter; Cross, Sheree E; Roberts, Michael S

    2010-02-01

    We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

  11. Segmental mismatch in crustacean appendages: the naupliar antennal exopod of Artemia (Crustacea, Branchiopoda, Anostraca).

    PubMed

    Maruzzo, Diego; Minelli, Alessandro; Fusco, Giuseppe

    2009-03-01

    Based on traditional techniques and confocal laser scanning microscopy for external morphology, and immunohistochemistry for the muscular system, we describe here the segmental features of the antennal exopod of Artemia nauplii. Two kinds of serial elements are present, i.e. setae (with cuticular folds at their base) and ringlets (serially arranged sclerites separated by joint-like cuticular folds not extending to form complete rings around the appendage). The two series are usually not in register. The cuticular folds of the setae and of the ringlets are also sites of intermediate insertions of the three exopod muscles: as the two tegumentary structures are discordant in periodicity, this is also mirrored in the pattern of muscle insertions on the two sides of the appendage. Similar cases of segmental mismatch are known for the trunk of several arthropods, but segmental mismatch along the appendages has received very little attention. The occurrence of segmental mismatch in the naupliar appendages of both extant and fossil crustaceans is reviewed and it is suggested here to be a primitive feature of the exopods of both second antennae and mandibles. Problems in the interpretation of morphological evidence are discussed, also in relation to development and evolution of segmentation of naupliar appendages.

  12. Input-Shaped Link Motion Control of Planar Space Robot Equipped with Flexible Appendage

    NASA Astrophysics Data System (ADS)

    Kasai, Shinya; Kojima, Hirohisa

    Control of a space robot without actuators on the main body is an underactuated control problem. Various stabilization methods, such as the time-varying feedback control method, discontinuous feedback control method, center manifold-based method, zero-dynamics method and sliding-mode control method have been proposed. However, past studies have not considered underactuated space robots equipped with a flexible appendage, such as solar panels. If the manipulators are simply controlled to achieve the target state for the robot using the past controllers without taking a flexible appendage into consideration, residual vibration remains even after the link motion has finished. In order to suppress the residual vibration on the flexible appendage, we apply the input-shaping technique to the link motion of an underactuated planar space robot. Numerical and experimental studies are carried out to validate the proposed method for a planar dual-link space robot with a flexible appendage. The results show that the proposed method is capable of not only controlling the link angles and the main body attitude to the goal angles, but also suppressing the residual vibration on the flexible appendage.

  13. Genomic determinants of epidermal appendage patterning and structure in domestic birds

    PubMed Central

    Boer, Elena F.; Van Hollebeke, Hannah F.; Shapiro, Michael D.

    2017-01-01

    Variation in regional identity, patterning, and structure of epidermal appendages contributes to skin diversity among many vertebrate groups, and is perhaps most striking in birds. In pioneering work on epidermal appendage patterning, John Saunders and his contemporaries took advantage of epidermal appendage diversity within and among domestic chicken breeds to establish the importance of mesoderm-ectoderm signaling in determining skin patterning. Diversity in chickens and other domestic birds, including pigeons, is driving a new wave of research to dissect the molecular genetic basis of epidermal appendage patterning. Domestic birds are not only outstanding models for embryonic manipulations, as Saunders recognized, but they are also ideal genetic models for discovering the specific genes that control normal development and the mutations that contribute to skin diversity. Here, we review recent genetic and genomic approaches to uncover the basis of epidermal macropatterning, micropatterning, and structural variation. We also present new results that confirm expression changes in two limb identity genes in feather-footed pigeons, a case of variation in appendage structure and identity. PMID:28347644

  14. Specialized appendages in fuxianhuiids and the head organization of early euarthropods.

    PubMed

    Yang, Jie; Ortega-Hernández, Javier; Butterfield, Nicholas J; Zhang, Xi-guang

    2013-02-28

    The organization of the head provides critical data for resolving the phylogenetic relationships and evolutionary history of extinct and extant euarthropods. The early Cambrian-period fuxianhuiids are regarded as basal representatives of stem-group Euarthropoda, and their anterior morphology therefore offers key insights for reconstructing the ancestral condition of the euarthropod head. However, the paired post-antennal structures in Fuxianhuia protensa remain controversial; they have been interpreted as both 'great appendages' and as gut diverticulae. Here we describe Chengjiangocaris kunmingensis sp. nov. and Fuxianhuia xiaoshibaensis sp. nov. from a new early Cambrian (Stage 3) fossil Lagerstätte in Yunnan, China. Numerous specimens of both species show a unique 'taphonomic dissection' of the anterodorsal head shield, revealing the cephalic organization in detail. We demonstrate the presence of a pair of specialized post-antennal appendages (SPAs) in the fuxianhuiid head, which attach at either side of the posteriorly directed mouth, behind the hypostome. Preserved functional articulations indicate a well-defined but restricted range of limb movement, suggestive of a simple type of sweep feeding. The organization of the SPAs in fuxianhuiids is incompatible with the (deutocerebral) anterior raptorial appendages of megacheirans, and argue against the presence of protocerebral limbs in the fuxianhuiids. The positions of the fuxianhuiid antennae and SPAs indicate that they are segmentally homologous to the deutocerebral and tritocerebral appendages of crown-group Euarthropoda respectively. These findings indicate that antenniform deutocerebral appendages with many podomeres are a plesiomorphic feature of the ancestral euarthropod head.

  15. Atrial fibrillation and heart failure: is atrial fibrillation a disease?

    PubMed

    Tilman, V

    2014-09-01

    Atrial fibrillation in heart failure often occur together. The relationship between atrial fibrillation and heart failure has remained a subject of research. The main manifestation of the violation of hydrodynamics in heart failure is the increased end-diastolic pressure, which is transmitted through the intercommunicated system (left ventricle-left atrium-pulmonary veins-alveolar capillaries) causing increased pulmonary wedge pressure with the danger for pulmonary edema. End-diastolic pressure is the sum of left ventricle diastolic pressure and left atrial systolic pressure. Stopping the mechanical systole of the left atrium can reduce the pressure in the system in heart failure. Atrial fibrillation stops the mechanical systole of the left atrium and decreases the intercommunicating pressure and pulmonary wedge pressure. It is possible that atrial fibrillation is a mechanism for protection from increasing end-diastolic pressure and pulmonary wedge pressure, and prevents the danger of pulmonary edema. This hypothesis may explain the relationship between heart failure and atrial fibrillation and their frequent association. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Limited ability to activate protein C confers left atrial endocardium a thrombogenic phenotype. A role in cardioembolic stroke?

    PubMed Central

    Cerveró, Jorge; Montes, Ramón; España, Francisco; Esmon, Charles T.; Hermida, José

    2011-01-01

    Background and Purpose Atrial fibrillation is the most important risk factor for cardioembolic stroke. Thrombi form in the left atrial appendage rather than in the right. The causes of this different thrombogenicity are not well understood. The goal herein was to compare the activation of the anticoagulant protein C as well as the thrombomodulin and endothelial protein C/activated protein C receptor (EPCR) expression on the endocardium between right and left atria. Methods We harvested the atria of six monkeys (Macaca fascicularis) and quantified their ability to activate protein C ex vivo and we measured the thrombomodulin and EPCR expression by immunofluorescence. Results We found the ability to activate protein C decreased by half (P= 0.028), and there was lower expression of thrombomodulin in the left atrial endocardium than the right (52.5±19.9 and 72.1±18.8 arbitrary intensity units, mean ± standard deviation, P= 0.028). No differences were detected in EPCR expression. Conclusions Impaired protein C activation on the left atrial endocardium, due to low thrombomodulin expression may explain its higher thrombogenicity and play a role in cardioembolic stroke. PMID:21700937

  17. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... wall called the septum that normally separates the blue and red blood. In a person with an atrial septal defect, there's an opening in that wall. This hole in the wall lets oxygen-rich blood from ...

  18. Ultrastructural observations on feeding appendages and gills of Alvinella pompejana (Annelida, Polychaeta)

    NASA Astrophysics Data System (ADS)

    Storch, V.; Gaill, F.

    1986-09-01

    The feeding appendages of Alvinella pompejana obtained from a deep-sea hydrothermal vent environment are described. They are characterized by a ciliated groove, the cells of which have a very distinctive ultrastructure, by groups of bipolar receptor cells and by several kinds of gland cells. Among these, one cell type is in an upside down position suggesting a function completely different from other epidermal secretory cells. The gills differ considerably from the feeding appendages on the basis of their ultrastructure. Their epidermis is very irregular in height; basal infoldings give the blood access to a space coming very near to the external medium. The blood vascular system is open. On the other hand, the gills of Amphicteis gunneri are not effective sites of gas exchange, since their columnar epithelium is underlain with muscle cells. The cells composing the feeding appendages and gills of Alvinella pompejana are characterized by ultrastructurally very different mitochondria.

  19. Skin appendage-derived stem cells: cell biology and potential for wound repair.

    PubMed

    Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

    2016-01-01

    Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

  20. Acute myocardial infarction caused by left atrial myxoma: Role of intracoronary catheter aspiration.

    PubMed

    Al-Fakhouri, Ahmad; Janjua, Muhammad; DeGregori, Michele

    2017-01-01

    Acute ST-segment elevation myocardial infarction (STEMI) caused by left atrial myxoma is very rare. Catheter-based approaches or thrombolytic therapy are mostly the first step in the management of STEMI with less time delay. We report a case of acute anterior/lateral STEMI caused by a left atrial myxoma. The patient was successfully treated by intracoronary aspiration with an Export aspiration catheter, with excellent distal coronary flow. Intracoronary catheter aspiration in acute myocardial infarction caused by a left atrial myxoma may help to salvage the infarcting myocardium with less time delay.

  1. Atrial fibrillation and anabolic steroids.

    PubMed

    Sullivan, M L; Martinez, C M; Gallagher, E J

    1999-01-01

    A young male bodybuilder, consuming large doses of anabolic steroids (AS), presented to the Emergency Department (ED) with symptomatic rapid atrial fibrillation (AF). Echocardiogram revealed significant septal hypokinesis, and posterior and septal wall thickness at the upper limit of normal for highly trained athletes. The atrial fibrillation had not recurred at 10 weeks after discontinuation of AS use. Consumption of these agents in athletes has been associated with hypertension, ischemic heart disease, hypertrophic cardiomyopathy, and sudden death.

  2. Neovascularization in Left Atrial Myxoma

    PubMed Central

    Dubey, Laxman; Chaurasia, Amit Kumar

    2012-01-01

    Abstract We report a case with a left atrial mass who underwent coronary angiography to rule out coronary artery disease. Coronary angiography revealed an anomalous tortuous vascular structure originating from the left circumflex coronary artery to the left atrial tumor suggestive of neovascularization. P