Ablation Of Chronic Atrial Fibrillation Research Articles

Use of Complex Fractionated Atrial Electrogram Mapping System in Mapping and Ablating the Atrial Flutter of a Transplanted Heart

Atrial flutter in donor part of orthotopic heart transplant has been reported and treated by radiofrequency ablation in the past. Complex fractionated atrial electrogram (CFE) mapping has been used to simplify the ablation of chronic atrial fibrillation. Here, we report a case with atrial flutter in an orthotopic heart transplant whose circuit mapping was difficult. Using CFE helped us to define the arrhythmia circuit easily and perform curative ablation.

Focal left septal atrial tachycardia with exit block following left atrial ablation of chronic atrial fibrillation

u r S q c r t T ntroduction trial tachycardia (AT) may occur following catheter ablation f atrial fibrillation (AF). Post-ablation AT is usually due to acroreentry, but may also be due to a focal mechanism, or small localized area of reentry. Whatever the mechanism, here is invariably 1:1 conduction from the site of origin or sthmus to the remaining atrial tissue. The purpose of this eport is to describe a focal tachycardia arising from the left trial septum with exit block to the rest of the atrium.

What have we learned about atrial arrhythmias from ablation of chronic atrial fibrillation?

Accelerated by the recognition of the role pulmonary veins (PVs) in the genesis of atrial fibrillation (AF), the last decade has witnessed marked progress in catheter ablation of AF.1 Several mechanistic and clinical studies provided important information on the mechanisms of chronic AF.

Characterization of Electrograms Associated With Termination of Chronic Atrial Fibrillation by Catheter Ablation

This study sought to determine the characteristics of atrial electrograms predictive of slowing or termination of atrial fibrillation (AF) during ablation of chronic AF. There is growing recognition of a role for electrogram-based ablation. Forty consecutive patients (34 male, 59 +/- 10 years) undergoing ablation for chronic AF persisting for a median of 12 months (range 1 to 84 months) were included. After pulmonary vein isolation and roof line ablation, electrogram-based ablation was performed in the left atrium and coronary sinus. Targeted electrograms were acquired in a 4-s window and characterized by: 1) percentage of continuous electrical activity; 2) bipolar voltage; 3) dominant frequency; 4) fractionation index; 5) mean absolute value of derivatives of electrograms; 6) local cycle length; and 7) presence of a temporal gradient of activation. Electrogram characteristics at favorable ablation regions, defined as those associated with slowing (a >or=6-ms increase in AF cycle length) or termination of AF were compared with those at unfavorable regions. The AF was terminated by electrogram-based ablation in 29 patients (73%) after targeting a total of 171 regions. Ablation at 37 (22%) of these regions was followed by AF slowing, and at 29 (17%) by AF termination. The percentage of continuous electrical activity and the presence of a temporal gradient of activation were independent predictors of favorable ablation regions (p = 0.016 and p = 0.038, respectively). Other electrogram characteristics at favorable ablation regions were not significantly different from those at unfavorable ablation regions. Catheter ablation at sites displaying a greater percentage of continuous activity or a temporal activation gradient is associated with slowing or termination of chronic AF.

Catheter ablation of chronic atrial fibrillation

Catheter ablation of chronic atrial fibrillation

Effects of Stepwise Ablation of Chronic Atrial Fibrillation on Atrial Electrical and Mechanical Properties

Effects of Stepwise Ablation of Chronic Atrial Fibrillation on Atrial Electrical and Mechanical Properties

Radiofrequency Catheter Ablation of Chronic Atrial Fibrillation Guided by Complex Electrograms

Radiofrequency Catheter Ablation of Chronic Atrial Fibrillation Guided by Complex Electrograms

Evolving Treatment Strategies for the Ablation of Chronic Atrial Fibrillation

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Catheter ablation of chronic atrial fibrillation

Catheter ablation of chronic atrial fibrillation

Ablation of chronic atrial fibrillation

Although several studies suggested equivalent outcome for pharmacologic rhythm and rate-control strategies in patients with atrial fibrillation (AF), substudies demonstrated that patients in sinus rhythm had lower mortality, but use of antiarrhythmic drugs significantly increased mortality.1 Therefore, restoration and maintenance of sinus rhythm without using antiarrhythmic drugs should lead to greater benefit for patients with chronic AF. Catheter ablation targeting the pulmonary veins (PVs) has evolved over the past decade and has become the treatment of choice for drug-resistant paroxysmal AF.

Trials and Travails of Electrogram-Guided Ablation of Chronic Atrial Fibrillation

Catheter-based ablation has revolutionized arrhythmia management by offering the most definitive treatment for virtually all types of tachyarrhythmias. The reasons behind the success of ablation are many, but chief among them is the ability of the electrophysiologist to identify underlying mechanisms and to precisely localize and eliminate the tachycardia foci or circuits. Armed with many new tools to map and ablate these arrhythmias, electrophysiologists gain experience and become more proficient in the procedure, resulting in a shortened procedure time, increased rates of success, and decreased rates of complications. As a result, catheter ablation is gradually but inexorably replacing pharmacological approach as the first-line therapy for just about all supraventricular tachyarrhythmias except atrial fibrillation (AF). Article p 2606 Unlike ablation for other types of supraventricular tachyarrhythmias, ablation of AF generally is not based on mapping of target sites for ablation; rather, it relies largely on an approach that aims to electrically isolate the pulmonary veins, especially for paroxysmal AF.1–4 The rational behind this anatomic approach is 2-fold: that the pulmonary veins are the primary sites responsible for AF initiation and perpetuation in most patients and that human AF is too complex to map and the responsible reentrant wavelets are too capricious for point-to-point mapping. However, although pulmonary vein isolation is very successful in treating paroxysmal AF, it alone is not effective in treating chronic AF. Often, supplement linear ablations are added to the pulmonary vein isolation with a significantly improved success rate.1 It has become clear that to successfully ablate chronic AF, more extensive ablations are essential, but it remains unclear why and how this combined approach works. It is possible that the multiple linear lesions (ie, a mitral isthmus line, roofline) in addition to pulmonary vein isolation effectively modify AF substrate akin to a surgical Maze procedure. However, …

Radiofrequency Catheter Ablation of Chronic Atrial Fibrillation Guided by Complex Electrograms

Radiofrequency catheter ablation of atrial fibrillation (AF) guided by complex fractionated atrial electrograms has been reported to eliminate AF in a large proportion of patients. However, only a small number of patients with chronic AF have been included in previous studies. In 100 patients (mean age, 57+/-11 years) with chronic AF, radiofrequency ablation was performed to target complex fractionated atrial electrograms at the pulmonary vein ostial and antral areas, various regions of the left atrium, and the coronary sinus until AF terminated or all identified complex fractionated atrial electrograms were eliminated. Ablation sites consisted of > or = 1 pulmonary vein in 46% of patients; the left atrial septum, roof, or anterior wall in all; and the coronary sinus in 55%. During 14+/-7 months of follow-up after a single ablation procedure, 33% of patients were in sinus rhythm without antiarrhythmic drugs, 38% had AF, 17% had both AF and atrial flutter, 9% had persistent atrial flutter, and 3% had paroxysmal AF on antiarrhythmic drugs. A second ablation procedure was performed in 44% of patients. Pulmonary vein tachycardia was found in all patients in both previously targeted and nontargeted pulmonary veins. There were multiple macroreentrant circuits in the majority of patients with atrial flutter. At 13+/-7 months after the last ablation procedure, 57% of patients were in sinus rhythm without antiarrhythmic drugs, 32% had persistent AF, 6% had paroxysmal AF, and 5% had atrial flutter. Modest short-term efficacy is achievable with radiofrequency ablation of chronic AF guided by complex fractionated atrial electrograms, but only after a second ablation procedure in > 40% of patients. Rapid activity in the pulmonary veins and multiple macroreentrant circuits are common mechanisms of recurrent atrial arrhythmias.

Quantifying activation frequency in atrial fibrillation to establish underlying mechanisms and ablation guidance

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans. 1 Feinberg W.M. Blackshear J.L. Laupacis A. Kronmal R. Hart R.G. Prevalence, age distribution, and gender of patients with atrial fibrillation. Arch Intern Med. 1995; 155: 469-473 Crossref PubMed Scopus (1952) Google Scholar It also is the most common cardiac cause of stroke 2 Wolf P.A. Abbot R.D. Kannel W.B. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke. 1991; 22: 983-988 Crossref PubMed Scopus (5650) Google Scholar and can result in additional adverse outcomes. 3 Schumacher B. Luderitz B. Rate issues in atrial fibrillation: consequences of tachycardia and therapy for rate control. Am J Cardiol. 1998; 82: 29N-36N Abstract Full Text Full Text PDF PubMed Google Scholar Antiarrhythmic drugs are only partially effective in treating AF, and they have the potential for serious side effects, including life-threatening proarrhythmia. On the other hand, it recently has been demonstrated that paroxysmal AF in patients is initiated by focal triggers localized usually to one of the pulmonary veins (PVs) 4 Haissaguerre M. Jais P. Shah D.C. Takahashi A. Hocini M. Quiniou G. Garrigue S. Le Mouroux A. Le Metayer P. Clementy J. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998; 339: 659-666 Crossref PubMed Scopus (6265) Google Scholar and can be cured by a catheter-based ablation procedure. 5 Haissaguerre M. Shah D.C. Jais P. Hocini M. Yamane T. Deisenhofer I. Garrigue S. Clementy J. Mapping-guided ablation of pulmonary veins to cure atrial fibrillation. American Journal of Cardiology. 2000; 86: 9K-19K Abstract Full Text Full Text PDF PubMed Scopus (129) Google Scholar However, in persistent AF, the prevailing theory is that multiple random wavelets of activation coexist to create a chaotic cardiac rhythm, 6 Moe G.K. Abildskov J.A. Atrial fibrillation as a self-sustaining arrhythmia independent of focal discharges. Am Heart J. 1959; 58: 59-70 Abstract Full Text PDF PubMed Scopus (656) Google Scholar and therapy is more challenging. 7 Haissaguerre M. Jais P. Shah D.C. Arentz T. Kalusche D. Takahashi A. Garrigue S. Hocini M. Peng J.T. Clementy J. Catheter ablation of chronic atrial fibrillation targeting the reinitiating triggers. J Cardiovasc Electrophysiol. 2000; 11: 2-10 Crossref PubMed Scopus (196) Google Scholar , 8 Benussi S. Pappone C. Nascimbene S. Oreto G. Caldarola A. Stefano P.L. Casati V. Alfieri O. A simple way to treat chronic atrial fibrillation during mitral valve surgery: the epicardial radiofrequency approach. Eur J Cardiothorac Surg. 2000; 17: 524-529 Crossref PubMed Scopus (166) Google Scholar , 9 Knight B.P. Weiss R. Bahu M. Souza J. Zivin A. Goyal R. Daoud E. Man K.C. Strickberger S.A. Morady F. Cost comparison of radiofrequency modification and ablation of the atrioventricular junction in patients with chronic atrial fibrillation. Circulation. 1997; 96: 1532-1536 Crossref PubMed Scopus (27) Google Scholar , 10 Oral H. Pappone C. Chugh A. Good E. Bogun F. Pelosi Jr, F. Bates E.R. Lehmann M.H. Vicedomini G. Augello G. Agricola E. Sala S. Santinelli V. Morady F. Circumferential pulmonary-vein ablation for chronic atrial fibrillation. N Engl J Med. 2006; 354: 934-941 Crossref PubMed Scopus (805) Google Scholar

Effects of Stepwise Ablation of Chronic Atrial Fibrillation on Atrial Electrical and Mechanical Properties

This study sought to evaluate the effects of stepwise catheter ablation of chronic atrial fibrillation (AF) on atrial electrical and mechanical properties. Although stepwise catheter ablation of chronic AF is associated with acute arrhythmia termination and a favorable clinical outcome, atrial tissue damage following the procedure has not been evaluated. Forty patients who had previously undergone catheter ablation of chronic AF were studied. In the index procedure, termination of AF was achieved by catheter ablation alone in 36 of 40 patients (90%). Electroanatomical mapping was performed in sinus rhythm > or =1 month after the index procedure, during which the surface area of scar (bipolar voltage of <0.05 mV), low-voltage tissue (<0.5 mV), and atrial propagation were evaluated. Left atrial (LA) mechanical function was assessed by transthoracic echocardiography. Electroanatomical mapping showed areas of scar and low-voltage accounting for 31% +/- 12% and 32% +/- 17% of the total LA surface area respectively, with the ablated pulmonary vein region accounting for 20% +/- 4% of the LA surface area. The area of scar outside the pulmonary vein region represented 14% +/- 12% of the LA surface area using the initial randomized ablation strategy, and 6% +/- 8% (p = 0.02) using a specific ablation strategy. Atrial conduction was diversely affected by ablation with a wide range of LA conduction times observed (range 100 to 360 ms). The LA contraction was shown in all patients by the presence of late diastolic mitral flow (37 +/- 15 cm/s) and a mean LA active emptying fraction of 18 +/- 11%. At 9 +/- 5 months of follow-up, 39 patients (98%) were in sinus rhythm. Stepwise ablation achieving sinus rhythm in patients with chronic AF has a significant impact on LA electrical activity but is associated with recovery of LA function.

Catheter ablation for chronic atrial fibrillation

In recent years, radiofrequency catheter ablation has become an effective treatment modality for patients with atrial fibrillation (AF). Because triggers/drivers that originate from the pulmonary veins (PVs) 1 Haissaguerre M. Jais P. Shah D.C. Takahashi A. Hocini M. Quiniou G. Garrigue S. Le Mouroux A. Le Metayer P. Clementy J. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998; 339: 659-666 Crossref PubMed Scopus (6270) Google Scholar and other thoracic veins appear to be the primary mechanism of AF in patients with paroxysmal AF, 2 Lin W.S. Tai C.T. Hsieh M.H. Tsai C.F. Lin Y.K. Tsao H.M. Huang J.L. Yu W.C. Yang S.P. Ding Y.A. Chang M.S. Chen S.A. Catheter ablation of paroxysmal atrial fibrillation initiated by non-pulmonary vein ectopy. Circulation. 2003; 107: 3176-3183 Crossref PubMed Scopus (582) Google Scholar ablation strategies that target only thoracic vein arrhythmogenicity have been effective in the majority of patients with paroxysmal AF. 3 Haissaguerre M. Shah D.C. Jais P. Hocini M. Yamane T. Deisenhofer I. Chauvin M. Garrigue S. Clementy J. Electrophysiological breakthroughs from the left atrium to the pulmonary veins. Circulation. 2000; 102: 2463-2465 Crossref PubMed Scopus (861) Google Scholar , 4 Oral H. Knight B.P. Tada H. Ozaydin M. Chugh A. Hassan S. Scharf C. Lai S.W. Greenstein R. Pelosi Jr, F. Strickberger S.A. Morady F. Pulmonary vein isolation for paroxysmal and persistent atrial fibrillation. Circulation. 2002; 105: 1077-1081 Crossref PubMed Scopus (974) Google Scholar However, elimination of PV arrhythmogenicity has been insufficient to eliminate chronic AF. 4 Oral H. Knight B.P. Tada H. Ozaydin M. Chugh A. Hassan S. Scharf C. Lai S.W. Greenstein R. Pelosi Jr, F. Strickberger S.A. Morady F. Pulmonary vein isolation for paroxysmal and persistent atrial fibrillation. Circulation. 2002; 105: 1077-1081 Crossref PubMed Scopus (974) Google Scholar As the multifactorial nature of the genesis of AF has become better recognized, 5 Allessie M.A. Boyden P.A. Camm A.J. Kleber A.G. Lab M.J. Legato M.J. Rosen M.R. Schwartz P.J. Spooner P.M. Van Wagoner D.R. Waldo A.L. Pathophysiology and prevention of atrial fibrillation. Circulation. 2001; 103: 769-777 Crossref PubMed Scopus (617) Google Scholar catheter ablation has evolved into an effective treatment strategy also in patients with chronic AF.

Circumferential Pulmonary-Vein Ablation for Chronic Atrial Fibrillation

Circumferential Pulmonary-Vein Ablation for Chronic Atrial Fibrillation

Circumferential Pulmonary-Vein Ablation for Chronic Atrial Fibrillation

Circumferential Pulmonary-Vein Ablation for Chronic Atrial Fibrillation

Catheter ablation for chronic atrial fibrillation

Catheter ablation for chronic atrial fibrillation

Stepwise Catheter Ablation of Chronic Atrial Fibrillation:Importance of Discrete Anatomic Sites for Termination

Background: Chronic atrial fibrillation (CAF) can be acutely terminated using a combination of approaches targeting thoracic veins, left atrial areas showing rapid/heterogeneous electrical activity, and by linear ablation. This observational study emphasizes the crucial role for conventional endocardial mapping to identify discrete anatomical sites, ablation of which is indispensable for the achievement of atrial fibrillation (AF) termination. Methods: Eighty consecutive patients with CAF underwent catheter ablation using the stepwise approach. Pulmonary vein isolation and roof‐line ablation were performed as the initial two steps in all patients. In the presence of locally rapid or heterogeneous activity, ablation was then performed at all sites within the left atrium and coronary sinus (CS) region with the endpoint of local organization or slowing. If AF persisted, the mitral isthmus was targeted. Patients in whom AF terminated during one of these five ablation steps were differentiated from those in whom AF was terminated by radiofrequency ablation at a single discrete anatomic site within 1 minute. Electrograms at discrete anatomic sites of termination were classified according to morphology. Results: Termination of AF was achieved in 69 (86%) patients by ablation alone. In 50 patients (72%), this occurred while following the predetermined ablation schema. In the remaining 19 patients (28%), ablation targeting a discrete site (preferentially located at the CS, the base of left atrial appendage, and the interatrial septum) terminated AF. Such sites were identified by (1) continuous electrical activity and fractionation and (2) bursts of short cycle activity (130–160 msec), centrifugal activation or local activation gradients, indicating sources perpetuating AF. Conclusion: In 28% of patients with termination of CAF, the final successful ablation site is anatomically discrete and displays electrophysiological characteristics that can be effectively identified by point and activation mapping. Failure to identify these sites may significantly reduce the likelihood of termination of CAF by catheter ablation.

Catheter ablation for chronic atrial fibrillation

Catheter ablation for chronic atrial fibrillation