Mechanisms of Organized Left Atrial Tachycardias Occurring After Pulmonary Vein Isolation

Abstract

Background-A proarrhythmic consequence of pulmonary vein (PV) isolation can be a recurrent organized left atrial (LA) tachycardia after ablation. This arrhythmia is frequently referred to as "left atrial flutter," but the mechanism and best ablation strategy have not been determined. Methods and Results-Isolation of arrhythmogenic PVs was initially performed by segmental ostial PV ablation guided by a circular mapping catheter in 341 patients. Patients whose predominant recurrent arrhythmia was a persistent organized tachycardia returned for mapping and ablation. Recurrent organized LA tachycardias (cycle length 253Ϯ33 ms, range 213 to 328 ms) occurred in 10 (2.9%) of 341 patients (age 59Ϯ9 years, 1 woman). Mapping was consistent with a focal origin in 8 patients and with macroreentry in 1 patient and was unclear in 1 patient owing to degeneration to atrial fibrillation. Focal tachycardias originated from reconnected segments of prior isolated PVs (6 patients), the posterior LA (1 patient), or the superior septum (1 patient). Focal atrial tachycardias were ablated with point lesions that targeted the earliest activation. All reconnected PVs were also reisolated. Reentrant LA flutter occurred around the left PVs in 1 patient. After 6.7Ϯ2.3 months of follow-up, 9 (90%) of 10 patients were arrhythmia free (4 of whom were taking antiarrhythmic drug therapy), and one was having recurrent atrial fibrillation. Conclusions-Recurrent organized LA tachycardia after PV isolation is uncommon and typically has a focal origin from reconnected PV ostia. Reisolation of the PV and ablation of non-PV foci are sufficient to treat this proarrhythmia. Linear lesions are only required when a macroreentrant mechanism is present.

Impact of Complete Versus Incomplete Circumferential Lines Around the Pulmonary Veins During Catheter Ablation of Paroxysmal Atrial Fibrillation

“…But it confirms data from previous observational studies showing that patients with AF recurrences almost always have conduction gaps and indicates the challenge of creating durable lesions by sequential radiofrequency current ablation. 24 The correlation between PV reconduction and AF recurrence underlines the important role of the PVs as shown in multiple observational studies [12][13][14][15][16][17][18][19] and in an experimental study. 25 In vitro data from optical mapping of a 2×2 cm 2 area of the PVs in isolated perfused dog hearts showed conduction slowing at the proximal part of the PVs, repolarization heterogeneity with the longest action potential duration at the PV endocardium when compared with the PV epicardium, and sustained focal discharge from the endocardial surface when stimulated with isoproterenol.…”

“…10,11 Further evidence came from patients with symptomatic AF recurrences after successful PV isolation (PVI), with limited data in asymptomatic patients. [12][13][14][15][16][17][18][19] These studies showed that patients with recurrent AF after PVI had reconduction from the PVs to the left atrium in ≤95% of cases. Closure of these conduction gaps with radiofrequency current led to reisolation of the PVs with only few AF recurrences.…”

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…253,436,507,508,622,623, 624,625,630,870,871,995,996,997,998,999,1000,1001,1002 Most of these tachycardias originate in the LA, although RA cavotricuspid isthmus (CTI)-dependent flutters might also occur. Patients with a regular AT of new onset might complain of worsening symptoms due to a faster mean ventricular rate (frequently 2:1 ventricular response) than that during AF preablation.…”

Coronary Sinus Activation and ECG Characteristics of Roof-Dependent Left Atrial Flutter After Pulmonary Vein Isolation

“…All patients had experienced prior PVI targeting entry and exit block and elimination of non-PV triggers of AF as the end points of the initial procedure performed at our institutions. 7,8 Additional substrate-based ablation was not routinely deployed. If tolerated, all patients were routinely discharged on antiarrhythmic medication for at least 6 weeks after ablation.…”

“…[1][2][3][4][5][6][7][8][9][10] In this setting, the most common macroreentrant left AT is clockwise or counterclockwise reentry around the mitral valve. 3 Left atrial (LA) roof-dependent flutter is a common macroreentrant LA tachycardia that involves the LA roof and typically spins around ipsilateral pulmonary veins (PVs).…”