Single-ring posterior left atrial (box) isolation results in a different mode of recurrence compared with wide antral pulmonary vein isolation on long-term follow-up: longer atrial fibrillation-free survival time but similar survival time free of any atrial arrhythmia.

BACKGROUND: Electric isolation of the pulmonary veins and posterior left atrium with a single ring of radiofrequency lesions (single-ring isolation [SRI]) may result in fewer atrial fibrillation (AF) recurrences than wide antral pulmonary vein isolation (wide antral isolation [WAI]) by abolishing extravenous AF triggers. The effect of mitral isthmus line (MIL) ablation on outcomes after SRI has not previously been assessed. METHODS AND RESULTS: We randomly assigned 220 consecutive patients (58 ± 10 years old; 82% men) with highly symptomatic AF (61% paroxysmal, 39% persistent/longstanding persistent) to undergo either SRI or WAI. Half of each cohort was also randomly allocated to have left lateral MIL ablation (2 ×2 factorial study design). Patients were followed clinically and with 7-day Holter studies for arrhythmia recurrences. The primary end points were recurrence of AF and organized atrial tachyarrhythmias. AF-free survival at 2 years was better after SRI (74% [95% CI, 65%-82%]) than WAI (61% [51%-70%]; P=0.031). Organized atrial tachyarrhythmia-free survival was similar after SRI and WAI (67% [57%-75%] ersus 64% [54%-72%], respectively, at 2 years; P=0.988). MIL ablation resulted in better 2-year organized atrial tachyarrhythmia-free survival (71% [62%-79%] versus 60% [50%-69%]; P=0.07), which approached statistical significance. Survival free of any atrial arrhythmia after one procedure was not significantly affected by isolation technique or MIL ablation. Conclusions- SRI resulted in fewer AF recurrences compared with WAI on long-term follow-up but did not reduce the recurrence of all atrial arrhythmias. MIL ablation may reduce organized atrial tachyarrhythmia recurrences. Clinical Trial Registration- http://www.anzctr.org.au; ACTRN12606000467538.

Atrial arrhythmias after single-ring isolation of the posterior left atrium and pulmonary veins for atrial fibrillation: mechanisms and management.

BACKGROUND: Single-ring isolation of the posterior left atrium is feasible, but the incidence and mechanisms of postprocedural arrhythmias have not been described in detail. METHODS AND RESULTS: The first 100 consecutive patients (58.8+/-11.2 years old, 80 male) who underwent single-ring isolation for atrial fibrillation (66 intermittent, 18 persistent, 16 long-standing persistent) were followed up for 9.1+/-4.5 months. Recurrences were diagnosed by clinical symptoms and Holter monitoring. Patients with recurrences of sustained atrial arrhythmia >3 months after the procedure were offered a repeat procedure and were studied to determine the mechanisms of recurrence. Forty-six patients (46%) experienced sustained postprocedural atrial arrhythmias (35 had atrial fibrillation, and 34 had atrial flutter). Of these, 34 required a second procedure 7.0+/-3.1 months after their initial procedure. Reconnection of the posterior left atrium was seen in all patients with atrial fibrillation. Atrial flutter was most commonly due to mitral isthmus-dependent macroreentry (n=8, cycle length 368+/-116 ms) or macroreentry through 2 gaps in the ring of lesions (n=6, cycle length 328+/-115 ms). Posterior left atrium reisolation was achieved at the second procedure in all patients. Atrial flutter was successfully ablated and rendered noninducible in all patients. Six months after their last procedure, the Kaplan-Meier estimate of freedom from recurrence for all 100 patients was 81+/-5%. CONCLUSIONS: Atrial fibrillation and atrial flutter recurrence is common after single-ring isolation. Reconnection of the posterior left atrium and macroreentry are the common mechanisms. Repeat ablation results in satisfactory short-term outcomes.

Efficacy and late recurrences with wide electrical pulmonary vein isolation for persistent and permanent atrial fibrillation.

AIMS: Early recurrences of atrial arrhythmia after wide electrically isolating ablation for atrial fibrillation (AF) are well described, but the long-term risk of recurrence for patients with persistent and permanent AF has not been studied in detail. METHODS AND RESULTS Fifty-six consecutive patients [45 men (80.4%), age 55.9 +/- 8.7 years] with persistent [39(69.6%)] or permanent [17(30.4%)] AF were followed for 21.6 +/- 8.8 months after ablation. Atrial fibrillation duration prior to ablation was 6.4 +/- 5.6 years. Electrically isolating lesions encircling the left and right pulmonary veins (PVs) in pairs were created. After 1.5 +/- 0.7 procedures, 48 (85.7%) had sinus rhythm (SR) at 21.6 +/- 8.8 months of follow-up: achieved with 1 procedure in 27 (56.3%) and without anti-arrhythmics in 30 (62.5%). Atrial fibrillation recurrence was observed in 69.6% after the first and 46.4% after the last procedure. Of those with late recurrences (>90 days) following the last procedure, most [18 (69.2%)] did not have early recurrences. Pre-procedural AF duration (P = 0.007) and female gender (P = 0.005) were independent predictors of recurrence following the last procedure. CONCLUSION: Circumferential PV isolation is effective in most patients with persistent or permanent AF. However, repeat procedures are frequently required. Late recurrences are common and not precluded by the absence of early post-procedural arrhythmias.