Inability to perform 'en bloc' pulmonary vein isolation requiring ablation of the intervenous carina increases recurrence of atrial fibrillation: A meta-analysis.

INTRODUCTION: Failure to isolate ipsilateral pulmonary veins (PV) "en bloc" by wide-area circumferential ablation (WACA) may necessitate ablation at the intervenous carina. It is unknown how this scenario impacts rates of atrial fibrillation (AF) recurrence. METHODS: A standard random-effect meta-analysis of randomized or observational studies were performed, where the outcome of first-time AF ablation was reported in patients with "en bloc" isolation of PVs by WACA as compared with those in whom ablation at the intervenous carina was needed after WACA to achieve complete isolation. RESULTS: A total of five single-center, observational studies (N = 1185) and one, multi-center randomized trial (N = 234) were enrolled. PV isolation could be achieved by WACA "en bloc" in 902/1419 (63.6%) cases. The rest required additional ablation at one or both of the left and right intervenous carinas to achieve isolation. The follow-up time after ablation ranged from 1 to 2 years in the included trials. The incidence of AF recurrence proved to be significantly lower in patients with successful "en bloc" isolation compared to those requiring carina ablation(s) to achieve complete bilateral PV isolation (MH-OR 1.89, 95% CI 1.42-2.53, p < .01) CONCLUSION: This present meta-analysis demonstrates a lower arrhythmia recurrence rate in patients with bilateral "en bloc" isolation, as compared to those who needed additional carina ablation for complete PVI. Therefore, it is imperative that every effort be made to isolate ipsilateral PVs "en bloc" during PVI.

The incidence and location of epicardial connections in the era of contact force guided ablation for pulmonary vein isolation.

BACKGROUND: The effects of epicardial connections (ECs) involving pulmonary veins (PVs) in atrial fibrillation (AF) ablation have been revealed recently. However, no systematic approaches to identify and ablate the ECs were established. METHODS: Patients with AF undergoing radiofrequency (RF) catheter ablation were retrospectively analyzed. ECs were identified when (1) PV isolation (PVI) cannot be achieved after first-pass isolation; (2) PVI was still absent although the conduction gap was detected and ablated; (3) the earliest activation area (EAA) was revealed located within the PV antrum distant from the initial ablation line using high-density mapping (HDM) technique; (4) focal ablation at the EAA was effective to achieve PVI. Relevant pacing maneuvers were performed to elucidate ECs' bidirectional conduction. RESULTS: Overall, 36 ECs were identified and ablated in 35/597 (5.86%) patients. Among the 35 patients with ECs, at least one PV insertion of ECs was located at the carina region. The most common pattern was a single breakthrough in 31 (88.6%) patients, followed by multiple breakthroughs in 3 and wide breakthroughs in 1. The median distance from EAA to the initial ablation line was 10.0 mm. The average number of RF energy delivery was 1.75 ± 1.00, and single RF delivery was adequate in 16/36 (44.4%) patients. Continuous potentials were present at the EAA in 9/34 (26.5%) patients. CONCLUSION: ECs were confirmed and ablated successfully in 5.86% (35/597) AF patients using HDM. PV insertions of ECs were mainly located at the carina region. Continuous potentials might assist in the prediction of ECs.