Backgrounds Ablation index (AI) is useful to complete circumferential pulmonary vein isolation (CPVI) for atrial fibrillation (AF), but the role of radiofrequency power in AI‐guided CPVI remains to be elucidated. Methods We investigated 60 patients with AF undergoing AI‐guided CPVI (mean age, 66 ± 9 years; nonparoxysmal AF in 16). The first 40 patients were randomly assigned to low‐power (LP; n = 20) and medium‐power (MP; n = 20) groups and the following 20 patients to high‐power (HP). In LP, radiofrequency (RF) application was done at 30 W at the anterior and 20 W at the posterior left atrial (LA) wall, while in MP, it was at 40 W at the anterior and 30 W at the posterior LA wall. In HP, 50 W was applied at the anterior, 40 W at posterior LA wall and 30 W on the esophagus. At each ablation point, target AI was 400 at the anterior, 360 at the posterior LA wall, and 260 on the esophagus. Results The time to complete both‐side CPVI was shortest in HP (median, 40 minutes, interquartile range [IQR], 28‐63) followed by MP (58 [49‐83] minutes, P = .008 vs HP) and LP (84 [72‐93] minutes, P = .002 vs MP). Higher RF power application significantly increased first‐pass isolation rate (55% in LP, 80% in MP and 85% in HP, P = .002) and decreased LA‐PV reconnection rate (10% in LP, 8% in MP, and 0% in HP, P = .03). Conclusion In AI‐guided PVI, the HP RF application can shorten the time to complete PVI with a high rate of first‐pass isolation and a low rate of LA‐PV reconnection.

PV carina region origins may partly be responsible for an acute PVEI and potential recurrences.

A discrete prepotential was seen in 9 (26%) of 35 patients with CC-VA. In left and right CC-VA, the site of a discrete prepotential with ≥50 ms activation time may indicate a successful ablation site.