Regional differences in the predictors of acute electrical reconnection following high-power pulmonary vein isolation for paroxysmal atrial fibrillation.

Background Acute pulmonary vein reconnection (PVR) is associated with long procedure times and large radiofrequency (RF) energy delivery during pulmonary vein isolation (PVI). Although the efficacy of high-power PVI (HP-PVI) has been recently established, the determinants of acute PVR following HP-PVI remain unclear. Methods We evaluated data on 62 patients with paroxysmal atrial fibrillation undergoing unipolar signal modification (USM)-guided HP-PVI. A 50-W RF wave was applied for 3-5 seconds after USM. In the segments adjacent to the esophagus (SAEs), the RF time was limited to 5 seconds. Each circle was subdivided into six regions (segments), and the possible predictors of acute PVR, including minimum contact force (CFmin), minimum force-time integral (FTImin), minimum ablation index (AImin), minimum impedance drop (Imp-min), and maximum inter-lesion distance (ILDmax), were assessed in each segment. Results We investigated 1162 ablations in 744 segments (including 124 SAEs). Acute PVR was observed in 21 (17%) SAEs and 43 (7%) other segments (P = .001). The acute PVR segments were characterized by significantly lower CFmin, FTImin, AImin, and Imp-min values in the segments other than the SAEs and larger ILDmax values in the SAEs. Furthermore, lower Imp-min and larger ILDmax values independently predicted acute PVR in the segments other than the SAEs and SAEs (odds ratios 0.90 and 1.39 respectively). Acute PVR was not significantly associated with late atrial fibrillation recurrence. Conclusions Avoiding PVR remains a challenge in HP-PVI cases, but it might be resolved by setting the optimal target impedance drop and lesion distance values.