Recurrent atrial fibrillation after initial cryoballoon ablation: New perspectives for intensive ablation in right superior pulmonary vein ostium for atrial fibrillation.

A significant proportion of patients with recurrent atrial fibrillation (AF) require repeat radiofrequency (RF) ablation after cryoballoon (CB) ablation. However, little is known about the pulmonary vein (PV) potential reconnection to left atrium and localization of gaps in the initial lesion sets following cryoablation in patients with recurrent AF. The data of 29 consecutive patients with repeat RF ablation for recurrent AF were analyzed. During the second ablation procedures, PV foci of AF were explored in 116 PVs by the CARTO system. All patients had complete PV isolation from initial cryoablation procedure. The fluoroscopy duration, mean cryoablation time and mean cryoablation frequency were lowest for the right superior pulmonary vein (RSPV) (58.69 ± 9.18 s, 185.10 ± 49.25 s and 1.07 ± 0.26; p = 0.024, p = 0.042 and p = 0.032). A significantly higher incidence of conduction gaps per patient was found for the RSPVs compared to the other PVs (p < 0.05 or p < 0.01). For RSPVs, it seemed that gaps were predominantly located at the anterior segment (22 gaps) and inferior segment (22 gaps). RSPV reconnection was independently related to a lower risk of major adverse events after the second ablation during follow up in the study patients (HR 0.275, 95%CI 0.078-0.967, p = 0.044). AF recurrence in patients after cryoablation is significantly associated with conduction gaps in the anterior and inferior segments of RSPVs. Various ablation strategies of close touch of CB on anterior and inferior segments of RSPV ostium, more freezing time and frequency for RSPV may help achieving durable PV isolation during follow up.