LAUSR

Point-by-point radiofrequency ablation (RF) and one-shot cryoballoon ablation (CRYO) electrically isolate pulmonary veins (PVs) in atrial fibrillation (AF) using different techniques and energies. This study aimed to examine differences in PVs reconnection pattern and ablation lesions required to re-isolate PVs after failed RF and failed CRYO. Twenty-four patients who had their repeat ablation between January 2017-December 2020 were studied with six months of learning curve for CRYO. Fourteen patients had paroxysmal atrial fibrillation (PAF). Failed first ablations were defined by electrocardiogram (ECG) documented AF within twelve months following three months blanking period. Repeat ablations were performed using CARTO3® mapping system, which was utilized to locate ablation lesions and impedance drop details. 2,260 lesions were collected from 63 reconnected PVs (31 isolated after RF vs 32 isolated veins after CRYO). 849 lesions were targeted towards triggers. Repeat ablation procedure time was similar between both cohorts. However, repeat ablation after failed CRYO had longer fluoroscopy time (19.8±2 vs 12.4±2.1 minutes, P=0.019). The right lower pulmonary vein (RLPV) was reconnected after failed CRYO for AF in 92% of patients and 100% in PAF patients. Although PV reconnection pattern was similar between both cohorts, RLPV and left upper pulmonary vein (LUPV) required more ablation lesions after failed CRYO. Left lower pulmonary vein (LLPV) and right upper pulmonary vein (RUPV) required more ablation lesions after failed RF. Impedance drop was similar in both cohorts. After failed CRYO for PAF, RLPV was reconnected in all patients. RUPV and LLPV required more ablation lesions after failed RF, while RLPV and LLPV required more ablation lesions after failed CRYO. Type of funding sources: None. PVs reconnection pattern Lesions number and percentage comparison