Localization of gaps during redo ablations of paroxysmal atrial fibrillation: Preferential patterns depending on the choice of cryoballoon ablation or radiofrequency ablation for the initial procedure

Background. - Pulmonary vein (PV) isolation, using cryoballoon or radiofrequency ablation, is the cornerstone therapy for symptomatic paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drugs. One-third of the patients have recurrences, mainly due to PV reconnections. Aims. - To describe the different locations of reconnection sites in patients who had previously undergone radiofrequency or cryoballoon ablation, and to compare the characteristics of the redo procedures in both instances. Methods. - Demographic data and characteristics of the initial ablation (cryoballoon or radiofrequency) were collected. Number and localization of reconduction gaps, and redo characteristics were reviewed. Results. - Seventy-four patients scheduled for a redo ablation of paroxysmal AF were included; 38 had been treated by radiofrequency ablation and 36 by cryoballoon ablation during the first procedure. For the initial ablation, procedural and fluoroscopy times were significantly shorter for cryoballoon ablation (147.8 +/- 52.6 min vs. 226.6 +/- 64.3 min [P<0.001] and 37.0 +/- 17.7 min vs. 50.8 +/- 22.7 min [P=0.005], respectively). Overall, an identical number of gaps was found during redo procedures of cryoballoon and radiofrequency ablations. However, a significantly higher number of gaps were located in the right superior PV for patients first ablated with radiofrequency (0.9 +/- 1.0 vs. 0.5 +/- 0.9; P=0.009). Gap localization displayed different patterns. Although not significant, redo procedures of cryoballoon ablation were slightly shorter and needed shorter durations of radiofrequency to achieve PV isolation. Conclusions. - During redo procedures, gap localization pattern is different for patients first ablated with cryoballoon or radiofrequency ablation, and right superior PV reconnections occur more frequently after radiofrequency ablation. Redo ablation of a previous cryoballoon ablation appears to be easier. (C) 2016 Elsevier Masson SAS. All rights reserved.