High incidence of focal and macro-reentrant arrythmias during repeat procedures after paroxysmal atrial fibrillation ablation using second-generation cryoballoon with no “bonus freeze” application

Abstract

The second-generation cryoballoon (CB2) is effective in achieving pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF), however some repeat procedures (RP) were necessary. Describing clinical arrythmias during radiofrequency-based RP after PVI using CB2. Data from all consecutive patients requiring RP for symptomatic left atrial arrhythmias after PVI using CB2 28 mm with no “bonus freeze” application were analysed. A lasso catheter was used to check pulmonary veins’ (PV) electrical dissociation and map the clinical arrhythmia with a 3D mapping system, followed by ablation using radiofrequency (RF) energy. From January 2014 to December 2016, 31/270 patients (11.5%), mean age 56 ± 10 years, had RP for paroxysmal AF (24/31; 77.4%), persistent AF (1/31; 3.2%), atypical flutter (4/31; 12.9%) or left atrial tachycardia (2/31; 6.4%) after a median of 8 ± 8 months following PVI using CB2. Among them, 25 (80.6%) had at least one reconnected PV, but only 46/124 PVs (37.1%) were reconnected. Focal arrythmias was targeted in 12/31 (38.7%) patients, whereas left reentrant arryhthmias were found in 4/31 (12.9%) patients. Cavotricuspid isthmus ablation was performed in 7/31 (22.6%) patients due to induction of typical atrial flutter, typical atrioventricular nodal reentrant tachycardia was induced in one case (3,2%). The superior vena cava was isolated in 5/31 (16.1%) patients. Taking these complementary ablations into consideration, only 17/31 patients (54.8%) had PVI alone during those redo procedures using RF. After a 4-month follow-up, 14/24 (58.3%) patients were free from any symptom or recorded AF, reaching an overall 96.2% success rate after 2 or 3 procedures (only 4 patients). Atrial arrythmias’ recurrence can be related not only to PVs’ reconnection, but also to focal or reentrant atrial arrythmias. It supports the use of 3D-mapping-guided RF ablation for repeat procedures after CB2 ablation.