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 28mm 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.