Characterization of conduction recovery after pulmonary vein isolation using the “single big cryoballoon” technique

Background

Pulmonary vein isolation using the cryoballoon technique (CB-PVI) has evolved into a simple and safe alternative for point-by-point radiofrequency ablation. Systematic analysis of conduction recovery occurring after CB-PVI and causing recurrent atrial fibrillation has not yet been performed.

Objective

The purpose of this study was to analyze conduction recovery after PVI using the single big (28-mm) cryoballoon technique.

Methods

Twenty-six patients with recurrent atrial tachyarrhythmia after previous CB-PVI underwent repeat ablation. Pulmonary vein (PV) reisolation was performed by antral irrigated radiofrequency ablation using electroanatomic mapping. For analysis of the location of conduction gaps, the ipsilateral LA–PV junction was divided into six equally distributed segments.

Results

PV reconduction frequently occurred into multiple (>2) PVs (54% patients). Conduction gaps could be abolished by single point ablation in 63% (lateral) and 41% (septal) of patients or by incomplete circular lesions in the remaining patients. A significantly higher number of patients exhibited conduction recovery at inferior segments (85% lateral, 77% septal) compared with superior segments (42% lateral, 31% septal). Furthermore, the ridge between PV ostia and left atrial appendage (LAA) was highly associated with reconduction into lateral PVs (81% of patients). Retrospective analysis of the initial CB-PVI-procedure revealed lower freezing temperatures at superior than inferior PVs as well as sharp catheter angulations with loss of central cryoballoon alignment to reach inferior PVs.

Conclusion

Conduction recovery after CB-PVI occurs at a high incidence at inferior sites around ipsilateral PV ostia and the LAA–PV ridge. Modifications of the technique to ensure optimal balloon–tissue contact at predilection sites may improve long-term success rates.

Keywords: Arrhythmia, Atrial fibrillation, Balloon, Catheter ablation, Cryothermal energy

Abbreviations: AF, atrial fibrillation, CB, cryoballoon, LA, left atrium, LAA, left atrial appendage, LAT, left atrial tachycardia, LCPV, left common pulmonary vein, LIPV, left inferior pulmonary vein, LSPV, left superior pulmonary vein, PAF, paroxysmal atrial fibrillation, PV, pulmonary vein, PVI, pulmonary vein isolation, RFC, radiofrequency current, RIPV, right inferior pulmonary vein, RSPV, right superior pulmonary vein