Pulmonary Vein Isolation Using the First-Generation Cryoballoon Technique in Chinese Patients

BackgroundCryoballoon ablation is an alternative for the treatment of atrial fibrillation (AF). We assess the relationship among pulmonary vein (PV) electrophysiology, balloon temperature, and persistent PV isolation (PVI), and report procedural properties, safety, and efficacy of this technique in a Chinese center for the first time. MethodsA total of 70 patients with paroxysmal (n = 57) and persistent (n = 13) AF were consecutively enrolled. PVI was performed with cryoballoon catheter. Real-time recording of dissociation of PV potentials was attempted using a circumferential mapping catheter. ResultsSuccessful PVI was achieved in 274 of 282 (97.2%) PVs. Procedural duration was 115.2 24.8 minutes and fluoroscopy time was 29.6 +/- 8.9 minutes. Real-time PV potential recording was achieved in 232 (84.3%) PVs. Regarding time to isolation, a cut-off value of less than 60 seconds was predictive of persistent PVI with a sensitivity of 0.76 and specificity of 0.82 (area under curve = 0.835; P < 0.0001). The nadir balloon temperature was significantly lower in PVs without early reconduction (-46.3 +/- 0.5 degrees C vs -40.2 +/- 1.3 degrees C, P < 0.0001). However, there was an insignificant trend that the balloon temperature at isolation was higher in PVs without reconduction (-33.9 +/- 0.7 degrees C vs -36.4 +/- 2.0 degrees C, P = 0.14). The overall complication rate was 5.7%. After a median follow-up of 6.5 (range 3.2-14.9) months, 76% of patients were free of AF recurrence with a blanking period of 3 months. ConclusionsReal-time PV potentials can be recorded in most PVs. The time to isolation is predictive of the persistency of PVI. The nadir balloon temperature, not the balloon temperature at isolation, is significantly lower in PVs without reconduction.