Pulmonary vein isolation with real-time pulmonary vein potential recording using second-generation cryoballoon: Procedural and biophysical predictors of acute pulmonary vein reconnection

ObjectiveThe study sought to evaluate the procedural and biophysical factors related to acute pulmonary vein isolation (PVI) guided by real-time pulmonary vein (PV) potential recordings. MethodsA total of 180 consecutive patients with drug-resistant atrial fibrillation (AF) undergoing CB2 (second-generation version of cryoballoon) ablation were enrolled. Real-time monitoring of PV potentials was obtained using an inner lumen spiral mapping catheter. ResultsAcute isolation was achieved in all PVs without touch-up ablation. Real-time assessment of PV disconnection was possible in 611 of 711 (85.9%) PVs. A total of 617 (86.8%) PVs were isolated during the initial freeze. Longer time cycle integration (TCI) (TTI * freeze cycle, TCI) (254.6112.8 seconds vs 74.1 +/- 59.7 seconds, Pl0.001), time to isolation (TTI) (94.3 +/- 34.0 seconds vs 46.3 +/- 26.2 seconds, Pl0.001), higher nadir temperature (-45.5 +/- 5.3 degrees C vs -50.4 +/- 5.5 degrees C, Pl0.001), longer time to -40 degrees C (77.3 +/- 22.7 seconds vs 55.7 +/- 23.2 seconds, Pl0.001), faster interval rewarming time at 0 degrees C (9.4 +/- 4.3 seconds vs 12.4 +/- 4.9 seconds, P=0.008), and total balloon rewarming time (38.1 +/- 11.6 seconds vs 47.7 +/- 14.0 seconds, P=0.003) were observed in PVs with acute reconduction. TTI 65 seconds predicted absence of acute reconnection with 84.2% sensitivity and 75.7% specificity, whereas TCI 119 seconds presented 94.7% sensitivity and 80.2% specificity. At a mean follow-up of 4.7 +/- 1.4 months, 82.2% of patients were free of AF. None of those with PV reconnections suffered from AF recurrences. ConclusionsThe ablation using CB2 is effective in achieving acute PVI. Real-time assessment of PVI could be achieved during CB application in 86% of PVs. The incidence of spontaneous PV reconnection is very low, observed in just 3% of isolated PVs. TTI 65 seconds and TCI 119 seconds predicted absence of acute PV reconnection. Although they may identify effective cryoapplications in the acute phase, their performance still needs to be verified in the long term.