Introduction: Time-to-isolation (TTI) guided ablation protocols have been developed to ensure durable pulmonary vein isolation (PVI) in cryoballoon ablation (CBA). The aim was to determine the feasibility and safety of the fourth generation cryoballoon (CBG4) with a shortened tip.
Methods and results: Consecutive patients scheduled for initial atrial fibrillation (AF) ablation were prospectively included. PVI with the 28 mm CBG4 and the latest 20 mm spiral-mapping catheter (SMC) was performed. A total of 302 pulmonary veins (PVs) in 76 patients (64.8 ± 10.4 years, paroxysmal AF 49%) were treated with 617 applications. Left atrium (LA) time, fluoroscopy time, and dose-area product were 65.5 ± 19.2 minutes, 14.6 ± 5.6 minutes, and 1094 (738; 2097) cGy·cm2 , respectively. PVI in cryoballoon technique was achieved in 302 of 302 (100%) PVs. TTI was determined in 256 (84.8%) of PVs. The mean TTI was 45.3 ± 26.4 seconds. Single-shot isolation was achieved in 247 (82%) PVs. In 6 of 302 (2.0%) PV the SMC was changed to a stiff wire to isolate the PV because of instability, and in 17 of 302 (5.6%) of PVs, the 23 mm CB was used to isolate. No radiofrequency touch-up applications were applied. The mean nadir balloon temperature was -44.8°C ± 6.6°C. Balloon dislodgement during positioning occurred in 3 of 617 (0.5%) applications without complications. One PN palsy occurred which resolved until discharge. One patient suffered from the inflammatory syndrome.
Conclusion: The CBG4 with a shorter distal tip seems to be safe and effective, and allows determining the TTI in 84.8% of PVs. In case of balloon instability, the exchange of the SMC to a stiff wire or, in small PV, the 23 mm cryoballoon facilitate PVI.
Keywords: atrial fibrillation; catheter ablation; cryoballoon; spiral mapping catheter; time to isolation.
© 2019 Wiley Periodicals, Inc.