The fourth cryoballoon generation with a shorter tip to facilitate real‐time pulmonary vein potential recording: Feasibility and safety results

Abstract

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·cm 2 , 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. K E Y W O R D S atrial fibrillation, catheter ablation, cryoballoon, spiral mapping catheter, time to isolation

Predictors of durable electrical isolation in the setting of second‐generation cryoballoon ablation: A comparison between left superior, left inferior, right superior, and right inferior pulmonary veins

“…As confirmed by our results, late isolation (eg, later than 60 seconds) in the context of single freeze is associated with a significant rate of late PVr (50% vs 22.6%; P < .001) in line with previous observations . Technological innovation in recording catheters lead to higher rates of RT; however, encouraging success rates were reported even in CbA performed without a recording catheter . Despite the relatively low rate of RT in our population of redo procedures, we confirmed, overall, a comparable behavior of predictors in both groups of PVs (with and without available RT recordings).…”

Ultra–high‐density mapping of conduction gaps and atrial tachycardias: Distinctive patterns following pulmonary vein isolation with cryoballoon or contact–force‐guided radiofrequency current

“…Therefore, it is interesting to see whether the incidence of ATs that are either PV‐dependent or originate from the antral index ablation line can be prevented by optimizing the index procedure. To improve on these shortcomings, additional tools such as the ablation index for RFC ablation (which was only partially included in this study) or the release of the fourth‐generation CB are now implemented in clinical practice 25,26 . It has already been reported that a minimum ablation index is associated with PV reconnection 27 .…”

Cryoballoon Ablation for Patients With Paroxysmal Atrial Fibrillation

“…The CB4 with a shorter distal tip is safe and effective, and allows determination of TTI in 78-85% of PV. [44][45][46] Several randomized clinical trials have been carried out to investigate the efficacy and long-term outcomes of CB ablation (Table), which were almost identical to those of RFCA. 8,47-51 Furthermore, CB-based PV isolation seems to be less operator dependent and more reproducible than RF-based PV isolation in the setting of paroxysmal AF ablation, 52 although various parts of the procedure, such as the freezing protocol, were not standardized.…”

“…66 CB4 could record real-time online PV potential with a low incidence of CB dislodgment. [44][45][46] Further research into tailored CB ablation protocols using CB4 to reduce unnecessary cryoenergy applications is required.…”