P2850Time to isolation guided hot balloon ablation for pulmonary vein isolation

Abstract

Abstract Background One disadvantage of hot balloon ablation (HBA) system is that real time monitoring of pulmonary vein (PV) potential is technically impossible. Therefore, the optimal radiofrequency-generated thermal energy application duration and application number are not completely established. Purpose The aim of this study is to evaluate the utility of 2Fr 4-electrode unidirectional catheter inserted into PV along with HB for real time monitoring of PV potential and investigate the time to isolation (TTI) guided optimal application strategy for HB based PV isolation in the acute phase. Methods We evaluated 23 consecutive patients who performed PV isolation using HBA system. Real time monitoring of PV potential was performed by 2Fr 4-electrode unidirectional catheter inserted into PV along with HB (Figure1A). After HBA applications, PV isolation was validated by high-resolution mapping with the 20-pole steerable mapping (PENTARAY) catheter as a standard. PV potentials during HBA application were categorized into five patterns. PV potentials disappeared during HBA applications and not emerged again (acute isolation), disappeared but verified by PENTARAY catheter (pseudo isolation), once disappeared but emerged again during the same application (acute reconnection), visible but not disappeared (ineffective application) and Invisible (Figure1B). TTI, difference between TTI and time to reach target temperature (TTRT), balloon temperature at isolation and ablation time after isolation were examined for each applications. Results Out of 92 PVs, 69/92 (75.0%) PVs were isolated using HBA and 23/92 (25.0%) PVs required touch up ablation. In total, 120 applications were performed. Real time monitoring of the PV activity was obtained in 114 of 120 applications (95.0%). The distribution of PV potential patterns were 64/120 (53.3%), 2/120 (1.7%), 27/120 (22.5%), 23/120 (19.2%), for acute isolation, pseudo isolation, acute reconnection, ineffective application, respectively. TTI and difference between TTI and TTRT were significantly shorter in the acute isolation group. Balloon temperature at isolation was significantly lower, TTRT and ablation time after isolation was significantly longer in the acute isolation group. Among them, TTI and difference between TTI and TTRT were highly predictive by receiver operation characteristics curve analysis. TTI <36.5s predicted successful application with sensitivity 83.9% and specificity 79.3%. Difference between TTI and TTRT <6.5s predicted with sensitivity 82.3% and specificity 89.7%. Figure 1 Conclusions In HBA system, real time monitoring of PV potentials can be obtained using 2Fr 4-electrode unidirectional catheter and accuracy to confirm an ostial PV isolation is relatively high. TTI <36.5s and difference between TTI and TTRT <6.5s could be a suitable target for effective application.