Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-PO02 - Poster Session II (ID 47) Poster

D-PO02-124 - The Relation Between Power-setting Of Radiofrequency And Thermal Effects On Esophagus During Ablation Index-guided Pulmonary Vein Isolation (ID 1019)

 Y. Sakamoto: Nothing relevant to disclose.


Background: Few data exist regarding the relation between power-setting of radiofrequency (RF) and thermal effects on esophagus in atrial fibrillation (AF) ablation.
Objective: The purpose of this study was to compare the effect of low-power ablation (LPA) and high-power ablation (HPA) on luminal esophageal temperature (LET) during ablation index (AI)-guided pulmonary vein isolation (PVI).
Methods: Of 246 consecutive patients undergoing initial AI-guided PVI with CARTO3 (Biosense Webstar) for AF, 182 patients (78 %) propensity score-matched (91 in LPA group and 91 in HPA group) were enrolled retrospectively. AI targets were 550 for anterior/roof and 400 for posterior/inferior segments with permission of various power-setting except for sites close to esophagus. Esophagraphy was performed routinely to confirm the anatomical location and size of esophagus. A temperature probe (Esophastar, Japan lifeline), containing 5 thermocouples, was inserted into esophagus for monitoring LET. RF with 20-25 or 35 watts was delivered to sites close to esophagus in LPA or HPA group, respectively. If LET reached 39.5°C, RF delivery was immediately interrupted regardless of AI.
Results: The AI at closes site to esophagus was significantly lower in LPA group compared to HPA group (282±54 v.s 309±61, p<0.05). RF duration there was significantly longer in LPA group compared to HPA group (15±8 sec. v.s 10±6 sec., p<0.001). To achieve complete conduction block of PV-LA, the necessity of repeat ablation for the gaps close to esophagus was significantly higher in LPA than HPA group (14.2 % vs 3.3 %, p<0.001). Reconnection there provoked by time-waiting, isoproterenol, or adenosine triphosphate was more frequently observed in LPA group than HPA group (16.5 % v.s 1.1 %, p<0.001).
Conclusion: High-power ablation for sites close to esophagus reduced the interruption of RF delivery by LET rise during AI - guided PVI, which resulted in reaching higher AI, fewer gap formations, and fewer reconnections compared to low-power ablation.