RESUMEN
BACKGROUND: A lower cut-off of the oesophageal temperature (ET) during catheter ablation of atrial fibrillation (AF) should be safer, but its durability may become in question. We evaluated an ET cut-off of 38°C with an output of 25W on the posterior wall. METHODS: In 636 consecutive patients (age: 60±10years, male: 542, paroxysmal AF: 405, CHADS2 score: 0.7±0.9), an ET probe was utilised in 303 patients (259 pulmonary vein isolations [PVIs] and 44 simultaneous isolations of the posterior wall and all PVs box isolations [BOXIs]). When the ET increased to >38°C, the radiofrequency delivery was switched off and the ablation point was tagged as an "EsoTag" by the CARTO™ system (Biosense Webster, Irvine, CA, USA). We analysed the characteristics of the ablation lesions at the EsoTags with respect to the dormant conduction, gaps in the redo-session, and ablation outcome. RESULTS: EsoTags were identified in 94.6% of the left PVIs and all BOXIs, and dormant conduction at the EsoTags was identified in 12.0% and 6.8%, respectively. In 10,796 ablation points, the ablation at the EsoTags that were associated with dormant conduction had a significantly shorter duration, smaller force-time integral, and smaller Δimpedance. The duration of an ET of >38°C was significantly and positively correlated with the body mass index and negatively with the left atrial appendage flow velocity. During the redo-sessions in a 10.5±6.0months of follow-up (PVI: 14.7%, BOXI: 11.4%), reconnections at the EsoTags with dormant conduction were observed only in two patients after the PVI. The AF survival rate did not significantly differ in the presence of dormant conduction at the EsoTags (83.1% vs. 75.0%, p=0.696). There were no patients hospitalised for gastroparesis. CONCLUSIONS: Atrial fibrillation ablation utilising an oesophageal temperature cut-off of 38°C might be safe and durable.
