Background: The frequency and risk-factors for severe luminal esophageal temperature (LET) increase with high power short duration (HPSD) left atrial posterior wall (LAPW) ablation are not well understood.
Objective: We aimed to describe the frequency, risk-factors and predictability of severe LET increase (≥4°C) associated with HPSD LAPW ablation.
Methods: LET was sampled at 2Hz using a 12-point esophageal temperature monitor (CIRCA S-CATH, Circa Scientific, Inc.) in 16 patients undergoing LAPW ablation. Esophageal temperature sensor position and lesion locations were recorded using an electroanatomic mapping system with fluoroscopic integration (CARTO 3, CARTOUNIVU, Biosense Webster, Inc.) LAPW ablation was performed at 50W for 6s. Locations of temperature sensors, the first 20 LAPW lesions in each patient, and overlying esophagus were analyzed based on a 16 segment schema of the LAPW. The frequency, location, and risk-factors for LET increase ≥4°C were investigated. Three experienced, blinded electrophysiologists were surveyed to predict presence and location LET increase ≥4°C based on patient demographic and imaging data.
Results: Of 320 analyzed LAPW lesions, LET increase ≥4°C was observed in 8 lesions (2.5%) in 6 patients (38%). Patients with LET increase ≥4°C had greater weight (108 ± 10Kg vs 92 ± 14Kg, p = 0.03), otherwise baseline characteristics were similar between groups. Temperature sensors were present in 43 of 103 (42%) LAPW segments with overlying esophagus. HPSD ablation within an LAPW segment with an overlying temperature sensor were more likely have LET increase ≥4°C than HPSD ablation in a LAPW segment with overlying esophagus without a temperature sensor (21% vs 0%, p<0.001). Electrophysiologists correctly identified patients with LET increase ≥4°C with 27% accuracy, and identified location of maximum LET increase within one esophageal segment with 48% accuracy.
Conclusion: HPSD LAPW ablation results in unpredictable, severe esophageal temperature increases. LET increase ≥4°C are infrequent, but only observed with ablation immediately overlying a temperature sensor. Most esophageal segments overlying the LAPW remain without a temperature sensor despite use of a 12-sensor temperature probe.