Esophageal Temperature Changes During Pulsed Field Ablation With Three Catheter Systems

BACKGROUND: Pulsed field ablation (PFA) is considered less thermally injurious than conventional ablation technologies, but esophageal temperature elevation can still occur. Human data directly comparing esophageal temperature changes among different PFA catheter systems remain limited. We compared esophageal temperature changes during PFA using VARIPULSE, PulseSelect, and FARAPULSE. METHODS: This retrospective single-center study included consecutive patients with nonvalvular atrial fibrillation who underwent pulmonary vein isolation using PFA with luminal esophageal temperature monitoring between April 2025 and March 2026. Esophageal temperature was measured at five sites every 0.5 s. For each patient, esophageal temperature rise (ΔT) was defined as the maximum esophageal temperature recorded during PFA minus the mean esophageal temperature during the 5-min interval immediately preceding the PFA application associated with that maximum temperature. A sensitivity analysis using the same ΔT definition was performed in patients who underwent pulmonary vein isolation alone. RESULTS: A total of 70 patients were analyzed. ΔT differed among the three groups and was greatest with VARIPULSE (1.61 ± 1.00°C vs. 1.10 ± 0.61°C vs. 0.88 ± 0.43°C for VARIPULSE, PulseSelect, and FARAPULSE, respectively; p = 0.0302). In patients undergoing pulmonary vein isolation alone (n = 56), ΔT remained significantly different among the three groups (1.61 ± 1.03°C vs. 1.05 ± 0.61°C vs. 0.74 ± 0.38°C, respectively; p = 0.0386). Clinically significant temperature elevation (ΔT ≥ 2.0°C) occurred most frequently with VARIPULSE in both the overall cohort and the pulmonary vein isolation-only subgroup. Temperature elevation was most prominent during ablation near the left pulmonary veins and in anatomically adjacent regions to the esophagus. No patient developed symptoms suggestive of esophageal ulceration; however, systematic post-procedural endoscopic assessment was not performed. CONCLUSIONS: Measured esophageal temperature elevation during PFA differed according to catheter system and was greatest with VARIPULSE; this between-system difference persisted in patients undergoing pulmonary vein isolation alone. Because procedural characteristics differed among systems, these findings should not be interpreted as establishing a device-specific causal mechanism or esophageal safety.