Assessment of Biophysical Parameters and Acute Lesion Effectiveness in Atrial Fibrillation Ablation Using a Very High-Power Short-Duration Strategy

Background: Radiofrequency ablation (RFA) therapy is frequently performed to maintain sinus rhythm in patients with atrial fibrillation (AF). Objective: The purpose of this study was to assess the association between biophysical parameters (average contact force, maximum temperature, catheter stability, and impedance drop) and acute lesion effectiveness using a very high-power short-duration (90 W, 4 seconds, QDOT catheter, Biosense Webster, Irvine, California) ablation strategy for atrial fibrillation. Methods: We analyzed 986 ablation lesions from 13 consecutive patients who underwent RFA between June and September 2024. After the pulmonary vein antral isolation (PVAI) lesion set, each lesion was assessed for the presence or absence of capture with high-output pacing (10 mA, 2 ms). Group A included lesions with no local capture, and Group B included lesions with local capture. Lesion characteristics were obtained from data stored in the CARTONET cloud-based platform (Biosense Webster). For each lesion, average contact force, maximum temperature, impedance drop, and catheter stability were analyzed. Statistical analysis was performed using independent t-tests, treating lesions as the unit of analysis. Results: Group A had more ablation lesions, higher contact force, a higher maximum temperature, and better stability compared with Group B (Group A vs Group B: 818 vs 168 lesions, p < 0.01; 19.47 g vs 17.58 g, p < 0.01; 44.96 °C vs 40.64 °C, p < 0.01; 1.59 mm vs 9.58 mm, p < 0.01). Group B had a higher impedance drop than Group A (10.35 Ω vs 8.27 Ω, p < 0.01). There were no major complications in either group at the 30-day follow-up. Conclusion: Higher average contact force, higher temperature, and better stability were associated with successful lesion delivery utilizing a very high-power short-duration ablation strategy. In this cohort, an impedance drop beyond 8 Ω did not appear to be significantly associated with acute electrical isolation.