Comparative lesion metrics analysis of very high power and high power short duration radiofrequency ablation in a Porcine ex vivo model

Abstract

Abstract High-power, short-duration (HP-SD) ablation is a well-established radiofrequency (RF) ablation protocol in cardiac electrophysiology. Recently, very high-power, short-duration (vHP-SD) ablation has emerged as an alternative. This study compares lesion metrics between vHP-SD and HP-SD ablation protocols using the latest irrigated RF catheter with temperature-based power regulation, considering the impact of contact force (CF). RF ablations were performed in a porcine ex vivo model using myocardial preparations in a circulating saline bath. Three protocols were applied: vHP-SD (90 W for 4s), HP-SD-4 (50 W for 4s) and HP-SD-15 (50 W for 15s). A total of 360 lesions in 12 hearts were analyzed (vHP-SD: 120; HP-SD-4: 120, HP-SD-15: 120). The HP-SD-4 protocol produced the lowest mean lesion depth (2.42 ± 0.61 mm vs. 3.16 ± 0.41 mm vs. 4.49 ± 0.66 mm, p < 0.001), mean maximum lesion diameter (6.02 ± 1.00 mm vs. 7.34 ± 0.92 mm vs. 9.13 ± 1.59 mm), and mean lesion volume (52.0 ± 22.5 mm³ vs. 96.4 ± 28.8 mm³ vs. 211.4 ± 95.3 mm³, p < 0.001), followed by the vHP-SD protocol. In contrast, the HP-SD-15 protocol resulted in the highest values across all three parameters. Lesion depth, maximum lesion diameter, and lesion volume increased significantly with higher contact force (p < 0.001, p = 0.002, and p = 0.003, respectively). However, the absolute changes in these lesion dimensions were relatively small compared to those observed with power-controlled RF catheters, likely due to the effect of temperature-based power regulation.