B-PO02-109 SAFE AND EFFECTIVE DELIVERY OF HIGH-POWER, SHORT-DURATION RADIOFREQUENCY ABLATION LESIONS WITH A NOVEL, FLEXIBLE-TIP RADIOFREQUENCY ABLATION CATHETER

Abstract

High-power, short-duration (HPSD) radiofrequency (RF) ablation may reduce ablation time. Concerns that a catheter mounted thermocouple (TC) can underestimate tissue temperature and increase risk of steam pop formation limit widespread adoption of HPSD ablation. This study compared the safety and efficacy of HPSD and standard RF during pulmonary vein isolation (PVI). A novel irrigated ablation catheter with a contact force (CF) sensor and a TC in a flexible tip electrode was used to perform PVIs in 12 dogs. Two ablation protocols were performed: Standard: 30 W for up to 60 s and HPSD: 50 W for 10 s with the same irrigation rate (13 ml/m) and CF (5-20 g) for all lesions. RF delivery ended if the TC reached 45 C. PVI was assessed at 30 min and 28 ± 3 days post ablation. Baseline and follow up CT scans were performed to assess pulmonary vein stenosis (PVS). Lesions were evaluated with histopathology. All animals survived the follow up period. A total of 545 ablations were delivered: 252 with standard (0 steam pops) and 293 with HPSD RF (2 steam pops, p = 0.501). HPSD led to significantly shorter time to PVI. All 24 PVs were isolated 30 min after ablation with 12/12 standard and 11/12 HPSD remaining isolated at follow up. Histopathology showed all HPSD and standard ablations were transmural. Neither standard nor HPSD ablations produced significant PVS (LIPV narrowing 36.1 ± 11.2% (standard) vs 30.9 ± 22.8% (HPSD); LSPV narrowing 22.2 ± 5.9% (standard) vs 24.8 ± 7.8%(HPSD)). A novel ablation catheter safely and effectively delivered HPSD RF ablation lesions. Ablation time required to achieve PVI with HPSD was more than 3-fold shorter than with standard RF.