PO-04-001 COMPARISONS OF ABLATION LESION FEATURES ALONG PULMONARY VEIN ISOLATION LINES USING RADIOFREQUENCY ABLATION CATHETER AND CRYOBALLOON ABLATION CATHETER

Abstract

Direct cell injury and intense inflammatory response occur in radiofrequency ablation (RFA), therefore, heterogeneous ablation lesions were created. Conversely, in cryoballoon ablation (CBA), ablation lesion is created without injury of endocardial tissue architecture and catheter position is stable by adhesion of the catheter to tissues, hence homogeneous ablation lesions were created. However, few studies have investigated the homogeneity of border zone between the left atrium and pulmonary vein isolation (PVI) lines among energy sources. We hypothesized that heterogeneous lesion along PVI lines are more frequently found in patients undergoing RFA than those undergoing CBA. The purpose of this study was to investigate the association between homogeneity of ablation lesions along PVI lines and energy source of catheter ablation. In total, 79 consecutive patients who underwent second AF ablation with RhythmiaTM mapping system (age, 70 ± 9 years; female, 26 [33%]) were retrospectively enrolled. As an indicator of heterogeneous lesion, gaps and fractionated signals along previous PVI lines was assessed during pacing from the right atrium. Fractionated signal was defined as electrograms with at least 7 deflections highlighted by LUMIPOINTTM complex activation tool. The proportion of line length with fractionated signals to anatomical line length was compared between patients undergoing RFA and patients undergoing CBA. CBA were performed for 31 (39%) patients in initial AF ablation. There were more PV gaps in CBA group than in RFA group (1 [1-2] versus 0 [0-1], p < 0.001). Anatomical line length of left pulmonary vein and right pulmonary vein were similar in CBA group and RFA group (left pulmonary vein, 121 [109-136] mm versus 118 [107-133] mm, p = 0.78; right pulmonary vein, 126 [116-139] mm versus 121 [108-131] mm, p = 0.08). The proportion of line length with fractionated signals to anatomical line length of left pulmonary vein and right pulmonary vein was significantly higher in RFA group than in CBA group (Figure). In regions other than left posterior region, left bottom region and right bottom region, the proportion of line length with fractionated signals to anatomical line length was also significantly higher in RFA group than in CBA group (Figure). PVI lines created by RFA demonstrated serrated bordering zones, whereas PVI using CBA created sharply delineated lesions.