B-AB03-03 PULSED FIELD ABLATION OF LEFT VENTRICULAR MYOCARDIUM IN A SWINE INFARCT MODEL

Abstract

Pulsed field ablation (PFA) leads to cell death by irreversible electroporation. However, there is limited data about lesion characteristics in ventricular myocardium in the presence of myocardial scar. To evaluate the lesion characteristics of PFA in healthy and infarcted left ventricular (LV) myocardium. Swine (n=6) underwent 120min LAD balloon occlusion myocardial infarction (MI) and were survived 6-8 weeks. PFA was delivered to the LV endocardium of 1) healthy myocardium or 2) MI identified with electroanatomic mapping. Bipolar, biphasic PFA was delivered for 2.5secs x 4 applications/site (10secs total) using 2 different catheters: a linear quadripolar (FOCAL, 2000-2100V) or multi-spline 8-pole catheter (BASKET, 1800V) (FARAPULSE, Menlo Park, CA) (Figure). After sectioning, gross lesions were identified, measured using calipers and tissue stained for histology. 21 lesions were delivered to healthy LV and 20 to areas with MI, all without complications. Overall, there was no significant difference in lesion depth between groups (FOCAL vs. BASKET; depth: 5.6 ±1.1 mm vs. 5.5 ± 1.1 mm, P=0.740), while lesion width was greater for BASKET (10.6 ± 2.4 mm vs. 13.3 ± 3.3 mm, P=0.007). In regions of MI, histology showed ablation of surviving myocardium both within and epicardial to scar; lesion depth in MI was not significantly different between catheters (5.6 ± 1.5 mm vs. 4.6 ± 0.9 mm; P=0.235). PFA allows rapid, safe, and effective ablation of surviving islands of myocardium within and around infarcted LV substrate. This technology holds promise for treating infarct-related ventricular tachycardia in humans.