PO-622-01 CHRONIC PULSED FIELD ABLATION LESIONS IN THE PORCINE LV: DOSE DEPENDENCE AND CORRELATION WITH LATE GADOLINIUM ENHANCEMENT MRI

Abstract

Pulsed Field Ablation (PFA) is a promising modality for ventricular arrhythmia ablation due to its speed, apparent tissue selectivity, and the potential to create large lesions. Recent work showed that lesions in the left ventricle (LV) increase in size with number of PFA repetitions; however, the potential to create transmural lesions has not been reported. Investigate the extent of PFA lesions created using a range of pulse trains and evaluate late gadolinium enhancement (LGE) MRI for in vivo lesion visualization. PFA was performed in 8 swine via an 8F, 5 mm tip focal catheter setup and R-wave gated biphasic pulse trains of 1300 V (4 trains) and 1500 V (1, 4, 8, and 16 trains). After 6-7 weeks, animals were brought to a 3T MRI (GE) for imaging using LGE (TI=300 ms, resolution=1.4 mm3). Lesion dimensions were measured manually from corresponding MRI and excised tissue slices. PFA lesion dimensions measured using MRI and gross pathology were in strong agreement (Fig 1; R=0.88, p<0.01; bias=0.03±2.1 mm, 95% limits of agreement=[-4.0, 4.1]). 2/14 lesions created using 1500 Vx8 trains and x16 trains were transmural. Linear mixed effects models revealed significantly deeper lesions created using 1500 Vx16 trains compared to 1500 Vx1 train (Fig 2; pathology, p<0.05; MRI, p<0.01). Lesions created using 1300 Vx4 trains and 1500 Vx4 trains did not differ significantly, either from pathology or MRI. Similar trends were observed for lesion width and volume as a function of PFA trains. LGE MRI at 6-7 weeks post ablation accurately visualizes chronic PFA lesions in vivo. Lesions increased in depth and width with the number of PFA trains applied. Increasing pulse voltage and trains can achieve transmurality in the porcine LV.View Large Image Figure ViewerDownload Hi-res image Download (PPT)