B-ABO6-02 Pulsed Field Ablation Trains Reduce Tissue Impedance in Patients Undergoing Pulmonary Vein Isolation
Background: Pulsed field ablation (PFA) is proposed as a safe and effective modality for pulmonary vein isolation (PVI). However, its effects on tissue conduction and impedance are not well delineated. Objective: To study the effect of PFA on local tissue impedance and electrogram amplitude in patients undergoing PVI. Methods: Five patients with drug refractory PAF underwent PVI as part of the PULSED AF pilot trial using a nine-electrode circular ablation catheter (PVAC-Gold, Medtronic, Inc.) and a proprietary PFA generator. PFA was delivered at each PV ostium. Four sequential pulse trains of PFA were delivered over one minute at each site. Atrial electrogram amplitude, pacing capture at 5 V 0.5 ms, and pacing impedance from each of 4 bipoles were measured at baseline, and after each of the 4 PFA pulse trains. Results: Four patients were in sinus rhythm and one AF. Baseline atrial electrogram amplitude was 0.39±0.42 mV, and this was reduced to 0.06±0.04 mV after the 4th pulse train (pConclusion: PFA for PVI results in significant decrease in tissue impedance particularly after the first pulse train delivery. This decreasing tissue impedance should result in an increase of PFA current delivery and increased depth of voltage field into the affected tissues with each successive pulse train thereby increasing lesion size.
Shah KB, Mehta N, Kutinsky IB, Stewart MT, Verma A, Calkins H et al. [Haines DE] B-AB06-02 Pulsed field ablation trains reduce tissue impedance in patients undergoing pulmonary vein isolation. Heart Rhythm 2021 Aug; 18(8 Suppl):p.S10.