Impact of pulsed field ablation on ganglionated plexi function in atrial fibrillation

Abstract

BACKGROUND: Pulmonary vein isolation (PVI) using thermal energy may exert part of its antiarrhythmic effect via collateral injury to left atrial (LA) ganglionated plexi (GPs). Endocardial pulsed field ablation (PFA) is designed to be cardioselective, but its effect on human GP function is uncertain. OBJECTIVE: This study aimed to systematically evaluate the effect of endocardial PFA on LA GP activity. METHODS: In this prospective cohort study, consecutive patients with persistent atrial fibrillation undergoing first-time PFA were enrolled. Focal high-frequency stimulation during atrial fibrillation identified LA GP sites demonstrating atrioventricular delay (AVD) (AVD-GPs), defined as =50% RR prolongation or asystole during high-frequency stimulation. Wide antral PFA was delivered using a pentaspline catheter to achieve PVI with posterior wall ablation. Segments with AVD-GP sites overlying PFA lesions were retested, and active AVD-GP sites were subsequently targeted with radiofrequency (RF) ablation and reassessed. RESULTS: 10 patients (age 61.9 ± 7.1 years; 3 female [30%]) were enrolled. At baseline, 118 of 591 sites tested (20.0%) met AVD-GP criteria (11.8 ± 7.8 per patient), including 23 (19.5%) at pulmonary vein ostia. Transient AVD occurred during PFA application in 4 of 10 patients (40%). After PFA, 16 of 21 segments (2.0 ± 1.1 segments/patient) with AVD-GP sites overlying PFA-treated regions demonstrated persistent AVD response. After targeted RF ablation, no previously active AVD-GP sites showed AVD response. CONCLUSION: Endocardial PFA does not consistently abolish LA GP function despite lesion delivery at overlapping sites. RF ablation reliably eliminates GP-mediated AVD. These findings support the cardioselective nature of PFA and provide a mechanistic rationale for the prospective evaluation of adjunctive GP ablation following PFA-based PVI strategies.