PO-01-067 ATRIO-VENTRICULAR DELAY AFTER DELIVERY OF PULSED FIELD ABLATION OF THE PULMONARY VEINS

Abstract

Pulsed field ablation (PFA) has been introduced as a new ablation modality for PV isolation. While PFA appears to have increased safety through a lack of thermal injury leading to lower risks of collateral damage to bystander anatomical structures, PFA is known to cause sinus bradycardia, hypotension, and atrial fibrillation, probably mediated by high electrical field induced autonomic stimulation. However, the effect on atrioventricular (AV) nodal conduction is unknown. To measure AV delay immediately after PFA. 412 PFA deliveries recorded in 12 patients were analyzed using a novel electrophysiology recording system (ECGenius System, CathVison, Denmark). Each pulmonary vein was treated with a minimum of eight pulses of energy with a 20 electrodes pentaspline catheter. Energy was delivered in two anatomical positions with the catheter able to achieve two delivery shapes. Ten seconds of electrogram information was recoded pre and post every delivery and the PR interval was manually measured, with prolongations of 10 ms or more post ablation considered significant (Figure 1). Recovery of AV conduction was measured from the end of the energy delivery pulse to the first beat conducted with a delay of less than 10 ms from the measured pre-delivery baseline. The study enrolled 12 patients (4 female) with a mean age of 63.3 years (SD = 13.2). In total, 412 lesions were delivered. Two patients presented and were treated in an atrial arrhythmia and three patients had no measurable change in AV conduction. However, seven patients had 49 measurable delays in AV conduction after PFA energy delivery ranging from 10 ms to 214 ms with a mean delay of 36.2 ms (SD = 34.4 ms). Eight measured intervals exceeded 200 ms post delivery. Recovery from AV delay took an average of 5.17 sec (SD = 4.2 sec) with the longest recovery time being 25 sec. Table 1. shows delay and recovery by vein. This report details the observation of the occurrence of AV-delay after the delivery of PFA. The incidence of this phenomenon was 58.3% of patients in the study. Pulsed field ablation appears to have a transient effect on the intrinsic cardiac autonomic nervous system manifested in changes to atrioventricular node response.