Ventricular Fibrillation During Pulsed Field Ablation With Dual-Energy Focal Catheters in Patients With Cardiac Implantable Electronic Devices

BACKGROUND: Arrhythmia induction during catheter ablation in patients with cardiac implantable electronic devices (CIEDs) has been reported, but the risk associated with pulsed field ablation (PFA) remains poorly characterized. OBJECTIVE: To estimate the procedural incidence of unexpected ventricular fibrillation (VF) during PFA in patients with CIEDs and describe associated clinical and device findings. METHODS: We performed a retrospective single-center cohort study of consecutive PFA procedures in patients with CIEDs. All procedures were reviewed for unexpected VF. RESULTS: Among 107 consecutive procedures using PFA energy in patients with CIEDs, 83 were atrial and 24 were ventricular ablations. Unexpected VF occurred in 4 patients (overall incidence 3.7%, 95% CI 1.0% - 9.3%): 1 during left atrial PFA for pulmonary vein isolation and 3 during left ventricular PFA for ventricular tachycardia ablations. VF occurred at ablation sites both near and remote from CIED lead tips. Device electrograms demonstrated prominent ablation artifact with abnormal triggered activity and mode switch behavior. Intra-procedural recordings also demonstrated local capture and R on T mechanisms. CONCLUSIONS: Unexpected VF during PFA in patients with CIEDs occurred in 3.7% of procedures. These results complement prior adverse-event reports and support systematic pre-, intra-, and post-procedure CIED management, with external defibrillation immediately available, whenever PFA or dual-energy ablation is performed in patients with cardiac devices.