Temporary Loss of Pacemaker Capture During Focal Pulsed Field Ablation: A Case of Reversible Lead–Energy Interactions

BACKGROUND: Pulsed field ablation (PFA) is increasingly used for atrial arrhythmia ablation and is considered safe in patients with cardiac implantable electronic devices, though intraprocedural lead interactions remain undercharacterized. CASE: We report a 75-year-old woman with a dual-chamber pacemaker who underwent focal PFA for recurrent atrial tachycardia using a 9-mm lattice-tip catheter. Immediately following PFA near the superior vena cava-right atrial junction, atrial lead capture was lost with transient right atrial lead threshold elevation and T-wave oversensing. All parameters normalized within 1 h. CONCLUSIONS: This case highlights reversible lead-energy interactions and the importance of real-time device monitoring when ablating near indwelling leads.