Mitral Isthmus Conduction Delay After Pulsed Field Ablation of a Persistent Left Superior Vena Cava.

A persistent left superior vena cava (PLSVC) can contribute to atrial fibrillation (AF) and it often requires complex ablation because of multiple electrical connections with the left atrium. An 86-year-old woman underwent pulsed field ablation (PFA) for pulmonary vein and PLSVC isolation. After successful isolation without causing either phrenic nerve injury or coronary spasm, postprocedural remapping revealed a newly formed low-voltage area with conduction delay in the adjacent mitral isthmus. No atrial tachyarrhythmia recurrence was observed during the one-year follow-up. This case suggests that careful remapping may be warranted after PLSVC ablation using PFA.