Contact Strategies and Isolation Endpoints in Pulsed Field Ablation of Persistent Left Superior Vena Cava: A Case Series.

Persistent left superior vena cava (PLSVC) can trigger atrial fibrillation. Thermal ablation of this vessel carries risks of phrenic nerve palsy and coronary artery spasm, whereas pulsed field ablation still lacks procedural guidance for the PLSVC diameter taper, which narrows from the distal segment to a dilated coronary sinus ostium. We report two contact strategies applied in three patients: a guidewire-anchored rail with steerable sheath tension for a fixed-loop catheter, and loop-diameter adjustment for a variable-loop catheter. Acute bidirectional block was confirmed by pacing in all three cases; in one case, dissociated spontaneous potentials provided an endpoint more stringent than atrial fibrillation termination alone. No complications occurred. These findings provide initial guidance for ablating the tapered PLSVC, although long-term durability requires prospective validation.