Direct Atrial Fibrillation Termination During Pulsed Field Ablation: Association With Intracardiac Cycle Length.

Background

Pulsed field ablation (PFA) enables rapid and tissue-selective pulmonary vein isolation (PVI). However, the electrophysiological determinants of direct atrial fibrillation (AF) termination during PFA remain unclear.

Objective

To investigate the clinical and electrophysiological characteristics associated with direct AF termination during PFA-guided PVI.

Methods

This prospective, single-center study included 72 patients with persistent AF undergoing PFA-based PVI. Intracardiac tachycardia cycle length (TCL) was measured at each pulmonary vein before ablation. Patients were classified into termination and no-termination groups, and clinical and electrophysiological parameters were compared.

Results

Direct AF termination occurred in 14 patients (19.4%), most frequently at the right superior pulmonary vein (RSPV) (n = 8) , followed by the Left superior pulmonary vein (LSPV) (n = 6). Patients with termination had shorter AF duration, smaller left atrial size, and lower NT-proBNP levels. TCL at the superior pulmonary veins, particularly the RSPV, was significantly longer in the termination group, while no differences were observed at other pulmonary veins. At 3 months, AF recurrence tended to be lower in the termination group, although the difference did not reach statistical significance.

Conclusion

Direct AF termination during PFA is associated with favorable clinical characteristics and localized TCL prolongation in the superior pulmonary veins, suggesting their important role in AF maintenance rather than a purely random procedural effect.