Effects of Pulsed Field Ablation for Pulmonary Vein Isolation on Vein of Marshall Electrograms.

BACKGROUND

Pulsed field ablation (PFA) creates lesions without direct tissue contact and may affect adjacent nontarget structures. Given the close anatomical relationship between the vein of Marshall (VoM) and the left pulmonary veins (PVs), PFA-based PV isolation may influence VoM electrograms.

OBJECTIVES

This study aimed to characterize real-time changes in VoM electrograms during PFA-based PV isolation.

METHODS

A total of 72 patients undergoing PFA-based PV isolation were studied (FARAPULSE, n = 28; VARIPULSE, n = 21; PulseSelect, n = 23). A 1.6-F electrode catheter was positioned within the VoM to continuously record electrograms during the procedure.

RESULTS

VoM electrograms were eliminated in 16 patients (22%) and reduced in 16 patients (22%). The extent of VoM electrogram alteration differed among PFA systems and was greatest with FARAPULSE (P < 0.001). Electrogram effects were strongly associated with the PFA electrode-VoM distance (median [Q1-Q3]) (no effect, 5.7 millimeters [4.1-7.5 millimeters]; reduction, 3.0 millimeters [2.9-3.7 millimeters]; elimination, 1.8 millimeters [1.5-2.2 millimeters]; P < 0.001). Among patients with acute VoM electrogram elimination, persistent elimination was observed in 9 patients (56%), whereas partial recovery occurred in 1 patient (6%) and complete restoration occurred in 6 patients (38%) by the end of the procedure. All patients with acute VoM electrogram reduction showed complete recovery. Overall, persistent VoM electrogram modification was observed in 14% of patients undergoing PFA-based PV isolation.

CONCLUSIONS

The impact of PFA on VoM electrograms varied among PFA systems and was largely determined by the PFA electrode-VoM distance. Notably, the majority of VoM electrogram alterations were transient.