Background

Pulsed field ablation (PFA) yields a novel ablation technology for atrial fibrillation (AF). PFA lesions promise to be highly durable, however clinical data on lesion characteristics are still limited.

Objective

This study sought to investigate PFA lesion creation with ultra-high-density (UHDx) mapping.

Methods

Consecutive AF patients underwent PFA-based pulmonary vein isolation (PVI) using a multispline catheter (Farwave, Farapulse Inc). Additional ablation, including left atrial posterior wall isolation (LAPWI) and mitral isthmus isolation (MI) were performed in a subset of persistent AF patients. Extent of PFA-lesions and decrease of LA-voltage were assessed with pre- and post PFA UHDx-mapping (OrionTM catheter and RhythmiaTM 3D-mapping system, Boston Scientific).

Results

In 20 patients, acute PVI was achieved in 80/80 PVs, LAPW isolation in 9/9 patients, MI isolation in 2/2 (procedure time: 123±21.6minutes, fluoroscopy time: 19.2±5.5minutes). UHDx-mapping subsequent to PVI revealed early PV-reconnection in 5 case (5/80, 6.25%). Gaps were located at the anterior-superior PV ostia and were successfully targeted with additional PFA. Repeat UHDx mapping after PFA revealed significant decrease of voltage along the PV ostia (1.67±1.36mV vs. 0.053±0.038mV, P<0.0001) with almost no complex electrogram-fractionation at the lesion border zones. PFA-catheter visualization within the mapping system was feasible in 17/19 (84.9%) patients and adequate in 92.9% of ablation sites.

Conclusion

For the first time illustrated by UHDx mapping, PFA creates wide antral circumferential lesions and homogenous LAPW isolation with depression of tissue voltage to a minimum. Although with a low incidence, early PV reconnection can still occur also in the setting of PFA.

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