Pulsed‐field ablation combined with ultrahigh‐density mapping in patients undergoing catheter ablation for atrial fibrillation: Practical and electrophysiological considerations

Abstract

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 ultrahighdensity (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 ablation (MI) were performed in a subset of persistent AF patients. The extent of PFA-lesions and decrease of LA-voltage were assessed with pre-and post PFA UHDx-mapping (Orion™ catheter and Rhythmia™ 3D-mapping system, Boston Scientific).Results: In 20 patients, acute PVI was achieved in 80/80 PVs, LAPW isolation in 9/9 patients, MI ablation in 2/2 (procedure time: 123 ± 21.6 min, fluoroscopy time: 19.2 ± 5.5 min). UHDx-mapping subsequent to PVI revealed early PV-reconnection in five 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 a significant decrease of voltage along the PV ostia (1.67 ± 1.36 mV vs. 0.053 ± 0.038 mV, p < .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.

Pulsed field ablation in patients with complex consecutive atrial tachycardia in conjunction with ultra‐high density mapping: Proof of concept

“…Nevertheless, the limited published data on LAPWI so far demonstrate high acute and chronic LAPW isolation rates. 10,11 In our cohort, no esophageal lesion was detected. Also, in the Manifest-PF survey no esophageal lesion was found in a large patient cohort of 1758 patients undergoing PFA including LAPWI in a minor portion of patients.…”

Pulsed-field ablation for the treatment of left atrial reentry tachycardia

“…In a pre-market trial, the same PFA device that was used in our study was successful in LAPW isolation in 25/25 patients (13,14) . With a different PFA catheter platform allowing for focal lesions, application of a roof line using PFA was effective in 22/22 patients (23).…”

“…Gunawardene et al reported successful mitral isthmus ablation using PFA in two patients without the need for additional RFA. However, in one case, coronary artery spasm occurred after eight PFA applications and resolved upon administration of nitroglycerin (13). Although coronary arteries did not display particular susceptibility to PFA in animal models (22) or in our own clinical experience in any patients, the risk of coronary artery spasm during ablation of the mitral isthmus area needs further investigation.…”

“…In that regard, the tissue-selective properties of PFA should reduce the risk of esophageal damage even with largearea ablation (19)(20)(21)(22). Indeed, two studies found no esophageal lesions on post-procedural esophagogastroduodenoscopy after LAPW isolation using the same PFA system (13,14). Second, Pambrun et al showed the importance of epicardial bypass in cases with residual gaps in the roof line (5).…”

Left atrial field isolation with pulsed field ablation: a new option for challenging left atrial tachycardias?

“…However, this catheter is only approved for catheter ablation of AF by means of pulmonary vein isolation. Therefore, data on the use of PFA applied to substrates other than the pulmonary veins are limited (2,3).…”