Chronic remap findings post left atrial posterior wall ablation with the pentaspline pulsed field ablation platform

Persistent atrial fibrillation (peAF) patients often require multiple interventions and most common approach for beyond pulmonary vein isolation (PVI) is left atrial posterior wall (LAPW) ablation (1, 2). The unique safety profile of pulsed field ablation (PFA) makes the PVI+LAPW ablation promising in treating PerAF patients, but data on the durability of the lesion set is scarce (3).

We aimed to report the chronic remap findings after LAPW PFA using the multipolar pentaspline catheter including th:e PVI+PWA durability and additional arrhythmia substrates in patients who underwent re-do procedure due to AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence.

This was a retrospective observational study on the PWA+PVI durability in PeAF/long standing (ls)-PeAF patients undergoing a re-do ablation procedure. The durability of the lesion set was confirmed with electroanatomical mapping (EAM) where durably ablated tissue was defined as an area with voltage <0,05 mV combined with non excitability with high output pacing. Ablation of LAPW during the index procedure was performed using 2.0 kV biphasic waveforms, 2 deliveries for each application site. A LAPW lesion set included two anchor lesions per pulmonary vein extending to the LAPW and PFA application in two rows (upper and lower) between the anchor lesions with the catheter in a flower conformation and 75% overlap for the neighboring application sites at 3D EAM.

Nineteen patients underwent a remap procedure after LAPW ablation (9 perAF, 10 ls-PeAF). The age median was 67 years (Q1-Q3: 62-72,5 years; 74% male). The median number of application sites on the upper and lower LAPW was 6 (Q1-Q3; min-max: 5-7.5; 4-8) and 6 (Q1-Q3; min-max: 5-7; 4-8), respectively. Nine patients had AF as recurring arrhythmia, one patient had typical AFL, one had atypical AFL and eight patients had recurrence of multiple arrhythmia types. PVI was durable in 15 patients and there was no conduction across the LAPW due to the contingency of the inferior row lesion set in any of the patients. In 7 there was a typical regression of lesion set at the central superior part of LAPW (presumed anatomical trajectory of the septopulmonary bundle). In all but 2 patients re-do procedure was performed using focal PFA (Table 1).

Re-map procedures of persistent AF patients undergoing PVI+LAPW ablation with single-shot PFA have shown durable PVI in 79%, block of conduction across LAPW in all of the patients and a typical lesion regression pattern in 37% of patients. Our data suggests that arrhythmia recurrence post PFA PVI+PWA with pentaspline catheter could reflect inability of this platform to homogenously ablate LAPW and therefore patients should be offered remap procedure if they present with atrial arrhythmia recurrence after this procedure.