Evaluation of adaptability of a single shot pulsed field ablation device in pulmonary vein anatomical variants

Background

Pulsed field ablation (PFA) is a novel method of cardiac ablation (1) where there is insufficient knowledge on the ability of this single-shot device to accommodate for anatomic variations of the pulmonary veins (PVs). The aim of this study was to characterize lesions created by a PFA pentaspline catheter in first path isolation and localization of gaps depending on PV size and presence of anatomical variants.

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Methods

We enrolled 61 patients undergoing atrial fibrillation ablation with single-shot PFA PV isolation at our centre between December 2023 and January 2025. All patients had a previous computer tomography with reconstruction of the left atrium and the PVs anatomy. PV measurements were performed on high density electroanatomic maps. Patients were divided into two groups based on first-path isolation: 48 with complete isolation (A) and 13 with areas with persistent conduction (B). 10 patients presented anatomical variants, 4 with common trunk (CT) (7.01%) and 6 with accessory veins (AV) (10.52%), 5 right AV and 1 left AV. They were followed up for a minimum of 3 months up to a period of 12 months, gathering recurrences, cardioversion episodes (CVE), and the need for a redo procedure.

Results

48 patients (78.7%) achieved complete first path isolation. Venous reconnections found were: 18, with 13 patients (21.3%) presenting untreated areas identified by electroanatomical mapping. The circumference of the CT was greater (82.25 ± 17.5 mm) and the circumference of the AV smaller (39.33 ± 12.85 mm), with first-path isolation in all cases. For the PVs, the mean for each was: PVI (62.29 ± 12.52 mm), PVI (67.64 ± 7.7 mm), PVD (68.32 ± 18.5 mm), and PVI (65.98 ± 7.9 mm). No statistically significant relationship was found between venous circumference and the presence of gaps (Table 1). Most gaps were found in the superior PVs (LSPV 7 (39%); RSPV 5 (28%), followed by the inferior veins (RIPV 4 (22%), LIPV 2 (11%)). The vein with the greatest untreated areas was the RSPV (28’7 ± 18’48 mm), followed by the LIPV (22’13 ± 14’85), RIPV (20’90 ± 7’89mm) and the LSPV (18’84 ± 7’7mm), without significant differences. The anterosuperior (AS) region was the most frequently anatomical region with persistent conduction (Figure 1). There were no statistically significant differences in follow-up: 14 patients (25.45%) required ≥1 CVE: 20.93% in group A versus 38.46% in group B, p=0.274; the need for a second procedure also showed no significant differences between groups A and B: 0% vs 15.38% (p=0.51).

Conclusion

first-path isolation was independent of PV size and presence of anatomical variants of PVs without significant impact on long term outcome. The anterosuperior (AS) region tends to be the region which more frequently showed conduction persistence. Second-path ablation of gaps guided by electroanatomical mapping has similar results to patients without gaps.