The efficacy of ultra-high-density mapping guided partial antral ablation for pulmonary vein isolation in atrial fibrillation patients

The muscular discontinuities or lack of myocardial extensions around the pulmonary veins (PVs) antrum were previously reported. The objective of our study was to compare the efficacy of a partial antral ablation for PV isolation (PVI) using ultra-high density (UHD) mapping with a conventional wide antral circumferential ablation (WACA) in atrial fibrillation (AF) patients. A total of 119 patients medical records who received catheter ablation for AF in our hospital were analyzed. In one group of patients, detailed activation mapping of each PV was performed using a UHD mapping system. Each PV antral segment’s activation pattern was classified into “directly-activated from the LA” or “passively-activated from an adjacent PV segment” patterns. The ablation applications were performed at the directly-activated PV antral segment only for the PVI when the PV had “passively-activated segments” (partial antral ablation; PA-UHD group). Another patient group received a conventional WACA for the PVI (WACA group). Sixty patients received partial antral ablation (PA-UHD), and age/sex-matched 59 patients received WACA. In the PA-UHD group, passively-activated segments were observed in 58.3% of all PV segments. The success rate of a partial antral ablation for the PVI in PVs with passively-activated segments was 85%. The 1-year atrial tachyarrhythmia recurrence did not differ between the PA-UHD and WACA groups. Our study revealed the presence of passively-activated PV segments, which could potentially indicate muscular discontinuity at the PV-LA junction. In most PVs with passively-activated segments, PVI was successfully achieved by ablation with only directly-activated segments. The 1-year recurrence rate of atrial tachyarrhythmia in PA-UHD group was comparable to that observed in the WACA group.