Ablation of slow activation areas in addition to pulmonary vein isolation improves the maintenance of the sinus rhythm in patients with persistent atrial fibrillation.

Abstract

Background: Slow activation areas, characterized by decreased conduction velocities in the left atrium, are commonly observed in patients with persistent atrial fibrillation (PeAF). However, it remains unclear whether the ablation of slow activation areas combined with pulmonary vein isolation (PVI) improves clinical outcomes in these patients.

Methods: This single-center retrospective study included patients who underwent catheter ablation for PeAF. A total of 78 consecutive patients were included in the PVI + SAA group, while another 78 patients who underwent PVI with/without the roof line, matched 1:1 by propensity score, served as the control group. Slow activation area was defined as ≥ 4 10 ms-step isochrones within 10 mm distance. The endpoint was AF recurrence, atrial flutter, or atrial tachycardia (AT) lasting > 30 s after the blanking period.

Results: The mean mapping time was 10 ± 3 min in the PVI + SAA group. Slow activation areas were identified in 37 of the 78 patients, predominantly located in the anterior wall and often overlapping with the low-voltage areas. The proportion of atrial arrhythmia-free patients was significantly higher in the PVI + SAA group compared to the PVI group (Log-rank P = 0.024; hazard ratio [HR]: 0.40; 95% confidence interval [CI]: 0.19-0.85). Subgroup analysis showed no significant difference in AT/AF recurrence rates between patients who underwent additional ablation of slow activation area and those without identified slow activation areas in the PVI + SAA group (Log-rank P = 0.73; HR: 1.20; 95% CI: 0.42-3.42).

Conclusions: Slow activation areas can be efficiently identified using isochronal mapping. Targeted ablation of slow activation areas helps reduce AT/AF recurrence in patients with PeAF.