Relationship between the distribution of left atrial low-voltage zones and post-ablation atrial arrhythmia recurrence in patients with atrial fibrillation.

BACKGROUND: Low-voltage zones (LVZ) are surrogate markers for cardiac fibrosis, which contribute to the maintenance of atrial fibrillation (AF). The aim of this study was to investigate the effect of the distribution of left atrial (LA) LVZ on the outcome following catheter ablation. METHODS: This retrospective study enrolled patients with AF who underwent initial catheter ablation. LVZ were defined as areas with bipolar voltage amplitude <0.5 mV. The left atrium was divided into six regions (anterior wall, roof, posterior wall, lateral wall, septum, and inferior wall) to describe the distribution of LVZ. The primary endpoint was atrial arrhythmia (AA) recurrence lasting >30 s after the initial catheter ablation. RESULTS: Altogether, 148 patients were included, with a mean age of 61 ± 11 years, of which 53 (35.8%) had persistent AF. During a mean follow-up of 14 ± 3 months post-ablation, AA recurrence occurred in 25 (16.9%) patients after the initial catheter ablation. Kaplan-Meier analysis showed that patients without roof LVZ had a higher AA-free survival rate than those with roof LVZ (P = 0.047). In the multivariate Cox regression analysis, the proportion of LA LVZ ≥6% [hazard ratio (HR) 2.315, 95% confidence interval (CI) 1.048-5.114; P = 0.038] and a longer AF duration (HR 1.008, 95% CI 1.002-1.014; P = 0.006) were independent predictors of AA recurrence. CONCLUSIONS: In patients with AF, LA roof LVZ may increase the risk of AA recurrence after initial catheter ablation.