Advanced interatrial block predicts recurrence of atrial fibrillation after accessory pathway ablation in patients with Wolff-Parkinson-White syndrome.

Background: Paroxysmal atrial fibrillation (AF) frequently occurs in patients with Wolff-Parkinson-White (WPW) syndrome. Although successful ablation of the accessory pathway (AP) eliminates paroxysmal AF in some patients, in other patients it can recur.

Hypothesis: We investigated the clinical utility of advanced interatrial block (IAB) for predicting the risk of AF recurrence in patients with verified paroxysmal AF and WPW syndrome after successful AP ablation.

Methods: This retrospective study included 103 patients (70 men, 33 women; mean age, 44 ± 16 years) with WPW syndrome who had paroxysmal AF. A resting 12-lead electrocardiogram was performed immediately after successful AP ablation to evaluate the presence of advanced IAB, which was defined as a P-wave duration of >120 ms and biphasic [±] morphology in the inferior leads.

Results: During the mean follow-up period of 30.9 ± 20.0 months (range, 2-71 months), 16 patients (15.5%) developed AF recurrence. Patients with advanced IAB had significantly reduced event-free survival from AF (P < .001). Cox regression analysis with adjustment for the left atrial diameter and CHA DS -VASc score identified advanced IAB (hazard ratio, 9.18; 95% confidence interval [CI], 2.30-36.72; P = .002) and age > 50 years (hazard ratio, 12.64; 95% CI, 1.33-119.75; P = .027) as independent predictors of AF recurrence.

Conclusions: Advanced IAB was an independent predictor of AF recurrence after successful AP ablation in patients with WPW syndrome.