Advanced interatrial block predicts clinical recurrence of atrial fibrillation after catheter ablation

Abstract Background It has been demonstrated that advanced interatrial block (IAB) is associated with an increased risk of atrial fibrillation (AF); however, the impact of advanced IAB on recurrence of paroxysmal AF after catheter ablation is not clear. Methods 204 consecutive patients with paroxysmal AF who underwent index circumferential pulmonary vein (PV) isolation were prospectively enrolled. In all patients, a resting electrocardiogram in sinus rhythm was evaluated for the presence of advanced IAB, defined as a P-wave duration >120 ms and biphasic (±) morphology in the inferior leads. Advanced IAB was detected in 20.1% of patients. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30 s beyond 3 months after the catheter ablation in the absence of any antiarrhythmic treatment. Results During the mean follow-up period of 13.9 ± 6.2 months (range, 3–27 months), 62 patients (30.4%) developed recurrence of AF. The recurrence rate was higher in patients with advanced IAB than those without advanced IAB (46.3% vs. 26.4%, p  = 0.006). Cox regression analysis with adjustment for age, P-wave duration, CHADS 2 score, and PV isolation identified advanced IAB (hazard ratio, 2.111; 95% confidence interval, 1.034–4.308; p  = 0.040) and left atrial diameter (hazard ratio, 1.051; 95% confidence interval, 1.004–1.100; p  = 0.034) as two independent predictors of recurrence of AF. Conclusions Patients with advanced IAB were at an increased risk of AF recurrence after catheter ablation.