Interatrial block in ECG after immediate electrical cardioversion as a predictor of recurrence of atrial fibrillation

Abstract

The association between the presence of interatrial block and supraventricular arrhythmias has been widely demonstrated in various clinical scenarios. The aim of the present study is to demonstrate that its presence in the ECG performed post immediate electrical cardioversion (ECV) of atrial fibrillation is a predictor of recurrence of this arrhythmia. Methods: Between January and December 2015 there were 117 patients admitted for elective electrical cardioversion of paroxysmal or persistent atrial fibrillation (AF), 93 of which reverted to sinus rhythm and the presence of interatrial block (IAB) was analyzed through 12-lead ECG. The primary endpoint was recurrence of AF post-ECV at six months. The secondary endpoints were time to first recurrence in patients with and without interatrial block, time to first recurrence according to the subtype of IAB, and the correlation between IAB and dilation of the left atrium. Results: From the 93 patients with successful ECV, clinical and electrocardiographic monitoring was performed on 91 of them for six months. Patients with interatrial block had a left atrium area in the echocardiogram higher than in patients without block (p=0.04). During follow-up, a statistically significant difference was found in the recurrence of AF among patients with and
without interatrial block (p=0.04), with earlier recurrence in patients with block. No difference in recurrence of AF between interatrial block subtypes was observed (p=0.10). Conclusion: The presence of interatrial block in the ECG post immediate electrical cardioversion of atrial fibrillation can be a useful and simple tool to predict recurrence.