Bayés syndrome phenocopy in a patient with 1: 1 atrial flutter and corrected tetralogy of Fallot

Bayés syndrome is currently defined as the finding of advanced interatrial block (a-IAB) on 12-lead ECG associated with atrial fibrillation (AF) (1). Several studies have demonstrated the high risk of developing atrial fibrillation for patients with a-IAB, which has practical consequences of anticoagulant administration (2-4). Patients with tetralogy of Fallot have a high risk of developing supraventricular arrhythmias during their lifetime. The most common arrhythmias are represented by an atrial flutter, intraatrial reentry, and atrial fibrillation (5, 6). Minimal data exist in the literature reporting the presence of a-IAB on the 12-lead ECG in patients with corrected tetralogy of Fallot and atrial flutter or atrial fibrillation, and even less about phenocopies of Bayés syndrome in these patients.