Prognostic Significance of PR Interval Prolongation in Adult Patients With Total Correction of Tetralogy of Fallot

Background: Several studies have demonstrated the importance of mechanoelectrical interaction in patients with surgically corrected tetralogy of Fallot. However, the significance of atrioventricular conduction disturbance, that is PR interval prolongation, on adverse cardiac events in those patients remains to be elucidated. Methods: We examined electrocardiograms at baseline and their temporal change in a total of 176 patients with repaired tetralogy of Fallot (49% men; median age, 17.4 years). Then, we evaluated their correlation with right ventricular volume and function measured by cardiac magnetic resonance and the significance as a risk factor of adverse cardiac events: lethal ventricular arrhythmias, atrial arrhythmias, heart failure hospitalization, complete atrioventricular block (AVB), and all-cause death. Results: First-degree AVB was noted in 25 patients (14%). During a median follow-up of 10.0 (5.0–14.2) years, there was a progressive prolongation of PR interval (2.00±3.99 ms/y). Importantly,...