Prolonged PR Interval Predicts Clinical Recurrence of Atrial Fibrillation After Catheter Ablation

Background A prolonged PR interval is known to be a poor prognostic factor in cardiovascular disease. The aim of this study was to investigate the association between PR interval and clinical outcome in patients undergoing radiofrequency catheter ablation ( RFCA ) of atrial fibrillation ( AF ). Methods and Results We prospectively included 576 patients with AF (75.5% male, 57.8±11.6 years old, 68.8% paroxysmal AF ) who underwent RFCA . We analyzed preprocedural sinus rhythm ECG s obtained in the absence of antiarrhythmic drug, and all enrolled patients were categorized into 4 groups based on the quartile values of the PR interval (166, 182, and 202 ms), and were analyzed according to the left atrium (LA) volume (CT; Computed tomography), LA voltage (NavX), and clinical outcome of AF ablation. Based on quartile value of PR interval, the highest quartile of PR interval (Q4; PR ≥202 ms) was oldest ( P <0.001), and most likely to have persistent AF ( P <0.001) and hypertension ( P =0.013) compared with the other groups. However, there was no significant difference in LA conduction velocity and atrial effective refractory period. Q4 had the greatest LA dimension ( P <0.001) and volume index ( P <0.001), and lowest LA appendage‐emptying velocity ( P <0.032) and LA voltage ( P <0.001) compared with the others. For 13.1±7.5 months, the classification based on the PR interval was a significant predictor of AF recurrence after RFCA of AF ( HR =1.969, 95% CI 1.343 to 2.886, P =0.001). Conclusions The PR interval was closely associated with advanced LA remodeling due to AF , and had a noninvasive significant predictive value of clinical recurrence of AF after RFCA .