P-Wave Abnormality Predicts Recurrence of Atrial Fibrillation after Electrical Cardioversion: A Prospective Study

Background Maintenance of atrial fibrillation (AF) is related to atrial electrical inhomogeneity and resultant chaotic reentry. Our aim was to test the hypothesis that abnormalities of P morphology on the surface electrocardiogram (ECG) predict recurrent AF following electrical cardioversion (ECV). Methods A 12‐lead ECG was recorded after ECV for persistent AF in 77 patients (51 men, 65 ± 10 years) and repeated 1 month later. P‐wave duration was obtained in each lead using blinded on‐screen measurement. Maximum P‐wave duration (P‐max) was defined as the longest measurable P‐wave duration in any lead. P‐wave dispersion (PWd) was calculated as the maximum–minimum P‐wave duration. Results One month after ECV, 29 (38%) patients maintained sinus rhythm. Compared with the sinus rhythm group, those with recurrent AF had significantly greater PWd (66 ± 19 vs 57 ± 16 ms, P = 0.024) and included more patients with P‐max ≥142 ms (65% vs 38%, P = 0.023). Using a cutoff of ≥62 ms for PWd and ≥142 ms for P‐max, both indices had similar predictive value (sensitivity 66.7 and 64.6%, specificity 58.6 and 62.1%, respectively). In multiple regression analysis, including established clinical predictors, P‐max ≥142 ms was the only independent predictor of AF recurrence (P = 0.025). Conclusion A prolonged P‐wave duration measured by 12‐lead ECG predicts recurrent AF within 1 month after ECV.