Aims: To investigate the use of ambulatory electrocardiogram (ECG) monitoring in atrial fibrillation (AF) to predict recurrence after electrical cardioversion (ECV).
Methods: RR interval variables were obtained from 24 hours ECGs recorded before ECV in 119 patients (85 men, age 66 +/- 10 years) with persistent AF. Patients were followed for 1 month.
Results: Of the 119 patients, 16 (13%) failed ECV and 65 (55%) were in AF at 1 week and 81 (68%) at 1 month after ECV. The maximum RR interval (RR-max) and the minimum RR interval (RR-min) during AF were found to be reproducible. The RR-max was longer in those who had AF 1 week (2.55 +/- 0.49 vs 2.01 +/- 0.52 seconds, P = 0.005) and 1 month (2.56 +/- 0.50 vs 1.89 +/- 0.43 ms; P < 0.001) after ECV than in those who maintained sinus rhythm. Those in AF at 1 month included more patients with RR-max > or = 2.8 seconds (31% vs 11% P = 0.021). The average heart rate was lower in patients with RR-max > or = 2.8 seconds, but the average rate was not predictive of AF recurrence.
Conclusion: Ventricular pauses during AF predict relapse after ECV.