Heart Rate Variability as a Potential Marker for the Recurrence of Atrial Fibrillation after Electrical Cardioversion

Abstract

Backgound: Cardiac autonomic nerve activity is important in cardiac arrhythmogenesis. We evaluated whether heart rate variability (HRV) with pre and post-DC cardioversion (DCC) could be used as predictors for atrial fibrillation (AF) recurrence after successful DCC. Methods: Forty-one consecutive patients with persistent AF who had HRV evaluation were treated with DCC. Three patients failed sinus conversion and thirty-eight patients (59 ages, 68% men) were enrolled. After successful DCC, post-DCC HRV was measured for 2 to 3 hours before discharge. Results: Twenty-one (55%) patients showed AF recurrence within 2 months after DCC. With HRV measured before DCC, those with recurrence showed higher VLF (10911±6080 vs. 7183±3794 ms2), LF (5781±2921 vs. 3770±1686 ms2), total power (17552±9145 vs. 12030±5540 ms2), and SDANN (173±45 vs. 140±46 ms), whereas MSSD (97±25 vs. 138±261 ms) was lower than those in sinus rhythm (all, p<0.05). LF/HF ratio (3.49±1.36 vs. 4.49±2.29) showed no significant difference. Post-DCC HRV indices did not show any relationship with AF recurrence. There were no clinical and echocardiographic parameters related with AF recurrence except for LA volume (89±16 in sinus vs. 106±18 mm3 in AF recur, p=0.021). Conclusion: Increased HRV measured before DCC was associated with AF recurrence after successful DCC in persistent AF patients, suggesting important role of cardiac autonomic activity for AF recurrence.