Atrial stunning as predictor of early relapse into atrial fibrillation after cardioversion

Although the high rate of success after cardioversion, less than 50% of patients maintain sinus rhythm for the first year. In view for the high percentage of relapse into atrial fibrillation, it is interesting to analyze the relationship between atrial stunning after cardioversion and relapse into atrial fibrillation. Thus, we evaluated 101 patients with atrial fibrillation and successful cardioversion. Atrial mechanical function was assessed by measures of transmitral peak A wave velocity, determined before and weekly after cardioversion during 1 month. Fifty-five percent of patient relapse into atrial fibrillation during follow-up. No significant differences were found in clinical and echocardiographic variables between the group with and without relapse. However, the group of patients who relapsed into atrial fibrillation showed a lower peak A wave velocity immediately after cardioversion than patients who maintain in sinus rhythm at month (0.44 ± 0.27 vs. 0.60 ± 0.38 m/s p < 0.01). Impaired atrial function improves during the first 14 days after cardioversion.