The value of signal-averaged P wave ECG in the detecting of patients at risk of atrial fibrillation recurrence after successful cardioversion: The value of signal-averaged P wave after cardioversion

Atrial fibrillation is a very common arrhythmia and mortality and risk of t hromboembolism are higher in patients with atrial fibrillation. Therefore i t is essential to restoring sinus rhythm in patients with atrial fibrillati on. After successful cardioversion, recurrence rate of atrial fibrillation is high. However a good predictor of atrial fibrillation recurrence after s uccessful cardioversion has not been established yet. The aim of the study was to assess the value of high resolution analysis of signal-averaged ECG of P-wave in prediction of atrial fibrillation recurrence after cardioversi on of atrial fibrillation. Methods: The P wave triggered SAECG was recorded in 73 patients after succe ssful cardioversion. Duration of the filtered P-wave and the root mean squa re voltages for the last 20 msec (RMS20) of the P-wave were calculated. All patients were evaluated by echocardiography. Results: During 6 months follow-up period recurrence of atrial fibrillation was observed in 31 (42.5%) patients and in 42 (57.5%) patients sinus rhyth m was maintained. There was no difference in gender, age, presence of organ ic heart disease, left atrial diameter, left ventricular ejection fraction, use of antiaryhthmic drug, and duration of atrial fibrillation. The filter ed P-wave duration was longer and RMS20 value was lower in patients with re currence of atrial fibrillation than in patients who maintained sinus rhyth m (138.3+/-12.5 msec vs. 112.4+/-11.8 msec, p= 0.001; 1.9+/-0.7m v vs 2.5+/ -0.6 m v,.p=0.001). A filtered P-wave duration (3) 128msec associated with a RMS 20 pound 2.1m v had a sensitivity of 70 % and specificity of 76 % for the detection of patients with recurrence of atrial fibrillation after suc cessful cardioversion of atrial fibrillation. We found that the likelihood of recurrence of AF after cardioversion was increased 4.31 (95% confidence interval 2.08-9.83) fold if these parameters were used. Conclusion: These results suggest that signal-averaged ECG of P-wave may be helpful for identification of patients with recurrence of atrial fibrillat ion after successful cardioversion.