Value of the atrial signal-averaged electrocardiogram in identifying patients with paroxysmal atrial fibrillation.

Atrial signal-averaged electrocardiogram was compared between 25 patients with paroxysmal atrial fibrillation and 20 healthy persons without atrial arrhythmias (control). The duration time of the high frequency (50-250 Hz) P wave was significantly (P less than 0.01) prolonged in the groups of patients with paroxysmal atrial fibrillation compared with the control group (116 +/- 16.4 versus 92 +/- 8.1 msec). The diagnostic value of the duration of the high frequency P wave for identifying patients with paroxysmal atrial fibrillation was 104 msec. Using this criterion, a sensitivity of 76% and a specificity of 90% were achieved. Our observation has shown that the atrial signal-averaged electrocardiogram is a useful technique for identifying patients with paroxysmal atrial fibrillation.