Usefulness of P wavetriggered Signal averaged Electrocardiogram for the Estimation of Paroxysmal Atrial Fibrillation Risk in Cryptogenic Stroke

초록

Backgrounds: The paroxysmal atrial fibrillation(AF) is one of main cause for ischemic stroke. The P wave-triggered signal-averaged electrocardiogram(signal ECG) is one of useful method for identifying the paroxysmal AF. However, the data of signal ECG in the patients with stroke remained limited. Aims: To investigate the association between findings of signal ECG and the stroke etiology. Methods: We recruited the patients without AF on admission, who was admitted from June 2012 to September, and who took signal ECG and routine work-up. The criteria of ‘RMS20 ≤3.5 μV’ and ‘PWD>120msec’ was defined as ‘atrial late potential’. We analyzed the difference in the findings of signal ECG between the cryptogenic infarction and other stroke etiology. Results: A total of 160 subjects were enrolled and 66 patients with the cryptogenic infarction were identified. Compared to the subjects with known etiology, the patients with cryptogenic infarction had the longer P wave duration(PWD) and the lower Root mean square voltage of terminal 20ms of P wave(RMS20), significantly(P<0.01, respectively). The percentage of atrial late potential was higher in the patients with cryptogenic infarction than the control group(80% vs 43%, P<0.01). The patients with right insula lesion had the higher frequency of the atrial late potential than those without. During follow-up period, AF was found in 10% of the atrial late potential group and in 4.5% of those with other subjects. Conclusion: Our results suggest that the signal ECG might be the method for screening for the patients at high risk for paroxysmal AF. Key Words: The paroxysmal atrial fibrillation, signal ECG, P wave duration