Usefulness of P wave Triggered Signal Averaged Electrocardiography 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 (P-SAECG) is one of useful method for identifying the paroxysmal AF. However, the data of SAECG in the patients with stroke remained limited. Aims: To investigate the association between findings of SAECG and the stroke etiology. Methods We recruited the patients without AF on admission, who was admitted from June 2012 to September, and who took SAECG 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 SAECG between the cryptogenic cerebral infarction and other stroke etiology. Results A total of 252 patients were enrolled and 158 patients with the cryptogenic infarction were identified. Compared to the subjects with other stroke 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 other groups (79% vs. 20%, P<0.01). During follow-up period, AF was found in 29% of the cryptogenic infarction group and in 5% of those with other subjects. In regression analysis, independent predictors for AF occurrence were atrial late potential and advanced age (P<0.01, respectively) Conclusion Our results suggest that the P-wave SAECG might be the useful method for screening for the patients at high risk for paroxysmal AF. Keywords: paroxysmal atrial fibrillation, signal-averaged ECG, cryptogenic infarction