Author/Authors :
Reinhardt، نويسنده , , Lutz and Mنkijنrvi، نويسنده , , Markku and Fetsch، نويسنده , , Thomas and Schulte، نويسنده , , Gerrit and Sierra، نويسنده , , Gilberto and Martيnez-Rubio، نويسنده , , Antoni and Montonen، نويسنده , , Juha and Katila، نويسنده , , Toivo and Borggrefe، نويسنده , , Martin and Breithardt، نويسنده , , Günter، نويسنده ,
Abstract :
The aim of this study was to extract and combine non-invasive risk parameters from the signal-averaged electrocardiogram (SAECG) and heart rate variability (HRV) based on 24-hour ambulatory electrocardiography to optimize the prognostic value for arrhythmic events after acute myocardial infarction. A prospective series of 553 men <66 years of age enrolled in the Post-Infarction Late Potential study were analyzed. Within 2 to 4 weeks after acute myocardial infarction, all patients underwent SAECG and 24-hour ambulatory electrocardiography before hospital discharge. During 6 months of follow-up, 25 patients (4.5%) experienced arrhythmic events (sustained ventricular tachycardia, n = 11; ventricular fibrillation, n = 7; sudden cardiac death, n = 7). The predictive power of SAECG and HRV parameters was assessed using a Cox proportional-hazards model. In HRV analysis, the most significant differences between patients with and without arrhythmic events were observed for the beat-to-beat parameter root-mean-square of successive RR differences [RMSSD]): 25.7 ± 16.9 ms in patients with arrhythmic events versus 34.1 ± 18.6 ms in patients free of arrhythmic events (p = 0.004). Time domain analysis of the SAECG showed the QRS duration to be most significantly different in both patient groups: 106.4 ± 18.7 ms (arrhythmic events) versus 95.3 ± 18.7 ms (no arrhythmic events) (p = 0.001). Based on the Cox regression model, RMSSD and QRS duration were demonstrated to be independent significant risk factors (regression coefficient for QRS duration: cq = 0.014 ± 0.006 ms−1, p = 0.014; for RMSSD: cr = −0.041 ± 0.016 ms−1, p = 0.009). Based on the regression coefficients, an analytic risk model was developed describing the arrhythmic risk as a function of QRS duration, RMSSD, and time after infarction. We conclude that the combination of beat-to-beat changes of heart rate measured by RMSSD and QRS duration from the SAECG enhances noninvasive risk stratification after myocardial infarction. (Am J Cardiol 1996;78:627–632)
