Age-related normal values of signal-averaged electrocardiographic variables after acute myocardial infarction.

The study examined standard time domain variables of a signal-averaged electrocardiogram (SAECG) in 328 survivors of acute myocardial infarction. The correlation of these variables with age and the influence of age on the prediction of postinfarction arrhythmic complication (sudden death [n = 12] or sustained ventricular tachycardia, or both [n = 14]) from the SAECG were investigated. Statistically highly significant correlations (p less than or equal to 0.00002) between age and SAECG variables were found. Compared with patients aged less than 60 years, the SAECG-based stratification of arrhythmic complications after myocardial infarction in patients greater than 60 years had lower sensitivity for the same values of specificity and lower specificity for the same values of sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)