Two-dimensional echocardiography versus surface electrocardiography for the diagnosis of acute non-Q wave myocardial infarction.
The initial two-dimensional echocardiogram (2DE) and electrocardiogram (ECG) of 50 consecutive patients with chest pain and a possible acute non-Q wave myocardial infarction (MI) were compared to each other to determine the value of 2DE in this type of acute MI. The ECG markers for a non-Q wave MI were (1) greater than or equal to 0.15 mV ST segment depression, (2) ST segment elevations with reciprocal ST segment depression, and (3) new symmetrical deep T wave changes as compared to a recent preadmission ECG. The 2DE was considered positive for MI if akinesia, dyskinesia, or severe hypokinesia was seen in one or more left ventricular segments. The sensitivity, specificity, and predictive value of the 2DE as compared to the ECG was 66% and 52%, respectively (sensitivity); 91% and 95%, respectivity (specificity); and 91% and 94%, respectively (predictive value). Statistically, there were no differences in the proportion of patients who had a positive 2DE as compared to the proportion of patients who had a positive ECG (p greater than 0.2). The ECG and 2DE results were combined and the sensitivity increased to 76% but the specificity decreased to 86%. Myocardial infarction size was not significantly different in infarcted subjects who had a positive 2DE (395 +/- 125 IU/L) as compared to those who had a negative 2DE (727 +/- 187 IU/L, p greater than 0.1).
D000368:Aged; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*