Significance of ST Segment Re-elevation Early after Acute Myocardial Infarction Using Automatic Intermittent Recording 12-lead Electrocardiography

Abstract

The purpose of this study was to evaluate the significance of ST segment re-elevation within 24 hours after the onset of myocardial infarction. The study included 77 patients with their first anteroseptal (n=43) or inferior (n=34) MI who had 12-lead electrocardiograms recorded every 5 minutes using an automatic intermittent recording electrocardiograph. Thirty-five (45.5%) patients had ST segment re-elevation within 24 hours after the onset of myocardial infarction. The incidence of congestive heart failure and cardiogenic shock was significantly higher in patients with ST segment re-elevation than in patients without ST segment re-elevation (37.1% vs. 14.3%, p=0.04026 and 57.1% vs. 19.0%, p=0.00054, respectively). The peak serum creatine kinase activity was significantly higher in patients with ST segment re-elevation than in patients without ST segment re-elevation (5341±4281IU/L vs. 2908±2405IU/L, p=0.00276). The left ventricular ejection fraction was significantly lower in patients with ST segment re-elevation than in patients without ST segment re-elevation (48.2±10.1 vs. 56.9±11.8, p=0.00111). However, there were no significant differences between the two groups with respect to coronary angiographic findings (infarction related artery, presence of collateral arteries, presence of multivessel disease, or reocclusion after 1 month) or type of therapy employed (conservative or reperfusion therapy). These data suggest that ST segment re-elevation within 24 hours after the onset of myocardial infarction is a predictor of large infarct size, decreased cardiac function, and a high incidence of complications of myocardial infarction.