ST-Segment Elevation in Acute Myocardial Infarction

Abstract

Four hundred and four patients who were admitted to the hospital with their first myocardial infarction within 24 hours of the onset of symptoms were studied. In 315 patients the ECG findings in 12 standards leads (I, II, aVF, aVR, aVL, V₁-V₆) showed the infarction to be in the anterior wall, the inferior wall, or in multiple areas. The patients in each of these three categories were further subdivided into two groups according to the magnitude of the ST-elevation; those with major ST-elevation and those with minor ST-elevation. Occurrence of the risk factors of diabetes, hypertension, hyperlipidemias, age, and complicating chronic pulmonary and renal diseases were comparable, but since women predominated in one group (anterior wall infarction/ minor ST-elevation) the clinical course of the disease in men and women was studied separately. The patients with major ST-elevation had a more unfavorable course: cardiac arrest (P < 0.0005), congestive heart failure (P < 0.0005), death (P < 0.001), atrial fibrillation (P < 0.005), cardiogenic shock (P < 0.005), atrioventricular (A-V) block 2°-3° (P < 0.01), and ventricular extrasystoles and ventricular tachycardia (P < 0.025) all occurred with significant frequency. The magnitude of ST-elevation thus gives valuable prognostic information, useful in selecting patients for prolonged monitoring.