Indirect Assessment of Left Ventricular Performance in Acute Myocardial Infarction

Abstract

One hundred patients admitted to a cardiac care unit had indirect serial determinations of left ventricular systolic ejection times. Patients were divided into groups with transmural infarction, nontransmural infarction, and no infarction, according to clinical, biochemical, and electrocardiographic criteria. Total electromechanical systole and left ventricular ejection time were shortened in acute myocardial infarction, whereas the pre-ejection period and its components, the Q-S₁ and isovolumic contraction time intervals, were prolonged. The most abnormal measurements were observed in patients with transmural infarction. Patients with nontransmural infarction demonstrated less severe abnormalities of the systolic ejection times, and the patients without infarction were the least affected. Some of the greatest deviations in the measured intervals were observed in the transmural infarction patients who died. Indirect measurement of left ventricular systolic ejection time is a valuable adjunct in the bedside assessment of left ventricular performance and provides a prognostic index for patients with acute myocardial infarction.