Hemodynamic Alterations in Acute Myocardial Infarction. I. Cardiac Output, Mean Arterial Pressure, Total Peripheral Resistance, “Central” and Total Blood Volumes, Venous Pressure and Average Circulation Time 12

Despite its importance little is known of the hemodynamic abnormalities which accompany acute myocardial infarction in man. Aside from clinical observations, the measurement of venous pressure (1) and total blood volume (1, 2), few systematic studies have been carried out in clinical cases. The reason for this has been the impossibility of subjecting such acutely ill patients to diffi- cult or time-consuming technical procedures. However, recent studies (3, 4) indicated that the values for cardiac output obtained with the Hamil- ton dye injection method were not significantly dif- ferent from those obtained with the intravenous catheterization method using the Fick principle. It seemed probable, therefore, that the Hamilton dye method suitably modified could be used to de- termine cardiac output at the bedside in acutely ill patients. This report describes the changes ob- served using the dye injection method and other procedures in a series of cases with myocardial in- farction as compared to a group of normal sub- jects and hypertensive patients. METHODS Fourteen hemodynamic studies were carried out in 11 patients with acute myocardial infarction, eight determi-