Left ventricular performance after acute myocardial infarction.

Current knowledge concerning the major hemodynamic features of acute myocardial infarction has been reviewed and discussed in relation to present concepts of cardiac pathophysiology. The physical examination provides a great deal of information and new, noninvasive methods promise to supplement the bedside appraisal of left ventricular function. Direct hemodynamic methods of serially monitoring patients with acute myocardial infarction are finding increasing application and recently have added considerably to our understanding of this condition. Certain limitations in the use of the central venous pressure, pulmonary arterial pressure, and cardiac output in appraising left ventricular function have become apparent, but together with direct catheterization of the left ventricle such hemodynamic studies have now provided limited correlations between the clinical picture and various hemodynamic patterns. It is becoming increasingly clear that most of these features, including cardiogenic shock, probably reflect varying degrees of left ventricular failure. These initial findings and interpretations will require confirmation, however, and so far insufficient objective data are available concerning the natural history of acute myocardial infarction and its responses to various forms of therapy. The aims of investigations now being carried in specialized Myocardial Infarction Research Units and other cardiovascular research centers, are to gain such further understanding of the pathophysiology of this disease and to aid in its clinical management by developing accurate indirect monitoring techniques as well as new forms of therapy.