Serial left ventricular ejection fraction in acute myocardial infarction by cross-sectional echocardiography: correlation of changing ejection fraction with clinical course.

Left ventricular volume and ejection fraction were measured in 22 survivors of acute myocardial infarction by means of two-dimensional echocardiography and using a Simpson's rule algorithm. Ten of the 22 patients experienced complications. For the group as a whole, there were no significant trends in left ventricular volume and ejection fraction between the first and third days and the third month after infarction. In the subgroups with uncomplicated and complicated infarction, there were trends towards increasing and decreasing ejection fractions, respectively, which failed to attain statistical significance, however. The difference in ejection fraction between both subgroups had become significant at 3 months; 55.2 +/- 11.1% in uncomplicated v. 41.3 +/- 6.9% in complicated cases (P less than 0.01). Individual changes in ejection fraction falling outside the limits of reproducibility of the method as assessed previously were observed between day 1 and day 3 in only 2 patients with uncomplicated and in 2 patients with complicated infarction. Between day 1 and 3 months such changes occurred in 8 patients with uncomplicated infarction (upward in 5 and downward in 3), and in 8 patients with complicated infarcts (upward in 3 and downward in 5). We conclude that changes in ejection fraction as measured by two-dimensional echocardiography tend to correlate with complications.