Echocardiography in acute myocardial infarction.

Sixty-four patient with acute transmural myocardial infarction had daily echocardiograms while in the coronary care unit. Patients with previous infarction were excluded. The electrocardiographic site of infarction was anterior wall in 28, inferior wall in 33 and both anterior and inferior wall in 3 patients. Echocardiograms satisfactory for interpretation were obtained in 92 percent of cases. Abnormal left ventricular wall motion corresponding to the electrocardiographic site of infarction was seen in the echocardiogram in 84 percent of cases. Exaggerated normal motion in noninfarcted areas was seen in 30 percent. The left ventricular internal dimension correlated with clinical heart failure (P less than 0.005) and was increased in 50 percent. Abnormal mitral valve closure, which reflects increased left ventricular end-diastolic pressure, was present in 33 percent. This finding did not correlate significantly with clinical heart failure. By combining the measurements of left ventricular internal dimension and mitral valve closure, it was possible to predict hospital mortality from the echocardiograms. The results indicate that echocardiography is a useful technique in the study and management of patients with acute myocardial infarction.