Predicting the extent and location of coronary artery disease in acute myocardial infarction by echocardiography during dobutamine infusion

The feasibility, safety and usefulness of 2-dimensional echocardiography (2-D echo) during dobutamine infusion for identifying patients with multivessel coronary artery disease (CAD) after acute myocardial infarction (AMI) were evaluated in 30 patients 5 to 10 days after AMI. Patients underwent (1) 2-D echo under basal conditions and during dobutamine infusion at each dose from 5 to a maximum of 40 μg/kg/min, (2) limited multilead submaximal bicycle exercise testing and (3) coronary and left ventricular angiography. Echocardiograms were analyzed independently by 2 observers. The test response was considered positive if abnormal wall motion and reduced myocardial thickening were observed during dobutamine infusion in vascular distributions other than the area of infarction identified during basal conditions. Exercise testing was considered positive when more than 1 mm of ST depression occurred 80 ms after the J point. Dobutamine stress testing was well tolerated; no complications and no significant arrhythmia were observed. Echocardiographic recordings were adequate in all patients during the entire test; the concordance in interpretation between the 2 observers was perfect for the prediction and location of ischemic segments during dobutamine infusion.

In 15 of 17 patients without multivessel CAD, no asynergy was observed outside the infarct zone during dobutamine infusion (specificity 88%). In 11 of 13 patients with multivessel CAD, new wall motion abnormalities were identified in the segments corresponding to the arterial lesions diagnosed by angiography (sensitivity 85%). The overall accuracy of dobutamine stress 2-D echo (87%) was higher than that of dobutamine stress electrocardiography (70%) or exercise electrocardiography (59%). Thus, dobutamine stress 2-D echo is a well tolerated, widely available and cost effective stress test for detecting multivessel CAD early after AMI.