A noninvasive test for coronary artery disease in which dobutamine is given to patients to increase the workload of the heart, and then the heart is evaluated with ultrasonic imaging. Regions of the heart that do not receive adequate blood flow (ischemic regions) contract poorly during the stress of the test but normally when the patient is at rest. Heart muscle that does not contract normally either at rest or with stimulation has been injured previously by myocardial infarction.