Two-dimensional echocardiography is useful for the immediate diagnosis of acute myocardial infarction when diagnostic electrocardiographic changes are absent. The technique is also helpful in distinguishing myocardial infarction from other conditions that may clinically or electrocardiographically mimic infarction. The extent of myocardial infarction can be estimated by the two-dimensional echocardiographically derived wall motion score index. Therefore, two-dimensional echocardiography seems to be ideally suited for the initial noninvasive assessment of patients with acute chest pain syndromes, especially those who are considered for acute reperfusion therapy.