Role of echocardiography in patients with coronary artery disease.

Impaired left ventricular performance, one of the hallmarks of coronary artery disease, can be detected by echocardiography in various ways. One of these approaches is the recording of abnormal wall motion. Because of the way in which the left ventricle can be examined echocardiographically, this technique has the capability of detecting regional wall abnormalities. In fact echocardiography is probably the most sensitive technique available, including even contrast ventriculography, for the detection of akinetic, hypokinetic or dyskinetic wall segments. With increasing experience it is apparent that more areas of the left ventricle can be examined echocardiographically than had previously been thought possible. Newer techniques include directing the ultrasonic beam not only through the body of the left ventricle but also toward the apical portion of the ventricle near the vicinity of the papillary muscles. In addition the true anterior left ventricular wall can be examined by moving the transducer laterally away from the left sternal border. Yet another approach utilizes a subxiphoid position for the transducer while the ultrasonic beam is directed through the medial portion of the septum and posterolateral wall of the left ventricle. M-mode scanning techniques together with recently developed cross-sectional echocardiographic instruments give great promise of improved detection of abnormalities of ventricular shape, especially the presence of aneurysms. The cross-sectional approach makes it possible to examine the left ventricular apex, an area virtually impossible to record with M-mode echocardiography. Recording of left ventricular dimensions and abnormal mitral valve motion may help in assessing overall left ventricular performance. A dilated left ventricular dimension in the vicinity of the mitral valve seems to be an ominous finding both in patients with acute myocardial infarction and in patients with chronic coronary disease being considered for possible surgery. Another echocardiographic sign of abnormal ventricular performance is altered closure of the mitral valve, which reflects a significantly elevated left ventricular diastolic pressure. These echocardiographic techniques are still in the investigational stages and are more technically difficult than the usual echocardiographic applications. However, the preliminary data are encouraging and make us hopeful that echocardiography will prove to be an important tool in the overall evaluation of the left ventricle in patients with coronary artery disease.