Exercise echocardiography in coronary artery disease.

ABSTRACT

Exercise echocardiography is one of the stress echocardiography modalities, widely used nowadays, mainly in the patients with coronary artery disease. It is a first-line technique for the diagnosis of coronary disease and for prognostication in various patients' subsets, including patients with chronic coronary artery disease, patients with recent revascularization or myocardial infarction and women. This method relies on the fact that in the presence of a significant coronary stenosis, an adequate level of physical exertion produces a mismatch between oxygen demand and supply, resulting in a wall motion abnormality in the area supplied by that stenotic artery. The wall motion abnormalities that develop are detectable by echocardiography and are a marker of the degree of ischemia. The most commonly employed forms of exercise in conjunction with echocardiography are immediate post exercise imaging on a treadmill and exercising during supine or upright bicycle ergometry. Echocardiograms can be interpreted qualitatively, with a description of the recorded wall motion abnormalities, or quantitatively, calculating a wall motion score. The overall accuracy of exercise echocardiography in the diagnosis of coronary artery disease is about 80-90%. Exercise echocardiography has been shown to provide useful information for the purpose of risk stratification and prediction of coronary events after acute myocardial infarction, after angioplasty and after coronary artery bypass grafting. In women, the accuracy of electrocardiographic stress testing is less than in men and stress echocardiography offers a better alternative in the diagnosis of ischemic heart disease. For the patients with an intermediate pre-test probability of having ischemic heart disease and a resting electrocardiogram which precludes an optimal interpretation of the electrocardiographic stress test (digoxin use, left ventricular hypertrophy with repolarization abnormalities, preexcitation, or left bundle-branch block), exercise echocardiography represents a good alternative to radionuclide imaging.