Overview of stress echocardiography: uses, advantages, and limitations

Responses of the heart to changes in our environment are probably even more important than how the heart functions at rest. Accordingly, stress testing with noninvasive imaging has become important for diagnosis, prognosis, and monitoring the effects of therapy. Echocardiography at rest and with stress permits characterization of global and segmental left ventricular function as well as valvular structure and function. Moreover, echocardiography can be performed during or after a number of different physical or even mental stressors. Advantages of stress echocardiography include its ready availability, relatively low capital cost, and incremental value in that it allows characterization of cardiac anatomy as well as the myocardial response to a potentially ischemic stimulus. Moreover, echocardiography has the potential to image myocardial perfusion along with wall motion and wall thickening. Substantial literature has now been accumulated on the value of stress echocardiography for the diagnosis of ischemic disease, preoperative risk assessment, and assessment of myocardial viability. Echocardiography has compared generally well with nuclear imaging techniques for the detection of angiographic coronary artery disease. Overall sensitivity, however, has been slightly less, particularly for the detection of single-vessel coronary disease, although specificity has been on average somewhat higher than nuclear cardiology techniques. Because of the potential for variability in study acquisition as well as interpretation, careful safeguards need to be employed. Specifically, meticulous technique needs to be applied to obtain high-quality images and to assure that those images are obtained promptly after treadmill exercise stress. Only readers with specific interest and expertise should interpret stress echocardiography studies. Continuing efforts need to be made to assess and minimize variability and to assure continuing quality improvement. Advances in instrumentation, including evolving technology for real-time 3-dimensional imaging, and echocardiography contrast assessment of myocardial perfusion will likely improve the sensitivity of echocardiography and further extend its usefulness.