Dipyridamole echocardiography. A new diagnostic window on coronary artery disease.

Dipyridamole echocardiography testing is a highly feasible, inexpensive, and safe diagnostic tool, with excellent specificity and good sensitivity--especially in patients with multivessel disease and/or resting dyssynergy--for the diagnosis of coronary artery disease. The test does not offer an "all or none" binary result but rather a complex stratification of the ischemic response along the coordinates of time and space, accurately identifying the degree of physiological impairment of coronary reserve, the severity and extent of coronary disease, the geographic location of the area at risk, and the prognostic outlook. It offers highly competitive diagnostic information versus more sophisticated, time-consuming, and costly radionuclide techniques; in comparison with other stress echocardiography techniques, it is more feasible than exercise and less invasive and better tolerated than pacing. The electrocardiogram usefully integrates the information provided by the mechanical marker of ischemia during dipyridamole testing. The finding of echocardiographically silent ST segment depression represents a clue to the identification of angiographically normal coronary arteries. On the basis of this evidence, dipyridamole testing with two-dimensional echocardiography and 12-lead electrocardiography can be considered a reasonable choice for the exercise-independent diagnosis of coronary artery disease.