Background: Diagnosis of ischemic cardiomyopathy by noninvasive methods is a challenge for the clinician. Echocardiography with intravenous administration of dipyridamole has been proposed as an alternative to exercise stress test in this setting.
Methods: Intravenous administration of dipyridamole (0.84 mg/kg in 6 minutes) with two-dimensional echocardiography and 12-lead electrocardiographic monitoring was performed in 50 patients. The test was considered positive when contractility of any of the left ventricular segments decreased, at least, one grade. In that moment, dipyridamole administration was stopped and aminophylline (40-240 mg over 1 to 3 minutes) was given. All patients underwent exercise stress test and coronary angiography.
Results: Significant coronary artery disease (70% stenosis in, at least, one of the major vessels) was demonstrated in 32 patients. Twenty of these had a positive dipyridamole echocardiography test (62%) and 23 had a positive exercise stress test (71%). None of the patients without significant coronary artery disease had a positive dipyridamole echocardiography test and 5 patients (23%) has a positive exercise stress test. Dipyridamole echocardiography test had and overall sensitivity of 60% and a specificity of 100%. Exercise stress test had an overall sensitivity of 75% (NS) and a specificity of 67% (p less than 0.01). Dipyridamole echocardiography test was well tolerated: there were no complications during the test. One patient had a transitory type I second-degree AV block.
Conclusions: Dipyridamole echocardiography is a high specificity test for coronary artery disease and has a similar sensitivity than exercise stress test. It is well tolerated and in the authors' experience there were no complications.