DIGITAL DIPYRIDAMOLE STRESS ECHOCARDIOGRAPHY IN SILENT ISCHEMIA AFTERCORONARY-ARTERY BYPASS-GRAFTING AND OR AFTER HEALING OF ACUTE MYOCARDIAL-INFARCTION

This study evaluates dipyridamole stress echocardiography in silent is chemia. Fourteen patients with previous coronary artery bypass graftin g (group A) and 16 patients with healed myocardial infarction (group B ) were studied. All had 1 mm ST depression without chest pain during b icycle exercise testing. Left ventricular wall motion was analyzed usi ng a computerized display of digital systolic cineloops with a high fr ame rate. Test results were compared with coronary angiography. Dipyri damole echocardiography accurately identified patients with significan t coronary artery stenosis in both groups (3 of 4 in group A, 11 of 14 in group B). Retrograde flow to the occluded native artery was associ ated with positive results on dipyridamole testing in 6 of 7 patients in group A and all 3 in group B. Sensitivity, specificity and diagnost ic accuracy for detecting significant coronary stenosis or occlusions with retrograde flow was 78, 100 and 83%, respectively. Patients with angiographic multivessel disease had a significantly larger increase i n wall motion score index during dipyridamole stress than patients wit h 0- or 1-vessel disease, 0.18 +/- 0.11 versus 0.05 +/- 0.18 (p < 0.05 ). Two patients developed symptomatic bradycardia and hypotension duri ng dipyridamole infusion. It is concluded that dipyridamole echocardio graphy accurately identifies myocardial regions with restricted corona ry flow. Stress echocardiography is a valuable tool for assessing coro nary flow in silent ischemia.