Evaluation of coronary arterial disease by oral dipyridamole stress testing using 12-lead electrocardiography.

We studied the values of oral dipyridamole needed to detect coronary arterial disease using 12-lead electrocardiography. The relationship between dipyridamole-induced ST segment depression and coronary arterial lesions, coronary collaterals and myocardial infarction was investigated. 375 mg oral dipyridamole was given to 31 patients (22 with coronary arterial disease, 9 controls). 12-lead electrocardiogram was recorded before and 45 minutes after the test. The control group and the patients, who had no ST segment depression after dipyridamole, performed isometric contraction (handgrip) for 5 minutes and then the 12-lead electrocardiogram was recorded. All patients had coronary angiography. We also performed treadmill stress testing in 28 patients. Dipyridamole testing was positive (greater than or equal to 1 mm ST depression on electrocardiogram) in 7 of 22 patients with coronary arterial disease, of whom 6 had positive treadmill stress testing. Only 2 patients had previous myocardial infarction in the group with positive dipyridamole tests. Of the 15 in whom dipyridamole testing was negative, 5 had positive treadmill stress testing, while 13 of them had had previous myocardial infarction. All patients in the control group had negative dipyridamole stress testing and normal coronary angiograms. No additional ST segment changes were observed in the group who had performed isometric contraction test (both dipyridamole test negative and control groups). Sensitivity and specificity of the test were 32 and 100%, respectively. Comparison of collateral vessels between the groups positive and negative for dipyridamole revealed no difference. But the number of patients with old myocardial infarction was higher in those testing negative than in those who proved positive.(ABSTRACT TRUNCATED AT 250 WORDS)