[Value of the dipyridamole test in the diagnosis of coronary heart disease. Comparison with the stress ECG and coronary angiogram].

In 500 patients suffering from angina pectoris (454 males, 46 females) in whom coronary angiography had been performed a dipyridamole test was carried out. The test was positive in 319 of 396 patients with stenosing coronary heart disease (sensitivity 80%); ECG changes typical of ischaemia were demonstrated in 51%. The exercise ECG test was positive in only 68% of 229 patients with coronary heart disease. Among 104 patients without stenosing coronary heart disease the dipyridamole test was false-positive in 47, giving a specificity of 55%, while in 17 (16%) there were false-positive ECG-changes. The exercise test was falsely positive in 20 of 38 patients without stenosing coronary heart disease (specificity of 47%). Coronary blood flow was measured with the argon technique in 19 of 47 with a false-positive dipyridamole test and three with a false-positive exercise ECG. Maximal pharmacologically induced coronary blood flow was significantly reduced in all so that the diagnosis of "atypical coronary heart disease" or "small vessel disease" was made. The dipyridamole test or the exercise ECG test were falsely positive in these patients only with regard to the coronary arteriogram, correctly positive, however, in relation to angiographically non-demonstrable coronary blood flow abnormalities. The dipyridamole test is complementary to the exercise ECG test and has comparable accuracy. The same precautions must be observed for both tests.