Dabizzi P, Barletta G, Lo Sapio P, Del Bene R, Fantini F
Department of Internal Medicine, University of Florence, Italy.
Coron Artery Dis. 1994 Apr;5(4):365-8.
Several studies have indicated that ischemia induced by dipyridamole is frequently associated with angina or ischemic ST-segment depression and that it occurs mainly in patients with three-vessel disease, those with collateral vessels, or those with both.
In order to analyze the diagnostic relationships among them, we studied 227 consecutive patients who underwent coronary angiography and dipyridamole-thallium scintigraphy.
A perfusion defect was found in 134 patients. Of these, 88 patients (66%) showed no significant ECG modifications or angina; 46 (34%) had a transient ST-segment depression, which was associated with typical angina ('dipyridamole angina') in 12. These 12 patients had three-vessel disease with intercoronary collateral circulation. Among the 134 patients with coronary critical stenoses and a positive thallium-dipyridamole test, collateral vessels were detected in 91 (68%).
Dipyridamole angina, occurring during a positive dipyridamole-thallium test, is usually a manifestation of severe coronary stenoses with collateral circulation. However, as a diagnostic symptom it is characterized by high specificity but low sensitivity.
