Dipyridamole-stressed myocardial scan is a useful diagnostic tool of coronary artery disease, however clinical significance of dipyridamole-induced chest pain is not well documented.

To investigate clinical significance of chest pain after intravenous dipyridamole infusion, reversibility score was calculated in 320 patients using reconstructed polar map of dipyridamole ^99mTc-MIBI myocardial perfusion scan. In 81 patients who undertook both coronary angiogram and ^99mTc-MIBI myocardial scan within 5 weeks, jeopardy score and myocardial ischemic score were calculated using coronary angiogram.

Group 1 consisted of the patients with typical chest pain, group 2 consisted of the patients with atypical chest pain, and group 3 consisted of the patients without chest pain. Mean reversibility score of group 1(90.0+58.4) was significantly higher(p<0.05) than that of group 3(64.7±44.5). Mean myocardial ischemic score of group 1(632.5±272.3) was significantly(p<0.05) higher than that of group 2(356.9±244.6) or group 3(287.5±257.7). Proportion of normal coronary angiogram in group 1(2/27, 7.4%) was significantly lower than that in group 3(11/34, 32.4%).

These findings suggest that typical chest pain after intravenous dipyridamole infusion might represent myocardial ischemia and suggest more severe coronary artery disease.