Chest Pain during Dipyridamole (99m)Tc-MIBI Myocardial Scan

ABSTRACT

BACKGROUND: 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. METHOD: To investigate clinical significance of chest pain after intravenous dipyridamole infusion, reversibility score was calculated in 320 patients using reconstructed polar map of dipyridamole (99m)Tc-MIBI myocardial perfusion scan. In 81 patients who undertook both coronary angiogram and (99m)Tc-MIBI myocardial scan within 5 weeks, jeopardy score and myocardial ischemic score were calculated using coronary angiogram. RESULT: 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%). CONCLUSION: These findings suggest that typical chest pain after intravenous dipyridamole infusion might represent myocardial ischemia and suggest more severe coronary artery disease.