Importance of ST-Segment Depression during Dipyridamole Tl Myocardial Perfusion Imaging in the Diagnosis of Multivessel Coronary Artery Disease

Received 9/2/2004; revised 12/14/2004; accepted 12/16/2004. For correspondence or reprints contact: Chiang-Hsuan Lee, M.D., Department of Nuclear Medicine, Chang Gung Memorial Hospital, 123 Ta-Pei-Road, Niao-Sung, Kaohsiung 833, Taiwan, ROC. Tel: (886)7-7317123 ext. 2627, Fax: (886)77317123 ext. 2631, E-mail: [email protected] We describe a case of a 72-year-old female who underwent dipyridamole Tl myocardial perfusion imaging for the evaluation of coronary artery disease (CAD). The images showed no transient or fixed defect, but ST-segment depression on electrocardiography was noted after dipyridamole administration. Coronary angiography demonstrated multiple significant stenosis in the left main, left circumflex, and left anterior descending coronary arteries. Thus, dipyridamoleinduced ST-segment depression (DISTD) helped to identify the multivessel CAD. In this article, we emphasize that normal dipyridamole Tl myocardial perfusion images with DISTD still suggests the presence of CAD.