Myocardial involvement in systemic sclerosis may be caused, at least in part, by myocardial ischemia due to functional or structural abnormalities of small coronary arteries or arterioles. Coronary reserve, assessed by dipyridamole-induced coronary vasodilatation, was strikingly impaired in patients with systemic sclerosis. Thallium scans have shown numerous myocardial perfusion defects in scleroderma patients. Two studies, using oral nifedipine and intravenous dipyridamole, demonstrated that these thallium-201 myocardial perfusion defects in patients with systemic sclerosis were partially reversible. Finally, the preliminary results of long-term studies suggest that some coronary vasodilators may be beneficial in the long-term treatment of myocardial perfusion abnormalities in systemic sclerosis.