Effects of antianginal drugs on myocardial perfusion during exercise in patients with coronary artery disease

Exercise thallium-201 myocardial perfusion imaging was performed in 24 patients with coronary artery disease to quantitatively evaluate the effects of propranolol (P), nifedipine (N), and isosorbide dinitrate (I) on myocardial perfusion. Using initial uptake index (IUI) and redistribution index (RDI) obtained in normal subjects (n=17), IUI≤84% and RDI≥1.12 were defined as ischemic area; IUI≤84% and RDI<1.12 as infarct area; and IUI>84% abd RDI<1.12 as normal area. The patients were iv given 0.1 mg/kg/hr of either P or I, or orally given 20 mg of N up to the time when pressure-rate-products were attained. Although P had scarcely effects on the incidence of angina and ST depression, both N and I remarkably improved them. IUI was significantly increased by giving either N or I, although it was unchanged after iv injection of P. This suggested that N and I may directly increase myocardial perfusion when given during exercise. (Namekawa, K)