Effects of captopril on myocardial perfusion in patients with coronary insufficiency: evaluation by the exercise test and quantitative myocardial tomoscintigraphy using thallium-201.

Nine patients with coronary insufficiency were investigated using an exercise test coupled with quantitative myocardial tomoscintigraphy with thallium-201 before and after 48 hours' treatment with captopril. After captopril treatment, an improvement in ST segment depression was noted during exercise. The quantitative tomoscintigraphy showed a reduction in the ischaemic zone with captopril during exercise. However, in three patients, although there was an overall improvement in myocardial perfusion during exercise, aggravation of wash-out was observed in some regions, reminiscent of a coronary steal effect.