Myocardial perfusion in new-onset angina patients with single vessel disease.

The aim of this study was to investigate myocardial perfusion of the left ventricle during stress (exercise scintigraphy with thallium-201) in 25 patients having new-onset angina (NA) with single-vessel disease. In 14 cases (56%) the lumen of the vessel was obstructed by more than 75% and in 6 cases (24%) it was totally occluded. Angiographically visible collaterals to the occluded arteries from other vessels were present in all these cases. All of the patients studied had some form of myocardial perfusion disturbance. In 13 patients (52%) perfusion defects were limited to distribution within the obstructed artery; the other 9 patients (36%) had defects in the pool of the intact artery with or without defects in the pool of the obstructed artery. In the 4 patients (44.4%) having a totally occluded artery, perfusion defects were observed only in the pool of the intact artery supplying the collaterals, while in 5 patients (55.6%) perfusion defects were found both in the pool of the intact artery supplying the collaterals as well as in the obstructed vessel. We conclude that in patients with NA, stress dependent perfusion defects are present not only in the pool of the obstructed artery but also in the intact artery supplying the collaterals. This point to the possible presence of 'steal' syndrome in these patients.