To determine whether or not slow coronary flow (SF) depends on hemodynamic variables, we studied 17 patients (15 men, mean age = 47.8 years) with SF at coronariography. Exercise thallium-201 myocardial scintigraphy revealed perfusion abnormalities in 13 (76.4%) patients. We then selected 89 individuals submitted to cinecoronariography for comparison: 15 were normal and 74 had heart disease. The coronary flow velocity was evaluated by the number of heart beats (HB) needed for coronary artery dye filling. The patients in the SF group had normal hemodynamic variables which were significantly different from those of patients with heart disease (P = 0.001). Patients with heart disease needed no more than 4 HB to fill their arteries, in contrast to 6.88 +/- 1.68 (5 to 11) in the SF group (P < 0.0001). Thus, in our patients with myocardial scintigraphy suggesting ischemia, SF was found to be an event which did not depend on hemodynamic factors.