In 10 patients with coronary heart disease, local ventricular wall motion, local poststenotic flow, and distribution of myocardial perfusion were determined in the underperfused myocardium before and after 8 mg of Oxyfedrin intravenously. In 8 of the 10 patients there was a uniform reaction consisting of an improvement of wall motion, increase in flow, and homogeneity of flow distribution. These parallel changes of local wall movement and local blood flow in a poststenotic underperfused part of the myocardium can most probably be explained by the positively inotropic action of Oxyfedrin with a consecutive increase in blood flow. The results show that a therapeutic affect in patients with a coronary stenosis less than 60% in the left descending artery can be obtained with a positively inotropic substance.