[Intraoperative measurement of velocity and volume of coronary circulation using the Duplex system].

A high frequency ultrasound system processor was used for an intraoperative evaluation of coronary blood flow velocity and volume. In 12 patients with symptomatic coronary heart disease, morphology and hemodynamic parameters of the coronary artery system were examined intraoperatively. Optimal imaging was possible by keeping the ultrasound transducer at a constant distance of a few millimeters from the surface of the heart and the pericardial space between them filled with saline solution. Using this technique, large areas of the cardiovascular system were reproducible up to a peripheral vascular diameter of 2-3 mm. Blood flow velocity (20 to 33 cm/s) and blood volumes (33 to 94 ml/min) provide quantitative information on the degree of stenosis intraoperatively after coronary anastomosis during bypass surgery. All images were of outstanding quality and precision. This method is highly valuable for the intraoperative determination of blood flow parameters.