The influence of prostacyclin on hemodynamic and coronary blood flow in dogs.

Continuous intravenous infusion of prostacyclin (PGI2) was carried out for 30 to 120 min at the rates 25, 50, 75, 100 ng/kg/min in 149 experiments in 30 anesthetized dogs. PGI2 caused significant dose-dependent rise in heart rate, cardiac output, stroke volume and mean coronary artery blood flow. At the same time arterial blood pressures, total peripheral resistance and coronary vascular resistance decreased significantly while pulmonary artery pressures, central venous pressure, mean femoral artery blood flow and pressure rise velocity in left ventricle remained practically unaltered. Stady state of hemodynamic parameters was reached in 10 to 12 min. after the beginning of infusion. After discontinuation of infusion of PGI2 the values of recorded hemodynamic parameters returned to pre-infusion level in 10 to 15 min. Hemodynamic changes were well reproducible during repetitive infusions of PGI2 The purpose of this study was to determine the effects of PGI2 on various hemodynamic parameters.