Distribution of cardiac output in dogs

Abstract

Cardiac outputs and blood flows in 6 major channels were measured in a total of 60 mongrel dogs. The 6 vessels were the portal vein, the hepatic artery, the carotid arteries, and the femoral arteries. Cardiac output was determined by the thermal dilution method. Blood flows were measured by a-c electromagnetic blood flowmeters. Blood pressure was recorded using Statham 23AA pressure transducers. Heart rates were determined from the pressure recordings and/or from simultaneously recorded ecg. Stroke volume and peripheral resistance were calculated using standard formulas. The data collected in this study indicated a direct relationship between the stroke volume and the kilogram body weight of the dogs studied. The direct measurement of the blood flows through the selected vessels showed that approximately 12% (6.0% + 5.6%) of the cardiac output is distributed by the carotid arteries, 7% (3.70% + 3.66%) is carried by the femoral arteries, and a total of 29.6% (24.69% via the portal vein, 4.93% via the hepatic artery) enters hepatic circulation.