Ventricular volumes and body weight in mammals

and body weight in mammals. Am. J. Physiol. 215(3): 704-715. 1968.—Left and right ventricular end-diastolic (EDV), end-systolic (ESV), and stroke volumes, heart rates, cardiac output, total peripheral resistance (TPR), and other cardiovascular variables have been measured in the control state in nine species of mammals varying 1,790-fold (rat to horse) in body weight. The log-log relationships between these variables and body-weight (BW), body surface, metabolic rate, heart weight, and ventricular weight have been determined and are described by-power law equations. On the basis of these results relationshipsfor each ventricle are described by equations in which ventricu lar volumes are related to BW1-0, heart rate to BW °-20, cardiac output to BW075, and TPR to BW0-75. Evidence is presented that in the control state the heart rate of mammals is a function of metabolic rate per unit body weight, and left ventricular stroke work per unit body weight is constant. It is concluded