Demonstration of a Positive Relationship Between Cardiac Output and Oxygen Consumption

Abstract

The demonstration of a positive relationship between cardiac output and O2 consumption occurred in 42 normal subjects by using a high frequency ballistocardiograph table for cardiac output measurements and the Benedict-Roth apparatus for O2 consumption. A correlation coefficient of .545 was detd. and by further calculating the regression equation the ratio of change was determined. There occurred for each 10% rise in O2 consumption a 6.54% rise in cardiac output. To further substantiate this relationship, data of other investigators were similarly analyzed. These workers employed heart catheterization and ethyl iodide techniques for cardiac output and analysis of expired air for O2 consumption. In each instance the correlation coefficients were significant and the avg. values of the 4 observers on 150 subjects showed for each 10% increase in O2 consumption a 7.07% increase in cardiac output occurred. Thus despite the variance in methods used for determining cardiac output and O2 consumption under basal or non-basal subject conditions, the ratios of change detd. from the regression equations showed a definite constancy.