The consistency of cardiac output measurement (CO2 rebreathe) in children during exercise

Exercise cardiac output ($$\dot Q$$) was determined using the CO2 rebreathing equilibrium method. Five repeat tests in 12 boys and two tests over a 4 month interval in 47 boys were performed. Regression equations to predict $$\dot Q$$ from $$\dot V$$O2 were in close agreement with dye dilution studies in boys (Eriksson and Koch 1973). Group mean data were reproducible from trial to trial. The day-to-day variability of $$\dot Q$$, with a …