Reproducibility of cardiac output measurements by Doppler echocardiographyin prepubertal children and adults

The aim of this study was to examine reproducibility of stroke volume and c ardiac output measurements by Doppler echocardiography during submaximal an d maximal exercise in adults and children. Fourteen healthy children (8 gir ls and 6 boys aged 10.9 +/- 0.9 yr) and eleven healthy young adults (1 fema le and 10 males aged 22.3 +/- 3.8 yr) underwent a progressive maximal uprig ht cycle test until exhaustion with estimation of stroke volume and cardiac output by Doppler echocardiography on two separate occasions (one week apa rt). Maximal oxygen uptake and maximal heart rate were not significantly di fferent between both tests in the children and adults indicating that simil ar exhaustive efforts were achieved at each test. No significant difference s for mean values of stroke volume and cardiac output were observed at rest in the children and whatever the exercise intensity in the children and ad ults. No significant differences were observed between values of root mean square (precision and precision of error) in both groups. Thus we demonstra ted that stroke volume and cardiac output values obtained by Doppler echoca rdiography at rest and during submaximal and maximal exercise were reproduc ible on test-retest measurements in children and adults.