Journal of Human Sport and Exercise

Comparison between Modelflow® and echocardiography in the determination of cardiac output during and following pregnancy at rest and during exercise

Victoria L. Meah, Karianne Backx, Rob E. Shave, Eric J. Stöhr, Stephen-Mark Cooper


During pregnancy, assessment of cardiac output (Q ̇), a fundamental measure of cardiovascular function, provides important insight into maternal adaptation. However, methods for dynamic Q ̇ measurement require validation. The purpose of this study was to estimate the agreement of Q ̇ measured by echocardiography and Modelflow® at rest and during submaximal exercise in non-pregnant (n = 18), pregnant (n = 15, 22-26 weeks gestation) and postpartum women (n = 12, 12-16 weeks post-delivery). Simultaneous measurements of Q ̇ derived from echocardiography [criterion] and Modelflow® were obtained at rest and during low-moderate intensity (25% and 50% peak power output) cycling exercise and compared using Bland-Altman analysis and limits of agreement. Agreement between echocardiography and Modelflow® was poor in non-pregnant, pregnant and postpartum women at rest (mean difference ± SD: -1.1 ± 3.4; -1.2 ± 2.9; -1.9 ± 3.2 L.min-1), and this remained evident during exercise. The Modelflow® method is not recommended for Q ̇ determination in research involving young, healthy non-pregnant and pregnant women at rest or during dynamic challenge. Previously published Q ̇ data from studies utilising this method should be interpreted with caution.


Prenatal; Submaximal exercise; Finger photoplethysmography; Validity


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