Comparative estimation of central haemodynamics during dynamic load by impedance cardiography and radiocardiography.

77 unselected patients were examined simultaneously by impedance cardiography and radiocardiography in the recumbent position during dynamic exercise (bicycle ergometry). In all cases evaluable impedance curves were registered till the 100 W load. Stroke volume, estimated by impedance cardiography, is at rest and during exercise by about 30% lower compared to its value determined by radiocardiography. However, the percent increase during exercise is not significantly different with the use of either method. The stroke volumes estimated by both methods correlate significantly at rest and during exercise. This fact shows the usefulness of impedance cardiography for estimating central haemodynamics during dynamic exercise.