Noninvasive determination of stroke volume with spectral Doppler echocardiography

: To assess the determination of volume flow by Doppler echokardiography 15 patients were studied twice in intervals of 2 to 6 hours. Cardiac output was determined simultaneously by thermodilution and by Doppler echocardiography. In three patients (20%) no Doppler signal could be recorded. In the 24 successful determinations a correlation of r = 0.93 was found between the two techniques. Mean deviation was 0.57 l/min (0.15-1.16), 9% (1-20%) respectively. With serial measurements the correlation for changes in cardiac output was 0.94. Mean deviation was found to be 0.47 l/min (0.12-1.16), or 75% (9-395%). Thus, gross estimation of cardiac output by Doppler echocardiography seems possible. However, it cannot be judged as of yet whether a more than semiquantitative estimation of individual cardiac output changes is possible nor whether further information can be obtained besides that which is clinically available.