SIMULTANEOUS MEASUREMENT OF EFFECTIVE RENAL BLOOD FLOW AND CARDIAC OUTPUT IN RESTING NORMAL SUBJECTS AND PATIENTS WITH ESSENTIAL HYPERTENSION 1

Abstract

Unpublished data of Bradley and associates (1) indicate that about 25 to 30 per cent of the cardiac output, as measured by the ballistocardio- graph (2), perfuses the kidney of healthy adults at rest. This figure has been reported in a review on renal physiology (3). Levy and Blalock (4) obtained an average value of 18.5 per cent in un- anesthetized dogs, using the catheterization tech- nique or heart puncture and the direct Fick principle for the determination of the cardiac output. When normal human values for the resting car- diac output obtained by the direct Fick procedure (5, 6) are divided into the normal human values for effective renal blood flow (7), the resulting effective renal fraction is about 19 to 20 per cent.