Regional distribution of cardiac output: Normal values in man determined by video dilution technique

Densitometry by video dilution permits regional blood estimation by a modification of the indicator dilution technique originally described by Stewart and Hamilton. Contrast mass is measured from the video fluoroscopic image rather than from dye concentration in blood withdrawn through a sampling catheter. From more than 400 studies, 70 patients who presumably had normal regional flows were selected. Flows in the cerebral, splanchnic, renal, and extremity circulations were determined as a percentage of ascending aortic flow (cardiac output). The regional flows determined by video dilution technique compare well with results of other techniques described in the literature. It is now possible to measure distribution of cardiac output to any major artery during routine angiography, thus providing another determinant of arterial adequacy. These normal values are currently used by the investigators as standards for the evaluation of patients with a variety of vascular diseases.