Normal response curve to exercise of relative cardiac output measured with radio-iodinated serum albumin.

A simple, relatively precise, and clinically applicable indirect method of determining relative cardiac output is presented. The principle involved is a modification of the dye-dilution principle and is performed by external monitoring of intravenously injected radioiodinated serum albumin combined with a standard detecting and recording device. This procedure was performed serially before and after a standard Master test, and the results in 19 healthy individuals describe a relative cardiac output exercise response curve for normal individuals. The utilization of cardiac output in the manner presented may add another clinical measurement of cardiac function.