Comparison of the cardiac output measurements with electromagnetic flowmeter and dye-dilution technique in dogs, with a note on the comparison between radiocardiography and ear-dye method in man

There are relatively few studies and opinions are still divided as to the agreement between the electromagnetic flowmeter and dye-dilution technique in measurements of cardiac output in animals. Of 22 pairs of cardiac output measurements performed with an electromagnetic flow probe applied to the root of aorta in open-chest, anesthetized dogs and with peripheral venous injection of indocyanine green dye and an arterial cuvette, the measured points fell within the range of ± 20% on both sides of the line of identity in 19 instances. Studied on 8 human subjects with radiocardiography and ear-dye method performed simultaneously with peripheral venous injection of a mixture of R¹³¹ISA and indocyanine green, cardiac output given by ear-dye method was higher than that given by radiocardiography by an average of 9 ± 11 (SD)%. Agreement and disagreement in cardiac output measurements given by electromagnetic flow probe, dye-dilution method with arterial cuvette, dye-dilution method with ear-piece densitometer and radiocardiography were discussed.