[Simultaneous measurement of cardiac output by indium 113 m detected externally and by dye dilution of indocyanine green].

The cardiac output of 11 patients was measured by a method of dilution of a short-life radio-isotope, and compared with measurements obtained simultaneously by a dye dilution technique. After sudden intravenous injection of siderophilin (transferrin) labelled by Indium 113 m, the precoridal radioactivity was measured by a single panel detector probe. In 9 patients these measurements were carried out twice with a 15 minute interval. The correlation coefficient between the two methods was 0.884 for 20 measurements, and 0.939 for the first 11 measurements. The reproducibility of these measurements was comparable for the two techniques. The radio-isotope method of measuring cardiac output, which can be carried out at the bedside, is a simple, reliable and reproducible technique.