[New method of stroke volume measurements by means of radioactive isotopes]

A new radioactive method of measuring the stroke volume called "radiocardiometry" is described, and the results of a clinical trial of the method are presented. The results were compared with those obtained by means of radiocardiography that was conducted simultaneously with the stroke volume measurements performed according to the suggested method. The results coincided with an approximation of +/- 10% in all cases, with the exception of those with mitral insufficiency in which the results obtained by means of radiocardiometry were 12--31% higher than those calculated from radiocardiography. The circulating blood volume was measured by the administered activity and by the activity of the sample without any preparation of standard solutions. The error in the measurements of this parameter did not exceed +/-5%.