[Reliability and effectiveness of monitoring the stroke and minute volume of the heart by Kubicek's rheographic method].

Simultaneous measurements by the Fick direct method and the Kubicek rheographic method of cardiac output of 20 men with ischemic heart disease have shown that both methods are well correlated (r = 0.76, k = 0.92, n = 41). The reproducibility of the Kubicek data was slightly better than the Fick data (on the average +/- 6% instead of +/- 9-10%). An attempt of increasing the correlation of the Kubicek data with the Fick data by correcting the specific resistance with respect to the hematocrit data and the chest perimeter failed. In order to provide the necessary accuracy of the Kubicek method, it is required that the procedure be stringent and the five variables in the formula for calculating cardiac output be precisely measured. The cardiac output values determined simultaneously by the Kubicek method and by x-ray contrast ventriculography showed a better correlation (r = 0.88, k = 0.97, n = 15).