[A modification of the Roher-Kahlstorf method for estimating rapid changes in cardiac volume]

A simple roentgenological procedure is described, by which it is possible to measure the heart volume and its alteration during early orthostatic adaptation.--Long distance films are taken in the p.a.-projection using a 70-mm-camera with a frequency of 2 to 4 exposures per second. The length and width and there by the plane of the heart are determined from these films. The mean horizontal depth diameter, that is necessary to calculate the volume of the heart can be gained by indirect means. There is no statistically significant difference between the heart volumes, that have been determined in 12 test persons by the method described, and the commonly used method. -- The alteration of the heart volume in 10 test persons were investigated during acute orthostatic stress. The heart volume, which was 693 +/- 24,8 ml before the orthostatic stress, decreased within 6,9 +/- 1,6 sec statistically significant by 16,5% An influence of the movements of the diaphragm on the heart volume determination could be excluded.