[Central and regional hemodynamics during LBNP exposure studied by isotopic and impedance methods]

The potential of impedance and isotope (intravenous injections of 131I and 113mIn) methods to study regional and central hemodynamics was investigated on 12 test subjects exposed to LBNP. Both methods demonstrated marked changes in blood filling of the head and the chest, particularly during the first minutes of LBNP tests. This occurred together with a drastic increase in leg blood filling. The close similarity of regional hemodynamic changes detected by the two methods gives evidence that the simple and noninvasive impedance method can be well used for the above studies.