[Genesis of the initial heart rate course in a tilt table study and its value for the evaluation of autonomic integrity]

Abstract

With the help of the mathematical modelling is made evident that the course of the heart rate during the orthostatic immediate reaction can quantitatively not satisfactorily be reflected by the exclusive effect of the baroreceptor regulation. In addition to this, the non-reflex regulation of the frequency through the filling pressure of the right atrium - the dynamics of which established by animal experiments is demonstrated - is therefore involved. By means of the pharmacological blocking of the efferent cardiac nerves in six test persons the cooperation of this chronotropic autoregulation in the tilting table experiment is shown. The results render clear that an assessment of the autonomous integrity on the basis of the initial course of the heart rate with rapid changing of the position is only restrictedly possible on account of the nonreflex proportion of the chronotropic response.