[Modelling of relaxation phenomena in the myocardium]

A model describing relaxation phenomena on heart muscle preparations is proposed, permitting characterization of diastolic oscillations (aftercontractions) that are considered as being damped harmonic oscillations superposed an exponentially descending carrier function (oscillating case). If there is a high damping ratio diastolic oscillations cannot be observed except the phenomenon of hyperrelaxation. Relaxation without oscillations corresponds to the aperiodic case. Examples of relaxation time courses resulting from right ventricular rabbit papillary muscles (isometric conditions) as well as relaxation parameters and approximation curves obtained by the aid of the table computer EMG 666 are given. The model is realized by an electrical analog which is based on a hypothesis concerning the calcium sequestration in the myoplasm.