Modeling of steady-state and relaxation elastic properties of the papillary muscle at rest

The biomechanical modeling of a papillary muscle preparation as an adequate object for studying the properties of the myocardial tissue under uniaxial stretching has been performed. The steady-state and relaxation tests of the papillary muscle of laboratory animals (rabbit and rat) have been conducted in normal conditions and after the maceration of intracellular structures with high ionic strength solution. It has been shown that the main contribution to the viscoelastic properties in the initial range of physiological deformations is made by the connective tissue skeleton, whereas under large physiological deformations, by intracellular structures.