Biaxial quantification of passive porcine myocardium elastic properties by region

Considering accurate constitutive models is of the utmost importance when capturing the mechanical response of soft tissue and biomedical materials under physiological loading conditions. This paper investigated the behaviour of porcine myocardium in passive rested hearts. This was done by applying biaxial loads on the myocardium. The main objective of this research was to investigate the cardiac mechanics of various regions of a healthy passive rested porcine heart. The biaxial mechanical properties of myocardial tissue samples were captured using a biaxial testing system. The porcine heart was divided into three regions, namely, left ventricle (LV), septum and right ventricle (RV). In these regions, 18 18 mm2 equal samples were cut from six porcine passive hearts. For the LV sample, the biaxial elastic modulus in the fibre direction was 33.3% larger than in the cross fibre direction, for the mid-wall sample it was 18.8% larger, and for the RV sample it was 33.3% larger. It was concluded that the cardiac mechanics of LV, septum and RV exhibit mechanical behaviour that differs considerably. In developing adequate computational models, these data could be applied to estimate the material parameters of the myocardium.