I'm looking for some papers that shows clearly some mechanical properties of human native myocardium, such as elastic modulus, ultimate tensile strength and the ultimate tensile strain.
The biomechanical properties of myocardium, derived from ex vivo cadaver heart, might be different from in vivo properties due to tissue homeostasis.
The parameters required to estimate human myocardium are LV EDP of 10-13.6 mmHg (it depends on ex vivo and vivo) could be selected for the studies, fs and fn shear modes (shear stress and shear strains) can be calculated (generally in the range from 6 to 7 kPa for ex vivo whereas it was within the range from 1.2 to 1.8 kPa from in vivo) . These discrepancies might be due to the tissue homoeostasis in ex vivo conditions.
Comparison between true fibre strain and fibre stress (Cauchy stress); details of the slice position can be explained from your obtained figures. The arrow sign in zoom in boxes may show that the endocardium experiences high fibre stress for human ventricle whereas for pig, it starts after endocardium in posterior region of LV wall.