Viscoelastic Modelling of Right Ventricular and Septum Myocardia of Porcine Heart

This study presents a comparative biomechanical investigation of porcine right ventricular (RV) free-wall myocardium and interventricular septal (IVS) tissue, focusing on their time-dependent viscoelastic behavior under physiologically relevant loading conditions. Uniaxial tensile tests were conducted on excised tissue strips to evaluate region-specific stiffness, relaxation response, and hysteresis, allowing viscoelastic parameters to be fitted to a constitutive model capable of capturing nonlinear, rate-dependent deformation. The results show distinct mechanical signatures between RV and IVS myocardium, with the RV free wall exhibiting greater compliance and higher viscous damping, while the IVS displayed increased stiffness and reduced time-dependent relaxation. These differences provide new insight into how regional myocardial mechanics contribute to ventricular filling, septal motion, and pathological conditions such as RV dysfunction or pressure overload, offering improved foundations for computational model development and targeted therapeutic strategies.