Non-invasive measurements are important for the development of new treatments for heart failure, which is one of the leading causes of death worldwide. This study aimed to develop realistic subject-specific computational models of human biventricles using clinical data. Three-dimensional finite element models of the human ventricles were created using cardiovascular magnetic resonance images of rheumatic heart disease (RHD) patients and healthy subjects. The material parameter optimization uses inverse modeling based on the finite element method combined with the Levenberg–Marquardt method (LVM) by targeting subject-specific hemodynamics. The study of elastic myocardial parameters between healthy subjects and RHD patients showed an elevated stiffness in diseased hearts. In particular, the anisotropic material behavior of the healthy and diseased cardiac tissue significantly differed from one another. Furthermore, as the LVEF decreased, the stiffness and its orientation-dependent parameters increased. The simulation-derived LV myocardial circumferential and longitudinal stresses were negatively associated with the LVEF. The sensitivity analysis result demonstrated that the observed significant difference between the elastic material parameters of diseased and healthy myocardium was not exclusively attributable to an increased LVEDP in the diseased heart. These results could be applied to future computational studies for developing heart failure treatment.

Understanding the elastic material behavior of myocardium during the diastolic phase is critical for evaluating cardiac function and improving treatments for diastolic abnormalities. This study introduces a novel multi-objective optimization framework that incorporates both strain and volume measurements to enhance the accuracy of myocardial property assessments in Rheumatic Heart Disease (RHD) patients and healthy controls. By employing global volume and strain measurements instead of segmented strains from the sixteen AHA regions, we achieve a robust alignment with the Klotz curve across all groups, indicating an accurate simulation of end-diastolic pressure-volume relationships (EDPVRs). Our approach uniquely integrates combinations of longitudinal, circumferential, and radial strains, resulting in an unprecedented reduction in errors between clinical and simulated strain values, with less than one percent difference for targeted parameters. The results demonstrate that the alignment between computational predictions and clinical measurements depends significantly on the choice of optimization target. The study reveals significant differences in tissue mechanics between RHD patients and healthy controls, with notable variations in ventricular stiffness and fiber orientations across optimization targets, confirmed through rigorous statistical analyses. The observed variations in fiber angles, particularly the smaller angles for longitudinal strains and steeper angles for circumferential strains, underscore the intricate relationship between myocardial fiber architecture and cardiac deformation, offering deeper insights into ventricular biomechanics. By presenting qualitative and quantitative differences in stress and strain distributions, this research advances the understanding of myocardial mechanics, highlighting the clinical relevance of fiber orientation and material properties in modeling cardiac mechanics and distinguishing diseased from healthy myocardial behavior.