Non-invasive Derivation of 3D Systolic Nonlinear Wall Stress in a Biventricular Model from Tagged MRI

We present a nonlinear finite element method to calculate the local myocardial wall stress in a reconstructed biventricular MRI model. Nonlinear formulations are utilized in order to describe the ventricular large deformation. Using incremental force computation, a dynamic model showing the change of myocardium wall stress during systolic contraction was established. The preliminary results show that in the normal human heart the local stress increases by a factor of 104 from the end of diastole to the end of systole. Furthermore, during the systolic process the left ventricle develops three times more inner wall stress than the right ventricle, and the peak inner wall stress areas in both ventricles are located at the apex.