Key Points
- To formulate a structural three-dimensional constitutive law for the passive myocardium based on the individual strain energy contributions of its constituent tissues.
- Formulated a total strain energy function summing contributions from muscle fibers, collagen fibers, and their embedding fluid matrix, accounting for spatial orientation, resting waviness, and tensile stress-strain responses.
- Estimated material constants in the constitutive model using experimental biaxial mechanical test data.
- Achieved a high goodness of fit between calculated model stresses and measured experimental stresses under biaxial loading.
- Identified the collagen matrix as the dominant structural determinant of passive tissue stiffness despite representing a minor fraction of myocardial volume.
Structured PICO
PPopulationPassive myocardium tissue
IInterventionThree-dimensional constitutive law based on a structural approach
OOutcomeFit between measured and calculated stresses
The proposed three-dimensional constitutive law accurately describes the mechanical behavior of the passive myocardium, highlighting the collagen matrix as the primary driver of tissue stiffness.