Microstructure-based finite element model of left ventricle passive inflation

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Computational Biology

Background:

• Current models of heart tissue mechanics are often phenomenological, limiting understanding of individual constituent roles.
• A gap exists in computational frameworks capable of simulating realistic 3D heart geometry with microstructure-based models.

Purpose of the Study:

• To develop and validate a microstructure-based constitutive model for the myocardium.
• To implement this model within an efficient finite element framework for simulating left ventricular (LV) passive inflation.
• To investigate the load distribution among cardiac tissue constituents and their impact on LV diastolic function.

Main Methods:

• Developed a microstructure-based constitutive model of the myocardium.
• Implemented the model in an open-source finite element framework.
• Calibrated and validated the model using canine heart tissue data at constituent and organ levels.

Main Results:

• The model predicts LV compliance is sensitive to collagen ultrastructure, including fiber angle and waviness.
• Muscle fibers bear most load in sub-epicardial regions, while collagen dominates in sub-endocardial regions.
• Targeted interventions on collagen and myocyte stiffness are most effective in specific myocardial regions.

Conclusions:

• Microstructure-based modeling provides insights into tissue constituent contributions to heart function.
• Findings suggest region-specific therapeutic strategies for normalizing LV filling in heart diseases.
• This validated framework can advance the development of targeted pharmaceutical treatments for cardiac conditions.