Non-linear fluid-coupled computational model of the mitral valve

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Mitral valve dynamics depend on heart geometry, blood flow, and tissue integrity.
• Existing models often lack integrated fluid-structure interaction and detailed tissue microstructure.
• This study introduces a novel computational approach to model mitral valve function.

Purpose of the Study:

• To develop the first coupled fluid-structure computational model of the mitral valve.
• To simulate mitral valve kinematics based on blood flow and valvular microstructure.
• To establish a foundation for future studies on mitral valve competence under pathological conditions.

Main Methods:

• Constructed diastolic mitral valve geometry from experimental data.
• Modeled leaflets as collagen fiber networks within an isotropic matrix.
• Implemented a non-linear continuum description in a 3D membrane formulation with experimental chordal behavior.
• Simulated Newtonian blood flow and applied ventricular/atrial pressure curves.

Main Results:

• Peak closing flow and volume were 51 ml/s and 1.17 ml.
• Papillary muscle force varied dynamically from 0.0 to 2.6 N.
• Acoustic pressure (RMS) reached 3.3 Pa with a peak frequency of 72 Hz.
• Model predictions showed excellent agreement with experimental data for flow, force, and the first heart sound (S1).

Conclusions:

• The coupled fluid-structure model with microstructural detail advances mitral valve computational studies.
• This model provides a robust platform for investigating the impact of tissue alterations on mitral valve function.
• It lays the groundwork for predicting mitral valve competence in various pathophysiological states.