A viscoplastic model for the active component in cardiac muscle

Area of Science:

• Biophysics
• Cardiovascular Physiology
• Computational Biology

Background:

• The HMK model describes cardiac muscle active tension using calcium concentrations and tropomyosin kinetics.
• It models inelastic crossbridge response based on stretch history.

Purpose of the Study:

• To propose an alternative model for cardiac muscle active tension using a viscoplastic material approach.
• To develop an evolution equation for elastic stretch in the active component.
• To match experimental data with proposed constitutive equations.

Main Methods:

• Developed a viscoplastic material model for the active component of cardiac muscle.
• Formulated an evolution equation for elastic stretch.
• Proposed specific constitutive equations and validated them against experimental data.

Main Results:

• The proposed viscoplastic formulation successfully models separate crossbridge processes.
• It accurately captures rapid deactivation, slower reactivation, and low-rate relaxation effects.
• The model provides a better fit to experimental data compared to previous models.

Conclusions:

• The viscoplastic model offers a refined approach to simulating cardiac muscle mechanics.
• It provides a more comprehensive understanding of crossbridge kinetics and active tension dynamics.
• This model has potential applications in understanding and treating cardiac conditions.