Cardiac electromechanical models: from cell to organ.

Area of Science:

• Computational physiology and medicine
• Multiphysics and multiscale modeling
• Cardiac electrophysiology and mechanics

Background:

• The heart's complex function necessitates sophisticated mathematical models across multiple scales.
• Electromechanical (EM) coupling is crucial for understanding cardiac behavior.
• Existing models range from subcellular myofilament dynamics to whole-organ simulations.

Purpose of the Study:

• To review the development and application of electromechanical (EM) heart models.
• To provide an overview of models from the subcellular to the organ level.
• To highlight the integration of electrical and mechanical components in cardiac modeling.

Main Methods:

• Review of subcellular/single-cell models focusing on myofilament dynamics and Ca-based activation.
• Analysis of organ-level models integrating electrical (reaction-diffusion) and mechanical (continuum mechanics) components.
• Discussion of model complexity versus computational tractability trade-offs.

Main Results:

• Subcellular models elucidate cooperative mechanisms and the Frank-Starling law basis.
• Coupled electrophysiology and myofilament models form EM cell models.
• Organ-level models demonstrate how myocyte-generated tension deforms the heart.

Conclusions:

• EM heart models are essential tools in computational physiology and medicine.
• Model choices depend on application, balancing complexity and computational cost.
• Applications include cardiac resynchronization therapy and understanding arrhythmias.