Multiscale Interactions in a 3D Model of the Contracting Ventricle

Area of Science:

• Biophysics
• Computational Biology
• Cardiovascular Physiology

Background:

• Understanding myocardial function requires integrating cellular electrophysiology and mechanics.
• Existing models often lack a comprehensive multiscale approach linking cellular activity to global heart performance.

Purpose of the Study:

• To develop and present a detailed biophysical multiscale model of the myocardium.
• To investigate the contribution of interrelated cellular mechanisms to global myocardial function.
• To simulate ventricular contraction, pressure generation, and load interactions.

Main Methods:

• Integrated cellular electrophysiology (Ten Tusscher-Noble-Noble-Panfilov model) with a four-state sarcomeric contraction model (Negroni and Lascano).
• Employed a reaction-diffusion equation for electrical excitation propagation.
• Utilized a 3D geometrical model of the ventricle based on anatomically oriented contracting fibers and intraventricular blood elements.

Main Results:

• The multiscale ventricle model successfully simulated mechanical contraction and pressure generation.
• The model demonstrated interactions between contractile elements, preload, and afterload, producing pressure-volume loops.
• Individual contributions of ion currents to myocardial function were elucidated.

Conclusions:

• The developed multiscale model provides a robust platform for studying myocardial function.
• This integrated approach allows for the investigation of cellular mechanisms' impact on global cardiac performance.
• The model is capable of simulating complex cardiac dynamics and load dependencies.