Model of Anisotropic Reverse Cardiac Growth in Mechanical Dyssynchrony

Area of Science:

• Cardiovascular Physiology
• Computational Biology
• Biomechanics

Background:

• Single-cell experiments reveal longitudinal myocyte stretch leads to sarcomere addition.
• Cardiac growth and remodeling are complex processes influenced by mechanical stimuli.

Purpose of the Study:

• To develop an anisotropic growth constitutive model simulating long-term biventricular geometry changes.
• To investigate the role of elastic myofiber stretch as a growth stimulus in cardiac electromechanics.

Main Methods:

• Developed a volumetric growth framework incorporating anisotropic growth.
• Coupled the growth model with an electromechanics model.
• Calibrated the model using experimental data from chronic left ventricular free wall pacing.

Main Results:

• The model quantitatively reproduced ventricular wall thinning and thickening in response to pacing.
• Simulated global left ventricular dilation consistent with experimental findings.
• Demonstrated the role of myofiber stretch in driving both cellular and tissue-level growth.

Conclusions:

• Elastic myofiber stretch is a key stimulant for cardiac growth at both cellular and tissue levels.
• The developed electromechanics-growth model accurately predicts cardiac remodeling.
• This framework advances understanding of cardiac adaptation to altered mechanical loads.