Nonlinear multiscale circulation model reproducable linear end-systolic pressure-volume relationship

Area of Science:

• Cardiovascular Physiology
• Computational Biology
• Biomedical Engineering

Background:

• The linearity of the left ventricular end-systolic pressure-volume relationship (ESPVR) is a known cardiac property.
• The underlying mechanisms driving this linearity remain poorly understood in existing literature.

Purpose of the Study:

• To develop and utilize a multiscale circulation model for theoretical analysis.
• To investigate the mechanistic basis for the linearity of the ESPVR.

Main Methods:

• A multiscale model integrating a closed-loop lumped-parameter cardiovascular system, a geometric left ventricle model, and a ventricular myocyte model was developed.
• The model incorporates nonlinear sub-models to simulate cardiac function.

Main Results:

• The integrated multiscale model successfully reproduced a highly linear ESPVR.
• The model achieved this linearity without requiring arbitrary parameter adjustments, suggesting an inherent mechanism.

Conclusions:

• The developed multiscale model provides a valuable tool for understanding the ESPVR's linearity.
• The findings suggest that the integration of nonlinear components within the cardiovascular system inherently leads to a linear ESPVR.