A reference model for adult human cardiovascular mechanics

A previously developed computational model for cardiovascular mechanics is here calibrated using typical values of 22 clinically observed hemodynamic properties in healthy human subjects. The model includes spatially resolved representations of the four heart chambers. The left ventricle is represented as a truncated thick-walled prolate spheroid, with three modes of deformation (short and long axis contraction and torsion). The other chambers are represented as full or partial thick-walled spherical shells. Wave propagation and reflection in the aorta are represented using a one-dimensional model. The closed-loop system is completed using lumped elements representing vascular resistances, compliances and inertances. The resulting system of coupled ordinary differential equations can be solved computationally in less than 0.1 s per cardiac cycle. In the present study, the values of 19 key input parameters to the model are estimated by minimizing the deviation of model predictions from the 22 observed hemodynamic properties. The resulting calibrated reference model provides a baseline for theoretical studies exploring the relationship between fundamental properties of the cardiovascular system, such as ventricular contractility and stiffness or vascular resistance and compliance, and clinically available measurements such as blood pressures, chamber volumes or valve flow waveforms.