The Effect of Cardiac Properties and Aortic Geometry on Aortic Hemodynamics: A Simulation Study

In this study, computational fluid dynamics (CFD) simulations were carried out to investigate the influence of cardiac function and aorta geometry on aortic hemodynamics. Two idealized three-dimensional aortic models with (i) a constant diameter geometry and (ii) a more realistic geometry incorporating the effect of tapering, curvature, and torsion were coupled with a lumped parameter heart model at the inlet and three-element Windkessel models at each aortic branch outlets. Our results demonstrated that with the same boundary condition settings at baseline, utilizing a more realistic aortic geometry resulted in a higher aortic pressure and a lower flow rate, as compared to the constant aortic geometry. This geometrical model also exhibited less homogeneous spatial distributions of pressure, velocity, and wall shear stress, particularly at the distal descending aorta. Aortic pressure and flow rate decrease with a decrease in the left ventricular contractility (Emax) or an increase in the chamber diastolic stiffness (Emin) and vice versa. These findings highlight the important role of cardiac properties and aortic geometry in shaping aortic hemodynamics and emphasize the significance of considering their implications for understanding cardiovascular disease.