Effects of vessel dynamics and compliance on human right coronary artery hemodynamics with / without stenosis

Abstract

A computational study of effects of vessel dynamics and compliance on coronary artery hemodynamics with / without stenosis is presented. The coronary artery hemodynamics with stenosis has been a main subject as one of the major cardiovascular diseases induced by atherosclerosis; most computational models assume that the vessel movement and deformation are negligible (Zeng, et al., 2003; Kim, et al., 2010). However, it is till unclear whether the hemodynamic characteristics owning to vessel dynamics and compliance is clinically significant or not particularly under pathological conditions. In this study, we aim at investigating the hemodynamic effects of the vessel dynamics and compliance in right coronary artery under healthy situation without stenosis as well as under diseased conditions with stenosis. We constructed a three-dimensional geometric model of the right coronary artery based on X-ray angiographic images, in which both vessel movement and deformation were taken into account. A specific volumetric flow rate was employed as a boundary condition imposed on inlet. Furthermore, we carried out an extensive study on the inlet waveform dependence and the effects of the vessel compliance on coronary hemodynamics. Our results demonstrate that the conventional assumption on ‘rigid’ artery models holds only in the cases of normal coronary arteries but fails for stenosed coronary arteries where the vessel dynamics and compliance do extend significant influence on distributions of the oscillatory shear indices (OSIs). Moreover, we find that the effects of vessel dynamics and compliance on coronary hemodynamics seem to be independent of both inlet boundary conditions and the vessel compliance.

Keywords

• coronary artery
• compliance
• hemodynamics
• stenosis
• computational biomechanics