Mean wall shear stress was approximately 50% lower on the inside wall than the outside wall, with circumferential strain and wall shear stress being highly out of phase in the coronary model.
Computational modeling reveals that circumferential strain and wall shear stress are highly out of phase in coronary arteries, which may contribute to the localization of atherosclerosis.
The endothelial cells (ECs) lining a blood vessel wall are exposed to both the wall shear stress (WSS) of blood flow and the circumferential strain (CS) of pulsing artery wall motion. These two forces and their interaction are believed to play a role in determining remodeling of the vessel wall and development of arterial disease (atherosclerosis). This study focused on the WSS and CS dynamic behavior in a compliant model of a coronary artery taking into account the curvature of the bending artery and physiological radial wall motion. A three-dimensional finite element model with transient flow and moving boundaries was set up to simulate pulsatile flow with physiological pressure and flow wave forms characteristic of the coronary arteries. The characteristic coronary artery curvature and flow conditions applied to the simulation were: aspect ratio (lambda) = 10, diameter variation (DV) = 6 percent, mean Reynolds number (Re) = 150, and unsteadiness parameter (alpha) = 3. The results show that mean WSS is about 50 percent lower on the inside wall than the outside wall while WSS oscillation is stronger on the inside wall. The stress phase angle (SPA) between CS and WSS, which characterizes the dynamics of the mechanical force pattern applied to the endothelial cell layer, shows that CS and WSS are more out of phase in the coronaries than in any other region of the circulation (-220 deg on the outside wall, -250 deg on the inside wall). This suggests that in addition to WSS, SPA may play a role in localization of coronary atherosclerosis.
Qiu et al. (Sun,) conducted a other in Coronary atherosclerosis. Three-dimensional finite element model of pulsatile flow in a compliant curved tube was evaluated on Wall shear stress (WSS) and circumferential strain (CS) dynamic behavior. Mean wall shear stress was approximately 50% lower on the inside wall than the outside wall, with circumferential strain and wall shear stress being highly out of phase in the coronary model.