Diastole and its beneficial role in coronary atherogenesis

The purpose of this study is to elucidate the role, which wall shear stress (WSS) differentiation between diastole and systole plays in coronary atherosclerosis. A finite-element analysis of the 3D, pulsatile, non-Newtonian, haemodynamics of the normal human left main coronary artery bifurcation, based on published data, is performed. The time averaged mean WSS in the entire left coronary artery bifurcation region ranged from 0.086 to 5.97 N/m2. Arterial WSS was significantly lower on the lateral walls of the bifurcation, for all tested time steps of the pulse cycle. The distribution of low WSS along the walls is in agreement with the common locations of atheroma. It is the systolic period, rather than the diastolic one, which is probably associated with the development of atherosclerotic plaques, due to significantly lower WSS values during systole.