Effects of Cardiac Motion on Right Coronary Artery Hemodynamics

Abstract

The purpose of this work was to investigate the effects of physiologically realistic cardiac-induced motion on hemodynamics in human right coronary arteries. The blood flow patterns were numerically simulated in a modeled right coronary artery (RCA) having a uniform circular cross section of 2.48 mm diam. Arterial motion was specified based on biplane cineangiograms, and incorporated physiologically realistic bending and torsion. Simulations were carried out with steady and pulsatile inflow conditions (mean ReD=233, alpha=1.82) in both fixed and moving RCA models, to evaluate the relative importance of RCA motion, flow pulsation, and the interaction between motion and flow pulsation. RCA motion with a steady inlet flow rate caused variations in wall shear stress (WSS) magnitude up to 150% of the inlet Poiseuille value. There was significant spatial variability in the magnitude of this motion-induced WSS variation. However, the time-averaged WSS distribution was similar to that predicted in a static model representing the time-averaged geometry. Furthermore, the effects of flow pulsatility dominated RCA motion-induced effects; specifically, there were only modest differences in the WSS history between simulations conducted in fixed and moving RCA models with pulsatile inflow. RCA motion has little effect on time-averaged WSS patterns. It has a larger effect on the temporal variation of WSS, but even this effect is overshadowed by the variations in WSS due to flow pulsation. The hemodynamic effects of RCA motion can, therefore, be ignored as a first approximation in modeling studies.

Non-Newtonian blood flow in human right coronary arteries: steady state simulations

“…Experimental and numerical investigation of these relationships has been the subject of recent reviews (Caro, 2001;Liepsch, 2002). Much of the early numerical modelling was focused on the carotid artery bifurcation (Perktold and Resch, 1990;Perktold et al, 1991b;Perktold et al, 1991a), but, recently, this focus has shifted to the right coronary artery, both in terms of simulation (Krams et al, 1997;Kirpalani et al, 1999;van Langenhove et al, 2000;Myers et al, 2001;Wentzel et al, 2003;Zeng et al, 2003) and experimentally (Krams et al, 1997;Ojha et al, 2001;Feldman et al, 2002;Zhu et al, 2003).…”

Is arterial wall-strain stiffening an additional process responsible for atherosclerosis in coronary bifurcations?: an in vivo study based on dynamic CT and MRI

“…While the effects of vessel compliance (19), curvature (44), blood flow (36), and cardiac motion on coronary ESS have been widely explored (46), the effects of myocardial contraction on arterial WS/S distributions remain unclear. Surprisingly, no biomechanical studies have yet quantified WS/S distributions resulting from blood pressure and myocardium contraction acting together.…”

Clinical important hemodynamic characteristics for serial stenosed coronary artery

“…Second, in this model, vessel walls are assumed rigid, results might differ in elastic models of the coronary artery wall. Zeng et al [44] have incorporated the effects of physiologically realistic arterial motion into a simulation of blood flow patterns in the RCA. The results show that the arterial motion had little effect on the WSS distribution within the RCA and that flow in the moving artery followed the instantaneous dynamic geometry quite closely.…”