论文部分内容阅读
目的数值模拟心肌桥壁冠状动脉血液动力学,探索心肌桥壁冠状动脉近心端易发生动脉粥样硬化的血液动力学机理。方法建立随心搏运动的局部狭窄直圆管模型模拟心肌桥壁冠状动脉形态学,管壁为薄壁线弹性体,血流遵循不可压缩牛顿流体的一维管流方程组,用Lax-Wendroff方法数值求解。结果心肌桥壁冠状动脉血液动力学与正常冠状动脉血液动力学相比有很大差异,血流量#壁切应力和壁切应力梯度均不同。在心肌桥壁冠状动脉中,近心端壁切应力及壁切应力梯度的变化要远大于远心端。对于有两段心肌桥的情况,它们的壁切应力和壁切应力梯度变化趋势基本一致,但距心室较远的心肌桥,其壁切应力和壁切应力梯度要大于靠近心室的那段心肌桥,且随时间的变化程度也更剧烈。结论数值模拟结果表明,心肌桥壁冠状动脉血液动力学不同于正常冠状动脉血液动力学,近心端壁切应力及壁切应力梯度的变化要远大于远心端,从而对动脉管内皮细胞产生重要影响,这可能是心肌桥壁冠状动脉近心端易发生动脉粥样硬化的血液动力学机理。
Objective To simulate the hemodynamics of coronary artery in myocardial bridge and explore the hemodynamic mechanism of coronary atherosclerosis in myocardial bridge. Methods The model of coronary stenosis with myocardial stenosis was simulated with a straight-tube model of local stenosis. The wall of the coronary artery was thin-walled elastomers. The blood flow followed the one-dimensional flow equations of incompressible Newtonian fluid. The Lax-Wendroff method Numerical solution. Results There was a great difference between the hemodynamics of coronary artery in the myocardial bridge and the normal coronary hemodynamics. The wall shear stress and wall shear stress gradient of blood flow were different. In the coronary arteries of the myocardial bridge, the change of the stress near the end wall and the gradient of the wall shear stress is far greater than that at the telecentric end. In the case of two myocardial bridges, the trend of wall shear stress and wall shear stress gradient are basically the same. However, the myocardial bridge far away from the ventricle has larger wall shear stress and wall shear stress gradient than those close to the ventricle Bridge, and the degree of change over time more intense. Conclusions The results of numerical simulation show that the changes of coronary artery hemodynamics in myocardial bridge are different from that of normal coronary arteries, and the change of stress in proximal end wall and stress gradient in wall shear is far greater than that in telecentric end, Important effect, which may be myocardial proximal cardiac coronary artery prone to atherosclerosis hemodynamic mechanism.