BACKGROUND:Coronary artery disease (CAD) is reported as one of the most common sources of death all over the world. The presence of stenosis (plaque) in the coronary arteries results in the restriction of blood supply, which leads to myocardial infarction. OBJECTIVE:The aim of this study was to investigate the effect of multi stenosis on hemodynamics parameters in idealized coronary artery models with varying degrees of stenosis and interspace distance between the stenosis. METHODS:A finite volume-based software package (ANSYS CFX 17.2) was employed to model the blood flow. The hemodynamic stenosis parameters of blood, such as the pressure, velocity, and wall shear stress were obtained. RESULTS:The computed results showed that the pressure drop is maximum across the 90% area stenosis (AS). The pressure drop is increased as the distance between the proximal and distal stenosis is decreased across the proximal stenosis for the model P70_D70 durign the systolic period of the cardiac cycle. A recirculation zone is formed behind the stenosis and is restricted by the occurrence of distal stenosis as the interspacing distance decreases, which could lead to further progression of stenosis in the flow-disturbed area. The wall shear stress was found to increase as the distance between the proximal and distal stenosis is increased across the distal stenosis. The maximum wall shear stress was found at the 90% AS. CONCLUSIONS:In the clinical diagnosis an overestimation of distal stenosis severity could be possible. Furthermore, the low wall shear stress zone in between the proximal and distal stenosis may help atherosclerotic growth or merging of adjacent stenosis.

中文翻译：

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多狭窄冠状动脉脉动血流特性的数值模拟

背景：冠状动脉疾病 (CAD) 被报道为全世界最常见的死亡来源之一。冠状动脉狭窄（斑块）的存在导致血液供应受限，从而导致心肌梗塞。目的：本研究的目的是研究多处狭窄对具有不同狭窄程度和狭窄间隙距离的理想冠状动脉模型中血流动力学参数的影响。方法：采用基于有限体积的软件包（ANSYS CFX 17.2）对血流进行建模。获得血液的血流动力学狭窄参数，如压力、速度和壁剪切应力。结果：计算结果表明，压降在 90% 狭窄区域 (AS) 处最大。对于模型 P70_D70 在心动周期的收缩期，随着近端狭窄和远端狭窄之间的距离在近端狭窄处减小，压降增加。狭窄后方形成再循环区，随着间距的减小，远端狭窄的发生受到限制，这可能导致流动干扰区的狭窄进一步发展。发现壁剪切应力随着近端和远端狭窄之间的距离在远端狭窄处增加而增加。在 90% AS 处发现了最大壁剪应力。结论：在临床诊断中，可能会高估远端狭窄的严重程度。此外，