Clinical studies based on coronary computed tomography angiography (CCTA) images suggest that the presence of ramus intermedius (RI) in the left coronary artery (LCA) may aggravate the atherosclerotic depositions in the furcation region. In this study, computational fluid dynamics simulations are performed in patient-specific coronary models consisting of bifurcating LCA and two models having trifurcating LCA. Three-dimensional patient-specific coronary models are constructed from CCTA images obtained from North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, India. Results indicate that the flow redistribution happens in the left coronary branch due to the presence of RI and the flow to left anterior descending artery (LAD) is reduced significantly. Recirculation and flow separation regions are observed in the proximal parts of the LAD and left circumflex artery for trifurcation geometries. The qualitative and quantitative analysis of wall shear stress-based descriptors suggests that the presence of the intermediate branch may affect the atherosusceptibility of the proximal region of LAD. The study indicates that the presence of RI may act as a contributing factor for plaque development and progression in the furcation region and proximal parts of LAD.

中文翻译：

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左冠状动脉中支的血流动力学：针对患者的计算研究

基于冠状动脉计算机断层扫描血管造影（CCTA）图像的临床研究表明，左冠状动脉（LCA）中中间支（RI）的存在可能会加剧分叉区域的动脉粥样硬化沉积。在本研究中，在由分叉 LCA 和具有三叉 LCA 的两个模型组成的患者特异性冠状动脉模型中进行计算流体动力学模拟。三维患者特异性冠状动脉模型是根据从印度西隆东北英迪拉甘地地区健康与医学科学研究所获得的 CCTA 图像构建的。结果表明，由于 RI 的存在，左冠状动脉分支发生血流重新分配，流向左前降支 (LAD) 的血流显着减少。在 LAD 和左回旋动脉的近端部分观察到再循环和血流分离区域的三分叉几何形状。基于壁剪切应力的描述符的定性和定量分析表明，中间分支的存在可能影响 LAD 近端区域的动脉粥样硬化易感性。研究表明，RI 的存在可能是 LAD 分叉区域和近端部分斑块发生和进展的一个促成因素。