Artificial Organ Technology Laboratory, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, China.
Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
Biomech Model Mechanobiol. 2023 Aug;22(4):1447-1457. doi: 10.1007/s10237-023-01731-4. Epub 2023 Jun 30.
Hemodynamics play a vital role for the risk of thrombosis in the left atrial appendage (LAA) and left atrium (LA) for patients with atrial fibrillation. Accurate prediction of hemodynamics in the LA can provide important guidance for assessing the risk of thrombosis in the LAA. Patient specificity is a crucial factor in representing the true hemodynamic fields. In this study, we investigated the effects of blood rheology (as a function of hematocrit and shear rate), as well as patient-specific mitral valve (MV) boundary conditions (MV area and velocity profiles measured by ultrasound) on the hemodynamics and thrombosis potential of the LAA. Four scenarios were setup with different degrees of patient specificity. Though using a constant blood viscosity can classify the thrombus and non-thrombus patients for all the hemodynamic indicators, the risk of thrombosis was underestimated for all patients compared with patient-specific viscosities. The results with least patient specificities showed that patients prone to thrombosis predicted by three hemodynamic indicators were inconsistent with clinical observations. Moreover, though patients had the same MV inlet flow rate, different MV models lead to different trends in the risk of thrombosis in different patients. We also found that endothelial cell activation potential and relative residence time can effectively distinguish thrombus and non-thrombus patients for all the scenarios, relatively insensitive to patient specificities. Overall, the findings of this study provide useful insights on patients-specific hemodynamic simulations of the LA.
血流动力学在左心耳（LAA）和左心房（LA）中的血栓形成风险中起着至关重要的作用，对于患有心房颤动的患者。LA 中的血流动力学的准确预测可为评估 LAA 中的血栓形成风险提供重要指导。患者特异性是代表真实血流动力学场的关键因素。在这项研究中，我们研究了血液流变学（作为血细胞比容和剪切率的函数）以及特定于患者的二尖瓣（MV）边界条件（通过超声测量的 MV 面积和速度分布）对 LAA 的血流动力学和血栓形成潜力的影响。建立了四个具有不同程度患者特异性的场景。尽管使用恒定的血液粘度可以对所有血流动力学指标对血栓和非血栓患者进行分类，但与特定于患者的粘度相比，所有患者的血栓形成风险均被低估。特异性最低的结果表明，由三个血流动力学指标预测的易发生血栓形成的患者与临床观察结果不一致。此外，尽管患者具有相同的 MV 入口流量，但不同的 MV 模型会导致不同患者的血栓形成风险呈现不同的趋势。我们还发现，内皮细胞激活潜能和相对停留时间可以有效地区分所有情况下的血栓和非血栓患者，对患者特异性相对不敏感。总体而言，这项研究的结果为 LA 的患者特异性血流动力学模拟提供了有用的见解。
