In a normal cardiac cycle, the trileaflet aortic valve opening is progressive, which correlates with the phasic blood flow. Therefore, we aimed to determine the impact of including an anatomically accurate reconstructed trileaflet aortic valve within a fluid‐structure interaction (FSI) simulation model and determine the cyclical hemodynamic forces imposed on the thoracic aortic walls from aortic valve opening to closure. A pediatric patient with a normal trileaflet valve was recruited. Using the Cardiac Magnetic Resonance Data (CMR), a 3D model of the aortic valve and thoracic aorta was reconstructed. FSI simulations were employed to assess the tissue stress during a cardiac cycle as the result of changes in the valve opening. The blood flow was simulated as a mixture of blood plasma and red blood cells to account for non‐Newtonian effects. The computation was validated with phase‐contrast CMR. Windkessel boundary conditions were employed to ensure physiological pressures during the cardiac cycle. The leaflets' dynamic motion during the cardiac cycle was defined with an analytic grid velocity function. At the beginning of the valve opening a thin jet is developing. From mid‐open towards full opening the stress level increases where the jet impinges the convex wall. At peak systole two counter‐rotating Dean‐like vortex cores manifest in the ascending aorta, which correlates with increased integrated mean stress levels. An accurate trileaflet aortic valve is needed for capturing of both primary and secondary flow features that impact the forces on the thoracic aorta wall. Omitting the aortic valve underestimates the biomechanical response.

中文翻译：

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具有三叶主动脉瓣的胸主动脉在瓣膜打开的不同阶段的血流动力学和组织生物力学。

在正常的心动周期中，三叶主动脉瓣的开口是渐进的，这与阶段性血流相关。因此，我们旨在确定在流体结构相互作用 (FSI) 模拟模型中包含解剖学上准确的重建三叶主动脉瓣的影响，并确定从主动脉瓣打开到关闭施加在胸主动脉壁上的循环血流动力学力。招募了一名三叶瓣正常的儿科患者。使用心脏磁共振数据 (CMR)，重建了主动脉瓣和胸主动脉的 3D 模型。FSI 模拟被用来评估心动周期中瓣膜开度变化引起的组织应力。血流模拟为血浆和红细胞的混合物，以解释非牛顿效应。计算得到了相衬 CMR 的验证。Windkessel 边界条件被用来确保心动周期中的生理压力。在心动周期中，小叶的动态运动是用解析网格速度函数定义的。在阀门打开的开始，一个细的射流正在形成。从中间打开到完全打开，射流撞击凸壁处的应力水平增加。在收缩期峰值时，升主动脉中出现两个反向旋转的 Dean 样涡核，这与增加的综合平均应力水平相关。需要一个准确的三叶主动脉瓣来捕获影响胸主动脉壁力的主要和次要流动特征。省略主动脉瓣低估了生物力学反应。