Dynamic variation of hemodynamic shear stress on the walls of developing chick hearts: computational models of the heart outflow tract
Dynamic variation of hemodynamic shear stress on the walls of developing chick hearts: computational models of the heart outflow tract
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DOI：
10.1007/s00366-008-0107-0
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发表时间：
2009-01-01
影响因子：
8.7
通讯作者：
Rugonyi, Sandra
中科院分区：
文献类型：
--
作者：
Liu, Aiping;Wang, Ruikang K.;Rugonyi, Sandra
心脏形态发生和生长受到作用于心脏壁的血液动力学力（壁剪切应力和血压）的影响。血流动力学力影响心脏发育的机制还不清楚，部分原因是在体内测量这些力存在困难。在本文中，我们展示了如何壁切应力在心脏流出道（OFT）的鸡胚在早期发育阶段（HH 18）的几何形状和运动的OFT壁的变化的影响。特别是，我们对心脏垫的影响感兴趣，心脏垫是OFT壁向管腔的突起，位于瓣膜随后形成的位置。我们开发了理想化的有限元模型（FEM）的鸡OFT与心脏垫。在这些模型中使用的几何参数估计从使用光学相干断层扫描（OCT）技术获得的体内图像。FEM显示OFT中的显著反向血流（回流），与HH 18时鸡心脏中的实验观察结果一致，并显示心脏垫减少回流。此外，我们的有限元分析表明，壁面剪应力的空间分布的影响，与较大的绝对峰值观察到的缓冲垫。心脏垫和其他地方的细胞受到的机械刺激（壁面剪切应力）的差异可能会影响瓣膜形成和心脏发育。
Heart morphogenesis and growth are influenced by hemodynamic forces (wall shear stress and blood pressure) acting on the walls of the heart. Mechanisms by which hemodynamic forces affect heart development are not well understood, in part because of difficulties involved in measuring these forces in vivo. In this paper, we show how wall shear stress in the heart outflow tract (OFT) of chick embryos at an early developmental stage (HH18) are affected by changes in the geometry and motion of the OFT wall. In particular, we were interested in the effects of cardiac cushions, which are protrusions of the OFT wall toward the lumen and that are located where valves will later form. We developed idealized finite element models (FEM) of the chick OFT with and without cardiac cushions. Geometrical parameters used in these models were estimated from in vivo images obtained using optical coherence tomography (OCT) techniques. The FEMs showed significant reverse blood flow (backflow) in the OFT, consistent with experimental observations in the chick heart at HH18, and revealed that cardiac cushions decrease backflow. In addition, our FEMs showed that the spatial distribution of wall shear stress is affected by cardiac cushions, with larger absolute peak values observed at the cushions. Differences in mechanical stimuli (wall shear stress) that the cells in the cardiac cushions and elsewhere are subjected to may affect valve formation and heart development.