Nikou Amir, Gorman Robert C, Wenk Jonathan F
Department of Mechanical Engineering, University of Kentucky, Lexington, KY, USA.
Gorman Cardiovascular Research Group and Department of Surgery, University of Pennsylvania, Philadelphia, PA, USA.
Proc Inst Mech Eng H. 2016 Jun;230(6):594-8. doi: 10.1177/0954411916638685. Epub 2016 Mar 14.
The goal of this study was to investigate the sensitivity of computational models of the heart to their incorporated myofiber architecture during diastole. This architecture plays a critical role in the mechanical and electrical function of the heart and changes after myocardial tissue remodeling, which is associated with some of the most common heart diseases. In this study, a left ventricular finite element model of the porcine heart was created using magnetic resonance imaging, which represents the in vivo geometry. Various myofiber architectures were assigned to the finite element mesh, in the form of fiber and sheet angles. A structural-based material law was used to model the behavior of passive myocardium and its parameters were estimated using measured in vivo strains and cavity volume from magnetic resonance imaging. The final results showed noticeable sensitivity of the stress distribution to both the fiber and sheet angle distributions. This implies that a structural-based material law that takes into account the effect of both fiber and sheet angle distributions should be used. The results also show that although the simulation results improve using available data from histological studies of myocardial structure, the need for individualized myofiber architecture data is crucial.
本研究的目的是调查心脏计算模型在舒张期对其所纳入的肌纤维结构的敏感性。这种结构在心脏的机械和电功能中起着关键作用，并且在心肌组织重塑后会发生变化，而心肌组织重塑与一些最常见的心脏病相关。在本研究中，使用磁共振成像创建了猪心脏的左心室有限元模型，该模型代表体内几何形状。以纤维和片层角度的形式将各种肌纤维结构分配给有限元网格。使用基于结构的材料定律对被动心肌的行为进行建模，并使用磁共振成像测量的体内应变和腔室容积估计其参数。最终结果表明，应力分布对纤维和片层角度分布均具有显著的敏感性。这意味着应使用考虑纤维和片层角度分布影响的基于结构的材料定律。结果还表明，尽管使用来自心肌结构组织学研究的现有数据可改善模拟结果，但个性化肌纤维结构数据的需求至关重要。
