Effects of myocardial constraint on the passive mechanical behaviors of the coronary vessel wall
Effects of myocardial constraint on the passive mechanical behaviors of the coronary vessel wall
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DOI：
10.1152/ajpheart.00670.2007
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发表时间：
2008-01-01
影响因子：
4.8
通讯作者：
Kassab, Ghassan S.
中科院分区：
文献类型：
--
作者：
Liu, Yi;Zhang, Wei;Kassab, Ghassan S.
大的心外膜冠状动脉和静脉跨越心脏的表面，并逐渐渗透到心肌。最近的研究表明，心外膜静脉对压力超负荷的重塑强烈依赖于心肌支持的程度。与栓系区域相比，血管壁的非栓系区域显示出显著的内膜增生。我们的假设是，这种周向不均匀的结构适应血管壁是由于不均匀的壁应力和应变。周围心肌组织的支持显著影响血管应力和应变，这显著限制了血管的扩张。在这项有限元研究中，我们通过将左前降支动脉嵌入心肌不同深度来模拟不均匀的支撑，并分析血管壁的变形和应变。在生理压力下，未栓系区的周向壁应变远高于栓系区。假设的基础上，壁应变升高是刺激重塑，模拟结果表明，大心外膜冠状动脉血管有更大的趋势，在心肌约束的情况下，变得更厚。本研究为理解血管在不同程度的周围组织作用下的局部生长和重塑提供了力学基础。
The large epicardial coronary arteries and veins span the surface of the heart and gradually penetrate into the myocardium. It has recently been shown that remodeling of the epicardial veins in response to pressure overload strongly depends on the degree of myocardial support. The nontethered regions of the vessel wall show significant intimal hyperplasia compared with the tethered regions. Our hypothesis is that such circumferentially nonuniform structural adaptation in the vessel wall is due to nonuniform wall stress and strain. Transmural stress and strain are significantly influenced by the support of the surrounding myocardial tissue, which significantly limits distension of the vessel. In this finite-element study, we modeled the nonuniform support by embedding the left anterior descending artery into the myocardium to different depths and analyzed deformation and strain in the vessel wall. Circumferential wall strain was much higher in the untethered than tethered region at physiological pressure. On the basis of the hypothesis that elevated wall strain is the stimulus for remodeling, the simulation results suggest that large epicardial coronary vessels have a greater tendency to become thicker in the absence of myocardial constraint. This study provides a mechanical basis for understanding the local growth and remodeling of vessels subjected to various degrees of surrounding tissue.