POROUS-MEDIUM FINITE-ELEMENT MODEL OF THE BEATING LEFT-VENTRICLE
POROUS-MEDIUM FINITE-ELEMENT MODEL OF THE BEATING LEFT-VENTRICLE
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DOI：
10.1152/ajpheart.1992.262.4.h1256
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发表时间：
1992-04-01
影响因子：
--
通讯作者：
RENEMAN, RS
中科院分区：
文献类型：
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作者：
HUYGHE, JM;ARTS, T;RENEMAN, RS
所描述的轴对称模型将心肌组织表示为海绵状各向异性粘弹性材料。它包括围绕心室对称轴的扭转、纤维角的跨壁变化以及冠状动脉内血液在心肌壁中的重新分布。在模拟中，收缩末期主应变在心外膜壁厚的三分之二处等于0.45、-0.01和-0.24，在心外膜壁厚的三分之一处等于0.26、0.00和-0.19。最大缩短方向从心外膜到心内膜变化< 30 °，而纤维方向从心外膜到心内膜变化> 100 °。在正常心动周期峰值期间，赤道心肌内压与峰值心室内压相差< 5%。当冠状动脉内血液在心室壁的再分布受到抑制时，发现赤道心肌内峰压超过心室内峰压30%以上。无负荷左心室（左心室压力= 0 kPa）的模拟收缩产生与正常心动周期相似的收缩期心肌内压。跨壁收缩期纤维应力分布对所选择的跨壁纤维角度分布非常敏感。
The axisymmetric model described represents myocardial tissue as a spongy anisotropic viscoelastic material. It includes torsion around the axis of symmetry of the ventricle, transmural variation of fiber angle, and redistribution of intracoronary blood in the myocardial wall. In simulations, end-systolic principal strains were equal to 0.45, -0.01, and -0.24 at two-thirds of the wall thickness from the epicardium and 0.26, 0.00, and -0.19 at one-third of the wall thickness from the epicardium. The direction of maximal shortening varied by < 30-degrees from epicardium to endocardium, whereas fiber direction varied by > 100-degrees from epicardium to endocardium. During a normal cardiac cycle peak, equatorial intramyocardial pressure differed by < 5% from peak intraventricular pressure. When redistribution of intracoronary blood in the ventricular wall was suppressed, peak equatorial intramyocardial pressure was found to exceed peak intraventricular pressure by > 30%. Simulated contraction of an unloaded left ventricle (left ventricular pressure = 0 kPa) produced similar magnitude for systolic intramyocardial pressures as the normal cardiac cycle. Transmural systolic fiber stress distribution was very sensitive to the chosen transmural fiber angle distribution.