Lee J M, Boughner D R
Circ Res. 1985 Sep;57(3):475-81. doi: 10.1161/01.res.57.3.475.
Whereas most experiments on the mechanical function of the pericardium have been performed on dogs, very little is known about the applicability of those data to humans. To examine the tensile viscoelastic properties of fresh human pericardium, we have used the methods from our previous study of canine pericardium. Although the mechanical responses of canine and human pericardium were qualitatively similar, human pericardium displayed a significantly greater viscous character. Human pericardium was 7.3 times thicker than canine pericardium, but was more extensible in stress-strain tests, with lower stiffness at a given strain. The static (elastic) stiffness of human pericardium seems identical to that of canine pericardium; lower stiffness per unit thickness of the human tissue at predicted physiological stresses was almost exactly compensated by the greater wall thickness. This effect was also seen in data on fracture strength and stiffness. However, human pericardium displayed greater viscous responses than the canine tissue. This was seen in doubled cyclic hysteresis losses, and greater stress relaxation and creep. Our results suggest that experiments on the viscoelastic properties of canine pericardium may not be directly applicable to humans, especially where dynamic mechanical properties are most important: i.e., in studies of ventricular function and the time-course of pericardial effusions.
鉴于大多数关于心包机械功能的实验是在狗身上进行的，对于这些数据在人类中的适用性知之甚少。为了研究新鲜人体心包的拉伸粘弹性特性，我们采用了之前研究犬心包的方法。尽管犬心包和人心包的力学反应在定性上相似，但人心包表现出明显更大的粘性特征。人心包比犬心包厚7.3倍，但在应力-应变测试中更具延展性，在给定应变下刚度更低。人心包的静态（弹性）刚度似乎与犬心包相同；在预测的生理应力下，人体组织每单位厚度较低的刚度几乎完全被更大的壁厚所补偿。这种效应在断裂强度和刚度数据中也可见。然而，人心包比犬组织表现出更大的粘性反应。这在双循环滞后损失增加以及更大的应力松弛和蠕变中可见。我们的结果表明，关于犬心包粘弹性特性的实验可能不适用于人类，特别是在动态力学特性最为重要的情况下：即心室功能和心包积液时间进程的研究。
