Freeman G L, LeWinter M M
Circ Res. 1984 Mar;54(3):294-300. doi: 10.1161/01.res.54.3.294.
The manner in which the pericardium adapts to chronic cardiac dilation is not known. Recent work from our laboratory indirectly suggested that the size of the pericardium and/or its pressure-volume relation was altered by chronic cardiac enlargement. To examine this question further, we compared pericardial pressure-volume and stress-strain relations, surface area, mass, and average thickness in seven normal dogs and seven with chronic volume overload hypertrophy due to a systemic arteriovenous fistula. Dogs with significant cardiac hypertrophy had an increased pericardial volume at any pressure and a proportionality constant for the slope of the entire curve as determined by nonlinear regression analysis. This was associated with parallel increases in pericardial surface area and mass such that average thickness was unchanged. Stress-strain analysis of the data revealed that the mechanical properties of the pericardium were not significantly different in dogs with chronic cardiac dilation. These results indicate that during chronic cardiac dilation the pericardium enlarges in size and mass. The pericardial chamber is more compliant, although the intrinsic stiffness of the pericardium appears to be unchanged. Further, since pericardial mass is increased, the response to chronic dilation appears to also involve the addition of new pericardial tissue.
心包如何适应慢性心脏扩张尚不清楚。我们实验室最近的研究间接表明，慢性心脏增大改变了心包的大小和/或其压力-容积关系。为了进一步研究这个问题，我们比较了7只正常犬和7只因体循环动静脉瘘导致慢性容量负荷性肥大犬的心包压力-容积和应力-应变关系、表面积、质量及平均厚度。通过非线性回归分析确定，显著心脏肥大的犬在任何压力下的心包容积增加，且整个曲线斜率的比例常数增加。这与心包表面积和质量的平行增加相关，从而使平均厚度保持不变。对数据的应力-应变分析显示，慢性心脏扩张犬的心包力学特性无显著差异。这些结果表明，在慢性心脏扩张过程中，心包的大小和质量会增大。心包腔更具顺应性，尽管心包的固有硬度似乎未改变。此外，由于心包质量增加，对慢性扩张的反应似乎还涉及新心包组织的增加。
