Williams J F, Potter R D
Circ Res. 1981 Jul;49(1):211-5. doi: 10.1161/01.res.49.1.211.
The effect of myocardial hypertrophy on passive stiffness was determined from the stress (sigma)-strain relationship of right ventricular papillary muscles from 18 pulmonary artery-banded and 21 non-banded cats. By use of Lagrangian strain, (1-lo)lo is initial muscle length, and instantaneous stress elastic constants beta and alpha were calculated from the equation sigma = alpha(ebeta epsilon - 1). Elastic stiffness (d sigma/d epsilon) was determined from the formula d sigma/d epsilon = beta alpha + alpha beta. Banding produced an average increase in RV mass of 70%. Beta averaged 14.2 +/- 0.9 (SEM) and 16.0 +/- 0.8 in the non-hypertrophied and hypertrophied muscles, respectively (NS). However, elastic stiffness was significantly greater in hypertrophied muscles over the entire stress range. Contractile function varied widely among hypertrophied muscles but was not related to changes in stiffness. Thus, moderate degrees of pressure-induced hypertrophy are associated with a modest increase in the passive stiffness properties of the muscle, independent of changes in contractile function.
通过对18只肺动脉束扎猫和21只未束扎猫右心室乳头肌的应力（σ）-应变关系来确定心肌肥大对被动僵硬度的影响。使用拉格朗日应变，（1-lo）/lo为初始肌肉长度，瞬时应力弹性常数β和α由方程σ = α（eβε - 1）计算得出。弹性僵硬度（dσ/dε）由公式dσ/dε = βα + αβ确定。束扎使右心室质量平均增加70%。非肥厚和肥厚肌肉中的β平均值分别为14.2±0.9（标准误）和16.0±0.8（无显著性差异）。然而，在整个应力范围内，肥厚肌肉的弹性僵硬度显著更高。肥厚肌肉的收缩功能差异很大，但与僵硬度变化无关。因此，中度压力诱导的肥大与肌肉被动僵硬度特性的适度增加有关，与收缩功能的变化无关。
