Pouleur H, Rousseau M F, Charlier A A
Schweiz Med Wochenschr. 1985 May 11;115(19):638-43.
The mechanical performance of the myocardium depends upon factors intrinsic to the myofibrils ("contractility") and upon the physicochemical conditions surrounding the cells ("inotropic state"). A precise description of cardiac muscle performance requires a knowledge of 4 variables: length, force, velocity and time. In vivo the problem is further complicated by the presence in the ventricle of spatio-temporal nonuniformities (activation sequence, fiber orientation) and by the fact that major determinants of the inotropic state, such as sympathetic tone, are hard to verify. The indices expected to reflect the tension-velocity-length relation of the myofibrils, either during isovolumic contraction (peak(+)dP/dt) or during ejection (end-systolic relations between pressure or stress and volume, relations between ejection fraction and stress) can generally detect acute changes in inotropic state. Up to now, however, none of these indices has been shown to be very sensitive in detecting basal alterations in contractility. Considering the practical and theoretical limitations on study of an intact ventricle, it would appear indispensable, if we want greater precision in detecting functional alterations of the myocardium, to supplement study of ventricular mechanics by biochemical and morphological analysis of the myocardium.
心肌的机械性能取决于肌原纤维的内在因素（“收缩性”）以及细胞周围的物理化学条件（“变力状态”）。对心肌性能的精确描述需要了解四个变量：长度、力、速度和时间。在体内，由于心室中存在时空不均匀性（激活顺序、纤维方向），以及变力状态的主要决定因素（如交感神经张力）难以验证，问题变得更加复杂。预期反映肌原纤维张力-速度-长度关系的指标，无论是在等容收缩期间（峰值（+）dP/dt）还是在射血期间（压力或应力与容积之间的收缩末期关系、射血分数与应力之间的关系），通常都能检测到变力状态的急性变化。然而，到目前为止，这些指标在检测收缩性的基础改变方面都没有显示出非常敏感。考虑到对完整心室研究的实际和理论限制，如果我们想更精确地检测心肌的功能改变，通过对心肌进行生化和形态学分析来补充心室力学研究似乎是必不可少的。
