Frank-Starling心脏定律探讨—Frank-Starling定律并非定律

摘要

The law of the heart,Frank-Starling Law of the Heart (FSLH),says that the energy of cardiac contraction (cardiac work) is a function of the length of the muscle fiber (MFL)/the end-diastolic volume (EDV).The authors of this paper investigate into the FSLH via multidisciplinary knowledge from various angles and hold that:1)In the heart-lung preparation devised by Starling and his colleagues,which was aimed at studying the relationship between the inflow and cardiac work,the dog heart being put beneath the venous reservoir,relying on its own gravity,the blood in the venous reservoir flows into the right ventricle.That experimental condition is far from the physiological reality of human body vein hemodynamics.Therefore,the authors of this paper do not consider that the Frank-Starling phenomenon (the outflow increased with the rising of the filling pressure) observed in their experiments is a law of the heart working.2)The FSLH emphasizes the MFL/EDV,but it neglects the change in the MFL (e.g.,neglecting the end-systolic volume,ESV,i.e.,the end-point of the ventricular wall movement during the contraction).Lacking the ESV,the cardiac work (W) can not be calculated——the FSLH expression in the law of the heart working does not correspond to the basic principle of the “work” in physics.3)The mathematical relationship in the accepted formula for calculating the cardiac work “Stroke work =P × (EDV-ESV) ” shows that the stroke work does not always increase with the advent of the increased EDV,and does not always decrease with the advent of the decreased EDV either——there is no functional relation between the W and the EDV.Therefore,the authors of this paper hold that the FSLH expressing the fundamental principle of the heart working is a failure,and it is not a true law.%心脏搏动作功的规律:心脏收缩释放的能量(作功)是心肌纤维长度/心室舒张末期容积(EDV)的函数,即Frank-Starling心脏定律(简称“定律”),被誉为心脏生理学中的“经典”理论.笔者引用多学科知识从各种不同的角度对该“定律”行了讨论,认为:①在Starling及其同事设计的研究静脉回心血量和心脏收缩作功关系的心肺制备装置中,静脉储血瓶高置子狗心之上,储血瓶中的静脉血液依赖于自身的重力作用流入右心室的情况不符合正常人体静脉血流动力学实际,所以不能认为在他们的那种实验中观察到的Frank-Starling现象(心输出量随着心室充盈压的增加而增加)就是心脏搏动作功的规律;②“定律”强调了心脏收缩时心肌纤维的初长度,却忽略了其长度的变化(例如,忽略了心室收缩末期容积ESV,即心室肌壁收缩运动结束时的终点),如此表达心脏的作功规律,有违物理学中关于作功的基本原理——没有ESV,心脏作功不能计算；③在公认的计算心脏每搏射血作功(W)的物理学公式“W=P×(EDV-ESV)”中,心脏作功W和EDV之间的数学关系清楚地表明了W不一定随EDV的增加而增加,也不一定随EDV的减小而减少——W和EDV之间没有函数关系.所以笔者认为:Frank-Starling心脏定律未能正确表达心脏作功的客观规律,它不是一个真实的定律.