Uemura Kazunori, Sugimachi Masaru, Kawada Toru, Kamiya Atsunori, Jin Yintie, Kashihara Koji, Sunagawa Kenji
Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita 565-8565, Japan.
Am J Physiol Heart Circ Physiol. 2004 Jun;286(6):H2376-85. doi: 10.1152/ajpheart.00654.2003. Epub 2004 Feb 5.
A novel framework of circulatory equilibrium was developed by extending Guyton's original concept. In this framework, venous return (CO(V)) for a given stressed volume (V) was characterized by a flat surface as a function of right atrial pressure (P(RA)) and left atrial pressure (P(LA)) as follows: CO(V) = V/W - G(S)P(RA) - G(P)P(LA), where W, G(S), and G(P) denote linear parameters. In seven dogs under total heart bypass, CO(V), P(RA), P(LA), and V were varied to determine the three parameters in each animal with use of multivariate analysis. The coefficient of determination (r(2) = 0.92-0.99) indicated the flatness of the venous return surface. The averaged surface was CO(V) = V/0.129 - 19.61P(RA) - 3.49P(LA). To examine the invariability of the surface parameters among animals, we predicted the circulatory equilibrium in response to changes in stressed volume in another 12 dogs under normal and heart failure conditions. This was achieved by equating the standard surface with the individually measured cardiac output (CO) curve. In this way, we could predict CO [y = 0.90x + 5.6, r(2) = 0.95, standard error of the estimate (SEE) = 8.7 ml.min(-1).kg(-1)], P(RA) (y = 0.96x, r(2) = 0.98, SEE = 0.2 mmHg), and P(LA) (y = 0.89x + 0.5, r(2) = 0.98, SEE = 0.8 mmHg) reasonably well. We conclude that the venous return surface accurately represents the venous return properties of the systemic and pulmonary circulations. The characteristics of the venous return surface are invariable enough among animals, making it possible to predict circulatory equilibrium, even if those characteristics are unknown in individual animals.
通过扩展盖顿的原始概念，开发了一种新的循环平衡框架。在此框架中，对于给定的应激容量（V），静脉回流量（CO(V)）由一个平面来表征，它是右心房压力（P(RA)）和左心房压力（P(LA)）的函数，如下所示：CO(V)=V/W - G(S)P(RA) - G(P)P(LA)，其中W、G(S)和G(P)表示线性参数。在七只进行全心旁路手术的狗身上，改变CO(V)、P(RA)、P(LA)和V，通过多变量分析确定每只动物的三个参数。决定系数（r(2)=0.92 - 0.99）表明了静脉回流表面的平坦度。平均表面为CO(V)=V/0.129 - 19.61P(RA) - 3.49P(LA)。为了研究动物之间表面参数的不变性，我们预测了另外12只处于正常和心力衰竭状态的狗在应激容量变化时的循环平衡。这是通过使标准表面与单独测量的心输出量（CO）曲线相等来实现的。通过这种方式，我们能够较好地预测CO [y = 0.90x + 5.6，r(2)=0.95，估计标准误差（SEE）=8.7 ml·min(-1)·kg(-1)]、P(RA)（y = 0.96x，r(2)=0.98，SEE = 0.2 mmHg）和P(LA)（y = 0.89x + 0.5，r(2)=0.98，SEE = 0.8 mmHg）。我们得出结论，静脉回流表面准确地代表了体循环和肺循环的静脉回流特性。静脉回流表面的特征在动物之间具有足够的不变性，即使在个体动物中这些特征未知，也能够预测循环平衡。
