Curvilinearity of LV end-systolic pressure-volume and dP/dtmax-end-diastolic volume relations.
Curvilinearity of LV end-systolic pressure-volume and dP/dtmax-end-diastolic volume relations.
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左心室收缩末期压力-容积和 dP/dtmax-舒张末期容积关系的曲线。
DOI：
10.1152/ajpheart.1993.265.3.h910
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Little,WC
中科院分区：
文献类型：
--
作者：
Noda,T;Cheng,CP;DeTombe,PP;Little,WC
在8只麻醉开胸犬上，观察了收缩状态（CS）对左室收缩末期压力-容积（Pes-Ves）曲线的影响，以及dP/dtmax-舒张末期容积（dP/dtmax-Ved）关系。左心室容积由超声显微测量法测量的三个正交直径确定。在短暂性腔静脉阻塞和主动脉缩窄期间评估Pes-Ves关系和dP/dtmax-Ved关系，同时用多巴酚丁胺改变CS。在所有CS时，当腔静脉闭塞导致容积减少时，两种关系均呈线性。然而，在通过主动脉缩窄获得的较高体积下，关系变得非线性。CS增强后，Pes-Ves关系和dP/dtmax-Ved关系的非线性均增加。dP/dtmax-Ved关系在较大体积时开始偏离线性，但比Pes-Ves关系更接近基线操作体积。收缩末期平均周向应力与室壁应变（σ es-Ves）之间的关系在对照CS时为线性，而Pes-Ves关系为非线性，但随着CS增强而变为非线性。我们得出结论，无论是Pes-Ves关系和dP/dtmax-Ved关系是非线性的，饱和在较高的体积。随着CS的增加，两种关系的非线性增加。Pes-Ves关系的这种CS依赖的曲线性是由于σ-ε关系的CS依赖的非线性（与长度依赖的激活一致）和改变Pes和σ之间的关系的几何因素。
We investigated the effect of contractile state (CS) on the curvilinearity of the left ventricular (LV) end-systolic pressure-volume (Pes-Ves) and the dP/dtmax-end-diastolic volume (dP/dtmax-Ved) relations in eight anesthetized open-chest dogs. LV volume was determined from three orthogonal diameters measured by sonomicrometry. The Pes-Ves relation and dP/dtmax-Ved relation were assessed during transient vena caval occlusion and aortic constriction, while CS was altered with dobutamine. At all CS, both relations were linear when volumes were decreased by caval occlusion. However, at higher volumes obtained by aortic constriction, the relations became nonlinear. At enhanced CS, the nonlinearity of both the Pes-Ves relation and the dP/dtmax-Ved relation increased. The dP/dtmax-Ved relation began to deviate from linearity at larger volumes, but closer to baseline operating volume, than the Pes-Ves relation. The relation between end-systolic mean circumference stress and wall strain (sigma es-epsilon es) was linear at control CS when the Pes-Ves relation was nonlinear but became nonlinear with enhanced CS. We conclude that both the Pes-Ves relation and the dP/dtmax-Ved relation are nonlinear, saturating at higher volumes. With increased CS, the nonlinearity of both relations increases. This CS-dependent curvilinearity of the Pes-Ves relation is due to both CS-dependent nonlinearity of the sigma es-epsilon es relation (consistent with length-dependent activation) and geometric factors that alter the relation between Pes and sigma es.