The superiority of maximum fiber elastance over maximum stress-volume ratio as an index of contractile state.
The superiority of maximum fiber elastance over maximum stress-volume ratio as an index of contractile state.
复制标题
作为收缩状态指标，最大纤维弹性相对于最大应力体积比的优越性。
DOI：
10.1161/01.cir.72.3.648
复制
发表时间：
1985
期刊：
影响因子：
37.8
通讯作者：
J. Evans
中科院分区：
文献类型：
--
作者：
T. Wisenbaugh;G. Yu;J. Evans
收缩末期压力-容积关系已被用作心室泵性能的负荷无关性测量。由于不同大小和厚度的心室之间的负荷的比较可以更准确地进行与壁应力的测量比与压力，收缩末期的应力-容积关系在一个或多个水平的收缩末期应力已被用来估计肥厚的心室的收缩功能。不同负荷搏动的收缩末期应力对收缩末期容积的线性回归具有称为最大纤维弹性（纤维Emax）的斜率和称为Vo的容积截距;单次搏动的最大应力-容积比（MSVR）是纤维Emax的近似值，但假设Vo = 0。然而，前负荷、后负荷和正性肌力状态对这些指标的影响尚未被研究。因此，我们研究了七个开胸狗与超声晶体和微压计仪器的应力-体积关系。期外收缩后增强（PESP）增加了MSVR（5.7 +/- 1.83 vs对照组4.85 +/- 1.43，p <0.05）和纤维Emax（13.93 +/- 3.24 vs对照组9.24 +/- 2.15; p <0.05）。通过输注右旋糖酐增加前负荷，并使用硝普钠维持后负荷相对恒定，对MSVR或纤维Emax均无显著影响。Vo不受PESP的显著影响，但通过增加前负荷而转移到更高的值（17.5 +/- 14.8 vs 13.9 +/- 11.1 ml，对照组; p <0.05）。（250字处删节）
The end-systolic pressure-volume relationship has been used as a load-independent measure of ventricular pump performance. Since comparisons of load between ventricles of different size and thickness may be more accurately made with measurements of wall stress than with those of pressure, the end-systolic stress-volume relationship at one or more levels of end-systolic stress has been used to estimate contractile function in hypertrophied ventricles. Linear regression of end-systolic stress against end-systolic volume for differently loaded beats has a slope termed maximum fiber elastance (fiber Emax) and a volume intercept termed Vo; the maximum stress-volume ratio (MSVR) for a single beat is an approximation of fiber Emax but assumes Vo = 0. However, the influence of preload, afterload, and inotropic state on these indexes has not been examined. We therefore studied the stress-volume relationship in seven open-chest dogs instrumented with ultrasonic crystals and micromanometers. Postextrasystolic potentiation (PESP) increased both the MSVR (5.7 +/- 1.83 vs 4.85 +/- 1.43 at control, p less than .05) and fiber Emax (13.93 +/- 3.24 vs 9.24 +/- 2.15 at control; p less than .05). Augmentation of preload by infusion of dextran, with the use of nitroprusside to maintain afterload relatively constant, did not significantly influence either the MSVR or fiber Emax. Vo was not significantly influenced by PESP, but was shifted to higher values by augmentation of preload (17.5 +/- 14.8 vs 13.9 +/- 11.1 ml at control; p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)