Logistic characterization of left ventricular isovolumic pressure-time curve.
Logistic characterization of left ventricular isovolumic pressure-time curve.
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左心室等容压力-时间曲线的Logistic 表征。
DOI：
10.2170/jjphysiol.45.535
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
H. Suga
中科院分区：
文献类型：
--
作者：
H. Matsubara;J. Araki;M. Takaki;S. Nakagawa;H. Suga
虽然有研究者尝试用指数函数和正弦函数等数学函数来表达左心室压力-时间曲线，但没有一种函数能很好地拟合左心室压力-时间曲线。在本研究中，我们假设左室等容压力-时间曲线可以用两条压力上升和下降的s型曲线之差来表示，并提出了一种新的“混合逻辑”函数来表示左室等容压力-时间曲线。我们研究了这种混合逻辑函数对10只切除的交叉循环左心室在生理预负荷和收缩状态下实验观察到的左心室等容压曲线的拟合程度。该函数能较好地拟合不考虑预紧力和收缩力的等容压力曲线，相关系数均在0.9996以上，明显优于之前提出的函数。表征等容压力曲线大小和时间过程的观测值，如峰值+/- dP/dt，也与本文最佳拟合函数计算的相应理论值密切相关。结果表明，在预负荷和收缩力的生理范围内，新的混合逻辑函数能较好地表征犬左室等容压力-时间曲线。结果表明，该混合逻辑函数可用于综合评价左室收缩舒张。
Although some investigators have attempted to express the left ventricular pressure-time curve by mathematical functions such as exponential and sinusoidal functions, none of them reasonably fits the left ventricular pressure-time curve. In the present study, we hypothesized that a ventricular isovolumic pressure-time curve could be expressed as the difference between two S-shaped curves for pressure rising and falling, and proposed a new "hybrid logistic" function to express the left ventricular isovolumic pressure-time curve. We investigated how well this hybrid logistic function fits left ventricular isovolumic pressure curves experimentally observed under physiological preload and contractility in the excised cross-circulated left ventricles of 10 dogs. The new function precisely fitted the isovolumic pressure curves regardless of preload and contractility with correlation coefficients above 0.9996, much better than the previously proposed functions. The observed values characterizing the magnitude and time course of the isovolumic pressure curve such as peak +/- dP/dt also closely correlated with the corresponding theoretical values calculated by the present best-fit function. We conclude that our new hybrid logistic function reasonably characterizes the canine left ventricular isovolumic pressure-time curve within physiological ranges of preload and contractility. The present results indicate that this hybrid logistic function is useful to evaluate left ventricular contraction and relaxation comprehensively.