The stochastic nature of cardiac propagation at a microscopic level. Electrical description of myocardial architecture and its application to conduction.
The stochastic nature of cardiac propagation at a microscopic level. Electrical description of myocardial architecture and its application to conduction.
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微观水平上心脏传播的随机性质。
DOI：
10.1161/01.res.76.3.366
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发表时间：
1995
影响因子：
20.1
通讯作者：
Heidlage,JF
中科院分区：
文献类型：
--
作者：
Spach,MS;Heidlage,JF
本研究的目的是提供证据，证明心肌结构在细胞水平上产生电负荷的不均匀性，从而导致心脏传播本质上是随机的。即，从不同的细胞内事件和细胞之间的延迟的意义上来说，繁殖过程中的兴奋事件是不断变化和无序的。然而，在宏观层面上，这些随机事件变得平均并且看起来与连续介质一致。我们通过探索实验观察到的 V̇max 变异性是否反映了细胞内兴奋事件和连接延迟的不同模式，在心肌结构的二维 (2D) 模型中检验了这一概念。随机选择的细胞内位点的 V̇max 变异模式在实验上和 2D 模型中是相似的。二维细胞模型在间隙连接延迟方面产生了显着的变化；然而，平均而言，在不同方向的传导过程中，不同的间隙连接用于细胞间的电荷流动。在纵向传播（LP）期间，速度从每个肌细胞的近端到远端增加，V̇max在近端最低，在细胞远端四分之一处增加到最大值，并在远端减小。横向传播（TP）通过可变的细胞内激发序列产生快速的细胞内传导。在大多数亚细胞区域，TP V̇max大于LP V̇max，但在一些肌细胞末端附近，出现相反的“TP>LP V̇max”关系。钠电流携带的总电荷与 V̇max 成反比变化，证明了细胞负荷对亚细胞钠电流和钠通道动力学的反馈效应。结果表明，微观水平上正常传播的随机性质通过在激发事件发生微小变化后重建波前运动的总体趋势，对心律失常提供了相当大的保护作用。
The object of this study is to present evidence that the myocardial architecture creates inhomogeneities of electrical load at the cellular level that cause cardiac propagation to be stochastic in nature; ie, the excitatory events during propagation are constantly changing and disorderly in the sense of varying intracellular events and delays between cells. At a macroscopic level, however, these stochastic events become averaged and appear consistent with a continuous medium. We examined this concept in a two-dimensional (2D) model of myocardial architecture by exploring whether experimentally observed V̇maxvariability reflected different patterns of intracellular excitation events and junctional delays. The patterns of V̇maxvariability at randomly chosen intracellular sites were similar experimentally and in the 2D model. The 2D cellular model produced marked variability in gap junction delays; however, on the average, different gap junctions were used for cell-to-cell charge flow during conduction in different directions. During longitudinal propagation (LP), the velocity increased from the proximal to the distal end of each myocyte, and V̇maxwas lowest proximally, increased to a maximum at the distal fourth of the cell, and decreased distally. Transverse propagation (TP) produced rapid intracellular conduction with variable intracellular excitation sequences. TP V̇maxwas greater than LP V̇maxin most subcellular regions, but near the ends of some myocytes, a reversed “TP>LP V̇max” relation occurred. Total charge carried by the sodium current varied inversely with V̇max, demonstrating feedback effects of cellular loading on the subcellular sodium current and the kinetics of the sodium channels. The results suggest that the stochastic nature of normal propagation at a microscopic level provides a considerable protective effect against arrhythmias by reestablishing the general trend of wave-front movement after small variations in excitation events occur.
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影响因子：
20.1
作者：
LUO, CH;RUDY, Y
通讯作者：
RUDY, Y
心脏振荡简单理论模型中的复杂分岔和混沌
影响因子：
5.2
作者：
L. Glass;W. Zeng
通讯作者：
W. Zeng
影响因子：
5
作者：
DOLBER, PC;BEYER, EC;SPACH, MS
通讯作者：
SPACH, MS
在大鼠心室细胞对中研究的神经膜的电特性。
DOI：
--
发表时间：
1986
期刊：
Journal of Physiology
影响因子：
--
作者：
R. Weingart
通讯作者：
R. Weingart
离体大鼠心肌细胞的表面形态和细胞大小测量。
影响因子：
5
作者：
S. Bishop;J. Drummond
通讯作者：
J. Drummond