人类心室组织中波斑图引起的后除极化研究

发布时间：2018-05-09 06:35

本文选题：螺旋波 + 后除极化　；参考：《物理学报》2017年06期

【摘要】：突然的心脏死亡常常由心脏的心律失常引起,而心律失常常与后除极化有关.本文采用人类心脏模型研究了二维心肌组织中存在螺旋波或其他波斑图下后除极化的发生,通过改变L型钙电导和快钾电导让螺旋波演化,观察后除极化在空间的分布.研究发现:在单细胞和一维情况下不出现后除极化时,螺旋波可导致相II型和相III型早期后除极化、延迟后除极化、增强的自动性,以及延时激发和延时增强自动性的出现;还观察到螺旋波导致膜电位在动作电位I期出现弱振荡;后除极化一般出现在螺旋波波核区域,它是由螺旋波的相奇异点引起.后除极化也可以分布在更大的范围,当参数选取适当时,出现早期后除极化、延迟后除极化、增强自动性的空间点在空间呈螺旋线分布,展示记忆效应.通过观察各种离子电流变化发现:当激发细胞的钠电流很小时可诱发L型钙电流、钠钙交换电流的增大和慢钾电流、快钾电流的减少,导致各种后除极化的产生,因此增大钠电流可有效抑制后除极化的发生.
[Abstract]:Sudden cardiac death is often caused by cardiac arrhythmia, which is often associated with depolarization. In this paper, a human heart model was used to study the occurrence of depolarization in two-dimensional myocardial tissue under helical wave or other wave patterns. The spatial distribution of posterior depolarization was observed by changing L-type calcium conductance and fast potassium conductance to the evolution of spiral wave. It is found that in the case of single cell and one-dimensional depolarization, helical wave can lead to early depolarization of phase II and phase III, delayed depolarization, automatic enhancement, and the appearance of delay excitation and delay enhancement. It is also observed that the membrane potential oscillates weakly in phase I of the action potential, and the depolarization occurs in the region of the helical wave nucleus, which is caused by the phase singularity of the helical wave. The depolarization can also be distributed in a larger range. When the parameters are selected properly, the early depolarization, the delayed depolarization, and the spatial point of enhanced automatism are spiral distribution in space, showing the memory effect. By observing the changes of various ion currents, it was found that the L-type calcium current, the increase of sodium calcium exchange current, the decrease of slow potassium current and the decrease of fast potassium current could induce L type calcium current when the sodium current of the stimulated cells was very small, which resulted in the generation of various kinds of depolarization. Therefore, increasing sodium current can effectively inhibit the occurrence of depolarization.
【作者单位】：广西师范大学物理科学与技术学院;
【基金】：国家自然科学基金(批准号:11565005,11365003)资助的课题~~
【分类号】：R540.4

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