Analysis of Excitation Conduction in the Heart and the Reconstruction of Electrocardiogram Using Ionic -channel Models

心脏兴奋传导分析及离子通道模型心电图重建

基本信息

批准号：
60490011
负责人：
SUZUKI Ryoji
金额：
$ 4.61万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60490011/
关键词：
Excitation Conduction Ionic-channel Model Gap-junction Pacemaker AV conduction Reconstruction of ECG GEAR法

项目摘要

The normal excitation and conduction in the heart are maintained by the coordination between the dynamics of ionic conductance of each cell and the electrical coupling between cells.(1) Using a spatially-discrete model of conduction of excitation, we examined functional roles of these two factors. The model is one-dimensional and is composed of five kinds of myocardial cells. We first determined quantitatively the coupling coefficients from the apparent space constants, then found the conditions of cell number and the couping coefficients for the pacemaker activities of SA-node. We also investigated the very slow conduction in AV-node and revealed that the weak coupling coefficients between cells in AV-node has the strongest effect.(2) A digital computer model was constructed for the simulation of the electrocardiogram during ventricular activation and repolarization. The part of the ventricular septum and the left ventricula free wall of the heart were represented by a two dimensional array of 730 units. Ionic current models were used to determine the spatial distribution of the electric activities of these units at each instant of time during simulated cardiac cycle. In order to reconstruct the electrocardiogram, the model was expanded three dimensionally with equipotential assumption along the third axis and then the surface potentials were calculated using solid angle method. ECG for normal subject was well reconstructed. ECGs for hyper-and hypokalemia were also reconstructed by modifying the related ionic current dynamics. We used Euler-method for numerical integration through this project. However, in order to accomodate the improvement of ionic current model, we adopted GEAR method which has a power to solve so-called "stiff" differential equation.

通过在每个细胞的离子电导率和细胞之间的电耦合之间的协调来维持心脏中的正常激发和传导。（1）使用空间滴定激发的传导模型，我们检查了这两个因素的功能作用。该模型是一维的，由五种心肌细胞组成。我们首先定量确定来自明显的空间常数的耦合系数，然后发现了SA节点的起搏器活动的细胞数量和coutiving系数。我们还研究了AV节点的非常缓慢的传导，并发现AV节点中细胞之间的弱耦合系数具有最强的效果。（2）构建了数字计算机模型，以模拟心室激活和复制过程中心电图。心室隔膜的一部分和心脏的左心室无壁以730单位的二维阵列表示。离子电流模型用于确定模拟心脏周期中每个时间瞬间的电动活动的空间分布。为了重建心电图，将模型通过沿第三轴的等电位假设在三维上扩展，然后使用实体角法计算表面电位。正常受试者的心电图已很好地重建。通过修饰相关的离子电流动力学，还重建了高性行血和低钾血症的心电图。我们使用Euler方法通过该项目进行数值集成。但是，为了满足离子电流模型的改进，我们采用了齿轮方法，该方法具有求解所谓的“刚性”微分方程的能力。