对心脏起搏器异质性梯度模型的定性支持。

Qualitative support for the gradient model of cardiac pacemaker heterogeneity.

作者信息

Cloherty Shaun, Dokos Socrates, Lovell Nigel

机构信息

Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia.

出版信息

Conf Proc IEEE Eng Med Biol Soc. 2005;2006:133-6. doi: 10.1109/IEMBS.2005.1616360.

DOI:10.1109/IEMBS.2005.1616360

PMID:17282129

Abstract

In this study, we investigate the role of sinoatrial node (SAN) cellular heterogeneity in normal cardiac pacemaker function. Using detailed ionic models of electrical activity in SAN and atrial myocytes, we have formulated a number of models of SAN heterogeneity based on discrete-region (in which central and peripheral SAN type cell are separated into discrete regions), gradient and mosaic models of SAN organisation. Simulations of each of the different models were performed in one and two dimensions in the presence of both uniform and linearly increasing conductivity profiles. Simulation results suggest that the gradient model, in which cells display a smooth variation in membrane properties from the center to the periphery of the SAN, best reproduces action potential waveshapes and a site of earliest activation consistent with experimental observations in the intact SAN. We therefore propose that the gradient model of SAN heterogeneity represents the most plausible model of SAN organisation.

摘要

在本研究中，我们探究了窦房结（SAN）细胞异质性在正常心脏起搏功能中的作用。利用窦房结和心房肌细胞电活动的详细离子模型，我们基于离散区域（其中窦房结中央型和外周型细胞被分隔到离散区域）、梯度模型和窦房结组织的镶嵌模型，构建了多个窦房结异质性模型。在均匀和线性增加的电导率分布情况下，对每个不同模型进行了一维和二维模拟。模拟结果表明，梯度模型（其中细胞从窦房结中心到外周的膜特性呈现平滑变化）能最佳地重现动作电位波形以及与完整窦房结实验观察结果一致的最早激活位点。因此，我们提出窦房结异质性的梯度模型代表了最合理的窦房结组织模型。