Simulation and prediction of functional block in the presence of structural and ionic heterogeneity.
Simulation and prediction of functional block in the presence of structural and ionic heterogeneity.
复制标题
存在结构和离子异质性的情况下功能块的模拟和预测。
DOI：
10.1152/ajpheart.2001.281.6.h2597
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Henriquez,CS
中科院分区：
文献类型：
--
作者：
Sampson,KJ;Henriquez,CS
心肌结构和动作电位持续时间（APD）的不均匀性导致APD在整个心脏的弥散。据报道，APD梯度在20-125 ms/cm范围内会产生功能阻滞。在这项研究中，多细胞纤维模型被用来检查结构和离子不均匀性对过早刺激产生功能阻滞的可能性的影响。使用Fenton-Karma和Luo-Rudy II期膜模型，发现功能阻滞发生在组织中，最大梯度<45 ms/cm，并取决于空间范围。一般来说，范围越窄，所需的阻塞幅度越大。提出了一种简单的预测阻滞的关系，只需要组织的传导速度（CV）恢复特性和APD梯度的信息。分析表明，陡CV恢复斜率的影响可能有利于克服单个早搏的内在细胞异质性。
Inhomogeneities in myocardial structure and action potential duration (APD) lead to dispersion of APD throughout the heart. APD gradients in the range of 20–125 ms/cm have been reported to produce functional block. In this study, a multicellular fiber model was used to examine the effect of structural and ionic inhomogeneities on the likelihood of premature stimuli to produce functional block. With the use of both the Fenton-Karma and Luo-Rudy phase II membrane models, functional block is found to occur in tissue with a maximum gradient <45 ms/cm and depends on the spatial extent. In general, the narrower the extent the larger the magnitude needed for block. A simple relationship for predicting block is presented that only requires information about the conduction velocity (CV) restitution properties of the tissue and the APD gradients. Analysis reveals that the effects of a steep CV restitution slope may be beneficial in overcoming intrinsic cellular heterogeneity for a single premature beat.