Reentrant Action Potentials in Normal Myocardium

健康的心室心肌表现得更像一个连续的制服 可激发介质，尽管其结构的明显不连续性， 在亚毫米和亚毫秒尺度上的功能。 根据这个类比 以及相应的数值模型，据预测， 心肌应该对一定相位和大小的刺激敏感 这导致了以二维成对涡流形式的再入， 涡丝在3维，独立的不连续性和 这种异质性显然使患病组织更加脆弱。 这一点和相关的后果现在已经得到证实， 刺激和高分辨率心肌标测。 的目的 下一个支撑区间是（1）探索3- 三维涡度，无论是数值计算和合作， 实验生理学家，如前所述;（2）检查这些现象 通过最好的电生理学的解释透镜 （3）了解心肌细胞膜的结构和功能， 折返性心动过速发展为纤颤 可激发介质的非线性动力学，使用那些电生理学 膜模型;（4）检查可能的机制， 除颤从理论角度从而巩固。 通过计算模拟特定的离子机制， 特别是感兴趣的可兴奋介质，应该有可能 第一次定量地了解这些机制。 这将允许通过以下方式理解和控制膜特性： 改变电场。

Healthy ventricular myocardium behaves much like a continuous uniform excitable medium, despite its evident discontinuities of structure and function on sub-mm and sub-msec scales. On the basis of this analogy and the corresponding numerical models it has been predicted that myocardium should be vulnerable to a stimulus of certain phase and size which induces reentry in the form of paired vortices in 2 dimensions and vortex filaments in 3 dimensions, independent of the discontinuities and heterogeneity that apparently make diseased tissue more vulnerable. This and related consequences have now been confirmed by electrical stimulation and high-resolution myocardial mapping. The purposes for the next support interval are (1) to explore the implications for 3- dimensional vorticity, both numerically and in collaboration with experimental physiologists, as before; (2) to examine these phenomena through the interpretive lens of the best available electrophysiological model of ventricular myocardial membrane; (3) to understand the development of reentrant tachycardias into fibrillation in terms of the nonlinear dynamics of excitable media, using those electrophysiological membrane models; and (4) to examine possible mechanisms of defibrillation from the theoretical perspective thus consolidated. By computational modelling of specific ionic mechanisms of the particular excitable medium of interest, it should be possible to understand these mechanisms in quantitative detail for the first time. This will allow an understanding and control of membrane properties via altered electric fields.