Asymptotic approximation of an ionic model for cardiac restitution
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Cardiac restitution has been described both in terms of ionic models – systems of ODE's – and in terms of mapping models. While the former provide a more fundamental description, the latter are more flexible in trying to fit experimental data. Recently, we proposed a two-dimensional mapping that accurately reproduces restitution behavior of a paced cardiac patch, including rate dependence and accommodation. By contrast, with previous models only a qualitative, not a quantitative, fit had been possible. In this paper, a theoretical foundation for the new mapping is established by deriving it as an asymptotic limit of an idealized ionic model.
KeywordsCardiac dynamics Ionic model Mapping model Asymptotic analysis
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