Irregularly appearing early afterdepolarizations in cardiac myocytes: Random fluctuations or dynamical chaos?

52Citations
Citations of this article
42Readers
Mendeley users who have this article in their library.

Abstract

Irregularly occurring early afterdepolarizations (EADs) in cardiac myocytes are traditionally hypothesized to be caused by random ion channel fluctuations. In this study, we combined 1), patch-clamp experiments in which action potentials were recorded at different pacing cycle lengths from isolated rabbit ventricular myocytes under several experimental conditions inducing EADs, including oxidative stress with hydrogen peroxide, calcium overload with BayK8644, and ionic stress with hypokalemia; 2), computer simulations using a physiologically detailed rabbit ventricular action potential model, in which repolarization reserve was reduced to generateEADs and randomion channel or path cycle length fluctuationswere implemented; and 3), iterated mapswith or without noise.Bycomparing experimental,modeling, and bifurcation analyses,wepresent evidence thatnoise-induced transitions between bistable states (i.e., between an action potential with and without an EAD) is not sufficient to account for the large variation in action potential duration fluctuations observed in experimental studies. We conclude that the irregular dynamics of EADs is intrinsically chaotic, with random fluctuations playing a nonessential, auxiliary role potentiating the complex dynamics. © 2010 by the Biophysical Society.

Cite

CITATION STYLE

APA

Sato, D., Xie, L. H., Nguyen, T. P., Weiss, J. N., & Qu, Z. (2010). Irregularly appearing early afterdepolarizations in cardiac myocytes: Random fluctuations or dynamical chaos? Biophysical Journal, 99(3), 765–773. https://doi.org/10.1016/j.bpj.2010.05.019

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free