Bifurcation and chaos in a model of cardiac early afterdepolarizations.
Excitable cells can exhibit complex patterns of oscillations, such as spiking and bursting. In cardiac cells, pathological voltage oscillations, called early afterdepolarizations (EADs), have been widely observed under disease conditions, yet their dynamical mechanisms remain unknown. Here, we show that EADs are caused by Hopf and homoclinic bifurcations. During period pacing, chaos always occurs at the transition from no EAD to EADs as the stimulation frequency decreases, providing a distinct explanation for the irregular EAD behavior frequently observed in experiments.
Tran
Diana X
DX
Department of Medicine, Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA.
Sato
Daisuke
D
Yochelis
Arik
A
Weiss
James N
JN
Garfinkel
Alan
A
Qu
Zhilin
Z
D015220:Calcium Channels / Q000378:metabolism; D006321:Heart / Q000502:physiology*; D015640:Ion Channel Gating; D008564:Membrane Potentials; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism; D017711:Nonlinear Dynamics; D015221:Potassium Channels / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism
D015220:Calcium Channels; D015221:Potassium Channels; D015222:Sodium Channels