Bifurcation and Chaos in a Model of Cardiac Early Afterdepolarizations

• DOI: 10.1103/physrevlett.102.258103
• Publication Date: 2009-06-25T15:56:36Z
• Authors: Diana X. Tran; Daisuke Sato; Arik Yochelis; James N. Weiss; Alan Garfinkel; Zhilin Qu
• Keywords: Afterdepolarization; Bursting; Homoclinic bifurcation

Excitable cells can exhibit complex patterns of oscillations, such as spiking and bursting. In cardiac cells, pathological voltage 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 homoclinic bifurcations. During period pacing, chaos always occurs at the transition from no EAD to stimulation frequency decreases, providing a distinct explanation for irregular behavior frequently in experiments.