title: Chaotic dynamics in cardiac aggregates induced by potassium channel block.
abstract: Chaotic rhythms in deterministic models can arise as a consequence of changes in model parameters. We carried out experimental studies in which we induced a variety of complex rhythms in aggregates of embryonic chick cardiac cells using E-4031 (1.0-2.5 μM), a drug that blocks the hERG potassium channel. Following the addition of the drug, the regular rhythm evolved to display a spectrum of complex dynamics: irregular rhythms, bursting oscillations, doublets, and accelerated rhythms. The interbeat intervals of the irregular rhythms can be described by one-dimensional return maps consistent with chaotic dynamics. A Hodgkin-Huxley-style cardiac ionic model captured the different types of complex dynamics following blockage of the hERG mediated potassium current.
authors.affiliation: Department of Physiology, McGill University, 3655 Promenade Sir William Osler Montreal, Quebec H3G 1Y6, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Quail
authors.forename: Nevin
authors.initials: N
authors.lastname: McVicar
authors.forename: Martin
authors.initials: M
authors.lastname: Aguilar
authors.forename: Min-Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Alex
authors.initials: A
authors.lastname: Hodge
authors.forename: Leon
authors.initials: L
authors.lastname: Glass
authors.forename: Alvin
authors.initials: A
authors.lastname: Shrier
mesh_terms: D000818:Animals; D002449:Cell Aggregation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002642:Chick Embryo; D006352:Heart Ventricles / Q000166:cytology* / Q000187:drug effects; D042541:Intracellular Space / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D008955:Models, Cardiovascular; D017711:Nonlinear Dynamics; D010880:Piperidines / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D015221:Potassium Channels / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D016276:Ventricular Function / Q000187:drug effects*
chemical_list: D010880:Piperidines; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011725:Pyridines; C063968:E 4031