Arrhythmogenic transient dynamics in cardiac myocytes.
Biophys J
; 106(6): 1391-7, 2014 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-24655514
ABSTRACT
Cardiac action potential alternans and early afterdepolarizations (EADs) are linked to cardiac arrhythmias. Periodic action potentials (period 1) in healthy conditions bifurcate to other states such as period 2 or chaos when alternans or EADs occur in pathological conditions. The mechanisms of alternans and EADs have been extensively studied under steady-state conditions, but lethal arrhythmias often occur during the transition between steady states. Why arrhythmias tend to develop during the transition is unclear. We used low-dimensional mathematical models to analyze dynamical mechanisms of transient alternans and EADs. We show that depending on the route from one state to another, action potential alternans and EADs may occur during the transition between two periodic steady states. The route taken depends on the time course of external perturbations or intrinsic signaling, such as ß-adrenergic stimulation, which regulate cardiac calcium and potassium currents with differential kinetics.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
/
Potenciais de Ação
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Miócitos Cardíacos
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Modelos Cardiovasculares
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biophys J
Ano de publicação:
2014
Tipo de documento:
Article