Dietary fish oil reduces the incidence of triggered arrhythmias in pig ventricular myocytes.
Heart Rhythm
; 4(11): 1452-60, 2007 Nov.
Article
em En
| MEDLINE
| ID: mdl-17954406
ABSTRACT
BACKGROUND:
Fish oil reduces the incidence of sudden cardiac death in postmyocardial infarction patients. Triggered activity is the principal mechanism of arrhythmogenesis under these conditions.OBJECTIVE:
The purpose of this study was to test whether dietary fish oil in pigs inhibits Ca2+ overload-induced triggered activity.METHODS:
Pigs were fed a diet of fish oil or sunflower oil for 8 weeks. Ventricular myocytes (omega3 fish oil, n = 11; control sunflower oil, n = 8) were isolated by enzymatic dissociation and used for patch clamp studies and intracellular Ca2+ recordings. Triggered activity was induced by rapid pacing in the presence of norepinephrine.RESULTS:
Dietary fish oil reduced the incidence of triggered action potentials and delayed afterdepolarizations compared to control (9.1% in omega3 and 84.6% in control, P <.05), concomitant with a reduction in spontaneous Ca2+ release. Dietary fish oil prevented Ca2+ overload and reduced action potential prolongation in response to norepinephrine (DeltaAPD(90) 23.2 +/- 8.5 ms in omega3 and 107.4 +/- 15.9 in control, P <.05). omega3 myocytes displayed decreased sarcoplasmic reticulum Ca2+ content, reduced L-type Ca2+ current (I(Ca,L)), and less recruitment of the Na+/Ca2+ exchange current (I(NCX)) in response to norepinephrine compared to control. In the absence of norepinephrine, the slow component of the delayed rectifier current (I(Ks)) was larger in omega3 myocytes. In the presence of norepinephrine, I(Ks) increased to the same level in omega3 and control myocytes.CONCLUSION:
Dietary fish oil reduces the incidence of triggered activity and prevents Ca2+ overload and AP prolongation in response to norepinephrine. Fish oil may prevent arrhythmias in patients with heart failure.
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Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
/
Potenciais de Ação
/
Óleos de Peixe
/
Estado Nutricional
/
Morte Súbita Cardíaca
/
Células Musculares
/
Poeira
/
Ventrículos do Coração
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Heart Rhythm
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Holanda