Dietary fish oil reduces the occurrence of early afterdepolarizations in pig ventricular myocytes

Fish oil reduces sudden cardiac death in post myocardial infarction patients. Life-threatening arrhythmias in heart failure are associated with repolarization abnormalities leading to EAD1 formation. We examined the effects of incorporated fish oil ω3-PUFAs2 on EAD formation in pig myocytes. Pigs were fed a diet rich in fish oil or sunflower oil (control) for 8 weeks. Myocytes were isolated by enzymatic dissociation and patch-clamped. Susceptibility to EAD formation was tested using E4031 (5 μM), a blocker of IKr. The fish oil diet in pigs resulted in increased incorporation of ω3-PUFAs in the sarcolemma of the myocytes compared to the control diet and caused a reduced occurrence of E4031-induced EADs in pig myocytes. A shorter action potential, a reduced action potential prolongation in response to E-4031 and a reduced reactivation of ICa,L by ω3-PUFAs may explain the observed reduction in EADs. A diet rich in fish oil protects against EAD formation.