The Mechanism of Action of Omega-3 Fatty Acids in Secondary Prevention Post-Myocardial Infarction

Nigel Harrison; Brihad Abhyankar


Curr Med Res Opin. 2005;21(1):95-100. 

In This Article

Prevention of Arrhythmias by Omega-3 Fatty Acids

Pioneering investigations into the possible antiarrhythmic effects of omega-3 fatty acids in vivo were conducted by McLennan and colleagues in the 1980s. A clear-cut reduction in susceptibility to ventricular dysrhythmias during coronary artery occlusion and reperfusion was demonstrated in rats maintained on a diet enriched with omega-3 fatty acids.[14,15,16] Further research[17,18] confirmed that treatment with omega-3 fatty acids prevented ischaemia-induced arrhythmias in dogs. A salient aspect of these studies was that omega-3 fatty acids were administered intravenously immediately before the induction of ischaemia by exercise. This method of administration circumvented any possible confounding factors that might arise in feeding studies.

Although it seems likely that the effects of omega-3 fatty acids are multi-factorial,[19] the current consensus is that these fatty acids prevent the development of arrhythmias through electrical stabilization of myocytes. Kang and Leaf[20] reported distinctive effects of omega-3 fatty acids on membrane potentials in cultured neonatal rat myocytes and concluded that they exert protective actions on the final common pathway of arrhythmogenesis, regardless of the initiating stimulus. These protective actions involve hyperpolarization of cell membranes in ischaemic (and thus partly depolarized) cardiomyocytes, leading to prolongation of the inactivated state of the channels that convey the fast, voltage-dependent inward sodium current. In a recent publication, Schrepf et al.[21] showed that the intravenous infusion of omega-3 fatty acids results in the reduction of sustained ventricular tachycardia in some patients.

There are further studies being undertaken. One that reported recently did not show a statistically significant effect of omega-3 fatty acids on patients with implanted defibrillators.[22] Other trials such as SOFA[23] are still to report.


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