Prevention and termination of beta-adrenergic agonist-induced arrhythmias by free polyunsaturated fatty acids in neonatal rat cardiac myocytes.

Polyunsaturated omega-3 fatty acids, which have been shown to prevent ischemia-induced ventricular fibrillation in prepared dogs, were tested in cultured neonatal rat cardiac myocytes for their ability to prevent the tachyarrhythmias induced by isoproterenol, a beta-adrenergic agonist. We found that polyunsaturated fatty acids (5-10 microM), especially the fish oil omega-3 fatty acids, but not monouunsaturated and saturated fatty acids were able to effectively prevent and terminate the arrhythmias induced by isoproterenol (as well as by cAMP and cholera toxin) without affecting the cell contractility, and that their action was independent of their metabolites and incorporation into membrane phospholipid. These protective effects of the free fatty acids may contribute, at least in part, to their reported preventive effects on ischemia-induced ventricular fibrillation and sudden cardiac death.