The antiarrhythmic and anticonvulsant effects of dietary n-3 fatty acids

It has been shown in animals and probably in humans, that n-3 polyunsaturat ed fatty acids (PUFAs) are antiarrhythmic. We report recent studies on the antiarrhythmic actions of PUFAs. The PUFAs stabilize the electrical activit y of isolated cardiac myocytes by modulating sarcolemmal ion channels, so t hat a stronger electrical stimulus is required to elicit an action potentia l and the refractory period is markedly prolonged. Inhibition of voltage-de pendent sodium currents, which initiate action potentials in excitable tiss ues, and of the L-type calcium currents, which initiate release of sarcopla smic calcium stores that increase cytosolic free calcium concentrations and activate the contractile proteins in myocytes, appear at present to be the probable major antiarrhythmic mechanism of the PUFAs.