In animals and probably in humans n-3 polyunsaturated fatty acids (PUFA) ar
e antiarrhythmic. A report follows on the recent studies of the antiarrhyth
mic actions of PUFA. The PUFA stabilize the electrical activity of isolated
cardiac myocytes by inhibiting sarcolemmal ion channels,so that a stronger
electrical stimulus is required to elicit an action potential and the rela
tive refractory period is markedly prolonged. This appears at present to be
the probable major antiarrhythmic mechanism of PUFA.