[Anti-arrhythmic effect of adaptative activation of the vagus nerve system and a new synthetic acetylcholine analog].

A higher vagal tone or its stimulation under certain conditions is known to increase the threshold of cardiac fibrillation and even to arrest developing arrhythmias. This effect is usually evaluated as a result of limiting the excessive adrenergic effect on the heart, which is observed in stress and ischemia. The following two facts have been first identified: 1) adaptation to moderate continuous stress may induce tonic excitation of parasympathetic regulation of the heart and enhance its resistance to ischemic and reperfusion arrhythmias; 2) this antiarrhythmic effect is completely reproducible by the recently synthesized acetylcholine analogue EDIHYP, ethyl-3/2-ethyl-2,2-dimethylhydrazinium/propionate iodate.