[Effect of mezaton on experimental myocardial infarct with arrhythmias in rabbits].

In 35 of 40 rabbits operated upon experimental myocardial infarction (EMI) was reproduced. Immediately after legation of coronary arteries (CA) and during the next 2 days mesaton was introduced in a single dose into the marginal auricular vein of 12 rabbits with EMI. The results of the antiarrhythmic effect produced by the drug were judged on the basis of the dynamic ECG findings in three standard leads. From the materials thus obtained it followed that a single administration of mesaton during an acute period of EMI (the first 3 days of the experiment) prevented the development of composite disturbances of the rhythm and reduced lethality among the animals. A repeated introduction of mesaton to rabbits with EMI, but without any arrhythmia provoked ventricular extrasystole in 2 and sinus bradycardia in one of the 12 animals. Repeated administration of mesaton to rabbits with EMI complicated by ventricular extrasystole did not eliminate the upset function of excitation, while with the ventricular extrasystole transforming into ventricular tachycardia the eventual prognosis becomes unfavourable.