[Action of ethacizin on normal and anomalous forms of Purkinje fiber automaticity in the dog].

The effect of a new anti-arrhythmic drug etacysin was studied in various forms of dog Purkinje's fibres automativity: normal and abnormal arising at a late stage of experimental myocardial infarction (24 hrs after coronary artery ligation) and induced by ions Ba2+. An average 57% decrease in the frequency of automaticity of normal Purkinje's fibres due to steepening the slope of slow diastolic depolarization and almost complete depression of an abnormal one was observed for the drug concentrations 5 X 10(-7) and 10(-6) g/ml. Reduced automaticity was also related to decreased slow diastolic depolarization. Maximal values of diastolic potential were found unchanged.