[Effects of changrolin on electrophysiological properties of canine Purkinje fibers].
Histological identification of Purkinje fibers was carried out in 15 dogs. Action potential durations (APD) were found to be unlike on different portions of Purkinje fibers, longest on distal part (gate). Under the action of changrolin, the APD and effective refractory period (ERP) of Purkinjc fibers showed a marked but reversible lengthenint, their spontaneous thythm was slowed down, while an electrically evoked bigeminy was suppressed. Our study provides a theoretical ground for the clinical use of changrolin as a new type I anti-arrhythmic drug.