“…Compared to 16-epi-gitoxin the inexcitability of Purkinje fibres after ouabain remained irreversible. The semisynthetic glycoside 16-epigitoxin exerts a weaker effect on the specialized conducting system.Based on a great number of experimental (Cat tell and Gold, 1941; Far ah and Maresh, 1948; Gruhzit and Farah, 1953;Takahashi et at., 1936;White and Salter, 1946) and clinical studies (Batterman et al, 1952; Chavez, 1963;Schwiegk, 1960) it is supposed that there are no significant differences between therapeutic, toxic, and lethal doses of common digitalis preparations. However, in recent years it was shown that essential differences exist among natural glyco sides on the one hand (Ito et al, 1970) and between natural and semisynthetic glycosides on the other (Haustein et al, 1970;Haustein and Hauptmann, 1974).…”