抄録
In the preceeding paper it was observed that the atrial arrhymias like A-V block by methacholine were effectively antagonized by O, S-dicarbethoxythiamine (DCET) administration but the ventricular arrhythmias by epinephrine or ouabain were only slightly antagonized. In this paper the effects of DCET on the atrial fibrillation in cats were compared with quinidine, pronethalol, and atropine, because an atrial fibrillation was one of the common arrhythmias observed in clinic. DCET, in a dose 20-40 mg/kg, prevented the incidence of atrial fibrillation or decreased the duration of atrial fibrillation caused by methacholine-electrical stimulation. As a moderate shortening of atrial fibrillation was also observed by thiamine administration, antifibrillatory effects of DCET could not be considered as a specific effects of DCET but one of the common properties of thiamine derivatives. But the antifibrillatory effects of thiamine were inferior to those of DCET. Atropine, at a dose of 1mg/kg, completely suppressed the incidence of methacholine induced atrial fibrillation. While quinidine or pronethalol prevented the methacholine induced atrial fibrillation at the same dose range as in the prevention of epinephrine arrhythmias. Antiarrhythmic effects of DCET to methacholine induced atrial fibrillation may provide some reasonable evidence in the so-called "mass therapy" of thiamine derivatives.
