| abstract |
A drug for treating heart failure containing at least one of the pharmacologically acceptable salts thereof as an active ingredient is disclosed when the compound and salt of the following general formula (I) can be formed.n n n n n n n n Wherein X 1 and X 2 are absent or represent an oxygen atom, A represents an OH or C 1 to C 4 acyloxy group, B represents a hydrogen atom, or together with A forms a chemical bond X represents an oxygen atom, a nitrogen atom, a sulfur atom and the like, R 1 and R 2 each represent a hydrogen atom, a C 1 to C 4 alkyl group and the like, and R 3 and R 4 each represent a hydrogen atom, a C 1 to C 4 alkyl group or the like. Or these together represent a 1,4-butylene group or a 1,5-pentylene group.)n n n These compounds have potent myocardial contractility and heart rate reduction. These compounds are nontoxic and therefore useful as cardiac agents. |