The present invention relates to diarylpyridazinone derivatives that block the potassium Kv channels (specifically the Kv1.5, Kv4.3, and Kv11.1 channels) and to the use thereof for the treatment of humans. Said compounds have the general formula (I), where R1 and R2 are simultaneously or independently one or more groupings such as: halogen, such as F, Br, Cl, a straight or branched C1-C4 alkyl, hydroxy, a straight or branched C1-C4 alkoxy, arylsulfonamido, in which the aryl is optionally replaced with a straight or branched C1-C4 alkyl, or nitrile, as well as the various enantiomers and the mixtures thereof in any proportion, and the pharmaceutically acceptable salts thereof.