Abstract: Therapeutically active compounds of formula (I): wherein the variables shown in formula (I) are defined in the disclosure; and pharmaceutically acceptable salts and esters thereof. The compounds are potent inhibitors of the Na+/Ca2+ exchange mechanism.

Abstract: Therapeutically active compounds of formula (I): wherein X is —O—, —CH2— or —C(O)—; Z is —CHR9— or valence bond; Y is —CH2—, —C(O)—, CH(OR10)—, —CH(NR11R12)—, —O—, —S—, —S(O)— or —S(O2)—, provided that in case Z is a valence bond, Y is not C(O); the dashed line represents an optional double bond in which case Z is —CR9— and Y is —CH—, C(OR10)— or —C(NR11R12)—; R1 is —(CH2)nNR4R7 or one of the following groups: n is 1-4; R2 and R3 are independently H, lower alkyl, lower alkoxy, —NO2, halogen, —CF3, —OH, —NHR8 or —COOH, R4 and R7 are independently H, lower alkyl or lower hydroxyalkyl; R5 is H, lower alkoxy, —CF3, —NH2 or —CN; R6 is —NO2, —NR14R19, —CF3 or R8 and R16 are independently H or acyl; R9 is H or lower alkyl; R10 is H, alkylsulfonyl or acyl; R11 and R12 a

Abstract: Therapeutically active compounds of formula (I): in which R1 to R4 means hydrogen, alkyl, alkenyl, aryl, arylalkyl, carboxyalkyl, hydroxyalkyl or halogenalkyl, or R2 and R3 form a ring of 5-7 carbon atoms, R5 to R9 means hydrogen, alkyl, alkenyl, aryl, arylalkyl, acyl, hydroxy, alkoxy, alkoxycarbonyl, amino, acylamino, alkylamino, aryloxy, halogen, cyano, nitro, carboxy, alkylsufonyl, sulfonamido or trifluoromethyl, wherein each aryl residue defined above by itself or as a part of another group may be substituted, and pharmaceutically acceptable salts and esters thereof. The compounds increase the calcium sensitivity of contractile proteins of the cardiac muscle and are thus useful in the treatment of congestive heart failure.

Abstract: A method for obtaining direct dilatation of the coronary arteries by administering a therapeutically effective amount of a phospholamban inhibitor is described. Compounds which are effective in relieving the inhibitory effects of phospholamban on cardiac sarcoplasmic reticulum Ca2+-ATPase are also described.

Abstract: The compound (-)-[[4-(1,4,5,6 tetrahydro-4-methyl-6-oxo-3 pyridazinyl) phenyl]-hydrazono] propane dinitrile and its salts are prepared and used for treating congestive heart failure.

Abstract: Diastereomeric intermediate salts of formulae (IIIa) or (IIIb) ##STR1## are prepared.

Abstract: Optically substantially pure (-) enantiomer of [[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl]hydrazono)prop anedinitrile or pharmaceutically acceptable salt thereof, intermediates and a process for the preparation are described. The product is useful as a cardiotonic agent, antihypertensive and vasodilator for the treatment of congestive heart failure.