Quinolone inotropic agents

A quinolone inotropic agent of the formula: or a pharmaceutically acceptable salt thereof, wherein is an optionally substituted 5- or 6-membered monocyclic aromatic heterocyclic group attached by a carbon atom to the 5-, 6-, 7- or 8- position of said quinolone; R, which is attached to the 5-, 6-, 7- or 8- position, is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, C1-C4 alkylsulphinyl, C1-C4 alkylsulphonyl, halo, CF3, hydroxy, hydroxymethyl, or cyano; R is hydrogen, cyano (C1-C4 alkoxy)carbonyl, C1-C4 alkyl, nitro, halo, -NR R or -CONR R where R and R are each independently H or C1-C4 alkyl or together with the nitrogen atom to which they are attached form a saturated 5-or 6-membered heterocyclic group optionally containing a further heteroatom or group selected from O, S and N-R where R is H or C1-C4 alkyl; R is H, C1-C4 alkyl, or 2-hydroxyethyl; Y is H or C1-C4 alkyl; and the dotted line between the 3- and 4- positions represents an optional bond.