The present invention provides a novel amino compound that blocks the IKur current or the Kv1.5 channel potently and more selectively than other K+ channels. The present invention relates to an amino compound represented by General Formula (1):or a salt thereof,wherein R1 and R2 are each independently hydrogen or organic group；XA and XB are each independently a bond, alkylene, alkenylene, -CO-, -SO2-, or -CONH-, wherein each of the alkylene and alkenylene chains can optionally contain one or more substituents selected from the group consisting of -S-, -C(=S)-, -SO2-, -CO-, -O-, -NH-, -CONH- and -SO2NH-, and the hydrogen atom (H) bonded to the nitrogen atom (N) in XA and XB is optionnally substituted with a subsituent selected from the group consisting of lower alkyl, phenyl lower alkyl and phenyl；A1 is lower alkylene optionally substituted with one or more substituents selected from the group consisting of hydroxyl and oxo；R3 is (i) a heterocyclic group which is optionally substituted with one or more substituents, or(ii) an aryl group substituted with one or more substituents select from the group consisting of oxo, lower alkyl, carboxyl, halo-lower alkyl, lower alkanoyl lower alkyl, phenyl lower alkyl, cyclo lower alkyl, lower alkoxy, halo lower alkoxy, phenyl lower alkoxy, phenoxy, cyano, hydroxyl, halogen, nitro, lower alkylthio, lower alkanoyl,lower alkoxy carbonyl, lower alkenyl, phenyl, triazolyl, isoxazolyl, imidazolyl, pyrrolyl, benzo[d]oxazolyl,benzo[d]thiazolyl and the group represented by General Formula (2):wherein Y is a bond, lower alkylene, or -CO-； R4 and R5 are each independently hydrogen, lower alkyl, cyclo lower alkyl, phenyl, or lower alkanoyl； or R4 and R5 may be linked to form a ring together with the neighboring nitrogen, and the ring may optionally have one or more substituents.
