A compound of formula (I) Or its salts or pharmaceutically acceptable derivatives thereof wherein; A represents a chemical moiety with the general formula (II): X is selected from a group consisting of CH2, C(═O), CH(R5), C(R5)(R6) or C(R5)(R6)CH2; R1 is selected from the group consisting of optionally substituted arylalkyl, and optionally substituted heteroarylalkyl; R2 is selected from the group consisting of optionally substituted aryl or optionally substituted heteroaryl or NR7R8; R3 R4 R5 R6 R7 and R8 are as defined herein; and n=1 or 2 is provided. Pharmaceutical compositions comprising the compounds are also provided. The compounds are useful in treating various conditions including arrhythmia.