A compound of formula I wherein A, R1, R3, and R24 are described herein. The compounds are useful as inhibitors of potassium channel function and in the treatment of arrhythmia, maintaining normal sinus rhythm, IKur-associated disorders, and other disorders mediated by ion channel function.本發明闡述式I化合物其中A、R1、R3及R24闡述於本文中。該等化合物可用作鉀通道功能抑制劑且可用於治療心律不整、維持正常竇性節律、治療IKur-相關病症及其他由離子通道功能介導之病症。