A compound of formula Iwherein A, X, Y, Z, R1and R24are described herein. The compounds are useful as inhibitors of potassium channel function and in the treatment and prevention of arrhythmia, IKur-associated disorders, and other disorders mediated by ion channel function.本發明係關於一種式I化合物其中A、X、Y、Z、R1及R24如本文中描述。該等化合物適用作鉀通道功能抑制劑,且適用於治療及預防心律不整、IKur相關病症及其他由離子通道功能介導之病症。