5-(4-Chlorophenyl)furfural is a metabolite of Azimilide (A926950, 2 HCl); an oral type III potassium channel blocker agent that blocks both the rapid activating component and the slow activating component of the delayed rectifier potassium current. Both preclinical and clinical studies have demonstrated the efficacy of Azimilide and its safety in the treatment of supraventricular and ventricular tachyarrhythmia. Azimilide is also being studied in a worldwide multicenter trial for prevention of sudden cardiac death in patients after myocardial infarction.