Ibutilide fumarate is a Class III antiarrhythmic agent that is indicated for acute cardioconversion of atrial fibrillation and atrial flutter of a recent onset to sinus rhythm. Target: Calcium Channel Ibutilide fumarate is the first 'pure' class III antiarrhythmic drug to become available. Its predominant action is prolongation of the myocardial action potential duration. Intravenous ibutilide 0.01 to 0.025 mg/kg or 1 to 2 mg successfully converted atrial flutter or fibrillation to sinus rhythm in 33 to 49% of patients in 2 placebo-controlled trials involving 439 patients with sustained arrhythmia [1]. Ibutilide fumarate appears to be an effective alternative method for rapid conversion of recent-onset AF or AFl. The drug may be particularly useful in patients who have undergone recent cardiac surgery or those who are not ideal candidates for DCC [2].