13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

S-112

Pharmacologic conversion of atrial fibrillation and atrial flutter: the role of ibutilide

Philip T. Sager.
UCLA School of Medicine, Cardiac Electrophysiology, West Los Angeles Veterans Administration Hospital, Los Angeles, USA

Introduction

Atrial fibrillation (Afib) and atrial flutter (Aflut) are the most common arrhythmias observed in the general adult population^1,2 and are associated with significant symptoms and morbidity. The mainstay of termination of these arrhythmias has been electrical cardioversion or the administration of oral or intravenous class I antiarrhythmic agents. Electrical cardioversion requires general anesthesia, which may not always be easily available and requires specialized personnel, and has its own risks, such as those of general anesthesia and skin burns. Occasionally arrhythmias can recur soon after electrical cardioversion in patients who are not receiving antiarrhythmic medications, possibly secondary to cardioversion-induced increases in sympathetic output. Ibutilide is the first pure class III agent to become clinically available. It was specifically developed to function as a Achemical defibrillator³ to terminate Afib and Aflut by rapidly and transiently prolonging the atrial action potential duration (APD) and atrial effective refractory period (ERP). Its very rapid onset of action and short half life make it an excellent agent for acute intravenous therapy.

Ibutilide has been evaluated in patients with Afib/Aflut of recent onset. Additional studies have also examined its efficacy in patients developing the arrhythmias shortly after cardiac surgery and have compared ibutilide's conversion efficacy to that of d,l-sotalol and procainamide. This paper will review the pharmacology of ibutilide and the clinical studies examining ibutilide's efficacy and safety to terminate Afib and Aflut.