THE USE OF DRUGS FOR CARDIOVERSION OF RECENT-ONSET ATRIAL-FIBRILLATION AND FLUTTER - FOCUS ON IBUTILIDE

Atrial fibrillation (AF) is the most common sustained arrhythmia, part icularly in the elderly population. It is well recognised that AF is a major cause of stroke, even in the absence of underlying heart diseas e. Although AF and atrial flutter share many causes and may be seen in the same patient, there are differences between these arrhythmias: at rial flutter is less common, and the risk of stroke associated with it is less than that with AE In addition to stroke, both AF and atrial f lutter may cause cardiomyopathy, which may be fully reversible with ef fective treatment of the arrhythmia. Both AF and atrial flutter can re sult in severe symptoms and may precipitate heart failure, ischaemia a nd syncope. Recent research indicates that AF is a self-perpetuating a rrhythmia, and that the longer it is left untreated the less likely it is that effective cardioversion will be possible. Drugs are an attrac tive option for the cardioversion of AF and atrial flutter because the ir use does not require anaesthesia. Antiarrhythmic drugs in class III of the Vaughan-Williams classification are effective in the treatment of AF, but they have adverse effects; several new 'pure' class III ag ents are under development. The first of these to be made available is ibutilide, a methanesulphonamide derivative. Initial results are enco uraging, particularly for atrial flutter. However, the drug has the po tential for proarrhythmic effects and physicians who use it will need to be aware of these.