[Antiarrhythmic treatments of permanent atrial fibrillation]

The treatment of chronic atrial fibrillation has 3 different objectives: the control of the ventricular rate, the attempts to restore sinus rhythm, and the prevention of arrhythmia recurrences. Digitalis compounds, beta-adrenergic antagonists and calcium-channel blocking agents can be used to achieve reduction of the ventricular response, in recent-onset arrhythmia with rapid heart rate, and for long-term rate control in patients who cannot be converted to sinus rhythm. In some of them, a combination of 2 of these drugs is needed to slow the ventricular rate, at rest and on exertion. Sinus rhythm can be restored by direct-current cardioversion or by using various regimens of amiodarone, a type III antiarrhythmic drug, given orally or intravenously. Cardioversion might also be accomplished by type IA and IC antiarrhythmic drugs, including quinidine, flecainide and propafenone. However, proarrhythmic effects and haemodynamic deterioration are a major concern with these compounds. On the other hand the best indication of type IA and IC antiarrhythmic drugs is the control of arrhythmia recurrences; beta-blocking agents are highly effective in patients with a high sympathetic tone or hypertrophic cardiomyopathy. Finally the widespread use of amiodarone should be limited by its non-cardiac toxicity. Whatever the drug employed in the treatment of atrial fibrillation, monitoring the inotropic effect of the drug and the effect on cardiac conduction is mandatory.