[When, why, and how to treat atrial fibrillation].

Treatment of atrial fibrillation aims to convert it to sinus rhythm and maintain this rhythm after conversion, to reduce ventricular frequency when fibrillation is not converted and to prevent systemic embolies. Conversion to sinus rhythm is achieved with electrical cardioversion or with intravenous antiarrhythmic drugs (Lanatoside C, amiodarone or beta blockers). The most useful drugs to maintain sinus rhythm are amiodarone, quinidine alone or associated to verapamil, sotalol and propafenone. The best drug used to control cardiac frequency in a rapid atrial fibrillation is digitalis. However, when there is a decrease in vagal tone and an increase in sympathetic activity, digitalis losses its effectiveness and a betablocker or a calcium blocker must be added. Electrical cardioversion is the treatment of choice for atrial fibrillation of Wolff Parkinson White syndrome. When there is a rapid, symptomatic and uncontrollable atrial fibrillation, electrical ablation of atrio-ventricular junction and the implantation of a definitive pacemaker is the treatment of choice. Lately, a new procedure has been devised, called of the labyrinth, that can re-establish sinus rhythm, atrial contraction and atrio ventricular conduction. The embolic risk of atrial fibrillation depends on its etiology and the decision to anticoagulate must balance the risks and benefits of this treatment.