Antiarythmiques

The efficacy and limitations of the currently available antiarrhythmic agents (AAA) are well known. Class 1 AAA are efficient but contraindicated in coronary artery disease and heart failure, two conditions often associated with atrial fibrillation which is their main indication. Sotalol may be efficient but may induce torsades de pointes. Amiodarone is at present the most efficient AAA but it has a very poor tolerance, with frequent thyroid dysfunction. New AAA are being evaluated but they may also induce adverse events. Proarrhythmic effects of AAA may in 5% to 10% worsen atrial or ventricular arrhythmia or induce severe bradyarrhythmia. They may be in part prevented by low initial dose of AAA, avoidance of dangerous association, elimination of precipitating factors and close monitoring of exposed patients. Difficulties in medical approach of treating arrhythmias have led to the development of non pharmacological strategies (mainly radiofrequency ablation and defibrillation), and the prescription of AAA for sustained ventricular arrhythmia was markedly decreased compared to that of implantable defibrillator in the recent years. However, atrial fibrillation is so frequent that pharmacotherapy is chosen as first-line treatment in most patients, particularly when considering the complexity of non pharmacological approaches, and even if simple rate control may also be considered for some patients. Therefore, it remains necessary to develop new AAA agents with effective and safe profiles, particularly in heart failure.