[Basic mechanisms of the new antiarrhythmic drugs in atrial fibrillation].

Atrial fibrillation (AF) is the most common sustained arrhythmia seen in clinical practice. Despite of new technological breakthroughs and the understanding of the mechanisms underlying AF, based on animal models and ablation procedures in patients, the antiarrhythmic drugs remain the main therapeutic strategy to restore and maintain the sinus rhythm. New antiarrhythmic drugs are already available in the clinical practice and many others are under development. The new antiarrhythmic drugs have the capability to block atrial-specific ionic currents, which are involved in the maintenance of the arrhythmia. Parallel, increasing evidence supports the use of compounds to regulate the arrhythmogenic atrial substrate involved in the long-term maintenance of the arrhythmia (upstream therapies). This article reviews the new antiarrhythmic drugs and upstream therapies, based on the current knowledge of the mechanisms involved in the maintenance of AF.