[New concepts on atrial fibrillation]

Atrial Fibrillation (AF) is the most common sustained arrhythmia in humans. AF has a self-perpetuating nature. Perpetuation has been attributed to shortening of atrial action potential duration (APD) and APD adaptation to rate, the so called atrial electrical remodeling. There is evidence that alterations in gene expression of proteins involved in the Ca handling may be, at least partly, responsible for AF-induced electrical remodeling. This review focus on the possible cellular mechanisms involved in atrial remodeling, followed by a brief description of new therapeutic approaches that target the development of the arrhythmogenic substrate, rather than simply attacking the final electrophysiologic environment.