Atrial fibrillation occurs because of a complex interaction between an arrhythmogenic substrate, triggers factors and the autonomic nervous system. Underlying fundamental mechanisms are multiple, can cohabit and include schematically: multiple wavelet, stable microreentry, macro single meandering spiral wave reentry and focal atrial fibrillation arising from the pulmonary veins. More over, new concepts have emerged like the atrial fibrillation-induced electrical and structural remodeling which favors its own perpetuation. Experimental studies have shown a complex interaction between anatomical particularities of the atria and the activation fronts dynamic. All this recent progress open new and more efficient therapeutic perspectives for patients enduring atrial fibrillation.