Atrial fibrillation is a common arrhythmia, and its incidence rise sharply with age and with heart failure. Since the beginning of the new millennium, the debate on ectopic foci versus reentry as the mechanism underlying atrial fibrillation (AF) in humans has continuously evolved. The finding of ectopic beats proceeding from the pulmonary veins in the initiation of atrial fibrillation gave a different approach to the therapeutic management of this arrhythmia. Recently, the mechanism of AF is considered to be a spiral wave with a continuously changing pattern of the activation wavefront, that is, a random multiple reentry of independent wavelets wandering in the atria around arcs of refractory tissue or the accentuation of focal activity originating mainly from the pulmonary veins, the superior or inferior vena cava, the ligament of Marshall, or even the right atrium.
Credits: Ósmar Antonio Centurión MD, PhD, FACC