Figure 1: Panel (A) Principal factors involved in inducing and maintaining AF. Panel (B) AF is started by an extrasystole originated from a pacemaker region (commonly left upper pulmonary vein), initiated by atrial tachycardia remodeling (ATR induced APD shortening). The electrical perpetuator may be a single/mother wave and/or multiple wave/circuit re-entry. The main re-entry initiating factors are: atrial ischaemia and inflammation. The principal factors of structural/morphological remodeling: atrial (micro)fibrosis and left atrial dilation. List of abbreviations: AF=atrial fibrillation; RA=right atrium; LA=left atrium; EAD=early afterdepolarization; DAD=delayed afterdepolarization; PVs=pulmonary veins; APD=action potential duration; RP=refractory period; WL=wavelength). Modified from Ref [8] with permission.