(A) ‘Natural’ time course of atrial fibrillation (AF) in a patient. Before the diagnosis of AF, most patients probably experience asymptomatic episodes of the arrhythmia. With the exception of rare patients with ‘true lone AF’, AF recurrences become longer and more frequent over time, and finally result in chronic forms of AF. The majority of patients progresses from persistent AF—that is, AF that is managed by rhythm control interventions—to long lasting persistent AF and finally permanent or accepted AF that is managed by rate control and antithrombotic therapy. Reproduced with permission from Kirchhof et al.1 (B) Different ‘vicious circles’ that contribute to AF. In addition to electrical triggers, often located in the pulmonary veins and the posterior left atrium (red circle), shortening of the atrial action potential can promote multiple wavelet reentry (blue circle), and structural remodelling of the atria contributes to conduction disturbances and electrical isolation of atrial myocardium (green circle). Furthermore, there is a bidirectional interaction between left ventricular dysfunction and atrial dysfunction (brown circle) in AF patients. Unfortunately, only a part of the atrial damage can be prevented by preventing AF (black pie piece), while other parts are due to other, often extracardiac …