Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with associated deterioration of atrial mechanical function. It is the most common cardiac arrhythmia, becomes more prevalent with age, and is associated with an increased long-term risk of stroke, heart failure and all-cause mortality. It is likely that most AF occurs primarily in the context of an interplay between left atrial electrical and mechanical dysfunction and later becomes selfperpetuating by promoting further electromechanical change during ongoing fibrillation.