Mechanisms of atrial fibrillation in athletes: what we know and what we do not know

Fig. a. Schematic representation of the potential mechanisms underlying exercise-induced atrial fibrillation represented in a Coumel’s triangle of arrhythmogenesis, and their functional consequences

Fig. 1. Schematic representation of the potential mechanisms underlying exercise-induced atrial fibrillation represented in a Coumel’s triangle of arrhythmogenesis, and their functional consequences

Fig. 2. Potential factors leading to a pathological atrial remodelling in athletes (atrial fibrosis). Systemic blood pressure and, particularly, pulmonary pressure promote an increase in atrial intracavitary pressure during exercise. In the presence of chronically dilated atria and limited ability to increase wall thickness, atrial wall stretch has remarkably increased, which may promote the activation of profibrotic mechanisms. A pro-inflammatory status during each exercise bout and intake of an illicit performance enhancer may also contribute. RA right atrium, LA left atrium

Fig. 3. Representation of the factors contributing to the balance between the antiarrhythmic and the pro-arrhythmic effect of exercise