Fig 2. Illustration of the main mechanics of the model.
(a) Main elements governing the switching process between sinus rhythm and AF. (b) Time courses of activation rate and recovery rate during AF episodes and in sinus rhythm. activation rate of AF due to ageing, Aage, increases according to a sigmoid function, and age-based recovery rate Rage decreases exponentially. A healthy patient triggers an AF episode with rate A(t) and terminates an AF episode with rate R(t). In AF, episode-based remodelling Aepi transiently increases activation rate at a rate α and decreases the total recovery rate R at rate μ. When an episode terminates, the recovery rate ‘boosts’ above baseline by a factor of B. Back in sinus rhythm, Aepi decays to zero with rate β and Repi decays with rate ν back to the age-based baseline Rage.