Do age-associated changes of voltage-gated sodium channel isoforms expressed in the mammalian heart predispose the elderly to atrial fibrillation?

Figure 1 Peak and Late sodium currents on action potential morphology. A: Top left: An illustration of a normal sodium current within a cardiomyocyte with its rapid peak current and short late current; Bottom left: An action potential as a result of normal sodium ion influx. Plateau and repolarisation phases are not prolonged and no afterdepolarizations present; B: Top right: An Illustration of a pathologically enhanced late sodium current; Bottom right: An action potential as a consequence of enhanced late sodium current with a prolonged plateau and repolarisation period. The late upstroke between phase 2 and phase 3 represents an after depolarisation brought about due to the aberrant late sodium current. Adapted from Vadnais et al[74], 2010 with permission.