NOS1 and atrial fibrillation: Interestingly, our group has shown that atrial cardiomyocytes taken from patients in chronic atrial fibrillation (a condition in which the mechanical environment is likely to be perturbed, in which nNOS is depleted, and the potassium currents IKur and IK1 are increased) leads to the electrical remodeling characteristic of the condition (Reilly et al., 2016).