ADORA1 and atrial fibrillation: On the other hand, elevated APLs in AF might also activate adenosine A1 receptors (A1Rs) and trigger the atrial acetylcholine-activated inward rectifier potassium current (IKACh) reported in AF [9,10,11] that reduces the refractory period and facilitates electrical re-entry, which in turn may contribute to the development and maintenance of AF.