CAMK2G and atrial fibrillation: The positive feedback circle of [Ca2+]i-CaMKII-late INa-[Na+]i could progressively facilitate the genesis of DADs via activation of a sodium-calcium exchanger, leading to transient inward currents (Iti) and EADs via enhancement of ICa,L [2,21], thus promoting atrial hypertrophy, dilatation and AF progression [22].