CASQ2 and atrial fibrillation: The loss of Casq2, as a free Ca2+ buffer in the SR (Gaburjakova et al., 2013), resulted in bradycardia, sinoatrial node conduction abnormalities, and beat-to-beat heart rate variability in a study conducted by Glukhov et al. (2015), and Faggioni et al. (2014) found that there is an increased risk of AF in Casq2-/- mice.