Our study revealed that the expression of BMAL1, CRY2, NR1D1, NR1D2, PER2, RORA, RORC, and TIM was also associated with AHRE burden, which implies that other circadian clock genes may also play an important role in the variability of heart rate change, and then in the development of AF. Here, PER2 is linked to atrial fibrillation.