BECN1 and atrial fibrillation: The results showed that after stimulation with 100 μmol/L H2O2 for 0.5 h, the levels of autophagy-related proteins Beclin-1 and LC3 II/I began to increase in AF cells, and reached their peak after 1 h (P < 0.01), thereafter gradually declined at 2 and 4 h (Fig. 2a).