(2) In the process of OSA, repeated apneas can lead to hypoxemia and hypercapnia, as well as secondary sympathetic nerve activation and systemic inflammation, both of which promote glycogen deposition, apoptosis, and mitochondrial damage in LA cardiomyocytes, which occur in parallel with abnormally expressed ion channels (including K+, Na+, Ca2+, and HCN4) and Cx43 and Cx40. This evidence concerns the gene HCN4 and obstructive sleep apnea syndrome.