SAA1 and atrioventricular block: Through laboratory tests andcomparative proteomics analysis, we identified several differential expressedproteins (Serum amyloid A protein, Tetranectin, Neutrophil defensin 3) releatedto the inflammatory response, complement and coagulation cascades, and immuneresponse, which provides evidence of potential biomarkers and sheds light on thepathogenesis of COVID-19-related AVB.