VIP and atrial fibrillation: HIV: human immunodeficiency virus, HCV: hepatitis C virus, NASH: nonalcoholic steatohepatitis, NAFLD: non-alcoholic fatty liver disease, MAFLD: metabolic-associated fatty liver disease, AFib: atrial fibrillation, VIP: vasoactive intestinal peptide, HSC: hepatic stellate cell, APD: action potential duration