KCND3 and metabolic syndrome: In this study, we provided evidences that SSYX treatment: 1) ameliorates MetS-induced VA susceptibility, shortened ERP and increased APD; 2) reverses MetS-induced downregulation of ICa-L and Ito current densities; 3) improves MetS-induced gap junction remodeling, cardiac fibrosis; 4) reverses MetS-induced downregulation of protein expression of Cav1.2, Kv4.2, Kv4.3; 5) and down-regulated the TLR4/MyD88/CaMKII signaling pathway induced by MetS.