This review summarizes glucose metabolism in the normal heart and highlights the features and regulatory mechanisms of glucose metabolic reprogramming in myocarditis, including the hypoxia-inducible factor-1α/mammalian target of rapamycin axis, nuclear factor erythroid 2-related factor 2-mediated pentose phosphate pathway, immune-responsive gene 1/itaconate axis, and phosphoglycerate kinase 1. The gene discussed is PGK1; the disease is myocarditis.