Single-cell transcriptomic profiling of embryonic hearts showed that exposure to hyperglycemia environment as early as E9.5 and E11.5 led to diverse cellular responses, with differentially expressed genes (DEGs) enriched in pathways related to cell differentiation, voltage-gated calcium channels, potassium channels, regulators of cardiac contractility, and transcriptional and chromatin regulators. This evidence concerns the gene KCNA3 and Hyperglycemia.