Research on cardiac development and defects has made significant strides in understanding the complexities of human heart formation and the underlying mechanisms of congenital heart diseases. A pivotal study established a human cardioid platform that effectively recapitulates the development of all major embryonic heart compartments, including the right and left ventricles, atria, outflow tract, and atrioventricular canal. This model addresses the limitations of in vitro systems by providing insights into how mutations, drugs, and environmental factors affect heart compartment functions, which are critical for identifying the causes of congenital heart defects (ref: Schmidt doi.org/10.1016/j.cell.2023.10.030/). Furthermore, another study explored the potential for heart regeneration by metabolically reprogramming cardiomyocytes. By inhibiting fatty acid oxidation, researchers were able to induce an immature state in cardiomyocytes that promotes cell-cycle reentry and regeneration, highlighting a novel therapeutic avenue for cardiac repair (ref: Tang doi.org/10.1016/j.cmet.2023.10.007/). These findings collectively underscore the importance of innovative models and metabolic interventions in advancing our understanding of cardiac development and potential regenerative therapies for heart defects.