Figure 1.

The energy metabolism process of fatty acid, glucose and ketone body. Various metabolic substrates are transported to the cytoplasm to form corresponding intermediate product, such as pyruvate, fatty acyl CoA, etc. These intermediates enter the mitochondrial matrix through a specific transport system and generate NADH, FADH₂, GTP through the TCA cycle, fatty acid oxidation and other pathways. Then NADH and FADH₂ produce ATP through the electron transfer chain, which provides energy for cardiomyocytes.