Figure 1.

Schematic diagram of metabolism in cardiac myocyte. (A) Metabolism in normal cardiomyocytes. Under well-oxygenated conditions, cardiac energy requirement is largely met by fatty acid oxidation (~60%). Only a minor proportion (around 40%) is generated by glucose metabolism; and (B) Consequences of cardiac lipotoxicity. The precise balance between fatty acid uptake and oxidation is upset by metabolic disorders (i.e., HFD). Under these circumstances, excessive fatty acid is accumulated in cardiomyocytes and leads to cellular injury (e.g., mitochondria dysfunction, ER stress) and lipotoxicity, thereby predisposing to cardiac diseases (e.g., heart failure and arrhythmia). Dashed arrow: multistep processes; Solid arrow: direct effects. FA, fatty acid; TAG, triacylglyceride; GLUT-4, Glucose transporter type 4; TCA cycle, tricarboxylic acid cycle; HFD, high-fat diet; CD-36, cluster of differentiation 36 (also known as fatty acid translocase).