Fatty Acid Oxidation

The heart consumes vast amounts of energy, and cardiac energetic impairment is a characteristic feature of several inherited and acquired diseases of heart muscle. In the fasting state, the heart typically generates ≈70% of its energy from β-oxidation of fatty acids, 10% to 30% from oxidation of glucose, and the remainder from ketones, lactate, and amino acids. However, it is a metabolic omnivore, changing its substrate utilization according to metabolic demand, oxygen, and substrate availability, and this flexibility seems crucial for the maintenance of normal cardiac function. Acute adaptations (eg, to increased workload) occur via altered activity of metabolic enzymes. Chronic adaptations also occur in both health and disease related to altered gene expression and will be discussed in this review. Before proceeding to disturbances of these processes in cardiac disease and to the pharmacological modulation of cardiac metabolism, substrate metabolism and energy generation will be briefly reviewed.