Radionuclide Imaging of Myocardial Metabolism

C ardiac health is dependent on the heart's ability to utilize different substrates to support overall oxidative metabolism to generate ATP. Indeed, a loss in plasticity in substrate preference is characteristic of a variety cardiac diseases such as diabetic heart disease, in which fatty acid metabolism predominates, and dilated cardiomyopathy, in which glucose metabolism predominates. Because of the pleiotropic actions of myocardial substrate metabolism, a loss in plasticity in substrate preference can have detrimental effects well beyond impairment of energy production, including perturbations in various cell signaling pathways, alterations in cell growth, and decreased cell survival.