Studies of fatty acid metabolism with positron emission tomography in patients with cardiomyopathy

Positron emission tomography (PET) permits in vivo as well as noninvasive study of fatty acid metabolism. Parameters of ¹¹C-palmitate kinetics relate to the oxidation of fatty acids, and palmitic acid uptake is impaired in patients with coronary disease and cardiomyopathy. Normal myocardium shows homogenous fatty acid·metabolism and can resort to alternate substrates. Diseased myocardium exhibits regional heterogeneity in fatty acid uptake and utilization. In patients with cardiomyopathy, distinct patterns of fatty acid metabolism can be observed following changes of substrate availability by application of an oral glucose load. This intervention also enhances the heterogeneity of ¹¹C-palmitic acid (CPA) uptake and clearance. Thus, PET studies with CPA permit the noninvasive demonstration of effects on substrate availability and may help to characterize patients with ventricular dysfunction on the biochemical level.