The study of cardiac metabolism has grown in appreciation in recent years as alterations to metabolic function in the heart has been observed in cardiac disease and aging. The prevailing phenotype in cardiac disease and aging is a reduction in the ability to use fatty acids and an increased reliance on glucose as the fuel source to support contractile function in the myocardium. Lastly, these phenotypic metabolic changes are associated with contractile dysfunction in the myocardium. In most cardiac conditions, contractile dysfunction is best elicited under conditions which stress the myocardium. Glucose utilization in the myocardium changes under conditions of stress. Increases in cardiac workload and decreases in oxygen tension are known stressors which increase glucose utilization in the heart. Also, dobutamine and hypoxic stress are known to augment stroke work. Glucose utilization as measured by 18F-fluorodeoxyglucose (FDG) uptake will be determined during rest and stress conditions in order to better understand the relationship between glucose uptake and physiological stress on the heart. Cardiac imaging studies use a bolus injection of FDG in order to determine glucose utilization. This method has potential confounds, while continuous infusion of FDG will enhance our temporal resolution and allow us to more accurately measure dynamic changes in cardiac FDG uptake and contractile function under different conditions.
April 2016 to May 2017
This project led by: Marlowe Eldridge, MD