Energy metabolism in the heart of newborns with congenital heart defects
In some babies the heart does not properly form during fetal development, resulting in abnormalities in the anatomy of the heart. These defects, called, 'Congenital Heart Defects'(CHD's), can be life-threatening, and heart surgery may be necessary to repair the CHD's. This necessitates that the heart be stopped during the operation, resulting in a period of time where the heart does not receive any oxygen, a condition called 'cardiac ischemia'. If cardiac ischemia persists for extended periods of time, damage to the heart muscle can occur. It is therefore important to develop strategies to protect the heart during surgery to correct CHD's. Following birth, the heart of the newborn switches from using sugars to using fatty acids as it's main source of fuel. This maturation of energy metabolism is decreased in the hearts of infants with CHDs. What is responsible for the dramatic switch in fuel use by the heart and why it is delayed in infants with CHDs is not completely understood. We will use heart biopsy samples from newborns born with CHDs to determine what is responsible for the dramatic increase in fatty acid use in the newborn period, and why the presence of CHDs that cause the heart muscle to increase in size delays this increase in fatty acid use. We will also determine how this switch in energy metabolism contributes to damage to the heart muscle during cardiac ischemia. Our studies should help the development of new therapeutic strategies to protect the newborn heart during cardiac surgery to correct CHDs, thereby improving the health of infants who are born with CHD's