Beta-blocker Administration for Cardiomyocyte Division

Heart failure is a common long-term complication in patients with congenital heart disease (CHD). Medical treatments to promote regeneration of new healthy heart muscle cells have the potential to provide new heart failure treatments for these patients. The development of such therapies is limited by the poor understanding of the ways in which heart muscles grow after birth. Investigators have learned that humans without heart disease generate new heart muscles cells up to the age of 20 years old and that this is decreased in patients with congenital heart disease like Tetralogy of Fallot. Investigators are trying to determine if treatment with a medicine called Propranolol can increase heart muscle cell proliferation and, with that, normalize heart growth. Investigators will examine discarded heart muscle tissue that is obtained during surgery for the presence of new heart muscle cells. Propranolol is approved by the Food and Drug Administration (FDA) to treat a certain kind of benign tumor in infants (hemangioma), but it is not currently approved by the FDA to increase heart muscle growth.