Congenital heart disease: A malformation of the heart, aorta, or other large blood vessels that is the most frequent form of major birth defect in newborns. Abbreviated CHD. There are many types of CHD, including atrial septal defect (ASD), ventricular septal defect (VSD), pulmonary (valvular) stenosis, aortic stenosis, coarctation of the aorta, Tetralogy of Fallot, and transposition of the great arteries. Much of the practice of pediatric cardiology consists of the diagnosis and treatment of CHD. Also known as congenital heart defect, congenital heart malformation, congenital cardiovascular disease, congenital cardiovascular defect, and congenital cardiovascular malformation.