hypoplastic left heart syndrome

hypoplastic left heart syndrome A form of congenital heart disease in which the whole left half of the heart, including the aorta is underdeveloped (hypoplastic). Blood returning from the lungs has to flow through an opening in the wall between the upper chambers of the heart (an atrial septal defect). The right ventricle pumps blood into the pulmonary artery, and blood reaches the aorta through a shunt (the ductus arteriosus). A child with hypoplastic left heart syndrome may appear normal at birth, but symptoms appear within the first few days of life when the ductus arteriosus closes. The infant becomes ashen, has difficulty breathing, and has problems with feeding. This heart defect is usually fatal unless treated by a series of surgeries or a heart transplant. See also atrial septal defect; ductus arteriosus.