Hypoplastic left heart syndrome (HLHS) is a congenital malformation of the left side of the heart, affecting the aortic valve, mitral valve, left ventricle, and aorta. In babies with hypoplastic left heart syndrome, the aorta and left ventricle are very small, and the aortic and mitral valves are either too small to allow sufficient blood flow or are closed altogether. As blood returns from the lungs to the left atrium, it must pass through an atrial septal defect to the right side of the heart. As with most congenital heart defects, there is no known cause. Approximately 10% of patients with hypoplastic left heart syndrome also have other birth defects. The degree of underdevelopment differs from child to child.
The most critical defect in hypoplastic is the small, underdeveloped left ventricle. This chamber is normally very strong and muscular so it can pump blood to the body. When the chamber is small and poorly developed, it will not function effectively and cannot provide enough blood flow to meet the body's needs. For this reason, an infant with hypoplastic left heart syndrome is in a very critical situation. At first, a newborn with hypoplastic left heart may appear normal. Symptoms usually occur in the first few hours of life, although it may take up to a few days to develop symptoms. These symptoms may include bluish skin (cyanosis), cold feet and hands, lethargy, poor pulse, etc.
Treatment consists of a surgery o a heart transplant. Without life-prolonging interventions, HLHS is fatal, but with intervention, an infant may survive. A pediatric cardiothoracic surgeon may perform a series of operations or a full heart transplant. In the meantime, the ductus may be kept open to allow blood-flow using medication containing prostaglandin. Because these operations are complex and need to be individualized for each patient, a cardiologist must assess all medical and surgical options on a case-by-case basis.
Hypoplastic Left Heart Syndrome Surgery (Video)