Start » Glossary » Hypoplastic Left Heart Syndrome (HLHS)

One of the most serious congenital heart defects. Characteristic features are the underdevelopment of the left side of the heart, the open connection between the pulmonary and aorta (ductus arteriosus Botalli) and the patent foramen ovale (PFO). Also underdeveloped (too narrow, too small) are: the mitral and aortic valves, the aorta and the left atrium. Newborns have cyanosis and are also called "blue babies" because of the blue colour of the skin.