Hypoplastic Left Heart Syndrome
Hypoplastic Left Heart Syndrome Click Image to Enlarge What is hypoplastic left heart syndrome? Hypoplastic left heart syndrome (HLHS) is a combination of several abnormalities of the heart and great blood vessels. It is a congenital (present at birth) syndrome, meaning that the heart defects occur due to abnormal underdevelopment of sections of the fetal heart during the first 8 weeks of pregnancy. In the normal heart, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the r...