children s health issues
Hypoplastic Left Heart Syndrome
Introduction
Hypoplastic left heart syndrome is a birth defect in which the left side of the heart, including the lower heart chamber (left ventricle), heart valves (mitral and aortic valves), and aorta, does not develop sufficiently. Newborns with hypoplastic left heart syndrome also have an Atrial and Ventricular Septal Defects (ASD) and a Hypoplastic left heart syndrome causes heart failure shortly after birth—the heart pumps less than normal amount of blood to the body—and eventually death. Diagnosis is by echocardiography. Treatment is with emergency medications to keep the ductus arteriosus open followed by a series of surgical procedures or with heart transplantation. (See also Overview of Heart Defects .) Hypoplastic left heart syndrome accounts for 2 to 4% of heart defects. Hypoplastic is a medical term for a body part that is underdeveloped and small. In newborns with this heart defect, because the left side of the heart is underdeveloped, when blood flows from the lungs into the left side of the heart, there is very little space in their left atrium. This causes some of the blood to be pushed into the right side of the heart through an atrial septal defect (a hole in the heart wall between the left and right atria). Also, blood returning to from the body (blood with a low oxygen level) mixes with blood returning from the lungs (blood with a high oxygen level). The underdeveloped left side of the heart does not allow enough blood to return to the body, so the newborn depends on additional blood flow through the ductus arteriosus (a short-cut that is part of the fetal circulation allowing blood to flow directly from the pulmonary artery to the body), but this short-cut usually closes soon after birth (see Normal Fetal Circulation ). If the ductus is not kept open by quickly starting a medication called a prostaglandin, the newborn will die. Surgical treatment is required within the first weeks of life. 