Cyanotic heart defects include complex defects involving two or more structures in the heart and/or large blood vessels around the heart. A cyanotic heart defect results in low oxygen levels in the blood related to oxygen-rich blood mixing with oxygen-depleted blood. The body works to compensate for chronically low oxygen levels in the blood by increasing hemoglobin (the oxygen-carrying component of red blood cells) and by increasing the work of the heart so more blood is circulated to the body. Symptoms may include heart murmurs, bluish skin color, slow growth, and others depending on the type of defect. Treatment is based on the type and severity of the individual heart defect.
Types of Cyanotic Defects:
- Hypoplastic left-heart syndrome – Hypoplastic left-heart syndrome includes a combination of left-sided heart defects with the underdeveloped left ventricle being the most critical of these defects. The structures of the heart and great vessels around the heart that are involved with this syndrome include an underdeveloped mitral valve, left ventricle, aortic valve and the aorta. The left side of the heart is responsible for pumping oxygen-rich blood to the body, therefore surgical intervention is necessary to meet the body’s needs. Newborn infants show symptoms shortly after birth, which may include pale or cyanotic (blue in color) skin with rapid, labored breathing, fast heart rate, cold hands and feet and sweaty skin. The two surgical options include: 1) a series of operations that are done in stages with the first operation being done shortly after birth, and 2) heart transplantation.
- Pulmonary atresia – The valve (pulmonary valve) between the right ventricle and the pulmonary artery is nonexistent. This defect prevents oxygen-depleted blood from flowing to the lungs. Frequently the right ventricle and tricuspid valve are underdeveloped with this heart defect.
Tetralogy of Fallot – Tetralogy of Fallot is a defect that includes four heart and large vessel malformations. The four malformations are:
- Ventricular septal defect – A hole between the right and left ventricles.
- Pulmonary valve stenosis – The heart valve between the right ventricle and the pulmonary artery is narrowed, impeding blood flow to the lungs.
- Aorta overrides the ventricular defect - The aorta is shifted to the right over the ventricular septal defect. The aorta receives oxygen depleted and oxygen-rich blood.
- Right ventricular hypertrophy – The right ventricle of the heart must take on extra work due to the ventricular septal defect and the obstructions to blood flow. This extra workload leads to an enlarged right ventricle with thickening of the right ventricle wall. If the baby is small, treatment consists of surgery to place a temporary shunt followed by complete repair at a later time. If the baby is large enough, the initial surgery is a complete repair. A disturbance in heart rhythm (arrhythmia) may be experienced later emphasizing the need to have ongoing monitoring with a cardiologist experienced in adults with congenital heart defects.
For additional information and illustrations of the above defects follow the American Heart Association link at http://americanheart.org; click on “diseases and conditions”, “adults with congenital heart disease”, congenital heart defects, and select the specific defect.