Heart Disease - Types of Congenital Heart Defects
The most common congenital malformations are septal defects (either atrial septal defect (ASD) or ventricular septal defect (VSD)), transposition of the great arteries, and patent ductus arteriosus (PDA). These and other congenital heart defects are summarized below:
- Aortic stenosis: Narrowing of the aortic valve, limiting the flow of blood to the body. Possible symptoms include angina (chest pain), fatigue, dizziness or fainting. Depending on the severity of the defect, surgery may be necessary to enlarge the valve opening. Balloon valvuloplasty has shown some promise in patients with aortic stenosis, though long-term effects need to be assessed.
- Atrial septal defect (ASD): A hole exists in the septum (wall) separating the artria (upper chambers), causing blood from the left atrium to leak into the right atrium. Too much blood from the right atrium is passed to the lungs via the pulmonary artery and too little blood is passed to the rest of the body via the aorta. ASD may cause heart failure due to congestion in the lungs, pulmonary hypertension, and atrial fibrillation (rapid, abnormal heartbeat) as an adult. Treatment may include drug therapy (such as diuretics), cardiac catheterization, or in severe cases, open heart surgery to close the hole.
- Coarctation of aorta: Pinching or narrowing of the aorta. The narrowing typically occurs just past where the subclavian artery (supplies the neck, head and left arm) branches off the aorta, reducing the flow of blood to the lower part of the body. The heart compensates by raising blood pressure in the upper body and lowering pressure in the lower body. Signals of coarctation of aorta include a heart murmur, weak/absent pulses in the groin, lack of synchronization between groin and wrist pulses, and discrepancies in blood pressure measurements between the upper and lower body. Either immediate or delayed surgery, depending on the severity of hypertension, is necessary to remove the narrowed portion of the aorta and connect the remaining ends. Balloon angioplasty may be appropriate in some cases.
- Ebstein’s anomaly: Deformation and improper placement of the tricuspid valve (located between the right atrium and right ventricle). With this defect, the tricuspid valve is hanging down into the right ventricle and unable to close properly. This results in oxygen-poor blood flowing back into the right atrium instead of flowing in a single direction to the right ventricle, and out the pulmonary artery into the lungs. Atrial septal defects may also be present with Ebstein’s anomalies. Immediate or delayed surgery is typically necessary to replace or repair the tricuspid valve, close the atrial septal defect (if present), repair the damage to the ventricle, and reduce the size of the atrium (if enlarged).
- Hypoplastic left heart syndrome (HLHS)/ Left heart hypoplasia: Malformation of the left side: aorta, aortic valve, left ventricle, mitral valve. Resulting heart defects may include: mitral stenosis (narrowing of mitral valve, restricting blood flow from left atrium to left ventricle), mitral atresia (closure of mitral valve, restricting blood flow from left atrium to the left ventricle), aortic atresia (closure of aortic valve, restricting blood flow from left ventricle to the aorta), coarctation of the aorta (pinched aorta limits blood flow to body), or underdevelopment of the left ventricle. Immediate surgery is usually necessary, either the Norwood procedure or transplant. The Norwood procedure is performed in stages and helps re-route the blood flow around some of the defective areas of the heart by creating new pathways for blood circulation to and from the lungs. Transplants may be appropriate in some cases, although donor hearts are rare and pose added risks.
- Patent ductus arteriosus (PDA): Failure of the ductus arteriosus (fetal channel between the pulmonary artery and arota through which blood pumped by the right side of the heart is able to bypass the lungs) to close after birth, causing blood from the pulmonary artery and aorta to mix. Possible symptoms include failure to gain weight, shortness of breath during exertion, and chest infections. Treatment includes indomethacin for premature babies or surgery to close the channel.
- Pulmonary atresia: Permanent closure of the pulmonic valve before birth. This prevents the flow of blood from the right ventricle into the pulmonary artery and then to the lungs. Infants with pulmonary atresia typically have other defects, including patent ductus arteriosus, atrial septal defect, other right side defects, or tetralogy of fallot. Cyanosis (bluish appearance of the skin)is usually seen with pulmonary atresia. Other symptoms include dyspnea (shortness of breath) or rapid breathing, feeding difficulties, poor weight gain, and slowed growth. Early treatment includes prostaglandin to keep the ductus arteriosus from closing or creating a Blalock-Taussig shunt between the aorta and the pulmonary artery. In addition, corrective surgery is usually necessary.
- Pulmonary stenosis (PS): Obstruction of blood flow from the right ventricle. Causes include narrowing of the pulmonary valve at the exit of the chamber, narrowing of the pulmonary artery which carries blood to the lungs, or narrowing of the upper portion of the ventricle. Cyanosis may be present in severe cases. Treatment includes balloon valvuloplasty or surgery to open the valve.
- Tetralogy of fallot: Four heart abnormalities exist at once: displaced aorta, narrowed pulmonary valve, hole in ventricular septum, and thickened wall of the right ventricle. Because the blood from the heart is poorly oxygenated, cyanosis and breathlessness typically occur and may be accompanied by feeding difficulties, failure to gain weight and poor development. Surgery is typically necessary to correct the defects.
- Total anomalous pulmonary venous return (TAPVR): Pulmonary veins that bring oxygen-rich blood from the lungs back to the heart are not connected properly to the left atrium. Thus, oxygenated blood is re-rerouted to the right side where it continues to flow back to the lungs, preventing the rest of the body from receiving oxygen-rich blood. In most cases, immediate surgery is necessary to connect the pulmonary veins to the left atrium. Surgery to repair an atrial septal defect (ASD) may also be necessary if ASD is present.
- Transposition of the great arteries: The positioning of the pulmonary artery and aorta is reversed, resulting in the mixing of oxygen-rich and oxygen-poor blood. Cyanosis typically occurs and may be accompanied by increased dyspnea (shortness of breath) and poor feeding. Surgery should be performed immediately to create and/or enlarge the ductus arteriosus (hole) in the septum to allow oxygenated blood through and sustain life. Arterial switch surgery will then be performed to correct the positioning.
- Tricuspid atresia: Permanent closure of the tricuspid valve (located between the right atrium and right ventricle) before birth. This prevents the flow of blood from the right atrium to the right ventricle and then to the lungs for oxygen. Early treatment includes prostaglandin to keep the ductus arteriosus from closing. In some instances, the patent foramen ovale (the hole between the right and left atrium) may need to be enlarged to increase blood flow. In addition, corrective surgery to bypass the right ventricle (keeping oxygenated and non-oxygenated blood separated) is usually necessary.
- Truncus arteriosus: The great arteries (aorta, pulmonary artery) fail to separate, resulting in a single trunk of arteries. The abnormal blood flow and increased workload caused by the defect can lead to heart failure or death. Immediate surgery is necessary and consists of closing a large ventricular septal defect within the heart, detaching the pulmonary arteries from the large common artery, and connecting the pulmonary arteries to the right ventricle with a tube graft. Patients who undergo treatment for the defect should be monitored throughout their lives for heart problems.
- Ventricular septal defect (VSD): A hole exists in the septum separating the two ventricles. Similar to ASD, VSD causes blood from the left ventricle to leak into the right ventricle. VSD can cause enlargement and/or weakening of the right ventricle as it becomes strained. Other effects include endocarditis (inflammation of the heart lining), heart failure due to congestion in the lungs, pulmonary hypertension, blood clots (leading to stroke), and arrhythmia (abnormal heartbeat). VSDs close on their own in many cases and do not require additional treatment. If treatment is necessary, options include medications (such as diuretics) or sternotomy (involves making an incision through the sternum and closing the hole).
Updated: August 2006