What is tricuspid atresia?
Tricuspid atresia is a congenital (present at birth) heart defect that occurs when the tricuspid valve of the heart is not properly formed. The tricuspid valve lies between two of the chambers of the heart (the right atrium and right ventricle). In tricuspid atresia, there is solid tissue instead of the tricuspid valve. This sheet of tissue blocks blood flow from the right atrium to the right ventricle. Because of this blockage, the right ventricle usually is small and underdeveloped.
When tricuspid atresia is present, a sufficient amount of blood is not able to flow through the heart and into the lungs, where it would obtain oxygen as the blood in a normal heart would. As a result, the lungs of a baby with this defect are not able to provide the rest of the body with its required oxygen.
In a baby who is born with tricuspid atresia, blood flows from the upper right chamber (right atrium) to the upper left chamber (left atrium) of the heart through a hole in the septum, the wall between the chambers. The hole can be a heart defect (atrial septal defect) or an enlarged natural opening (foramen ovale). The foramen ovale should close soon after a baby is born. If there is no atrial septal defect, a surgeon may need to create a foramen ovale to allow blood flow.
In some babies with tricuspid atresia, there is a hole between the heart’s two lower chambers (ventricular septal defect). Blood can flow through this hole and into the right ventricle, which will pump the blood into the lungs.
What are the risk factors for tricuspid atresia?
Risk factors are traits that make a person more likely to develop a disease or condition. Risk factors for tricuspid atresia include:
- Down syndrome
- A parent who had a congenital heart defect
- A mother who
Symptoms and Causes
What causes tricuspid atresia?
Although there are known risk factors for tricuspid atresia, the exact causes are not known. Congenital heart diseases develop while the baby is in the womb and heart development is taking place.
What are the symptoms of tricuspid atresia?
In most cases, babies born with tricuspid atresia have symptoms within a week after being born. A baby with tricuspid atresia can show the following symptoms:
- Skin and lips that are bluish in color (cyanosis)
- Feeding difficulty
- Shortness of breath and rapid breathing
- Slow growth
- Heart murmur (unusual heart sounds)
In addition, some babies with this condition can develop heart failure symptoms. These include:
- Rapid weight gain from retaining fluids
- Swelling in the abdomen
- Swelling in the legs, ankles, and feet
- Weakness and fatigue
- Irregular or fast heartbeat
Diagnosis and Tests
How is tricuspid atresia diagnosed?
Tricuspid atresia is usually diagnosed with an echocardiogram. An echocardiogram uses high-pitched sound waves that bounce off the child’s heart to produce moving images that the doctor can see on a video screen. The echocardiogram tracks the flow of blood and can show:
- That the tricuspid valve is absent and the right ventricle is smaller than normal.
- How much blood is moving through the holes in the septum.
- Related defects of the heart, including a ventricular septal defect or an atrial septal defect.
Management and Treatment
How is tricuspid atresia treated?
Tricuspid atresia has potentially fatal complications, including not getting enough oxygen to the body’s tissues, and a high red blood cell count, which may cause clots that can lead to stroke or heart attack. These complications can be avoided with prompt treatment.
While medications can help babies who have tricuspid atresia, this condition is usually treated with surgery. Surgeries for tricuspid atresia include:
- Balloon septostomy: This is a surgery which creates an atrial septal defect (or widens an existing one). This procedure may be required soon after the child’s birth if the child is very blue as a life-saving measure. One of the following two surgical operations may then follow depending upon the condition of the child.
- Modified BT shunt: In a cyanosed (blue) child, an artificial tube is placed between a big artery in the chest and arteries of the lungs to increase the blood flow to the lungs and improve the oxygen supply to the body. This is done by an open operation usually within the first few days of life.
- Pulmonary artery banding: In a child who has heart failure due to excessive blood flow to the lungs, a flexible band is placed surgically around the pulmonary artery to restrict the blood flow to the lungs. This surgery is required within days to weeks after birth.
- The Glenn procedure: This procedure, done between four and six months of birth, is one in which the surgeon connects the superior vena cava to the pulmonary artery. Blood can then flow directly to the lungs (instead of the heart) and pick up oxygen.
- The Fontan procedure: During this surgery, the surgeon forms a path that allows oxygen-poor blood that is going back to the heart to flow directly into the arteries that transport blood into the lungs. Most children with tricuspid atresia do not have the Fontan procedure until they are at least 2 years of age. Some children are not good candidates for this surgery.
What follow-up care is required after treatment?
Your baby will need lifelong follow-up care so that a cardiologist can monitor his or her health. The cardiologist can let you know whether your child has to continue taking preventive antibiotics before procedures such as dental care. Sometimes, the cardiologist will recommend that your child limit physical activity that is too vigorous.
Outlook / Prognosis
What is the outlook for children with tricuspid atresia?
In general, the short-term and intermediate-term outlook for children who have surgery is promising, though the surgery does not cure the child. The outlook usually is worse, however, for children who have surgery later in life. If the surgery fails, the child may need a heart transplant.