Tricuspid atresia

Tricuspid atresia is a heart problem present at birth, known as a congenital heart defect. The valve isn't formed between the two right heart chambers. Instead, a solid sheet of tissue blocks the blood flow between the right heart chambers. The condition limits blood flow through the heart. Tricuspid atresia causes the right lower heart to be underdeveloped.

People with tricuspid atresia can't get enough oxygen through the body. So they tire easily and they are often short of breath. Their skin and lips may look blue or gray.

Tricuspid atresia is treated with multiple surgeries. Most babies with tricuspid atresia who have surgery live well into adulthood, though follow-up surgeries are often needed.

Other names for tricuspid atresia are:

• Tricuspid valve atresia
• TV atresia

Tricuspid atresia symptoms are usually seen soon after birth. Symptoms of tricuspid atresia may include:

• Blue or gray skin and lips due to low blood oxygen levels
• Difficulty breathing
• Tiring easily, especially during feedings
• Slow growth and poor weight gain

Some people with tricuspid atresia also develop symptoms of heart failure. Heart failure symptoms include:

• Fatigue and weakness
• Shortness of breath
• Swelling in the legs, ankles and feet
• Swelling of the belly area, a condition called ascites
• Sudden weight gain from a buildup of fluid

Serious congenital heart defects are diagnosed before or soon after your child is born. If you notice that your baby has changes in skin color, trouble breathing, slow growth or poor weight gain, contact your health care provider.

Most congenital heart defects, including tricuspid atresia, result from changes that occur early as the baby's heart is developing before birth. The exact cause is usually unknown.

How the heart works

To understand more about tricuspid atresia, it may be helpful to know how the heart typically works.

The heart is divided into four chambers, two on the right and two on the left.

• The right upper chamber is called the right atrium.
• The right lower chamber is called the right ventricle.
• The left upper chamber is called the left atrium.
• The left lower chamber is called the left ventricle. The left ventricle is the heart's main pumping chamber.

To pump blood throughout the body, the heart uses its left and right sides for different tasks.

• The right side of the heart moves blood to the lungs through the lung arteries. These are the pulmonary arteries.
• In the lungs, blood picks up oxygen and then returns to the heart's left side through the pulmonary veins.
• The left side of the heart pumps the blood through the body's main artery, called the aorta. The blood then flows out to the rest of the body.

Valves control the flow of blood into and out of the heart. The heart valves open to allow blood to move to the next chamber or to one of the arteries. The heart valves close to keep blood from flowing backward.

What happens in tricuspid atresia

In tricuspid atresia, the tricuspid valve is missing. A sheet of tissue blocks the flow of blood between the right heart chambers. There's no way for blood to move from the right upper chamber to the right lower chamber. The right side of the heart is no longer able to pump blood to the lungs.

Instead, blood flows from the heart's right upper chamber directly to the left upper chamber through a hole in the wall between them. The hole is either a congenital heart defect called an atrial septal defect or a natural opening called the foramen ovale. When the foramen ovale doesn't close after birth, it's called a patent foramen ovale.

How blood flows after that depends on whether there are other heart structure problems. In some babies with tricuspid atresia, blood moves from the left lower heart chamber into the body's main artery, the aorta. Then it goes to the lungs through a temporary connection called the ductus arteriosus. This connection typically closes after birth.

Many babies born with tricuspid atresia also have a hole between the lower heart chambers. This hole is called a ventricular septal defect or ventricular septal defect (VSD). If this occurs, some blood can flow through the hole directly to the main lung artery. The amount of blood going to the lungs depends on the size of the VSD and whether the pulmonary valve is narrowed. If the VSD is large, too much blood can move to the lungs. This can cause heart failure.

It's not entirely clear why congenital heart defects such as tricuspid atresia occur. But some risk factors have been identified. Many babies born with a genetic disorder called Down syndrome have tricuspid atresia.

Other things that might increase your baby's risk of tricuspid atresia include:

• Having German measles (rubella) or another viral illness during early pregnancy
• Family history of congenital heart disease
• Drinking alcohol during pregnancy
• Smoking before or during pregnancy
• Poorly controlled diabetes during pregnancy
• Use of certain medications during pregnancy, including some used to treat acne, bipolar disorder and seizures

Tricuspid atresia restricts blood flow from the heart to the lungs. The right lower heart chamber is small and underdeveloped. A life-threatening complication of tricuspid atresia is a lack of oxygen to the body's tissues. This condition is called hypoxemia.

Prompt treatment greatly improves the outcome for babies with tricuspid atresia. But complications may develop later in life. Complications of tricuspid atresia may include:

• Easy tiring during activity
• Irregular heart rhythms
• Kidney or liver disease
• Heart failure

Because the exact cause of most congenital heart defects is unknown, it may not be possible to prevent tricuspid atresia.

If you have a family history of congenital heart defects or are at high risk of giving birth to a child with one, genetic screening may be recommended before or during pregnancy. Consider talking with a genetic counselor and a pediatric heart doctor about your specific risks.

Some ways you can help prevent your baby's overall risk of congenital heart defects are to:

• Get proper prenatal care. Regular checkups with a health care provider during pregnancy can help keep you and your baby healthy.
• Take a multivitamin with folic acid. Taking 400 micrograms of folic acid daily has been shown to reduce problems with the brain and spinal cord at birth. It may help reduce the risk of congenital heart defects as well.
• Get a rubella (German measles) vaccine. A rubella infection during pregnancy may affect a baby's heart development. Get vaccinated before trying to get pregnant.
• Check with your provider before taking any medications. Some medications taken during pregnancy can cause health problems in the baby. Tell your provider about all the medications you take, including those bought without a prescription.
• Don't smoke tobacco or drink alcohol during pregnancy. Either can increase the risk of congenital heart defects.
• Avoid chemical exposure whenever possible. While you're pregnant, it's best to stay away from chemicals, including cleaning products and paint, as much as you can.
• Manage other health conditions. If you have other health conditions, talk to your health care provider about the best way to treat and manage them.