What Is Tricuspid Atresia?
Tricuspid atresia is a condition seen in newborns in which they’re born without an important part of the heart called “the tricuspid valve.” This valve plays a part in the heart’s essential function, which is to pump blood between the lungs and body.
In some newborns, the tricuspid valve is missing or hasn’t properly developed. Tricuspid atresia is a rare heart disorder that’s congenital, or present at birth. It’s a serious condition, and it can be life-threatening.
In a properly functioning heart, blood flows from the body to the heart and then to the lungs, where each blood cell will be loaded up with oxygen. This process is known as oxygenation. After oxygenation, the blood returns to the heart and is pumped out to the body.
Four different heart valves control the flow of blood in your heart. The valves allow the blood to flow between the four different chambers that make up your heart. These four chambers are the right and the left atria and ventricles. A wall known as the septum separates them.
The tricuspid valve is one of the four valves that allow blood to flow through your heart. It’s on the right side of your heart. When a newborn is missing their tricuspid valve, their heart has to circulate blood through the heart using two holes in the septum instead. One hole is between the left and the right atria. The other is between the left and the right ventricles. All unborn babies have a hole between the atria known as the foramen ovale, but it usually closes up before birth, as part of the development of the fetus.
In newborns with tricuspid atresia, the missing tricuspid valve causes the heart to circulate blood using the hole between the atria instead. Instead of closing up, the hole stays open, or in some cases gets even larger. The hole stays open or enlarges between the two atria to allow blood to circulate from the body into the heart. When this happens, the hole is called an atrial septal defect (ASD).
For the heart to be able to then pump blood out to the body and the lungs, a baby with tricuspid atresia has to develop another hole as well. This hole is known as a ventricular septal defect (VSD). A baby has to be born with a VSD when their tricuspid valve is missing so that their heart can effectively pump blood. The VSD is located between the left and the right ventricles. This allows blood to flow from the left ventricle to the pulmonary artery in the right ventricle.
In some newborns with tricuspid atresia, a fetal vessel called the ductus arteriousus stays open to allow blood to circulate to the lungs from the aorta.
There are three forms of tricuspid atresia. The type is based on how large the VSD is:
If the hole in your newborn’s heart is large, too much blood may go to the lungs. This can result in a condition known as congestive heart failure (CHF).
If your newborn has a moderate VSD, the hole is medium-sized. This hole allows some blood to pump to the lungs. Newborns with this condition will experience less distress than those with large or small holes.
If the hole is small, not enough blood pumps to the lungs to pick up oxygen. A lack of oxygen to vital organs can cause your newborn’s skin to turn blue. This is called cyanosis.
The symptoms of tricuspid atresia depend on the specific heart defect that’s present. Babies that are born with tricuspid atresia usually show signs of distress within the first few hours of life. However, some babies may be healthy at birth and only begin to show symptoms in the first two months of life.
Common symptoms associated with tricuspid atresia include:
- rapid breathing
- shortness of breath, or dyspnea
- a bluish skin color, or cyanosis
- fatigue that occurs during feeding
- slow growth
If the hole in the newborn’s heart is big enough to cause CHF, there may be other symptoms associated with this condition. These include coughing and swelling in the legs and feet, which is known as “edema.”
The heart begins to form when a fetus is just 8 weeks old. Tricuspid atresia is a result of the tricuspid valve failing to develop during this period of growth. Doctors don’t know why this happens. Tricuspid atresia is often common in families. It also occurs with certain genetic or chromosomal abnormalities, including Down syndrome.
Your doctor may identify tricuspid atresia while your baby is still in the womb. Routine prenatal ultrasounds that monitor the growth of your baby may detect abnormalities in the heart of the fetus.
After your baby is born, your doctor will be able to diagnose tricuspid atresia by performing a physical exam. Your doctor may find a heart murmur and may notice a bluish tone to your baby’s skin. Your doctor may also perform several tests to confirm the diagnosis. Tests may include:
- an ultrasound of the heart
- an electrocardiogram
- an echocardiogram
- a chest X-ray
- a cardiac catheterization
- an MRI of the heart
If your baby is diagnosed with tricuspid atresia, they’ll enter a neonatal intensive care unit (NICU). In the NICU, your baby will receive specialized care to treat the condition. If your baby can’t breathe, they may go on a breathing machine, or ventilator. Your baby may also receive medication to maintain their heart function.
After your baby’s condition stabilizes, they’ll need surgery to correct the heart defect. For infants who have tricuspid atresia, three surgeries are typically necessary as the child’s heart and body grow and change.
In most infants with this condition, the first heart surgery happens in the first few days of life. This procedure involves placing a shunt in the heart to keep blood flowing to the lungs.
Following the surgery, your baby can go home. They’ll need medications and monitoring to detect complications. A pediatric cardiologist will oversee your baby’s care. This doctor will determine when your baby is ready for a second surgery.
The second surgery typically happens when your baby is between 3 and 6 months old. This operation is known as the Glenn shunt or hemi-Fontan procedure.
The vein that carries blood into your heart after it has delivered oxygen throughout your body is called the superior vena cava. The artery that funnels blood from your heart to your lungs is called the right pulmonary artery. This procedure is done to connect the superior vena cava to the right pulmonary artery.
Following that surgery, your baby will require one more procedure that will take place when your baby is between 18 months and 5 years of age. This procedure is known as the Fontan procedure. In this final surgery, your child’s surgeon will create a path for oxygen-depleted blood returning to the heart to flow into the arteries that will take it directly to the lungs.
In the rare instance that your child isn’t a candidate for these surgical procedures, your child’s doctor will discuss the possibility of a heart transplant.
If your baby has tricuspid atresia, they’ll need continued care for years after successful treatment. Open-heart surgery will be necessary. This surgery carries with it a number of potential complications, including heart failure.
After the surgeries to correct tricuspid atresia are done, your baby will require ongoing care and monitoring into adulthood. Children with tricuspid atresia are at increased risk for the following across their lifespan:
- a stroke
They may need to take medications to help prevent these conditions. Your healthcare team will work with you to figure out a plan of care for your baby.