Tricuspid atresia

Definition

Tricuspid atresia is a type of congenital heart disease in which the tricuspid heart valve is missing or abnormally developed. The defect blocks blood flow from the right atrium to the right ventricle.

Alternative Names

Tri atresia

Causes, incidence, and risk factors

Tricuspid atresia is an uncommon form of congenital heart disease that affects about 5 in every 100,000 live births. Twenty percent of patients with this condition will also have have other heart problems.

Normally, blood flows from the body into the right atrium, then through the tricuspid valve to the right ventricle and on to the lungs. If the tricuspid valve does not open, the blood cannot flow from the right atrium to the right ventricle. Blood ultimately cannot enter the lungs, where it must go to pick up oxygen (become oxygenated).

Infants with tricuspid atresia generally are cyanotic (bluish discoloration of skin) and easily become short of breath.

Symptoms

• Cyanosis (bluish discoloration of the skin)
• Easily fatigued
• Shortness of breath (dyspnea)
• Fast breathing
• Poor growth

Signs and tests

This condition may be discovered during routine prenatal ultrasound imaging or when the baby is examined shortly after birth. Cyanosis is present from birth. A heart murmur is often present at birth and may increase in loudness over several months.

Tests may include the following:

• ECG
• Echocardiogram
• Chest x-ray
• Cardiac catheterization
• MRI of the heart

Treatment

Once the diagnosis is made, the baby will be admitted to the neonatal intensive care unit (NICU). A breathing machine (ventilator) may be needed to help the baby breathe. A medicine called prostaglandin E1 is used to maintain circulation of blood to the lungs.

The condition always requires surgery. If the heart is unable to pump enough blood out to the lungs and rest of the body, the first surgery usually occurs within the first few days of life. In this procedure, an artificial shunt is inserted to maintain blood flow to the lungs. In some cases, this first surgery is not necessary.

Afterwards, the baby usually goes home. The child will need to take one or more daily medicines and be closely followed by a pediatric cardiologist, who will determine when the second stage of surgery should be done.

Stage II of the operation is called the Glenn shunt or Hemifontan procedure. This procedure connects half of the veins carrying blue blood from the upper half of the body directly to the pulmonary artery. The surgery is usually done when the child is between 4 - 6 months of age.

During stage I and II, the child may still appear somewhat blue (cyanotic).

Stage III, the final step, is called the Fontan procedure. The remainder of the veins carrying blue blood from the body is connected directly to the pulmonary artery leading to the lungs, and the left ventricle now only has to pump to the body and no longer the lungs. This surgery is usually performed between the ages of 18 months and 3 years of age. After this final step, the baby is no longer blue (cyanotic).

Some patients may need more surgeries in their 20s or 30s if they develop hard to control arrhythmias or other complications of the Fontan procedure.

In a few hospitals, heart transplantation is considered to be a better alternative to the 3-step surgery process, but there are few donated hearts available for small infants.

Support Groups

Expectations (prognosis)

Improvement can be expected with most surgical procedures. Unexpected death may occur with heart arrhythmias.

Complications

• Irregular, fast heart rhythms (arrhythmias)
• Chronic diarrhea (from a disease called protein loosing enteropathy)
• Heart failure
• Fluid in the abdomen (ascites) and in the lungs (pleural effusion)
• Blockage of the artificial shunt
• Strokes and other neurological complications
• Sudden death

Calling your health care provider

If your infant has new changes in breathing patterns, eats less (decreased feeing), or has skin or mucous membranes that are turning blue (cyanotic), contact your health care provider immediately.

Prevention

There is no known way to prevent tricuspid atresia.

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References

Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed. St. Louis, Mo; WB Saunders; 2007.