Tri 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

Causes

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 have also have other heart problems.

Normally, blood flows into the right atrium, then through the tricuspid valve to the right ventricle and on to the lungs. If the tricuspid valve is missing or broken, there is no outlet for blood flow from the right ventricle to right atrium. 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)
• Clubbing of fingers or toes
• Heart failure
• Fast breathing
• Poor growth

Exams and Tests

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

Tests may include the following:

• ECG
• Echocardiogram
• Chest x-ray
• Cardiac catheterization

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 body.

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 (Norwood operation) usually occurs within the first few days of life. In stage I of the Norwood procedure an artificial shunt is inserted to maintain blood flow to the lungs.

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 body directly to the lungs that get oxygen. The surgery is usually done when the child is between 4 and 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 lungs, and the right ventricle now serves as the only pumping chamber for the heart. 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 some 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.

Outlook (Prognosis)

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

Possible Complications

• Irregular, fast heart rhythms (arrhythmias)
• Chronic diarrhea
• Heart failure
• Fluid in the abdomen (ascites)
• Blockage of the artificial shunt
• Strokes and other neurological complications
• Sudden death

When to Contact a Medical Professional

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.

Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed. St. Louis, Mo; WB Saunders; 2005:233.

Rakel P, ed. Conn's Current Therapy 2006. 58th ed. Philadelphia, Pa: WB Saunders; 2006:404.

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