Tricuspid atresia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at August 3, 2016
StartDiseasesTricuspid atresia

Unlike many other types of heart defects, tricuspid atresia is a congenital (present at birth) defect of the heart valve. This particular defect affects the tricuspid valve, which is located on the right side of the heart. Because babies can't talk or communicate in any way to let adults know something may be wrong, testing at birth is required to reveal the presence of tricuspid atresia.

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Definition & Facts

According to the Centers for Disease Control and Prevention (CDC), approximately 1 in every 10,000 infants is born with tricuspid atresia. Because of the severity of this congenital heart defect, tricuspid atresia is considered a critical birth defect that must be treated immediately.

Tricuspid atresia is not considered common, but it does co-occur with other heart defects in approximately 20 percent of cases. With this defect, the heart valve either has a structural abnormality that causes it to block blood flow, or it is completely missing. Because of the defect, blood cannot get from the right atrium of the heart to the right ventricle.

Symptoms & Complaints

The most common symptoms of tricuspid atresia include the following:

If any or all of these symptoms is present, it is of the utmost importance to schedule a medical appointment right away.

Causes

At this point, medical researchers are still not clear exactly what causes tricuspid atresia. It is thought that mutations or abnormalities in the chromosomes can cause tricuspid atresia. It is suspected that environmental triggers such as medications, toxins, or lifestyle choices the mother makes while pregnant may give rise to heart defects such as tricuspid atresia. Suspected causal factors include the following:

  • The presence of an autoimmune disease. Lupus is thought to be a particular trigger for tricuspid atresia.
  • Taking some types of medications. Certain anti-seizure, anti-acne, or medications to treat bipolar disorder may contribute to heart valve defects like tricuspid anemia.
  • Smoking. If the mother smokes during pregnancy this can cause heart valve defects.
  • Past history of certain diseases. German measles/rubella and other viruses are thought to contribute to a greater risk of an infant being born with tricuspid atresia.
  • Diabetes mellitus. If the mother has untreated diabetes, this could lead to heart defects.
  • Heart defect in the parent. If one or both parents has a heart defect, this could predispose an infant towards having a heart defect also.
  • Another possible trigger for tricuspid atresia is the presence of another congenital disorder such as Down syndrome.

Diagnosis & Tests

Tricuspid atresia can be diagnosed prior to birth during prenatal testing. One common way that this valve abnormality is detected is during the routine ultrasound tests. If an ultrasound test indicates there may be a heart issue, more tests can be done to determine if tricuspid atresia may be the problem.

The other common way tricuspid atresia is diagnosed is at birth or shortly thereafter. Since the most common diagnostic criteria, the heart murmur, may not yet be audible through a stethoscope test just after birth, additional tests are typically needed to make a clear diagnosis. These tests can include the following:

  • Echocardiogram (ECG). This ultrasound-based test can create a picture of the heart at work.
  • Electrocardiogram (EKG). This test can measure the electrical activity in the heart to detect imbalances and irregularities.
  • Pulse oximetry. This test uses an oximeter to measure the amount of oxygen in the blood. 
  • Cardiac catheterization. This test threads a thin tube up into the heart to take a look at the valves from the inside out and detect abnormalities.
  • Magnetic resonance imaging (MRI). This test creates a picture of the heart as it is working.

Generally speaking, doctors will try the least invasive tests first and only proceed to more invasive testing if the diagnosis is still unclear.

Treatment & Therapy

Treatment for infants with tricuspid atresia usually begins with medications and follows with surgical correction. The goal of the medications is to release extra fluid, strengthen the cardiac muscle and keep their blood pressure within normal ranges while helping the infant stabilize and strengthen.

Sometimes food is delivered through a feeding tube when an infant's tricuspid atresia causes it to be too fatigued to eat. If the infant does have energy to eat, often the treatment includes feeding a specially formulated high-calorie formula diet. In addition, a medicine called prostaglandin E1 may be prescribed to assist with blood flow to and around the lungs

Cardiac surgery to repair the damaged valve (or insert a replacement valve if the valve is missing altogether) typically follows, and the specific type and number of surgeries will depend on whether tricuspid atresia is the sole defect or there are additional defects in the heart that need to be treated. 

Prevention & Prophylaxis

To date, there is no definitive way to fully prevent tricuspid atresia. However, for the mother in particular, making a concerted effort to eat well, manage any health issues (such as diabetes or lupus), refrain from smoking and steer clear of high-risk medications may greatly reduce the risk of having an infant that is born with tricuspid atresia.