What are the other Names for this Condition? (Also known as/Synonyms)

• Congenital Agenesis of the Tricuspid Valve
• Cyanotic Heart Disease-Tricuspid Atresia
• Tri Atresia

What is Tricuspid Atresia? (Definition/Background Information)

• Congenital heart defects are relatively common birth defects involving the heart, and these may be of several types. A rare but critical heart-related birth defect that occurs in children is Tricuspid Atresia (TA), in which the tricuspid valve of the heart is either missing or is poorly-formed
• The tricuspid valve regulates blood, flowing from the upper right heart chamber (right atrium) to the lower right heart chamber (right ventricle). In individuals with Tricuspid Atresia, the blood flow from the right atrium to the right ventricle is obstructed. 
• This condition often coexists with other defects in the heart vessels including:
  • Aortic arch interruption
  • Aortic coarctation
  • Pulmonary atresia/stenosis
  • Transposition of the great arteries
  • Ventricular septal defect (in a vast majority of cases)
• Babies with Tricuspid Atresia may present poor feeding, breathing difficulties, and bluish discoloration of skin. If left unrecognized or untreated, Tricuspid Atresia can result in heart failure. The condition is generally treated via surgery; often, multiple surgeries may be planned to correct this valve defect. With adequate treatment, the prognosis is generally improved

Who gets Tricuspid Atresia? (Age and Sex Distribution)

• Tricuspid Atresia is a rare congenital disorder that is noted at a frequency of about 1:10,000
• The presentation of symptoms may occur before or soon after birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Tricuspid Atresia? (Predisposing Factors)

The risk factors for Tricuspid Atresia may include the following:

• A family history of congenital heart defect(s)
• Parents’ being older at the time of conception (late 30s, early 40s)
• A viral infection in mother during pregnancy (such as Rubella infection)
• Obesity in the mother during pregnancy
• Maternal diabetes with poor glycemic control
• Smoking before conception and during pregnancy
• Alcohol consumption during pregnancy
• Use of certain medications by a pregnant mother. Examples include acne medication containing isotretinoin and medication for certain psychological disorders
• Certain genetic abnormalities in the developing baby that can cause heart defects (such as Down syndrome)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Tricuspid Atresia? (Etiology)

The exact cause of development Tricuspid Atresia is presently not well-understood. However, several factors have been associated with the absent or under-developed tricuspid valve in a newborn, including:

• Family history of congenital heart disease
• Older parents at conception
• Certain genetic diseases in the baby (that may cause heart defects as well)
• Maternal uncontrolled diabetes or obesity
• Smoking/alcohol consumption by the mother during pregnancy
• Use of certain medications during pregnancy

What are the Signs and Symptoms of Tricuspid Atresia?

The signs and symptoms of Tricuspid Atresia may vary among the affected children in type and severity. The signs and symptoms in newborns may include:

• Cyanosis (skin and lips turning blue in a baby)
• Rapid breathing
• Shortness of breath
• Fatigue
• Poor feeding
• Poor weight gain
• Excessive sleepiness

Since the condition may lead to heart failure, the signs and symptoms of heart failure in individuals with Tricuspid Atresia may include:

• Fatigue
• Shortness of breath
• Edema or swelling in the feet, ankles and legs
• Weight gain due to fluid retention
• Ascites (fluid retention in the abdomen)

How is Tricuspid Atresia Diagnosed?

Tricuspid Atresia is diagnosed on the basis of the following information:

• Complete physical examination and thorough medical (family) history evaluation
• Assessment of the presenting signs and symptoms, particularly pale skin of the child, breathing difficulties, extreme sleepiness, and poor feeding
• Imaging studies, including fetal echocardiography, electrocardiography, and chest X-rays
• CT and MRI scan studies of the chest and abdomen 
• Prenatal ultrasonography of the developing baby
• Newborn pulse oximetry to measure oxygen saturation in blood
• Cardiac catheterization

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Tricuspid Atresia?

Some complications of Tricuspid Atresia include:

• Hypoxemia or very low oxygen in blood
• Development of protein-losing enteropathy leading to chronic diarrhea
• Arrhythmia
• Pleural effusion
• Endocarditis
• Liver and/or kidney malfunction
• Heart failure
• Stroke

Complications may occur with or without treatment, and in some cases, due to treatment as well

How is Tricuspid Atresia Treated?

Currently, there is no cure for Tricuspid Atresia since it is not possible to replace a faulty tricuspid valve. Typically, treatments are undertaken to manage the signs and symptoms, and improve the quality of the affected individual’s life.

The following treatment methods may be employed:

• Medications to remove excess fluid from the body, lower blood pressure, and gain heart muscle strength
• Oxygen supplementation for ease of breathing
• Children who have feeding difficulties may be recommended specialized high-calorie formulas or even the insertion of a feeding tube
• The surgical procedures adopted include:
  • Placement of a shunt in the heart to bypass the tricuspid valve. When necessary, replacement of the shunt
  • Atrial septostomy, which allows better blood flow between the right and left atria
  • Pulmonary artery band placement, if necessary may be performed, if excess blood is flowing from the heart to lungs
  • Bi-directional Glenn procedure: It is a corrective surgery that is more permanent for a baby with a shunt, and is usually undertaken during 4-6 months of baby birth
  • Fontan procedure, in which a permanent path is created for blood to flow from inferior vena cava directly into the pulmonary arteries. It is usually undertaken when the child is about 2 years old

In addition, for a child born with Tricuspid Atresia, the following treatment/monitoring methods may be necessary throughout his/her life:

• Proper nutrition 
• Adequate and regular physical activity in childhood, adolescence, and adulthood 
• Preventing infections with proper personal hygiene practices and vaccinations
• Regular check-ups

How can Tricuspid Atresia be Prevented?

Currently, no methods or guidelines are available for the prevention of Tricuspid Atresia. 

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Some general guidelines for prevention of birth defects in children may include the following:
• Taking vitamins with folic acid
• Abstaining from alcohol consumption 
• Smoking cessation 
• Consulting with the healthcare provider to ensure that all current medications and supplements being used by the mother are safe, and not likely to harm the developing baby
• Avoiding exposure to chemicals and their fumes
• If diabetic, good glycemic control by the mother 
• An individual born with Tricuspid Atresia may require prophylactic antibiotics before surgical and dental procedures, to avoid infections that may become life-threatening such as endocarditis
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired congenital heart disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Tricuspid Atresia? (Outcomes/Resolutions)

• The prognosis of Tricuspid Atresia is dependent upon the severity of the signs and symptoms and associated complications, if any
• With a timely diagnosis, proper surgical treatment and continued monitoring, most individuals are reported to live a full and good quality of life

Additional and Relevant Useful Information for Tricuspid Atresia:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/