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

• Congenital Pulmonary Atresia
• Pulmonary Atresia
• Pulmonary Atresia with Intact Ventricular Septum

What is Pulmonary Valve Atresia? (Definition/Background Information)

• Pulmonary Valve Atresia (or Pulmonary Atresia) is a critical congenital defect of the pulmonary valve that is located between one of the heart chambers and the pulmonary artery. This valve is not fully developed in Pulmonary Atresia resulting in improper oxygenation of blood
• Pulmonary Atresia commonly leads to breathing difficulties, blush discoloration of the skin, irritable and lethargic babies. Due to this condition, severe complications such as stroke, seizure, or heart failure, and even a delayed development and growth may occur
• Surgical repair or replacement of the pulmonary valve is the most effective treatment option available for Pulmonary Atresia. However, the prognosis depends on many factors and can vary from one child to the other

Who gets Pulmonary Valve Atresia? (Age and Sex Distribution)

• Pulmonary Valve Atresia is a congenital condition that is present at birth
• The incident of the condition is estimated at around 1 in 7,100 live births
• It is slightly more common in males than in females
• The condition is seen worldwide

What are the Risk Factors for Pulmonary Valve Atresia? (Predisposing Factors)

The possible risk factors associated with Pulmonary Valve Atresia are:

• Rubella infection (German measles) during pregnancy
• Infants born to diabetic mothers
• Taking certain medications during pregnancy such as thalidomide and anti-seizure medication
• Drinking alcohol during pregnancy
• Certain genetic or hereditary defects

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 Pulmonary Valve Atresia? (Etiology)

Pulmonary Valve Atresia occurs due to abnormalities in heart development during the first 8 weeks of pregnancy.

• The exact cause is generally unknown, but it can occur due to a defect in the genetic make-up of the baby, caused by an environmental exposure to certain toxins, viruses, drugs, or sometimes due to a family history of the condition. Most often it occurs sporadically i.e., occurs randomly by chance
• The pulmonary valve is located between the right ventricle of the heart and pulmonary artery. Normally it has three leaflets and functions as a one-way door, only allowing the movement of blood from the right ventricle to the pulmonary artery
• In Pulmonary Atresia, this valve is not fully-developed, and a solid sheet of tissue is present between the heart and pulmonary artery, which does not allow the flow of blood from the right heart to the lungs. This prevents the proper oxygenation of blood

The development of the fetus with such a valve condition is generally not affected before birth, because of two key reasons:

• The placenta is responsible for oxygenation of the baby and not the lungs. In fact, the lungs are not functional before birth
• Blood entering the right side of the heart moves to the left heart via a patent foramen ovale. This blood is oxygen-rich and is supplied to the other parts of the body

Pulmonary Valve Atresia may be associated with ventricular septal defect, another cardiac anomaly noted at birth. Based on this association, the following two types of Pulmonary Atresia are noted:

• Pulmonary Atresia with an intact ventricular septum
• Pulmonary Atresia with a ventricular septal defect

What are the Signs and Symptoms of Pulmonary Valve Atresia?

The signs and symptoms of Pulmonary Valve Atresia may include:

• The baby turns blue (cyanosis) soon after birth due to lack of oxygen in blood
• Rapid breathing: In order to increase the amount of oxygen, the baby tries to breathe faster
• Irritability
• Lethargy
• Extreme sleepiness
• Cool and moisture-laden skin
• Heart murmurs (abnormal heart sounds)

How is Pulmonary Valve Atresia Diagnosed?

The diagnosis of Pulmonary Valve Atresia may include:

• Complete evaluation of medical history along with a thorough physical exam. During the physical exam, the physician will examine the lungs and heart
• Assessment of the presenting signs and symptoms
• Chest X-ray: It is a diagnostic test in which electromagnetic (invisible) rays are used to produce images of the heart and lungs on a film
• Electrocardiogram (EKG): It is a graphic representation of the heart’s electrical activity
• Fetal echocardiogram: This is a procedure which involves using sound waves to evaluate the structure and functioning capacity of the heart
• Cardiac catheterization: It is an invasive procedure to measure the pressure and oxygen concentration in all four chambers of the heart. The procedure involves inserting a small, thin, flexible tube (catheter) into a blood vessel in the groin and then guiding it into the heart. A contrast material can also be injected to clearly visualize the structures inside the heart
• Newborn pulse oximetry screening may help the healthcare suspect the condition prior to symptom presentation

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 Pulmonary Valve Atresia?

There may be certain serious complications noted as a result of Pulmonary Valve Atresia that includes:

• Delayed growth and development of the child
• Seizures: This can occur due to decreased oxygen supply to the brain
• Stroke: Decreased oxygen to a specific part of the brain can result in weakness in any part of the body or speaking difficulties or other cognitive defects depending upon the area of the brain involved
• Infectious endocarditis: It is an infection of the heart valves, which can be life-threatening if not identified and treated early
• Heart failure: It is failure of the heart to pump enough oxygenated blood into circulation for proper functioning of the body's various organs and tissues
• Treatment and post-treatment (surgery) complications

How can Pulmonary Valve Atresia be Treated?

Specific treatment for Pulmonary Valve Atresia would depend on many factors and would be best determined by the pediatrician. These factors may include, but is not limited to, the child’s age, overall health, extent of the disorder, and the response of the child to various medication, therapies, or procedures.

• Pulmonary Atresia is usually an emergent condition and the child will require care in an intensive care unit (ICU). The child may require to be put on oxygen support or even a ventilator (machine to support breathing). Intravenous medication may be necessary to help with proper functioning of the heart and lungs.
• Cardiac catheterization: Along with providing assistance in making the diagnoses, a cardiac catheterization procedure can employ a balloon procedure, which involves passing a balloon through the narrowed pulmonary valve and inflating it. This improves blood flow to the lungs to improve oxygenation
• Balloon atrial septostomy may also be performed to improve a better mixing of oxygenated and un-oxygenated blood. During cardiac catheterization, a special catheter can be used to create an opening between the right and left atrium

The above-mentioned interventions are temporary measures to stabilize the condition of the baby. The definite treatment for the condition is surgical repair of the valve or a valve replacement procedure. Even after surgery, the baby might require ICU care and support for recovery. The child may need to be kept on medication for a certain period of time.

The surgical procedures are planned based on various factors such as the child’s health and growth. In some cases, a few more surgical interventions may be necessary as the child gets older.

How can Pulmonary Valve Atresia be Prevented?

Currently, there are no known methods to prevent Pulmonary Valve Atresia.

• It is important for the pregnant women to closely follow-up with their physician and attend all pre-natal sessions and examinations
• Women who are pregnant or expecting a baby must completely avoid alcohol
• Pregnant women must notify their physician of all medications that they were/are taking
• If there is a family history of genetic (heart) disorders, then genetic counseling will help assess risks, before planning for a child

Regular medical screening at periodic intervals with tests, scans, and physical examinations are mandatory for those who have already undergone surgical correction of the defect.

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

• Pulmonary Valve Atresia is a serious life-threatening condition that can occur with underlying heart defects (such as ventricular septal defect). The long-term prognosis depends upon several factors and varies from child to child
• It is important to follow-up at a health center with specialized care for this condition. The child may also require multiple surgeries, and hence, a close follow-up is critical to identify and treat any complication as early as possible

Additional and Relevant Useful Information for Pulmonary Valve Atresia:

Some health conditions, such as pregnancy or non-cardiac surgeries, can pose a risk later in the life of individuals with Pulmonary Atresia. In such cases, these should be discussed with a cardiologist for an informed decision.