What is Pulmonary Atresia with Intact Ventricular Septum (PA IVS)? 

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare congenital heart defect where the pulmonary valve does not form properly, blocking (obstructing) blood flow from the heart’s right pumping chamber (ventricle) to the lungs. There is also no opening or connection (intact septum) between the right and left ventricles. This combination results in not enough blood flowing to the lungs, which means not enough oxygenated blood reaches the body. 

Additionally, the right ventricle is usually small or underdeveloped (hypoplastic) in a child with PA/IVS. This is called single ventricle congenital heart disease. PA/IVS can also impact how the coronary arteries (the blood vessels that supply oxygen-rich blood to the heart muscle) form before birth. This can lead to an abnormal connection between the coronary arteries and the right ventricle. 

Signs and symptoms of Pulmonary Atresia with Intact Ventricular Septum (PA IVS)

The symptoms of pulmonary atresia with intact ventricular septum may include:

• Blue or purple tint to lips, skin and nails (cyanosis)
• Shortness of breath
• Difficulty feeding
• Fatigue or listlessness
• Heart murmur (abnormal heart sounds heard with a stethoscope)

Pediatricians from other hospitals often refer newborns to the Cardiac Center at Children’s Hospital of Philadelphia (CHOP) when they notice these symptoms.

Testing and diagnosis for Pulmonary Atresia with Intact Ventricular Septum (PA IVS)

Pulmonary atresia with intact ventricular septum may be diagnosed before birth with a fetal ultrasound, called an echocardiogram. Sometimes, it's diagnosed a few hours or days after birth when the ductus arteriosus (the extra blood vessel that connects the pulmonary artery to the aorta while a baby is in the womb) begins to close. Because the baby will then have no blood flow to the lungs, they will become very blue (cyanotic). 

Diagnosing pulmonary atresia with intact ventricular septum may require some or all of these tests:

• Echocardiogram (also called echo or ultrasound), which uses sound waves to create an image of the heart
• Electrocardiogram (ECG), which takes a record of the electrical activity of the heart
• Pulse oximetry, a noninvasive way to monitor the oxygen content of the blood 
• Chest X-ray
• Cardiac CT or cardiac MRI, which allows doctors to see a 3D image of the heart’s structures in detail
• Cardiac catheterization, which is when a thin tube (catheter) is inserted into the heart through the large veins or arteries in the leg to take measurements throughout the heart

Treatment for Pulmonary Atresia with Intact Ventricular Septum (PA IVS)

Treatment for pulmonary atresia with intact ventricular septum depends on each child's heart anatomy. Sometimes, PA/IVS can be treated with a cardiac catheterization technique called balloon valvuloplasty. In this procedure, an interventional cardiologist will insert a thin tube (catheter) through a vein in the leg to reach the heart. With the catheter, the doctor can create a hole in the closed-off pulmonary valve. Then, another catheter, which has a balloon on the end of it, is inserted. The interventional cardiologist will briefly inflate the balloon to open up the valve, then deflate the balloon and remove the catheter. 

In other cases, open heart surgery is needed to allow enough blood to flow to the lungs. Surgeons may open the pulmonary valve using a special patch. In other cases, they may place a narrow tube (called a Blalock-Taussig-Thomas shunt) from the aorta to the pulmonary artery (the large blood vessel that carries blood from the heart to the lungs) to make sure enough blood can reach the lungs. Other times, an interventional cardiologist can place a stent in the ductus arteriosus during a cardiac catheterization procedure, allowing blood to pass from the aorta to the lungs.

If your child’s right ventricle is poorly developed and cannot function properly, a series of surgeries, called staged reconstruction, may be needed. These staged procedures create a pathway for blood to flow back to the heart and directly to the lungs, bypassing the right ventricle.

Follow-up care

Through adolescence

Children who have had surgery to repair pulmonary atresia with intact ventricular septum need lifelong care by a cardiologist, which will include ongoing diagnostic evaluations, medications to manage symptoms and prevent complications, lifestyle modifications to support cardiovascular health, and emotional and psychosocial support.

As single ventricle survivors get older, doctors are recognizing that, while some children do not experience complications, many do, including lung, liver and gastrointestinal complications. At CHOP’s Single Ventricle Survivorship Clinic, part of the Fontan Rehabilitation, Wellness, Activity and Resilience Development (FORWARD) Program, experts from across specialties provide individualized care for single ventricle survivors.

In addition, children with complex congenital heart defects who have had open heart surgery as infants are at a higher risk for neurodevelopmental issues than children without congenital heart defects. CHOP’s Cardiac Kids Developmental Follow-up Program provides expert evaluation, screening and clinical care for children with complex congenital heart disease who are at risk for neurodevelopmental problems.

Into adulthood

Our pediatric cardiologists follow children until they are young adults, coordinating care with primary care physicians. We then support our adolescent and young adult patients through a smooth and seamless transition to adult cardiology care. The Philadelphia Adult Congenital Heart Center, a joint program of CHOP and Penn Medicine, meets the unique needs of adults who were born with heart defects.  

Long-term outlook for children with Pulmonary Atresia with Intact Ventricular Septum (PA IVS)

With advancements in medical and surgical treatments for congenital heart disease, the prognosis for children with PA/IVS has greatly improved. The outlook can vary depending on how severe the condition is and how well the treatments work. However, many children grow into adulthood, often after having a Fontan procedure and additional treatments over time, and go on to lead fulfilling lives.