Pulmonary atresia with ventricular septal defect: What you should know

Pulmonary atresia with ventricular septal defect, also known as tetralogy of Fallot with pulmonary atresia, has become a prevalent topic in cardiology due to TV personality and comedian Jimmy Kimmel’s announcement in May that his new son has this form of congenital heart disease.

Healio.com spoke with pediatric interventional cardiologist Dennis W. Kim, MD, PhD, director of cardiac catheterization labs at Children’s Healthcare of Atlanta, Sibley Heart Center Cardiology, and an associate professor at Emory University School of Medicine, to learn more about pulmonary atresia with ventricular septal defect, treatment options and associated outcomes.

Question: What is pulmonary atresia with ventricular septal defect?

Answer: It is a form of congenital heart disease where the natural outflow of blood to the lungs doesn’t exist. The valve is sealed shut, and there is a hole between the two bottom chambers of the heart, called a ventricular septal defect (VSD). Blood comes from the veins into the right upper filling chamber and goes into the right lower pumping chamber (right ventricle) that normally would pump blood out to the lungs through the pulmonary valve, but because that’s sealed, it sends blood through the VSD out into the main body artery, the aorta. This results in oxygen levels in the body that are lower than normal.

Q: How common is it?

A: It’s somewhere around 3% of all congenital heart disease, and slightly more prevalent in males. Of all congenital birth defects, heart disease is the most common, affecting almost 1% of all live births.

Most states and hospitals routinely check the oxygen levels in all newborns by pulse oximetry. [Pulmonary atresia with ventricular septal defect] is considered one of the ‘critical congenital heart disease’ diagnoses and ought to be picked up by routine screening by pulse oximetry. Jimmy Kimmel’s son had a very observant nurse that noticed duskiness, and it was confirmed by pulse oximetry leading to the cardiac evaluation.

Q: What are the risks of pulmonary atresia with ventricular septal defect?

A: One of the issues is that in order to get blood flow to your lungs to become oxygenated, blood has to pass through the lung vessels. If there is an inability to get blood into the lung arteries, then the oxygen levels in the body can be dangerously low.

All kids are born with a connector vessel between the pulmonary artery and the aorta, the ductus arteriosus. After a baby is born, blood is allowed into the lung vessels through this connector vessel that is a temporary vessel that’s naturally programmed to shrink shut after the baby is born.

The way I like thinking about it is if the lungs vessels are a house, and there’s a party for the red blood cells going on in there; they have to either come through the front door, the normal pulmonary valve, or through the back door, which is the patent ductus arteriosus. In this setting, there’s no front door, so everything has to come in through the back door. After a baby with this condition is born, it’s important that the patent ductus arteriosis (PDA) remains open in order to allow blood to get to the lung vessels. If the PDA closes, as it is naturally programmed to do, no blood flow will go to the pulmonary arteries and these babies can present profoundly cyanotic and in shock.

Q: What are the treatment options?

A: The treatment options involve what to do shortly after birth, and then there’s a different set of operations and procedures that are done later in life. After a baby is born, the primary option is to try to make sure that there is a back door to allow blood to get into the lung vessels.

The two ways to do this are to create a surgical shunt; the technical term is a modified Blalock–Taussig shunt. This involves a small tube graft that’s placed between one of the body arteries, usually the subclavian or the innominate artery into the lung vessels. Basically, it creates an artificial ductus arteriosus because the ductus is programmed to close by itself.

The other option, which Jimmy Kimmel’s son did not have, is called a ductal stent. Because there’s a natural bridge between the aorta and the pulmonary artery, the PDA, if we can put a stent in there, we can keep the natural back door from completely closing off.

Q: Is pulmonary atresia with ventricular septal defect something that is managed throughout life?

A: The initial treatment revolves around ensuring that there is a way to get a stable source of pulmonary blood flow. Somewhere down the road, within probably the first 6 months to a year after birth, the next surgery occurs, in which blood flow then is diverted from the right ventricle straight into the lung vessels, and that’s done through a jump graft called a conduit that usually has a valve inside of it. At that point, the hole between the bottom chambers of the heart (the VSD) is closed surgically so that all of the blue blood coming to the right ventricle goes directly to the lungs through the conduit. Then the modified Blalock–Taussig shunt or ductal stent is ligated. Now you have blood going the natural way that it should. Sometimes they use just a regular tube, but most often, it’s some kind of valved conduit.

The problem that then happens is that as a child grows, these conduits that are put in place don’t grow with the kid, and so at some point, they’re going to become too small. That graft or the conduit is going to have to be replaced with a larger one.

Q: Once it’s replaced, do patients have to have any more surgeries?

A: The patient does require further procedures because the function of the valve inside the conduit does not last forever, because it’s not living tissue and cannot grow with the child. It can be prone to either becoming narrow because of calcium build-up or shrinkage, or the valve function could deteriorate so that the valve leaflets don’t completely close correctly, and you have a lot of leakage backwards through the conduit.

Typically, the primary issue is that you end up having a relative narrowing because they outgrow the conduit. After they have their next conduit, depending on the size, then they’ll need to have further surgeries done to place a larger conduit.

Once you have a larger conduit in, there are some opportunities to restore valve function and conduit function with catheter-based methods, either with stenting the whole conduit to enlarge it or even to use transcatheter valve technology to implant a new valve inside the existing conduit.

When these valves wear out in 5 to 10 years, there can be an alternating strategy of transcatheter valve implantation and surgical valve replacement.

Q: How does pulmonary atresia with ventricular septal defect impact quality of life?

A: Quality of life ideally will be similar for any child with heart disease as those who do not. We want them to have the same quality of life as a child born without heart disease. When you have issues with the pulmonary valve or conduit over time, then those kids might get tired with exercise. That might be their presenting symptoms, although remarkably a lot of younger patients and teenagers are can be relatively asymptomatic. Adult patients tend to be more symptomatic from dysfunction of their valves, but for the most part, many or most of these kids can lead pretty normal and active lives.

Q: Can this lead to other CV conditions throughout life?

A: The short answer is yes. Some patients can have issues with arrhythmias that develop … If the function of the outflow of valves is diminished for a long time, there can be effects on the function of the right ventricle. It’s rare, but when you have a prosthetic conduit in place, there is some risk for endocarditis, so these kids generally will end up requiring antibiotic prophylaxis before things like dental procedures to decrease that risk. However, it is possible for people born with these heart conditions to lead relatively normal lives. It may be possible for women to have children later in life, though very close follow-up with an adult congenital heart disease specialist is needed.

Q: Do you have any final thoughts for clinicians?

A: Pulmonary atresia with ventricular septal defect requires lifelong care and management, but these kids can grow up to be active adults with relatively normal lives. A lot of potential transcatheter therapies can be applied to patients with this spectrum of heart disease, particularly as it relates to pulmonary valve function so the total number of open heart surgeries can be reduced. Further innovations in less invasive therapies will undoubtedly develop. It is crucial that kids born with congenital heart disease to maintain follow up with adult congenital heart specialists in order to keep their hearts in the best shape possible. The goal of lifelong therapy is to provide as normal of a life as possible for those born with this and other types of congenital heart disease. – by Darlene Dobkowski

For more information:

Dennis Kim, MD, PhD, can be reached at 2835 Brandywine Road, Suite 300, Atlanta, GA 30341; email: kimd@kidsheart.com.

Disclosure: Kim reports speaking for Edwards Lifesciences.