Pulmonary atresia with intact ventricular septum
Pulmonary atresia (uh-TREE-zhuh) is a rare heart problem present at birth (congenital heart defect).
In pulmonary atresia, the valve between the heart and lungs (pulmonary valve) isn't fully developed. Blood can't flow from the right lower heart chamber (right ventricle) to the lungs.
Some blood may move through a natural opening between the artery carrying oxygen-rich blood out of the heart (aorta) and the pulmonary artery. This opening — called the ductus arteriosus — typically closes soon after birth, but it can be kept open with medications.
In pulmonary atresia with intact ventricular septum (PA/IVS), there isn't a hole between the two pumping chambers of the heart. If there is a hole, the condition is called pulmonary atresia with ventricular septal defect (VSD).
A baby with pulmonary atresia doesn't get enough oxygen in the blood. Urgent treatment is needed. Treatment for pulmonary atresia with intact ventricular septum may include a combination of medication, procedures or surgery to correct the congenital heart defect.
Several tests may be used to diagnose pulmonary atresia with intact ventricular septum (PA/IVS), including:
- Pulse oximetry. A small sensor attached to a hand or foot measures the amount of oxygen in the blood. Pulse oximetry is simple and painless.
- Electrocardiogram (ECG or EKG). This simple test measures the electrical activity of the heart. Sticky patches (electrodes) with sensors detect the heartbeat. A monitor connected to the wires prints or displays results. An ECG can reveal irregular heart rhythms (arrhythmias or dysrhythmias) and may show other heart problems.
- Chest X-ray. A chest X-ray shows the shape and size of the heart and lungs.
- Echocardiogram. Sound waves are used to show the beating heart. An echocardiogram can show how blood moves through the heart and heart valves, including the pulmonary valve. An echocardiogram can be done during pregnancy (fetal echocardiogram) to diagnose pulmonary atresia in the baby.
- Cardiac catheterization. A heart doctor (cardiologist) threads a thin tube (catheter) through a blood vessel in the arm or groin to an artery in the heart and injects dye through the catheter. This makes the heart arteries show up more clearly on an X-ray.
Babies with pulmonary atresia need immediate treatment, preferably at a medical center with surgeons and other health care providers who have experience with complex congenital heart disease.
Treatment for pulmonary atresia with intact ventricular septum (PA/IVS) may include medications and one or more procedures or surgeries.
A drug called alprostadil (Prostin Vr Pediatric) can be given by IV to prevent the ductus arteriosus from closing before surgery.
Surgeries or other procedures
A baby with pulmonary atresia with intact ventricular septum (PA/IVS) most likely will require one or more procedures to improve heart function and blood flow. Some surgeries and procedures are done in the first days to weeks of a baby's life. Others are done later. The type of surgery done depends on many things including the size of the right lower heart chamber (right ventricle) and other heart valves, and if the baby has other heart problems.
Procedures in the first days to weeks of life
- Balloon valvotomy. If the leaflets in the pulmonary valve are fused, a balloon can be used to enlarge the opening. The surgeon inserts a long, thin tube (catheter) into a large vein in the baby's groin and guides it to the heart. A balloon on the tip of the catheter is inflated to widen the valve opening.
- Balloon atrial septostomy. Sometimes a heart doctor (cardiologist) may use a balloon catheter procedure to open the foramen ovale (a natural opening between the two top chambers of the heart), which may close soon after birth. This lets low-oxygen blood leave the right side of the heart and mix with oxygen-rich blood in the left side of the heart so it can be pumped to the aorta. Blood then flows to the lung artery through a connection called the ductus arteriosus.
- Stenting. Placement of a rigid tube (stent) in the natural connection between the body's main artery (aorta) and pulmonary artery (ductus arteriosus) lets blood move to the lungs.
- Shunting. Creating a bypass (shunt) from the main blood vessel leading out of the heart (aorta) to the pulmonary arteries allows for adequate blood flow to the lungs. This procedure may be needed in the first few days of life to increase blood flow to the lungs. However, babies usually outgrow this shunt within a few months. An example of such a procedure is the Blalock-Taussig shunt procedure.
Later surgical procedures
- Bidirectional Glenn procedure. This procedure is usually done between 4 and 6 months of age. In this surgery, one of the large veins that normally returns blood to the heart is connected directly to the pulmonary artery instead. This procedure sometimes can be done without using a heart-lung machine (off-pump Glenn procedure).
- Fontan procedure. The Fontan procedure is a type of heart surgery that's typically done when a child is 2 or 3 years old. It creates a pathway that allows most, if not all, of the blood that would have gone to the right heart to flow directly into the pulmonary artery.
- One and one-half ventricle repair. In this procedure, the surgeon connects the superior vena cava to the pulmonary artery (bidirectional Glenn). Then the surgeon creates a connection from the right lower heart chamber (right ventricle) to the pulmonary artery. This can be the final procedure if the right ventricle in a baby's heart is big enough and will not require the Fontan procedure. This approach reduces the likelihood of the long-term issues that can occur with the Fontan procedure.
- Hybrid procedures. Hybrid procedures are surgical and catheter procedures that are done at the same time, sometimes without the use of the heart-lung machine.
After treatment, babies with pulmonary atresia should have regular checkups, ideally with a pediatric heart doctor (pediatric cardiologist). Due to advances in treatment and technology, many people with pulmonary atresia with intact ventricular septum (PA/IVS) survive into adulthood. Adult patients with PA/IVS should be followed by a cardiologist with specialized training in adult congenital heart disease.