Congenital heart defects, or diseases, are problems with the heart’s structure that are present at birth. They may change the normal flow of blood through the heart. Congenital heart defects are the most common type of birth defect, occurring in about one percent of live births in the United States.
There are many types of congenital heart defects. The most common defects involve the inside walls of the heart, the valves of the heart, or the large blood vessels that carry blood to and from the heart. Some defects are simple and require no treatment, while others are critical and require treatment soon after birth.
Doctors often do not know why congenital heart defects occur, but several factors can raise the risk of having a baby born with a heart problem. Some risks include smoking or taking certain medicines during pregnancy, and a family history of congenital heart defects.
Congenital heart defects can usually be found by a doctor based on symptoms or by newborn or prenatal screenings. Sometimes, a doctor may need to run heart tests to help diagnose you or your baby with a congenital heart defect.
Over the last several years, the diagnosis and treatment of congenital heart defects has improved. For example, there are better options for treatment, such as medicines and procedures. Now, many children and adults are living with or have recovered from congenital heart defects. Managing your condition by receiving routine follow-up care, taking care of your mental health, and monitoring your condition can all help reduce complications and improve your quality of life.
What causes congenital heart defects?
Congenital heart defects happen because the heart does not develop normally while the baby is growing in the womb. Doctors often do not know why congenital heart defects occur. Researchers do know that genetic can sometimes play a role.
It is common for congenital heart defects to occur because of changes, or mutations, in the child’s DNA. The mutations in the DNA may or may not have come from the parents.
Rarely, congenital heart defects are caused by particular genes that are inherited from the parents. That means a parent who has a congenital heart defect may be more likely to have a child with the defect.
What raises the risk of having a baby with a congenital heart defect?
Congenital heart defects are the most common type of birth defect, occurring in about one percent of live births in the United States. The risk of having a baby with a congenital heart defect is influenced by many factors including:
- Family history and genetics. Congenital heart disease is not usually passed along to your children, but there is some risk. The risk is greater if your baby’s other parent, or another of your children, has a congenital heart defect
- Smoking during pregnancy or exposure to secondhand smoke
- Some medicines taken during the first trimester of pregnancy, such as angiotensin-converting enzyme (ACE) inhibitors for high blood pressure and retinoic acids for acne treatment
- Other medical conditions like diabetes, phenylketonuria (a rare, inherited disorder that affects how your body processes a protein called phenylalanine), or a viral infection called rubella
There are many types of congenital heart defects. They range from simple to complex and critical.
- Simple defects may get better on their own without surgery. Sometimes, a baby with a simple defect will not have any symptoms. Examples of simple heart defects include atrial and ventricular septal defects, patent ductus arteriosus, and pulmonary stenosis.
- Complex and critical defects may cause life-threatening symptoms that require immediate treatment. An example of a critical heart condition is the Tetralogy of Fallot. Babies born with this or another critical congenital heart defect typically have low levels of oxygen soon after birth and need surgery within the first year of life.
Atrial septal defect: An atrial septal defect is a hole in the wall of the heart between the left and right atria, which are the two upper chambers of the heart. The hole causes blood to flow from the left atrium and mix with the right atrium, instead of going to the rest of the body. An atrial septal defect is considered a simple congenital heart defect because the hole may close on its own as the heart grows during childhood.
Ventricular septal defect: A ventricular septal defect is a hole in the wall between the left and right ventricles, which are the two lower chambers of the heart. Blood may flow from the left ventricle and mix with blood in the right ventricle, instead of going to the rest of the body. If the hole is large, the heart and lungs may need to work harder to pump blood. In addition, it may cause fluid to build up in the lungs.
Patent ductus arteriosus: This common type of simple congenital heart defect occurs when a connection between the heart’s two major arteries, the aorta and the pulmonary artery, does not close properly after birth. This leaves an opening through which blood can flow when it should not. In many cases, small openings may close on their own.
Pulmonary stenosis: Pulmonary stenosis is a type of heart valve disease in which the pulmonary valve is too narrow or stiff. This affects how well blood can move from the heart to the pulmonary artery, the blood vessel that connects the heart to the lungs. Many children with pulmonary stenosis do not need treatment.
Tetralogy of Fallot: Tetralogy of Fallot is the most common complex congenital heart disorder and is a combination of four defects:
- Pulmonary stenosis
- A large ventricular septal defect
- An overriding aorta. With this defect, the major blood vessel that carries blood to the body (aorta) is out of place. Instead of being above the left ventricle, it is located between the two ventricles. As a result, oxygen-poor blood from the right ventricle can flow directly into the aorta instead of into the blood vessel that carries blood to the lungs (pulmonary artery)
- Right ventricular hypertrophy is when the heart has to work harder than normal which makes the muscle of the right ventricle thicker than normal
Symptoms of congenital heart defects depend on many factors. For example, symptoms may be different for newborns and adults. They also depend on the number, type, and severity of the heart defect. Some common symptoms are:
- Bluish tone to a baby’s skin and lips
- Fatigue, or feeling constantly tired
- Heart murmurs, which are unusual sounds heard between heartbeats. Murmurs sometimes sound like a whooshing or swishing noise
- Poor blood circulation
- Rapid breathing
- Shortness of breath during physical activity can happen in children or adults with a congenital heart defect
Diagnostic tests and procedures
You or your baby may need one or more of the following tests to determine whether symptoms are caused by a congenital heart defect:
- Echocardiography or echo is a painless test that uses sound waves to create moving pictures of the heart. It can help diagnose a heart defect or be used to follow progress over time. Echocardiography used during pregnancy (fetal echocardiography) can sometimes be used to help find a congenital heart defect before a baby is born
- Electrocardiogram (EKG or ECG) to evaluate the rhythm of the heartbeat
- Cardiac catheterization to measure the pressure and oxygen level inside the heart chambers and blood vessels. This can help the doctor figure out whether blood is flowing from the left side of the heart into the right side of the heart, instead of going to the rest of the body
- Chest X-ray to show whether the heart is enlarged. It can also show whether the lungs have extra blood flow or extra fluid, which can be a sign of heart failure
- Genetic testing to determine if particular gene or genetic conditions are causing the congenital heart defect. Your doctor may refer you or your child to a doctor who specializes in genetic testing
- Cardiac MRI to diagnose a heart defect or follow progress over time
- Pulse oximetry to estimate how much oxygen is in the blood
How are congenital heart defects treated?
The type of treatment will depend on which type of congenital heart defect you or your baby has and how serious it is. Most simple congenital heart defects will get better over time and do not require treatment at all. However, critical congenital heart defects often require treatment.
Medicine is often used if your baby has a specific type of congenital heart defect called patent ductus arteriosus. Usually, patent ductus arteriosus goes away on its own, however, sometimes medicine is needed to close the patent ductus arteriosus in premature infants.
- Indomethacin or ibuprofen triggers the patent ductus arteriosus to constrict or tighten, which closes the opening
- Acetaminophen is sometimes used to close patent ductus arteriosus
Procedures: Cardiac catheterization is a common procedure that is sometimes used to repair simple heart defects, such as an atrial septal defect and patent ductus arteriosus, if they do not get better on their own. It may also be used to open heart valves or blood vessels that are too narrow.
In this procedure, a thin, flexible tube called a catheter is put into a blood vessel in the groin or neck. The tube is then threaded to the heart. Possible risks of cardiac catheterization include bleeding, infection, and pain where the catheter was put into the body, and damage to blood vessels.
Surgery: In heart surgery, a surgeon opens the chest to work directly on the heart. Surgery may be required for many reasons:
- To repair a hole in the heart, such as a ventricular septal defect or an atrial septal defect
- To repair a patent ductus arteriosus
- To repair complex defects, such as problems with the location of blood vessels near the heart or how they are formed
- To repair or replace a valve
- To widen narrowed blood vessels
Surgeries that are sometimes needed to treat congenital heart defects include:
Heart transplant: Children may receive a heart transplant if they have a complex congenital heart defect that cannot be repaired surgically or if the heart fails after surgery. Children may also receive a heart transplant if they are dependent on a ventilator to breathe or have severe symptoms of heart failure. Some adults with congenital heart defects may eventually need a heart transplant.
Palliative surgery: Some babies are too small or not strong enough to have heart surgery. Instead, they must have palliative surgery, or temporary surgery, to improve oxygen levels in the blood prior to heart surgery. During palliative surgery, the surgeon installs a tube that creates an additional pathway for blood to travel to the lungs to get oxygen, called a shunt. The surgeon removes the shunt when the baby’s heart defects are fixed during the full repair.
Ventricular assist device: This device is a mechanical pump that supports heart function and blood flow in people who have weakened hearts However, the abnormal structure of the heart in people with a congenital heart defect can make these devices difficult to use.
Total artificial heart : A total artificial heart is a pump that is surgically installed to provide circulation and replace heart ventricles that are diseased or damaged. The ventricles pump blood out of the heart to the lungs and other parts of the body. Machines outside the body control the implanted pumps, helping blood flow to and from the heart. A total artificial heart may be needed instead of a ventricular assist device in people with a complex congenital heart defect.