Parents may feel frightened and alone when they learn their baby has a heart defect. But congenital heart defects are not uncommon—nearly one out of every 100 infants is born with one. Some of these babies have mild problems, but the diagnosis can be highly emotional when a newborn is among the one in four who has a critical defect. About half of all congenital heart defects are considered major, requiring cardiologic intervention or surgery.

Since its initial development in the 1970s and '80s, surgery for these conditions has come a long way. Today, better techniques and a deeper understanding of physiology and circulation have helped pediatric heart surgeons achieve excellent outcomes. Recent discoveries have also uncovered the role of genetics on the developing heart.

Congenital heart defect is a term that covers a large variety of cardiac abnormalities that develop during pregnancy. Those abnormalities can change the normal flow of blood through the heart, and affect how a new heart will develop and function throughout a person’s life.

A baby’s heart starts to form in the womb at six weeks of gestation, and problems can develop in the walls or valves in the heart and/or the nearby arteries and veins. This can result in a wide spectrum of defects and diseases, requiring different kinds of treatments, operations, and procedures.  

While there are many kinds of congenital heart defects, the most common ones affect the walls inside of the heart, the valves, or the large vessels that carry blood from the heart. Some of these defects will never need to be treated, while others may involve multiple structural problems and require surgery soon after a baby is born.

Examples of common congenital heart defects include:

Atrial septal defect (ASD): A “hole” in the wall between the two top chambers of the heart is normal at birth, but it should close after birth. If it doesn’t close, it can cause abnormal blood flow inside the heart. Children with an ASD have few symptoms. Depending on the size of the hole, using a catheter-based technique or open-heart surgery to close it can often prevent serious problems later in life.

Ventricular septal defect (VSD): The wall that separates the two lower pumping chambers of the heart is normally intact. However, if a ‘hole’ or VSD is present, higher pressure from the left ventricle can cause the blood to flow into the right ventricle. The latter can cause extra blood to be pumped into the lungs and create congestion in the lungs. If the hole is large, the baby can have poor growth and require surgery to avoid heart failure and permanent damage to the arteries in the lungs.

Tetralogy of Fallot:  This more complex defect actually includes four components, which are as follows: A narrowing of the blood vessel that brings oxygen-poor blood to the lungs; a large hole in the two lower heart chambers (or VSD); an aorta that lies over the hole in the VSD, causing oxygen-poor blood to flow directly into the aorta instead of the pulmonary artery; and a thickening of the right pumping chamber muscle (which is working harder than normal). Most children with tetralogy of Fallot have open-heart surgery during infancy.

Transposition of the Great Arteries (TGA): This is a complex heart defect where the two large blood vessels coming out of the heart are connected to the wrong sides of the heart. In this condition, instead of going to the lungs, the oxygen-poor blood is returned to the body. And conversely, instead of going to the body, the oxygen-rich blood is returned to the lungs. This leads to a situation where the body is deprived of oxygen. A baby with this condition cannot survive without surgery, which is typically carried out within one to two weeks after birth.

Hypoplastic Left Heart Syndrome (HLHS): An extremely complex defect where the left lower pumping chamber is either absent or too small. The main blood vessel that delivers blood to the body, the aorta, is also poorly developed. In order to survive, a baby will require three operations by 2 to 3 years of age, beginning at birth.

Today, serious heart defects are usually detected prenatally or soon after a child is born. The majority can be diagnosed during fetal development using echocardiography, a simple, noninvasive ultrasound technique to evaluate the heart. Appropriate planning and management strategies can be put into place to provide the safest delivery and postnatal care. All newborns are screened with pulse oximetry, a test that involves placing sensors on the skin to check for low oxygen levels that may be a sign of a congenital heart problem.

Babies with a congenital heart defect may have no symptoms at all, or there may be such signs as excessive fatigue, difficulty breathing, or their lips and nails appear to have a blue tint. Some symptoms may not be apparent until a couple of days after they go home from the hospital, or they may not be detected until much later. 

A health care provider may suspect a problem in a child who may be experiencing abnormal heart rhythms, heart sound, or shortness of breath, among other symptoms, during a checkup.

Children are not just small adults, and surgery to treat a pediatric heart problem is very different than it would be for an adult. Pediatric heart surgeons are specially trained in the delicacies of treating hearts in small bodies that are just starting to grow. They typically work with a team that includes pediatric cardiologists and other pediatric heart specialists, who are all expertly trained in taking care of babies and children with congenital heart defects.

The types of surgeries for congenital heart disease vary widely, ranging from fairly simple and straightforward to highly complex, all depending on the patient’s heart abnormality and condition. They range from fairly minor, minimally invasive procedures, to open heart surgery using a heart-lung machine (which takes over the function of the heart and lungs so that the surgeon can stop the heart and operate), and some need multiple operations over many years.

For some problems, patients can avoid surgery with the help of an innovative, nonsurgical treatment called cardiac catheterization, which involves making a tiny needle puncture in the skin and inserting a thin tube (called a catheter) through a blood vessel to the heart, where the doctor can fix the problem. This procedure, performed under anesthesia, requires no incision and a much shorter hospital stay. It has been used to close atrial septal defects—holes between the right and left upper heart chambers—among other things.  

Surgeries for pediatric congenital heart disease are more advanced than ever. At one time, children with a critical heart defect rarely survived; but one study estimates there are now more than 2 million infants, children, adolescents, and adults living with congenital heart disease in the United States.

Better survival is partly a result of successful surgical care when these patients were babies and small children. Today, about 95 percent of babies born with a non-critical defect are expected to live to at least 18 years of age, and almost 70 percent of those with a critical defect are expected to survive to 18 years of age.

Treatments continue to improve as doctors learn more about such factors as genetics, which can impact not only congenital heart disease, but how well babies do after surgical treatment.    

Yale Medicine’s pediatric cardiac surgeons have extensive experience operating on infants, children, and adults. Our surgeons collaborate with many different specialists, including pediatric cardiologists, neonatologists, intensivists, anesthesiologists, and perfusionists (health care professionals who use a heart-lung machine during cardiac and other types of surgeries to manage a patient’s physiological state).

They are supported by the comprehensive heart center at the Yale New Haven Children’s Hospital, and Yale Medicine specialty clinics and programs, including Yale Medicine Cardiac Surgery, a Pediatric Interventional Cardiac Catheterization Program, a Pediatric Cardiogenetics Program, and an Adult Congenital Heart Program.

Our surgeons and scientists have been recognized for excellence by the National Institutes of Health (NIH) and major surgical societies.