Critical congenital heart disease (CCHD) is a term that refers to a group of serious heart defects that are present from birth. These abnormalities result from problems with the formation of one or more parts of the heart during the early stages of embryonic development. CCHD prevents the heart from pumping blood effectively or reduces the amount of oxygen in the blood. As a result, organs and tissues throughout the body do not receive enough oxygen, which can lead to organ damage and life-threatening complications. Individuals with CCHD usually require surgery soon after birth.

Although babies with CCHD may appear healthy for the first few hours or days of life, signs and symptoms soon become apparent. These can include an abnormal heart sound during a heartbeat (heart murmur), rapid breathing (tachypnea), low blood pressure (hypotension), low levels of oxygen in the blood (hypoxemia), and a blue or purple tint to the skin caused by a shortage of oxygen (cyanosis). If untreated, CCHD can lead to shock, coma, and death. However, most people with CCHD now survive past infancy due to improvements in early detection, diagnosis, and treatment.

Some people with treated CCHD have few related health problems later in life. However, long-term effects of CCHD can include delayed development and reduced stamina during exercise. Adults with these heart defects have an increased risk of abnormal heart rhythms, heart failure, sudden cardiac arrest, stroke, and premature death.

Each of the heart defects associated with CCHD affects the flow of blood into, out of, or through the heart. Some of the heart defects involve structures within the heart itself, such as the two lower chambers of the heart (the ventricles) or the valves that control blood flow through the heart. Others affect the structure of the large blood vessels leading into and out of the heart (including the aorta and pulmonary artery). Still others involve a combination of these structural abnormalities.

People with CCHD have one or more specific heart defects. The heart defects classified as CCHD include coarctation of the aorta, double-outlet right ventricle, D-transposition of the great arteries, Ebstein anomaly, hypoplastic left heart syndrome, interrupted aortic arch, pulmonary atresia with intact septum, single ventricle, total anomalous pulmonary venous connection, tetralogy of Fallot, tricuspid atresia, and truncus arteriosus.

About 1 in every 4 babies born with a heart defect has a critical congenital heart defect (critical CHD, also known as critical congenital heart disease). Babies with a critical CHD need surgery or other procedures in the first year of life. Learn more about critical CHDs below.

What are Critical Congenital Heart Defects (Critical CHDs)?

In the United States, about 7,200 babies born every year have critical CHDs. Typically, these types of heart defects lead to low levels of oxygen in a newborn and may be identified using pulse oximetry screening at least 24 hours after birth. Some specific types of critical CHDs are listed in the box to the right. Babies with a critical CHD need surgery or other procedures in the first year of life. Other heart defects can be just as severe as critical CHDs and may also require treatment soon after birth.

Some Specific Critical CHDs

• Coarctation of the aorta
• Double-outlet right ventricle
• d-Transposition of the great arteries
• Ebstein anomaly
• Hypoplastic left heart syndrome
• Interrupted aortic arch
• Pulmonary atresia (with intact septum)
• Single ventricle
• Total anomalous pulmonary venous return
• Tetralogy of Fallot
• Tricuspid atresia
• Truncus arteriosus

Importance of Newborn Screening for Critical CHDs

Some CHDs may be diagnosed during pregnancy using a special type of ultrasound called a fetal echocardiogram, which creates pictures of the heart of the developing baby. However, some heart defects are not found during pregnancy. In these cases, heart defects may be detected at birth or as the child ages.

Some babies born with a critical CHD appear healthy at first, and they may be sent home before their heart defect is detected. These babies are at risk of having serious complications within the first few days or weeks of life, and often require emergency care. Newborn screening is a tool that can identify some of these babies so they can receive prompt care and treatment. Timely care may prevent disability or death early in life.

How Newborn Screening for Critical CHDs is Done

Newborn screening for critical CHDs involves a simple bedside test called pulse oximetry. This test estimates the amount of oxygen in a baby’s blood. Low levels of oxygen in the blood can be a sign of a critical CHD. The test is done using a machine called a pulse oximeter, with sensors placed on the baby’s skin. The test is painless and takes only a few minutes.

Pulse oximetry screening does not replace a complete history and physical examination, which sometimes can detect a critical CHD before oxygen levels in the blood become low. Pulse oximetry screening, therefore, should be used along with the physical examination.

Possible Physical Symptoms of Critical CHDs

• Problems breathing
• Pounding heart
• Weak pulse
• Very pale or blue skin color
• Poor feeding
• Very sleepy

Timing of Critical CHD Screening

Screening is done when a baby is at least 24 hours of age, or as late as possible if the baby is to be discharged from the hospital before he or she is 24 hours of age.

Pulse Oximetry Screening Results

Pulse oximetry screening is most likely to detect seven of the critical CHDs. These seven defects are hypoplastic left heart syndrome, pulmonary atresia, tetralogy of Fallot, total anomalous pulmonary venous return, transposition of the great arteries, tricuspid atresia, and truncus arteriosus. Other heart defects can be just as severe as these seven and also require treatment soon after birth. However, pulse oximetry screening may not detect these heart defects as consistently as the seven listed above.

Pass

If the baby passes the screen (also called “negative” or “in-range” result), it means that the baby’s test results did not show signs of a low level of oxygen in the blood. A baby that passes the screen is unlikely to have a critical CHD. However, not all babies with a critical CHD will have a low level of oxygen in the blood that is detected during newborn screening. Thus, it is possible for a baby who passes the screen to still have a critical CHD or other CHD.

Fail

If the baby fails the screen (also known as “positive” or “out-of-range” result), it means that the baby’s test results showed low levels of oxygen in the blood, which could be a sign of a critical CHD. This does not always mean that the baby has a critical CHD but could mean that more testing is needed. There may be other causes, such as breathing problems, for low levels of oxygen in the blood. The baby’s doctor might recommend that the baby get screened again or have more specific tests, like an echocardiogram (an ultrasound picture of the heart), to diagnose a critical CHD.

The heart is an organ, about the size of a fist. It is made of muscle and pumps blood through the body. Blood is carried through the body in blood vessels, or tubes, called arteries and veins. The process of moving blood through the body is called circulation. Together, the heart and vessels make up the cardiovascular system.

Structure of the Heart

The heart has four chambers (two atria and two ventricles). There is a wall (septum) between the two atria and another wall between the two ventricles. Arteries and veins go into and out of the heart. Arteries carry blood away from the heart and veins carry blood to the heart. The flow of blood through the vessels and chambers of the heart is controlled by valves.

Blood Flow Through the Heart

(Abbreviations refer to labels in the illustration)

The heart pumps blood to all parts of the body. Blood provides oxygen and nutrients to the body and removes carbon dioxide and wastes. As blood travels through the body, oxygen is used up, and the blood becomes oxygen poor.

1. Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart.
2. The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart.
3. From there, the blood flows through the tricuspid valve (TV) into the right ventricle (RV), or the right lower chamber of the heart.
4. The right ventricle (RV) pumps oxygen-poor blood through the pulmonary valve (PV) into the main pulmonary artery (MPA).
5. From there, the blood flows through the right and left pulmonary arteries into the lungs.
6. In the lungs, oxygen is put into the blood and carbon dioxide is taken out of the blood during the process of breathing. After the blood gets oxygen in the lungs, it is called oxygen-rich blood.
7. Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins.
8. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
9. The left ventricle (LV) pumps the oxygen-rich blood through the aortic valve (AoV) into the aorta (Ao), the main artery that takes oxygen-rich blood out to the rest of the body.

In most cases, the cause of CCHD is unknown. A variety of genetic and environmental factors likely contribute to this complex condition.

Changes in single genes have been associated with CCHD. Studies suggest that these genes are involved in normal heart development before birth. Most of the identified mutations reduce the amount or function of the protein that is produced from a specific gene, which likely impairs the normal formation of structures in the heart. Studies have also suggested that having more or fewer copies of particular genes compared with other people, a phenomenon known as copy number variation, may play a role in CCHD. However, it is unclear whether genes affected by copy number variation are involved in heart development and how having missing or extra copies of those genes could lead to heart defects. Researchers believe that single-gene mutations and copy number variation account for a relatively small percentage of all CCHD.

CCHD is usually isolated, which means it occurs alone (without signs and symptoms affecting other parts of the body). However, the heart defects associated with CCHD can also occur as part of genetic syndromes that have additional features. Some of these genetic conditions, such as Down syndrome, Turner syndrome, and 22q11.2 deletion syndrome, result from changes in the number or structure of particular chromosomes. Other conditions, including Noonan syndrome and Alagille syndrome, result from mutations in single genes.

Environmental factors may also contribute to the development of CCHD. Potential risk factors that have been studied include exposure to certain chemicals or drugs before birth, viral infections (such as rubella and influenza) that occur during pregnancy, and other maternal illnesses including diabetes and phenylketonuria. Although researchers are examining risk factors that may be associated with this complex condition, many of these factors remain unknown.

CCHD is often a sporadic condition, meaning it usually happens to families with no history of heart defects. If you have a child with CCHD, that child’s siblings and any future siblings have a higher chance of having CCHD.

In some cases, CCHD occurs as part of a genetic syndrome, like Down syndrome or 22q11.2 deletion syndrome (also called DiGeorge syndrome). In these cases, there are usually other parts of the body that also have health issues.

Genetic counselors and medical geneticists can help families learn about the genetics of CCHD and the chance of having children with it.

Some babies born with CCHD look and act healthy at birth but have serious symptoms just hours or days later. Parents should be on the lookout for early signs of CCHD in their babies.

Early signs of CCHD include:

• Loss of healthy skin color
• Blue color to the skin, lips, and fingernails (cyanosis)
• Rapid or troubled breathing (tachypnea)
• Swelling or puffiness in the face, hands, feet, legs, or areas around the eyes
• Shortness of breath or getting tired easily
• Sweating around the head
• Poor weight gain

Newborn screening for CCHD is done by measuring the oxygen levels in your baby’s body. During screening, a special piece of equipment called a pulse oximeter measures how much oxygen is in your baby’s blood. Oxygen is important for the body to function. Babies with low oxygen levels might have CCHD.

What Happens After an Out-of-Range Screening Result?

If your baby’s pulse oximetry result for CCHD shows low oxygen levels, your baby’s health care provider will let you know right away. Together, you will discuss next steps and follow-up plans.

An out-of-range screening result does not mean that your baby definitely has CCHD. It does mean that your baby needs more follow-up testing. All babies with low blood oxygen during screening need follow-up testing. This testing will determine why the baby’s oxygen levels are low and if the heart and lungs are working well.

Your baby may need any of the following tests after an out-of-range screening result:

• Repeat pulse oximetry screen
• Ultrasound picture of the heart (echocardiogram)
• Test of the heart’s electrical signals (electrocardiogram, ECG or EKG)
• Chest X-ray to look at the heart and lungs
• Blood tests to look for infections
• Tests to see if their lungs are working correctly

You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems soon after birth if they are not diagnosed and treated quickly.

Not every baby with low blood oxygen during screening has CCHD. Sometimes, oxygen levels can be low for other reasons, including:

• Screening too early, before the baby is 24 hours old
• Illness that affects breathing, such as a respiratory infection
• Lung disorders

It is also important to know that not every baby with CCHD will have low oxygen levels. Other signs of CCHD may include:

• Too fast or too slow heart rate
• Overly sleepy or fussy
• Pale or blue skin
• Breathing too fast or too slow
• Cold body temperature

Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.

Babies with CCHD need treatment, like surgery or other care, early in life. The type of treatment a baby needs depends on the baby’s heart problem and symptoms. A cardiologist (heart doctor) works with the families of babies who have CCHD to make sure they get the best possible care.

Children who receive early and ongoing treatment for CCHD can have healthy growth and development.

As medical care and treatment have improved, babies and children with congenital heart defects (CHDs) are living longer and healthier lives. Most are now living into adulthood. Ongoing, appropriate medical care can help children and adults with a CHD live as healthy as possible.

Health Care

It is important for parents of children with a heart defect and adults living with a heart defect to talk with a heart doctor (cardiologist) regularly. Regular visits with a cardiologist are important, because they allow the parents of children with heart defects to make the best possible choices for the health of their child. These visits also allow adults living with a heart defect to make the best possible choices for their own health.

Children and adults with CHDs can help with their health care by knowing their medical history, including the:

• Type(s) of heart defect(s) they have.
• Procedures or surgeries they have had performed.
• Medicines and doses of these medicines that they are prescribed currently and were prescribed in the past.
• Type(s) of medical care they are receiving now.

As children transition to adult health care, it is important to notify any new healthcare provider(s) about the child’s CHD. Ongoing appropriate medical care for their specific heart defect will help children and adults with a CHD to live as healthy a life as possible.

Care Across the Lifespan

At this time, even with improved treatments, many people with a CHD are not cured, even if their heart defect has been repaired. As a person with a heart defect grows and gets older, further heart problems may occur. Additional medications, surgeries, or other procedures may be needed after the initial childhood surgeries.  Some people with heart defects need lifelong care to stay as healthy as possible and address certain health issues.

Nutrition

Some babies with a CHD can become tired while feeding and might not eat enough to gain weight. Furthermore, because of the extra work that their heart may have to do to compensate for having a defect, some children with CHDs burn more calories. As they grow up, these children might be smaller and thinner than other children. After treatment for their heart defect, growth and weight gain often improve. It is important to talk with a healthcare provider about diet and nutrition.

Medications

Some children and adults with a CHD will need medicine to help with problems associated with their heart defect. For example, some medicines help make the heart stronger, and others help lower blood pressure. It is important for children and adults with a CHD to take medications as prescribed.

Physical activity

Physical activity is an important part of staying healthy, and it can help the heart become strong. Adults and parents of children with a CHD should discuss with their healthcare providers which physical activities are safe for them or their children, respectively, and if there are any physical activities that should be avoided.

Pregnancy

Having a CHD is one of the most common heart problems for pregnant people. Pregnancy can put stress on the heart of people with some types of CHDs. Many people with CHDS have healthy, uneventful pregnancies. People with CHDs who are considering having a baby should talk with a healthcare provider before becoming pregnant to discuss how the pregnancy might affect them. Some people may need to have procedures done related to their heart condition before becoming pregnant or take certain medications to help their heart during pregnancy. If you have a CHD or a family history of CHDs, talking with a genetic counselor could be helpful.

Other Potential Health Problems

Many people with a CHD live independent lives. Some people with a heart defect have little or no disability. For others, disability might increase or develop over time. People with a heart defect might also have genetic problems or other health conditions that increase the risk for disability. People with a CHD can develop other health problems related to their heart defect over time. These problems may depend on their specific heart defect, the number of heart defects they have, and the severity of their heart defect.

Some health problems that might need treatment include:

Infective Endocarditis

Infective endocarditis is an infection in the layers of the heart. If left untreated, it can lead to other problems, such as a blood clot, heart valve damage, or heart failure. Guidelines recommend that individuals with certain heart defects take oral antibiotics before having certain procedures, such as dental or surgical procedures. However, these guidelines have been updated, and many people with a CHD, such as those with valve stenosis or an unrepaired ventricular septal defect, no longer need to take antibiotics before procedures. Each person should discuss his or her condition with the doctor to find out if antibiotics are recommended for him or her.

Arrhythmia

Arrhythmia is a problem with how the heart beats. The heart can beat too fast, too slow, or irregularly. This can lead to a problem with the heart not pumping enough blood out to the body and can increase the risk for blood clots. Some people with a heart defect can have an arrhythmia associated with their heart defect or as a result of past treatments or procedures for their heart defect. Some people can have an arrhythmia even in the absence of any heart defects.

Pulmonary Hypertension

Pulmonary hypertension is high blood pressure in the arteries (blood vessels) that lead from the heart to the lungs. Certain heart defects can cause pulmonary hypertension, which forces the heart and lungs to work harder. If the pulmonary hypertension is not treated, over time the right side of the heart can become enlarged, and heart failure can occur.

Liver Disease

People with single ventricle heart defects can develop liver disease associated with their heart defect or as a result of past treatments or procedures for their heart defect. It is important for people with this type of heart defect to see a healthcare provider regularly to stay as healthy as possible.

Other Conditions

As adults with CHDs age, they can get other diseases of adulthood, such as diabetes, obesity, or atherosclerosis (buildup of cholesterol in the arteries). However, because of the problems associated with a CHD, these diseases might affect adults with a CHD differently from adults without a CHD. Therefore, they must have annual follow-up visits with cardiologists who are trained to care for adult patients with a CHD.

Congenital heart defects are present at birth and can affect the structure of a person’s heart and its ability to work properly. As medical care and treatment have advanced, people with heart defects are living longer and healthier lives, many into adulthood. Learn about heart defects and about Mary, an adult living with a heart defect. You can also learn what CDC is doing to improve the lives of people with heart defects.

What Are Heart Defects?

Heart defects are present at birth and can affect the structure of a person’s heart and its ability to work properly. They can also affect how blood flows through the heart to the rest of the body. Heart defects can vary from mild (such as a small hole in the heart) to severe (such as missing or poorly formed parts of the heart).

Some affected people might need one or more surgeries on the heart or blood vessels. It is important to note that even with these treatments, many people with heart defects are not cured, as heart defects are lifelong conditions. As a person with a heart defect grows and gets older, further heart problems may occur.

How Many People Are Born with Heart Defects?

Heart defects are the most common type of birth defect, affecting nearly 1% of births – or about 40,000 births – per year in the United States. It is estimated that more than two million people in the United States are living with heart defects.

Mary’s Story — In Her Own Words

Mary was born with multiple congenital heart defects. As a Doctor of Nursing Practice, she wants to empower her patients to take an active role in their health. Read her story below.

I was born in 1991. My mom had a normal pregnancy, and I seemed to be a healthy baby. My dad, a medical residency student at the time, anxious to hear my heartbeat, heard a heart murmur and called a pediatric cardiologist. I was diagnosed with hypoplastic right heart syndrome, atrial septal defect, transposition of the great vessels, and isthmus coarctation of the aorta. This combination of defects in one baby is incredibly rare. I was admitted to the neonatal intensive care unit (NICU), and at 9 days old, I had my first open heart surgery. I would go on to have three more surgeries by the time I was 2 years old.

From ages 2 through 15 years, I remained relatively healthy. I had routine checkups with my pediatric cardiologist that included regular echocardiograms and electrocardiograms. I would sometimes have to wear a Holter monitor, a device that measures and records the heart’s activity, while enduring stress tests. This was my normal.

When I was 15 years old, I learned I would need a pacemaker and defibrillator because my heart rate was too slow, causing me to feel fatigued and out of breath easily. Shortly after I turned 16 years old, I had surgery to place my pacemaker and defibrillator in my abdomen. One month after surgery, I went to my high school junior prom with my date, who would, years later, become my husband.

Receiving a pacemaker/defibrillator as a teenager was frightening. I thought, “I’m dying,” because I only knew of older individuals having pacemakers. Having a pacemaker restricted me from jumping on a trampoline, riding rollercoasters, and riding horses, but these were things that I could live without doing.

Due to the pacemaker/defibrillator, my doctors increased the number of medications I was taking. Although my pacemaker was helping to regulate my heartbeat, I was still having irregular heartbeats. I needed medication to help my heart function properly.

The defibrillator was placed to help shock my heart back into rhythm if it slowed down or stopped beating. I remember asking the nurse practitioner that set up my pacemaker/defibrillator to describe the feeling of being shocked. She told me, “like getting kicked by a donkey.” I had never been kicked by a donkey, and had no intention of experiencing it.

Unfortunately, I was shocked two separate times after they set up my pacemaker/defibrillator. The first time was 2 months after having my pacemaker/defibrillator placed. My settings were wrong, but this was no fault of the doctors. Setting these devices is often trial and error. Every single person is different, and they set the pacemaker/defibrillator for what a person of your age and condition would typically use. This may not be what you need. The second time I was shocked, I was home alone after attending nursing school that day, and my device shocked me multiple times. I was able to call 911 and crawl to the door to let the paramedics in. This occurred the day before my first day of nursing school clinical work, of which I was required to attend. My dad drove me to the hospital because I wasn’t allowed to drive so soon after being shocked. When I walked in, the instructor looked at me as if she saw a ghost. I eventually graduated, and went on to become a Doctor of Nursing Practice (DNP).

Given my experiences, I understand what it’s like to be a patient, which has helped me as a nurse. I learned to become an advocate for my own health. I want to empower my patients to take an active role in their health and become advocates for themselves, too. I love educating people and spreading awareness, and being a nurse practitioner allows me to do that.

I got married shortly after receiving my DNP. I met my husband when we were in high school, so he has been through a lot with me. While we were dating, I made the decision to have my tubes tied because pregnancy can be risky for some women with heart defects. Before we got married, I wanted to make sure my husband was okay with this decision. We both agreed that adoption or surrogacy were options we were open to considering if we wanted to have children in the future. For now, we have two lively and loveable dog-babies, Brindle and Rogan.

Heart defects are the most common type of birth defect, accounting for more than 30 percent of all infant deaths due to birth defects. CCHD represents some of the most serious types of heart defects. About 7,200 newborns, or 18 per 10,000, in the United States are diagnosed with CCHD each year.