Nationally ranked care. Another way our love for kids just keeps on growing.


Congenital heart defect symptoms

Children at different ages will show different symptoms of a potential congenital heart defect.

Before a baby is born

Congenital heart defects are usually diagnosed when children are very young babies. Still, fetal echocardiograms, like those performed in the Dallas Heart Center, can detect heart problems in babies after just 17 or 18 weeks gestation.

When babies are determined to have a congenital heart defect, the pediatric cardiologist will work with the parents to explain the diagnosis and what it means for the baby. The cardiology team can work with the parents to determine a treatment plan and the best way to help the baby’s individual heart defect and unique situation.

Shortly after a baby is born

Some congenital heart defects may be diagnosed shortly after birth, through a simple bedside test called pulse oximetry. In this test, sensors are placed on a baby’s skin to determine the amount of oxygen in a baby’s blood and the baby’s pulse rate. Low levels of blood can be a sign of congenital heart defects. The test, done when a baby is 24 to 48 hours old, is painless and takes only a few minutes to complete. The test does not replace a physical examination for babies but can be another sign that a heart defect is present.

As babies grow

For babies who are not diagnosed in utero or immediately after birth, severe heart disease symptoms typically begin to appear in the first few months. Some babies with congenital heart defects will actually appear to be blue in the lips and fingernails, particularly babies with cyanotic congenital heart disease. Some babies may have very low blood pressure shortly after birth. Other heart defects may cause breathing difficulties, feeding problems or poor weight gain. Pediatricians often diagnose minor heart defects during a routine medical checkup.

After a heart problem is suspected, your child’s pediatrician or your family physician will likely refer you to a pediatric cardiology team, such as the one at SSM Health Cardinal Glennon Children's Hospital. Pediatric heart teams have specialized training and equipment to diagnose and treat heart problems in infants, children and young adults. Your child’s pediatric heart team will work with you to determine a treatment plan that is right for your child’s particular needs.

call 314-577-5674 to make a cardiology appointment for your child at cardinal glennon in st. louis 

Diagnosing congenital heart defects

The pediatric heart team works with families to diagnose congenital heart defects every day. Through every step of the process, the team strives to keep the family informed and help them understand their child’s condition. Your child’s journey at the Dallas Heart Center will begin with a full medical history discussion and thorough physical exam so the team has the best information about your child’s individual situation.

Cardiologists may use a variety of tests to identify a child’s heart condition. The cardiologist will talk to you about each test and explain it completely. If you have any questions about any test, don’t hesitate to ask the cardiologist, nurse or technician. Informed parents are the best advocates for their child’s health.

Many young patients will need blood tests to help diagnosis congenital heart problems, particularly those with cyanosis and single ventricle hearts.

Common diagnostic procedures include:

Pediatric cardiac catheterization

Cardiac catheterization provides more accurate and detailed information about the structure of a child’s heart and how it works. This common test helps doctors diagnose the problem accurately and helps them choose the best treatment option for your child. Physicians usually use non-invasive diagnostic tests, but cardiac catheterization is often necessary to give the team a more comprehensive look at what is happening within your child’s heart. Many babies who have heart surgery will have a cardiac catheterization before the operation.

During cardiac catheterization, a specially trained pediatric cardiologist will thread long, flexible tubes called catheters through your child’s large blood vessels and into their heart. This helps our team measure pressures and draw blood samples to find out how blood is circulating to different parts of your child’s body. The cardiologist may perform an angiogram as well, by injecting X-ray dye through the catheters to more clearly see important anatomic details of your child’s heart.

Learn more about cardiac catheterization and what you and your child can expect from this common and important diagnostic tool. See a video here about the only pediatric hybrid cardiac catheterization suite in St. Louis.


Also known as an EKG, an electrocardiogram is a simple diagnostic test that records the electrical activity of your child’s heart. All new patients at the Dallas Heart Center receive an EKG as part of the screening process. The electrical current produced by the contraction of the heart muscle is recorded on paper for the cardiologist to review. In an EKG, electrodes wil be placed on your child’s chest, arm and legs. Your child will need to be still for about 10 seconds while the EKG is recording. The test itself generally lasts less than one minute and is painless.


Also known as an echo, an echocardiogram is an ultrasound of the heart. At the Dallas Heart Center, our physicians have access to a 3-D cardiac ultrasound machine that allows physicians to see the heart in real time. This common test uses ultrasound waves to create a picture of your child’s heart and the pattern of blood flowing through it. During the test, gel is placed on your child’s chest and a special wand is used to create sound waves that produce a moving image of the beating heart on the screen. The pediatric cardiologist can use this image to determine the thickness, size and function of the heart as well as the structures of the heart.  An echo is a safe and painless test.

Cardiac MRI

Cardiac MRI is a painless and non-invasive test that uses imaging technology commonly known as MRI (magnetic resonance imaging) to take detailed photos of your child’s heart to examine the structure and function of it and the blood vessels. This technology enables physicians to create three-dimensional (or 3-D) images of the heart and measure how well the heart is pumping blood.

For the convenience of our patients, the Imaging Center is located right next to the Dallas Heart Center on the ground floor.

Holter Monitor

Your child’s cardiologist may recommend that your child wear a Holter Monitor, a painless portable device that will create a 24-hour continuous recording of your child’s heartbeat. The monitor is attached to electrodes on the chest and typically worn around the neck or belt. The test is similar to an EKG but records the heartbeat over a longer period of time. This test may be ordered for recurring symptoms such as chest pain, palpitations, fainting spells, dizziness or a variety of other symptoms.

An event recorder is a monitor that is kept for 30 days to record symptoms at home or at school. This monitor will be sent to you at home. Istructions will be reviewed with you over the phone after you receive the monitor.


Pulse oximetry is a test used to determine the oxygen saturation of the blood. Pulse oximetry is a simple and painless test performed by putting a clip-type advice on the patient’s finger or toe. This test is performed on newborn babies still in the hospital to detect congenital heart defects very early, but is also used on older children.

Stress (Treadmill) Test

A stress test is a continuous recording of your child’s heart rhythm and blood pressure during exercise on a treadmill. The test is used to evaluate whether the blood supply to the heart is enough to meet the body’s need when its workload is increased, during exercise and other strenuous activity.

A stress test lasts 30 to 45 minutes and is typically done on a separate day from your office visit. Your child should dress comfortably in shorts or sweats and good walking or running shoes. Parents must accompany all children under 18 years old. Our treadmill testing area is comfortable and easily accommodates mom or dad.

information and causes of congenital heart defects in children, infants

treating a congenital heart defect takes the best cardiac care for kids at cardinal glennon in st. louis

Back to the cardiology/heart surgery homepage »

Cardinal Glennon on Facebook
Cardinal Glennon on Twitter
Cardinal Glennon on InstaGram
Cardinal Glennon on YouTube
Cardinal Glennon on Flickr
SSM Health offers free flu vaccinations October 7
Learn more »
SSM Health Cardinal Glennon Children’s Hospital Ranked in U.S. News & World Report 2017-2018 Best Children’s Hospitals
Learn more »