Congenital heart defects are often, but not always, diagnosed in infancy. Some may be diagnosed before birth, and many may not be detected until much later in childhood or even in adulthood.

If the heart problem is significant, your child’s pediatrician or family physician will likely refer your child to a pediatric cardiologist. Pediatric cardiologists are trained to diagnose and treat heart problems in infants, children and young adults. They have the training and equipment to find out what tests and treatments your child will need, and how often your child will need heart checkups in the future.

Diagnostic Evaluation

Pediatric cardiologists first take your child’s medical history and perform a physical exam. They may also order an electrocardiogram (called an EKG or ECG), chest X-ray, or an echocardiogram (ultrasound movie of the heart). These tests are described in more detail below. You can reassure your child that these tests won’t hurt. Less often, blood tests are needed, but they’re usually not done during a child’s first evaluation.

The pediatric cardiology staff will talk to you and your child about each test, but being prepared for the tests will help you to keep your child as comfortable as possible. Don’t hesitate to ask the pediatric cardiologist, nurse or technician to explain these tests to you or your child.

Electrocardiogram (ECG or EKG)

An electrocardiogram (ECG or EKG) is a test that measures the electrical activity of the heartbeat. The ECG machine may look frightening to you or your child, but it’s harmless. Although its name has “electro” in it, it doesn’t send electricity into the body. Instead, it receives tiny electrical impulses that the beating heart makes and records them in a zigzag pattern on a moving strip of paper.

The test is often performed by a technician who is skilled in doing the test. The technician will place stickers on your child’s arms and legs and over the front of the chest. The stickers are then connected to separate wires or leads that connect to the ECG machine. Once the leads are placed, the test is recorded in seconds. The test itself doesn’t hurt — but after the test is done, the technician will remove the stickers which is similar to pulling off a Band-Aid — which some children can find uncomfortable.

An ECG gives two major kinds of information. First, by measuring time intervals on the ECG, a doctor can determine how long the electrical wave takes to pass through the heart. Finding out how long a wave takes to travel from one part of the heart to the next shows if the electrical activity is normal or slow, fast or irregular. Second, by measuring the amount of electrical activity passing through the heart muscle, a pediatric cardiologist may be able to find out if parts of the heart are too large or are overworked.

Chest X-rays

The chest X-ray gives the pediatric cardiologist information about your child’s lungs and the heart’s size and shape. The amount of radiation from a chest X-ray is extremely small and doesn’t cause any long-term side effects.

Echocardiogram

An echocardiogram is an ultrasound movie of the heart and blood vessels. It shows the structure of the heart and surrounding blood vessels, how well the heart is pumping, and how the blood is flowing through the heart and vessels. It can detect nearly every congenital heart defect or any problem of the heart muscle function.

The test is often performed by a specialized technician, called a sonographer, or a physician. The test requires placing a few stickers (like those used for the ECG) on your child’s chest. The sonographer will use a special ultrasound device (called a probe) and place a small amount of gel on the end of it. The probe is then placed on the front of your child’s chest, upper abdomen and the root of the neck. This does not hurt, but some children are unhappy about the feel of the gel and movement of the probe. Various pictures of the heart are recorded from these viewing points. The sonographer will make many adjustments in the ultrasound machine during the study to get the clearest pictures possible. The sonographer may ask that your child turn on the left or right side or extend the neck backward for portions of the study.

Depending on the child’s age and the diagnosis being studied, an echocardiogram will usually take 10–60 minutes to perform. If your infant or young child is particularly anxious or unable to cooperate for the study, your pediatric cardiologist may recommend that he or she be sedated for the test.

Initial Results

After these tests are completed, the doctor will explain the results to you. If you do not understand the results, don’t hesitate to ask questions. In some cases, further testing will be needed to fully understand what is going on with your child’s heart and to give an accurate diagnosis. These tests (discussed below) include cardiac catheterization and angiography, magnetic resonance imaging (MRI), CT scanning, TEE, and special rhythm testing like a Holter recording and stress testing.

Cardiac Catheterization and Angiogram

A cardiac catheterization is a procedure that allows the pediatric cardiologist to get direct information about the blood pressures and patterns of blood flow within your child’s heart. An angiogram is an X-ray movie that’s taken while special fluid (called contrast) that’s visible by X-ray is injected into a cardiac chamber or major blood vessel.

Your pediatric cardiologist or nurse will explain the reason for this procedure and how it will help in the care of your child. They will also explain the test’s possible risks, which fortunately are rare. After you’ve heard about the test and have had a chance to ask questions, you’ll be asked to sign a consent form for your child to have the test. Since a catheterization and angiogram require special X-ray equipment that’s only found in hospitals or large medical facilities, the test must usually be scheduled in advance.

Many children are admitted to the hospital on the day of the catheterization, but some may need to be admitted the day before. For several hours before the catheterization, you’ll be told not to give your child anything to eat or drink. Before the test is done, your child will likely be given a sleeping medicine by mouth or in a small shot under the skin. An intravenous line (IV) is sometimes placed in one of the veins.

During the catheterization your child will be cared for by a team of nurses, doctors and technicians. You won’t see your child at this time, but the staff will make every effort to keep your child completely comfortable. The catheterization test usually causes little discomfort and your child will sleep through most of the test. In some cases the procedure will be done under general anesthesia.

The catheterization involves placing small IV tubes in the vein and artery of a leg, arm or the neck. Through the special IV tubes the cardiologist can pass thinner tubes (called catheters) into the circulation. Catheters are small, hollow plastic tubes that are the size of spaghetti noodles. The catheter is slowly moved through the circulation until it reaches the heart. From there it can be passed to different chambers of the heart and to the veins and arteries connected to the heart. Your cardiologist can learn very important information about your child’s heart condition from the blood samples and blood pressures that are measured through the catheter at different places in the circulation.

During the catheterization an angiogram is usually performed. This is done by injecting special fluid (called dye or contrast) through the catheter into a blood vessel or a chamber of the heart. Since the dye is visible by X-ray, an X-ray movie of the circulation can be recorded. An angiogram requires much more X-ray than is needed for a simple chest X-ray. For this reason the test is performed only when it’s definitely necessary for your child’s care. Be reassured that many studies have been done that show no long-term effect in people who had cardiac catheterization and angiography in childhood.

Sometimes a child’s heart defect can be treated during the cardiac catheterization. This is called an interventional or therapeutic catheterization. These treatments include opening up a hole in the wall between the upper chambers, opening up a blocked valve or vessel, plugging off the unnecessary vessel or closing unnecessary holes in the heart. Your pediatric cardiologist will discuss these treatments with you before the catheterization.

After the catheterization and angiogram, the small catheter tubes and IV lines will be taken out of your child’s leg or arm and a pressure bandage will be placed over the area. Your child will return to the room and will likely be sleepy for several hours. There may be a slight fever or an upset stomach after the test, but these symptoms usually go away in a few hours.

After the catheterization, your cardiologist will discuss the results of the test with you. Your child will be able to go home later that day or the next morning, depending on the details of the procedure.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging is another way to take clear pictures of the heart and surrounding blood vessels and measure heart function. The MRI uses painless magnet waves to evaluate the heart and the blood vessels connected to the heart and lungs. Often a small IV will need to be placed in the hand to give medications that show the blood flow in the heart or to give medications for sedation.

The test usually requires 30–60 minutes to perform and your child must be perfectly still for the test. For this reason infants and young children need to be placed under general anesthesia for the test. During the test your child will be placed on a table within the magnet. Most of your child’s body will be within a small tunnel in the center of the magnet. This can be disturbing even for older children and adults, but many centers have special headphones and video masks than can help to keep your child calm during the test.

Sometimes the test is done instead of or in addition to the cardiac catheterization and angiogram. Your pediatric cardiologist will decide if your child needs either test, or both.

Computerized Tomography (CT)

The CT scan uses multiple X-ray images to take an X-ray movie of the heart, blood vessels and lungs without placing catheters into the circulation. Like the MRI, this test sometimes takes clearer pictures than an angiogram. The test only requires a simple IV in the hand and it can be done more quickly than an MRI. Unlike MRI imaging, the CT scan uses about the same amount of X-ray as is needed for an angiogram.

Sometimes the test can be performed on infants and children with just a sedative, rather than general anesthesia.

Transesophageal Echocardiogram (TEE)

A transesophageal echocardiogram is a special type of ultrasound movie of the heart that produces much clearer pictures than a standard echocardiogram that’s performed on your child’s chest. A TEE is performed by using a TEE probe. This is a special long tube with a small ultrasound probe on the end. The tube is placed in your child’s esophagus (the food pipe that connects the throat to the stomach). The study is performed under deep sedation or general anesthesia in children and adolescents.

A TEE is performed when the standard echocardiogram isn’t clear enough to make the diagnosis that’s suspected. It’s also performed in children who are having heart surgery so the surgeon can learn instantly whether the operation has been successful and if the heart needs more repair. The risk of a TEE is minimal and your pediatric cardiologist will discuss with you the reasons your child needs a TEE in addition to standard echocardiography.

Special Heart Rhythm Testing

Children with heart defects and with structurally normal hearts can have problems with their heart’s rhythm. If there is a possibility that your child is having rhythm issues, there are some special tests that the doctor may perform. The most common are Holter monitors, event monitors and exercise stress tests. If a child has an implanted pacemaker or cardioverter/defibrillator (ICD), data is often relayed to the doctor by transtelephonic pacemaker/ICD transmission. In some cases, an electrophysiology study may need to be performed in the catheterization lab.

Holter Monitor

A Holter monitor is a way to record every beat of your child’s heart for 24 hours. It’s usually performed to make sure that your child isn’t having any dangerous heart rhythms that might need more treatment.

A small recorder is worn and attached to your child’s body by stickers similar to those used to make an electrocardiogram (ECG). A Holter recording doesn’t hurt, but sometimes the stickers can irritate the skin during the recording time. You and your child will be asked to keep a diary of events during the 24-hour period. It’s helpful to know when your child is active, is sleeping, or is having any symptoms that might be caused by a heart rhythm problem.

Once the recording has been completed, the recorder and stickers are disconnected, and the recorder is taken back to the heart center for review. A technician will process the information from the recorder for your pediatric cardiologist to review. Your doctor will get back to you as soon as the results are read and analyzed. This may take a week or two.

Since a Holter recording is usually only worn for 24 hours, it’s particularly helpful when your child is having symptoms that are happening at least once a day. If symptoms are happening less often, an event monitor may be recommended instead.

Event Monitor

Event monitoring is a way to record the heart rhythm when your child has symptoms less often than once a day. The event monitor is a recorder that’s even smaller than a Holter recorder. It’s worn for most of each day — typically for 30 days at a time. The monitor is always recording, but not saving. When your child has a symptom, you or your child will be told to push a button on the recorder. When pushed, the recorder will save the rhythm just at that time and sometimes for a brief time before the button was pushed. When a recording has been made, you’ll be told how to send it through your telephone to your doctor’s office.

Implantable Event Recorder

An implantable event recorder (also known as an implantable loop recorder) is a device that can record your child’s heart rhythm for up to 14 months. This device is placed under the skin through a minor operation. This is the best way to record very serious rhythm problems that may be happening only rarely. The recorder can be programmed to record certain heart rhythms automatically or when you or your child places a special activator over the device itself. The heart rhythms that are recorded can be displayed and printed later by a special instrument used by your pediatric cardiologist.

Transtelephonic Pacemaker/ICD Transmission

Patients who have pacemakers and implantable cardioverter/defibrillators (ICDs) are often required to send in a telephone transmission routinely to check pacemaker/ICD function. This consists of a rhythm strip and sometimes a recording with a magnet over the device. A new technology used by ICD and pacemaker patients allows all of the information from the device (including settings and recordings of arrhythmias) to be sent to your doctor not only by fax, but by Internet.

Exercise Stress Testing

Exercise stress testing is a test of your child’s heart rhythm and stamina while your child exercises. The exercise may be running on a treadmill at standard speeds and ramps or riding a stationary bike at a steadily increasing resistance. During exercise your child is connected to ECG leads and the heart rhythm is continuously recorded. In some centers your child may be asked to breathe into a tube so the amount of oxygen used can be measured. This gives information about how well the heart works.

The stress test gives information about the effect on exercise on your child’s blood pressure, heart rate, heart muscle and heart rhythm. If your child has symptoms during exercise, this test will help to recreate those symptoms to see whether the symptoms are caused by the heart.

The test takes about 10–15 minutes to set up, 10–15 minutes to do and an additional 10–15 minutes of observation afterward. If your child is scheduled for the test, have your child bring gym clothes and sneakers that would be appropriate for jogging.

Electrophysiology Study

An electrophysiology study (EP study) is a specialized cardiac catheterization that looks at the heart’s electrical or rhythm function instead of its blood flow. The heart’s rhythm function is what controls the beginning of each heartbeat and controls the heart rate.

EP studies in young patients are done mostly to fix an abnormal fast rhythm problem (using ablation) but can also be done to assess the potential for developing abnormal rhythms (arrhythmias) that may need treatment with medication or surgery. Read more detailed information on arrhythmias in children.

Source: American Heart Association