You can access the most advanced diagnostic services in the region at the St. Louis Children’s and Washington University Heart Center. We perform tests with patience and compassion, always looking after your child’s comfort, calmness and safety.

Offsite Clinic Locations

Why Choose St. Louis Children’s Hospital for Heart Diagnostic Services?

Our expert doctors and staff perform noninvasive cardiac testing and imaging to pinpoint your child’s condition with precision. We offer:

  • Noninvasive or minimally invasive testing techniques
  • World-renowned pediatric cardiologists with exceptional diagnostic expertise, who in 2016 performed:
    • 11,166 echocardiograms (heart ultrasounds)
    • 670 fetal echocardiograms
    • 136 cardiac MRI scans
    • Experienced nursing staff who care for your child with special attention
    • The most advanced imaging technology currently available for pediatric diagnosis
    • Decades of experience with all types of congenital or acquired heart conditions, resulting in more accurate diagnoses
    • National experts in diagnosing and treating the highest risk conditions
    • Family-centered, compassionate care in a child-friendly center

Testing and Imaging Services We Provide

We understand that medical procedures can be scary for children. That is why we have nurses and imaging technologists specially trained in caring for children, to provide a comfortable experience for your child.

During some tests, we may ask your child to stand or lie very still so that we can get the best possible images. If needed, we can give your child a sedative medication to drink that promotes light sleep. Some of the noninvasive and minimally invasive tests that we offer at The Heart Center include:

Cardiac Catheterization

Our pediatric cardiologists insert catheters (thin, flexible tubes) with micro instruments through a blood vessel and guide it to the heart. We perform this procedure to diagnose and treat a wide variety of heart conditions. Learn more about the types of cardiac catheterization we perform.

Chest X-Ray

This painless, noninvasive procedure gives the cardiologist an image of the size and shape of your child's heart and can detect fluid in the lungs. We may take chest X-rays from different views, including your child’s front and side, while standing or lying down. 


An echocardiogram is a type of ultrasound, which uses sound waves to produce images of your child’s heart structure. This painless, noninvasive test lasts about 30 to 45 minutes. During the test, all your child will feel is the instrument (transducer) touching the chest. The technician applies a clear gel to your child’s chest to help the transducer move smoothly.

Electrocardiogram (EKG)

An EKG measures the heart’s electrical activity, rate and rhythm, and can show any damage to the heart muscle. Our experienced nurses and technicians place electrodes (sticky patches containing wires) on your child’s chest, arms and legs. This painless, noninvasive procedure takes about 15 minutes.

Electrophysiology (EP) Study

An electrophysiology (EP) study is a catheterization procedure that helps diagnose arrhythmias (abnormal heart rhythms). An EP study shows where the irregular heartbeats begin so we can plan the right treatment.

Holter Monitor

This type of EKG measures heart rate and rhythm for a 12- to 24-hour period. A Holter monitor has a shoulder strap and electrodes that we attach to your child’s chest. The monitor and electrodes operate painlessly during the entire time your child wears them. A nurse or family member writes down your child's activities, such as playing, eating or crying, and the times they occur. Your doctor uses this information to evaluate how these activities affect your child’s heart rate and rhythm.

Magnetic Resonance Imaging (MRI)

An MRI uses a magnetic field and radio waves to provide a detailed view of the heart. During this test, your child lies on a sliding table that goes inside a large tube. Except for electrodes attached to your child's chest (a painless, noninvasive procedure), nothing touches your child.

The exam lasts about one hour. Your child may receive a sedative (medication to help relax) or anesthesia (medication that promotes sleep), if needed.

Stress Lab

Tests performed in our state-of-the-art Stress Lab, also known as an exercise physiology lab, are often referred to as exercise or stress tests. Children are tested to better understand how their heart and lungs respond to exercise, and your child will be tested either using a treadmill or stationary bicycle. 

Pediatric Heart Care at St. Louis Children’s Hospital

After we establish a diagnosis, our pediatric cardiology team works together to develop a personalized treatment plan tailored to your child’s needs. For complex cases, we also work with a conference of doctors from across our system. This group reviews all the diagnostic results to make a decision.

We also reach out to pediatric heart centers across the country, as needed, to get their opinions on complex cases. We are committed to finding the right solution for your child. Learn more about the programs and services we offer for expert heart care for children.

Heart Diagnostic Testing Locations

For your convenience, we offer many of our testing and imaging services at our off-site clinic locations throughout Missouri and Illinois.

Schedule a Diagnostic Evaluation

Contact us to make an appointment or find out more about The Heart Center’s testing, imaging and diagnostic services - call 314.454.5437 or 800.678.5437 or email us.