To determine whether you have a type of congenital heart disease or if the congenital heart defect is causing recent health problems, your doctor will take a medical history and conduct a physical exam, including listening to your heart with a stethoscope.

Your doctor then might order tests, including:

  • Electrocardiogram (ECG). This measures the pace and amount of electrical activity of your heart to determine if the electrical activity is normal. An ECG can determine if a part of the heart is enlarged.
  • Chest X-ray. These images help your doctor further evaluate your heart and lungs.
  • Echocardiogram. Sound waves (ultrasound) produce images of the moving heart that your doctor can use to identify heart abnormalities.
  • Transesophageal echocardiogram. This special type of ultrasound produces images of your heart that provide more information than does a standard echocardiogram. While you're sedated, your doctor places an instrument with a small ultrasound probe on the end into the tube that connects your throat with your stomach (esophagus).
  • Pulse oximetry. A small sensor attached to a finger can estimate how much oxygen is in your blood.
  • Exercise stress test. Connected to ECG leads, you exercise on a treadmill or a stationary bicycle so that your doctor can determine your level of conditioning and your heart's electrical activity, heart rate and blood pressure during exercise.

    If you can't exercise, your doctor might give you medication to increase your heart rate. Your stress test may also include an echocardiogram and special sensors to determine your oxygen use.

  • Cardiac CT scan or MRI. For a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest.

    Cardiac MRI uses a magnetic field and radio waves to create images of your heart. You lie on a table inside a long tubelike machine.

  • Cardiac catheterization. Your doctor might use this test to check blood flow and blood pressures in your heart. You'll likely be given sleeping medication before a catheter is inserted into an artery, starting in your groin, neck or arm. It's then threaded to your heart with guidance from an X-ray machine.

    Dye is injected through the catheter, and the X-ray machine makes images of your heart and blood vessels. The pressure in the heart chambers can be measured during this procedure.