Tests and diagnosis

By Mayo Clinic Staff

After your baby is born, your baby's doctor might suspect tetralogy of Fallot if your baby has blue-tinged skin or if a heart murmur — an abnormal whooshing sound caused by turbulent blood flow — is heard in your baby's chest. Your baby's cardiologist will conduct a physical examination and use several tests to confirm the diagnosis.

Tests may include:

  • Echocardiography. Echocardiograms use high-pitched sound waves to produce an image of the heart. Sound waves bounce off your baby's heart and produce moving images that can be viewed on a video screen.

    This test is generally used to diagnose tetralogy of Fallot. It allows your baby's doctor to determine if there is a ventricular septal defect and where it's located, if the structure of the pulmonary valve and pulmonary artery is normal, if the right ventricle is functioning properly, and if the aorta is positioned properly. This test can also help your baby's doctors to plan treatment for your baby's condition.

  • Electrocardiogram. An electrocardiogram records the electrical activity in the heart each time it contracts. During this procedure, patches with wires (electrodes) are placed on your baby's chest, wrists and ankles. The electrodes measure electrical activity, which is recorded on paper.

    This test helps determine if your baby's right ventricle is enlarged (right ventricular hypertrophy), if your baby's right atrium is enlarged and if the heart rhythm is regular.

  • Chest X-ray. A chest X-ray can show the structure of your baby's heart and lungs. A common sign of tetralogy of Fallot on an X-ray is a "boot-shaped" heart, because the right ventricle is enlarged.
  • Oxygen level measurement (pulse oximetry). This test uses a small sensor that can be placed on a finger or toe to measure the amount of oxygen in your baby's blood.
  • Cardiac catheterization. Doctors may use this test to evaluate the structure of the heart and plan surgical treatment. During this procedure, your baby's doctor inserts a thin, flexible tube (catheter) into an artery or vein in your baby's arm, groin or neck and threads it up to his or her heart.

    Your baby's doctor injects a dye through the catheter to make your baby's heart structures visible on X-ray pictures. Cardiac catheterization also measures pressure and oxygen levels in the chambers of the heart and in the blood vessels.

Oct. 08, 2015