Tetralogy of Fallot (ToF, Tet)
ToF may be discovered through a regular medical exam. A pediatric cardiologist will listen to your baby’s heart and lungs, feel the baby’s pulses, measure the oxygen level in the blood (non-invasively) and make observations that help to determine the diagnosis.
In most cases, your child’s doctor will use some combination of the following medical tests to diagnose ToF:
- Echocardiogram (cardiac ultrasound): An echocardiogram evaluates the structure and function of your child’s heart using electronically recorded sound waves that produce a moving picture of the heart and heart valves. No discomfort is involved. It takes 30 to 60 minutes. Many younger (less than 3 years old, approximately) children may need to be sedated. An ultrasound can also detect ToF prenatally.
- Electrocardiogram (EKG): An EKG is used to evaluate the electrical activity of your child’s heart. An EKG is often the initial test for evaluating the causes of symptoms and detecting heart abnormalities. It is performed by placing electrodes on the arms, legs and chest to record the electrical activity. The test takes five minutes or less and involves no pain or discomfort.
- Cardiac magnetic resonance imaging (MRI): A cardiac MRI is a non-invasive test using 3-D imaging technology to accurately determine the shape, size and function of your child’s heart. No pain is involved, although an IV may be needed. It takes about an hour. Children under 10 years old usually need anesthesia.
- Chest x-ray: A conventional chest x-ray will evaluate the size and spatial relationships of the heart within the child’s chest. It takes a few moments. There’s no pain or discomfort.
- Cardiac catheterization: With cardiac catheterization, a needle is placed into a large vein and dye is injected. This provides measurements of and detailed information about the structures inside the heart.
- Pulse oximetry: This non-invasive test (a test that doesn’t require penetrating the body) measures the amount of oxygen in the blood.