Tetralogy of Fallot

Q: What is Tetralogy of Fallot?


Tetralogy of Fallot is a congenital heart defect that is associated with four specific defects inside the heart. These defects include:

  • Ventricular septal defect – a hole in the heart between two lower chambers
  • Pulmonary stenosis – the pulmonary valve is tight and does not open properly which limits the amount of blood able to go to the lungs
  • Right ventricular hypertrophy – thickening of the wall on the right side of the heart which happens because the ventricle is pumping against the stiff pulmonary valve
  • Overriding aorta – which means the aortic is located directly over the ventricular septal defect

Q: What kind of testing and diagnostic tools are used to determine diagnosis or disease stage?


Your child’s cardiologist will perform a comprehensive physical exam as well as an EKG, echocardiogram (ultrasound of the heart), and chest X-Ray to diagnose TOF. A pulse oximetry test may be done to detect the amount of oxygen there is in the blood and is now done for all babies prior to leaving the hospital to test for congenital heart disease. Other tests your baby may need could include a cardiac catheterization or a cardiac MRI.

Q: Are there any known causes?


The majority of cases of Tetralogy of Fallot have no known cause. Some conditions that have been associated with the heart defect include exposure to rubella, alcohol use, poor nutrition during pregnancy, and genetic causes. For example, a mother with TOF as an infant is more likely to have a baby with TOF.

Q: What are common symptoms? How does this problem present itself?


Cyanosis is a common symptom of TOF. Cyanosis is when the baby’s lips and tongue turn blue or purple due to low oxygen levels. A doctor can also detect this by listening to the baby’s heart and hearing a heart murmur. However, it is important to know that there are many different types of heart murmurs and not all heart murmurs mean that your baby has TOF. Some other common signs include sleepiness, shortness of breath, increased fussiness, and in an extreme cases, your baby may pass out. Also, some babies with TOF also have DiGeorge Syndrome, a genetic condition frequently associated with congenital heart defects. Please consult a doctor if you see any of these signs.

Q: What are possible treatment options?


Open heart surgery is needed to repair TOF and typically occurs during the first few months of life. In some cases, the pulmonary valve will need to be removed completely. If this is the case, your child will require another surgery or a cardiac catheterization later in life. Some infants with severe TOF will require surgery soon after birth. In these cases, your baby will also need a “complete” TOF repair during infancy since the full repair since your baby will be too small as a newborn.

View our pediatric cardiac surgery outcomes.

Q: What happens during surgery to treat TOF?


The three main parts of the TOF repair include closing the hole in your child’s heart (VSD) opening the right ventricle outflow tract, and repairing the pulmonary valve. The VSD is closed using a Gore-Tex patch and the valve is opened up. Here at the University of Maryland, we specialize in valve-sparing TOF repair which means we try very hard to keep your child’s pulmonary valve so that he/she will not need additional surgery later in life.

Q: What happens after surgery? Will my child require care throughout childhood/adulthood?


After surgery for TO, your child will stay in the hospital between 3 to 10 days. If your child is a newborn and requires surgery right away, the hospitalization will likely be longer. Your child will stay in the ICU and be monitored closely until discharge. Once your child goes home, they are usually fully recovered by 6-8 weeks. Your surgeon and nurse practitioner will discuss your child’s particular restrictions with you following the surgery. It is unlikely that your child will have any lifelong restrictions for sports or other activities. It is important to know that your child will be followed by a cardiology for his/her entire life following surgery.