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Tetralogy of Fallot
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Tetralogy of Fallot

Tet; TOF; Congenital heart defect - tetralogy; Cyanotic heart disease - tetralogy; Birth defect - tetralogy

Tetralogy of Fallot is a type of congenital heart defect. Congenital means that it is present at birth.

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Heart - section through the middle
Tetralogy of Fallot
Cyanotic 'Tet spell'

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Causes

Tetralogy of Fallot causes low oxygen levels in the blood. This leads to cyanosis (a bluish-purple color to the skin).

The classic form includes four defects of the heart and its major blood vessels:

Tetralogy of Fallot is rare, but it is the most common form of cyanotic congenital heart disease. It occurs equally as often in males and females. People with tetralogy of Fallot are more likely to also have other congenital defects.

The cause of most congenital heart defects is unknown. Many factors seem to be involved.

Factors that increase the risk for this condition during pregnancy include:

Children with tetralogy of Fallot are more likely to have chromosome disorders, such as Down syndrome, Alagille syndrome, and DiGeorge syndrome (a condition that causes heart defects, low calcium levels, and poor immune function).

Symptoms

Symptoms include:

Exams and Tests

A physical exam with a stethoscope almost always reveals a heart murmur.

Tests may include:

Treatment

Surgery to repair tetralogy of Fallot is done when the infant is very young, typically before 6 months of age. Sometimes, more than one surgery is needed. When more than one surgery is used, the first surgery is done to help increase blood flow to the lungs.

Surgery to correct the problem may be done at a later time. Often only one corrective surgery is performed in the first few months of life. Corrective surgery is done to widen part of the narrowed pulmonary tract and close the ventricular septal defect with a patch.

Outlook (Prognosis)

Most cases can be corrected with surgery. Babies who have surgery usually do well. More than 90% survive to adulthood and live active, healthy, and productive lives. Without surgery, death often occurs by the time the person reaches age 20.

People who have continued, severe leakiness of the pulmonary valve may need to have the valve replaced.

Regular follow-up with a cardiologist is strongly recommended.

Possible Complications

Complications may include:

When to Contact a Medical Professional

Call your health care provider if new unexplained symptoms develop or the child is having an episode of cyanosis (blue skin).

If a child with tetralogy of Fallot becomes blue, immediately place the child on their side or back and put the knees up to the chest. Calm the child and seek medical attention right away.

Prevention

There is no known way to prevent the condition.

Related Information

Rubella
Diabetes
Blue discoloration of the skin
Ventricular septal defect
Delayed growth
Seizures
Pediatric heart surgery
Pediatric heart surgery - discharge

References

Bernstein D. Cyanotic congenital heart disease: evaluation of the critically ill neonate with cyanosis and respiratory distress. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 21th ed. Philadelphia, PA: Elsevier; 2019:chap 456.

Fraser CD, Kane LC. Congenital heart disease. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 20th ed. Philadelphia, PA: Elsevier; 2017:chap 58.

Webb GD, Smallhorn JF, Therrien J, Redington AN. Congenital heart disease in the adult and pediatric patient. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier; 2019:chap 75.

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Review Date: 10/22/2019  

Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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