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Tetralogy of Fallot

Tetralogy of Fallot is a topic covered in the 5-Minute Clinical Consult.

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  • Tetralogy of Fallot is a ventricular septal defect associated with right ventricular (RV) outflow obstruction (infundibular and/or valvular pulmonic stenosis), concentric RV hypertrophy, and overriding aorta (1).
    • Pathophysiology depends primarily on severity of RV outflow tract obstruction.
    • RV and left ventricular (LV) pressures generally are equal owing to the defect.
    • RV pressures can be elevated with ventricular septal defect proximal to the level of RV obstruction.
    • Right-to-left shunting predominates, resulting in varying degrees of arterial oxygen desaturation.
  • System(s) affected: cardiovascular, pulmonary

Pediatric Considerations
Congenital disorder

Pregnancy Considerations
Pregnancy is usually well tolerated following successful surgical repair.


  • 5–10% of all congenital heart disease (1)
  • Most common cardiac anomaly within the 1st year of life requiring intervention
  • Predominant age: newborn; case reports of adult presentation
  • Predominant sex: male = female

In the United States: 3.9/10,000 live births

Etiology and Pathophysiology


  • Minority of cases are familial, autosomal dominant mode of inheritance.
  • 20% association with velocardiofacial syndrome (22q11 deletion) by FISH analysis

Risk Factors

  • Predominately sporadic
  • Increased incidence with advanced maternal age

Commonly Associated Conditions

  • Stenotic pulmonary artery
  • Patent ductus arteriosus
  • Atrial septal defect
  • Right-sided aortic arch: 25%
  • Atrial septal defect: 15%
  • Anomalous coronary arteries: 9%
  • 20–25% associated with a syndrome, including Down, Alagille, DiGeorge, and velocardiofacial

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Stephens, Mark B., et al., editors. "Tetralogy of Fallot." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2019. 5minute, www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/816269/all/Tetralogy_of_Fallot.
Tetralogy of Fallot. In: Stephens MB, Golding J, Baldor RA, et al, eds. 5-Minute Clinical Consult. 27th ed. Wolters Kluwer; 2019. https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/816269/all/Tetralogy_of_Fallot. Accessed May 21, 2019.
Tetralogy of Fallot. (2019). In Stephens, M. B., Golding, J., Baldor, R. A., & Domino, F. J. (Eds.), 5-Minute Clinical Consult. Available from https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/816269/all/Tetralogy_of_Fallot
Tetralogy of Fallot [Internet]. In: Stephens MB, Golding J, Baldor RA, Domino FJ, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2019. [cited 2019 May 21]. Available from: https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/816269/all/Tetralogy_of_Fallot.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Tetralogy of Fallot ID - 816269 ED - Stephens,Mark B, ED - Golding,Jeremy, ED - Baldor,Robert A, ED - Domino,Frank J, BT - 5-Minute Clinical Consult, Updating UR - https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/816269/all/Tetralogy_of_Fallot PB - Wolters Kluwer ET - 27 DB - 5minute DP - Unbound Medicine ER -