Tetralogy of Fallot

Not to be confused with Teratology.
Tetralogy of Fallot
Other namesFallot’s syndrome, Fallot’s tetrad, Steno-Fallot tetralogy[1]
Diagram of a healthy heart and one with tetralogy of Fallot
SpecialtyCardiac surgery, pediatrics
SymptomsEpisodes of bluish color to the skin, difficulty breathing, heart murmur, finger clubbing[2]
ComplicationsIrregular heart rate, pulmonary regurgitation[3]
Usual onsetFrom birth[4]
CausesUnknown[5]
Risk factorsAlcohol, diabetes, >40, rubella during pregnancy[5]
Diagnostic methodBased on symptoms, echocardiogram[6]
Differential diagnosisTransposition of the great arteries, Eisenmenger syndrome, Ebstein anomaly[7]
TreatmentOpen heart surgery[8]
Frequency1 in 2,000 babies[4]

Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy,[9] is a congenital heart defect characterized by four specific cardiac defects.[4] Classically, the four defects are:[4]

At birth, children may be asymptomatic or present with many severe symptoms.[10] Later in infancy, there are typically episodes of bluish colour to the skin due to a lack of sufficient oxygenation, known as cyanosis.[2] When affected babies cry or have a bowel movement, they may undergo a "tet spell" where they turn cyanotic, have difficulty breathing, become limp, and occasionally lose consciousness.[2] Other symptoms may include a heart murmur, finger clubbing, and easy tiring upon breastfeeding.[2]

The cause of tetralogy of Fallot is typically not known.[5] Risk factors include a mother who uses alcohol, has diabetes, is over the age of 40, or gets rubella during pregnancy.[5]: 62  It may also be associated with Down syndrome and other chromosomal defects that cause congenital heart defects.[11]

TOF is typically treated by open heart surgery in the first year of life.[8] The timing of surgery depends on the baby's symptoms and size.[8] The procedure involves increasing the size of the pulmonary valve and pulmonary arteries and repairing the ventricular septal defect.[8] In babies who are too small, a temporary surgery may be done with plans for a second surgery when the baby is bigger.[8] With proper care, most people who are affected live to be adults.[4] Long-term problems may include an irregular heart rate and pulmonary regurgitation.[3]

The prevalence of TOF is estimated to be anywhere from 0.02 to 0.04%.[4] Though males and females were initially thought to be affected equally, more recent studies have found males to be affected more than females.[4][12] It is the most common complex congenital heart defect, accounting for about 10 percent of cases.[13][14] It was initially described in 1671 by Niels Steensen.[1][15] A further description was published in 1888 by the French physician Étienne-Louis Arthur Fallot, after whom it is named.[1][16] The first total surgical repair was carried out in 1954.[3]

  1. ^ a b c Lehn M. "Fallot's tetralogy". Whonamedit?. Archived from the original on 3 October 2016. Retrieved 2 October 2016.
  2. ^ a b c d "What Are the Signs and Symptoms of Tetralogy of Fallot?". NHLBI. 1 July 2011. Archived from the original on 5 October 2016. Retrieved 2 October 2016.
  3. ^ a b c Warnes CA (July 2005). "The adult with congenital heart disease: born to be bad?". Journal of the American College of Cardiology. 46 (1): 1–8. doi:10.1016/j.jacc.2005.02.083. PMID 15992627.
  4. ^ a b c d e f g "What Is Tetralogy of Fallot?". NHLBI. 1 July 2011. Archived from the original on 4 October 2016. Retrieved 2 October 2016.
  5. ^ "How Is Tetralogy of Fallot Diagnosed?". NHLBI. 1 July 2011. Archived from the original on 29 April 2017. Retrieved 7 May 2017.
  6. ^ Prasad R, Kahan S, Mohan P (2007). In a Page: Cardiology. Lippincott Williams & Wilkins. ISBN 9780781764964. Archived from the original on 2021-05-15. Retrieved 2017-09-15.
  7. ^ a b c d e "How Is Tetralogy of Fallot Treated?". NHLBI. July 1, 2011. Archived from the original on 5 October 2016. Retrieved 2 October 2016.
  8. ^ Diaz-Frias J, Guillaume M (2021). "Tetralogy of Fallot". StatPearls. Treasure Island (FL): StatPearls Publishing. PMID 30020660. Archived from the original on 2020-08-12. Retrieved 2021-12-05.
  9. ^ Hay WW, Levin MJ, Deterding RR, Abzug MJ (2016-05-02). Current diagnosis & treatment: pediatrics (Twenty-third ed.). New York, NY. ISBN 9780071848541. OCLC 951067614.{{cite book}}: CS1 maint: location missing publisher (link)
  10. ^ "What Causes Tetralogy of Fallot?". NHLBI. 1 July 2011. Archived from the original on 5 October 2016. Retrieved 2 October 2016.
  11. ^ Cite error: The named reference NORD was invoked but never defined (see the help page).
  12. ^ Yuh DD (2014). Johns Hopkins textbook of cardiothoracic surgery (2nd ed.). New York: McGraw-Hill Companies. ISBN 9780071663502. OCLC 828334087.
  13. ^ "Types of Congenital Heart Defects". NHLBI. 1 July 2011. Archived from the original on 5 October 2016. Retrieved 2 October 2016.
  14. ^ Van Praagh R (2009). "The first Stella van Praagh memorial lecture: the history and anatomy of tetralogy of Fallot". Seminars in Thoracic and Cardiovascular Surgery. Pediatric Cardiac Surgery Annual. 12: 19–38. doi:10.1053/j.pcsu.2009.01.004. PMID 19349011.
  15. ^ Fallot A (1888). Contribution à l'anatomie pathologique de la maladie bleue (cyanose cardiaque), par le Dr. A. Fallot, ... (in French). Marseille: Impr. de Barlatier-Feissat. pp. 77–93. OCLC 457786038.