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Long QT syndrome

Last updated: December 16, 2019

Summary

Long QT syndrome (LQTS) is a congenital or acquired heart condition in which the QT interval (i.e., ventricular depolarization and repolarization) is prolonged. Most patients with LQTS are asymptomatic, but some present with seizures, syncope, or even life-threatening arrhythmias and sudden death. Treatment depends on the underlying cause: Beta blockers and implantable cardioverter defibrillator (ICD) insertion are commonly used for congenital LQTS, whereas treatment of the underlying cause (drug, electrolyte abnormality, etc.) is the first-line therapy for acquired LQTS.

Etiology

A prolonged QT interval may be congenital or acquired.

Congenital LQTS

Acquired LQTS

References:[5][6][7][8][9][10][11]

Clinical features

References:[5]

Diagnostics

  • Genetic testing confirms the diagnosis of LQTS.

References:[6][12]

Treatment

All treatment modalities aim to reduce the risk and severity of cardiac events!

References:[6]

Complications

References:[13]

We list the most important complications. The selection is not exhaustive.

References

  1. Herold G. Internal Medicine. Herold G ; 2014
  2. Jervell and Lange-Nielsen syndrome. http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=12056&Disease_Disease_Search_diseaseGroup=jervell&Disease_Disease_Search_diseaseType=Pat&Krankheite(n)/Krankheitsgruppe=Jervell-Lange-Nielsen-Syndrom&title=Jervell-Lange-Nielsen-Syndrom&search=Disease_Search_Simple. Updated: October 1, 2009. Accessed: December 6, 2017.
  3. Romano-Ward Syndrome. http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=14727&Disease_Disease_Search_diseaseGroup=romano&Disease_Disease_Search_diseaseType=Pat&Disease(s)/group%20of%20diseases=Romano-Ward-syndrome&title=Romano-Ward-syndrome&search=Disease_Search_Simple. Updated: October 1, 2009. Accessed: December 6, 2017.
  4. Berul CI. Acquired Long QT Syndrome: Definitions, Causes, and Pathophysiology. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/acquired-long-qt-syndrome .Last updated: January 3, 2018. Accessed: December 6, 2017.
  5. Seslar SP, Zimetbaum PJ, Berul CI. Clinical features of congenital long QT syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. http://www.uptodate.com/contents/clinical-features-of-congenital-long-qt-syndrome.Last updated: December 4, 2014. Accessed: February 13, 2017.
  6. Sovari AA. Long QT Syndrome. In: Rottman JN, Long QT Syndrome. New York, NY: WebMD. http://emedicine.medscape.com/article/157826. Updated: December 31, 2015. Accessed: February 13, 2017.
  7. Zimetbaum PJ. Genetics of Congenital and Acquired Long QT Syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/genetics-of-congenital-and-acquired-long-qt-syndrome.Last updated: January 8, 2016. Accessed: November 13, 2017.
  8. Jervell and Lange-Nielsen Syndrome. https://ghr.nlm.nih.gov/condition/jervell-and-lange-nielsen-syndrome. Updated: November 7, 2017. Accessed: November 13, 2017.
  9. Jervell and Lange-Nielsen Syndrome.
  10. Berul CI, Zimetbaum PJ. Acquired Long QT Syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/acquired-long-qt-syndrome.Last updated: October 16, 2017. Accessed: November 14, 2017.
  11. Yap YG, Camm AJ. Drug induced QT prolongation and torsades de pointes. Heart. 2003; 89 (11): p.1363–1372.
  12. Seslar SP, Zimetbaum PJ, Berul CI. Diagnosis of congenital long QT syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/diagnosis-of-congenital-long-qt-syndrome?source=search_result&search=long%20qt%20syndrome.Last updated: May 1, 2014. Accessed: May 3, 2017.
  13. Zimetbaum PJ, Berul CI. Prognosis and Management of Congenital Long QT Syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/prognosis-and-management-of-congenital-long-qt-syndrome.Last updated: September 28, 2017. Accessed: November 14, 2017.