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Genetic and Rare Diseases Information Center (GARD)

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Long QT syndrome


* Not a rare disease
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What causes long QT syndrome?

Acquired long QT syndrome can be caused by certain medicines and medical conditions. Some medications that cause long QT syndrome include antihistamines and decongestants, antibiotics, antidepressants, and cholesterol-lowering medicines. Examples of medical conditions that can cause long QT syndrome include excessive diarrhea or vomiting and certain thyroid disorders.[1]

Inherited forms of long QT syndrome are caused by changes in genes that control the heart muscle’s electrical activity.[1] Inherited long QT syndrome may be isolated (occur alone without other associated symptoms) or be due to a genetic syndrome, such as Romano-Ward syndromeJervell Lang-Nielsen syndrome, Anderson-Tawil syndrome, and Timothy syndrome.[2]
Last updated: 10/4/2013

  1. Long QT syndrome. National Heart Lung and Blood Institute. 2007; Accessed 12/17/2008.
  2. Sovari AA, Kocheril AG, Assadi R Baas AS, Zareba W, Rosero S. Long QT syndrome. eMedicine. 2010; . Accessed 4/15/2011.