Pediatric Long QT Syndrome Clinical Presentation

Updated: Dec 27, 2020
  • Author: Sreekanth S Raghavan, MBBS, , FACC; Chief Editor: Stuart Berger, MD  more...
  • Print


The clinical diagnosis of long QT syndrome is prompted by a high degree of clinical suspicion, which arises from the presenting complaints. [11] A detailed family history for similar symptoms is warranted. The presenting complaints may include the following:

  • Unexplained bradycardia - Especially in the newborn

  • Syncope - Especially when associated with a triggering event (eg, drowning, near drowning) [11]

  • Epilepsy - Especially not controlled by conventional medications

  • Palpitations

  • Aborted or sudden cardiac death in the patient or family history of sudden cardiac death

  • Sudden infant death syndrome (SIDS)

  • Depressive symptoms [12]


Physical Examination

Certain physical findings in long QT syndrome, such as skeletal abnormalities (eg, short stature, scoliosis), may suggest Andersen syndrome, whereas congenital heart diseases, along with cognitive and behavioral problems, musculoskeletal diseases, and immune dysfunction, may suggest Timothy syndrome. Congenital deafness is seen in JLN syndrome, although the incidence of long QT syndrome in patients with congenital deafness is very low.