Long QT syndrome revisited.

Congenital Long QT Syndrome (cLQTS) is an inherited disease in children and adolescents who have structurally normal hearts but present with sudden death in a high proportion of untreated patients. More than 300 mutations have been identified in 7 LQT genes. Diagnosis still depends on ECG, clinical presentations and family history. Molecular genetic testing is useful to unravel borderline family members of LQT probands, but it continues to be a research tool at present. Beta blockers remain the mainstay of treatment. ICDs are highly effective in reducing SCD for high risk patients. Gene based therapy is still preliminary. Considerable thought is needed to address and treat the asymptomatic LQT family members. The main cause of Acquired LQTS is inhibition of Ikr current, usually by drugs. Care must be taken to avoid further exposure to QT prolonging drugs or conditions. Physicians need to be aware of the pharmacodynamic and pharmacokinetic interactions of various important drugs.