Update on the Diagnosis and Management of Familial Long QT Syndrome

Heart Lung Circ. 2016 Aug;25(8):769-76. doi: 10.1016/j.hlc.2016.01.020. Epub 2016 Mar 5.

Abstract

This update was reviewed by the CSANZ Continuing Education and Recertification Committee and ratified by the CSANZ board in August 2015. Since the CSANZ 2011 guidelines, adjunctive clinical tests have proven useful in the diagnosis of LQTS and are discussed in this update. Understanding of the diagnostic and risk stratifying role of LQTS genetics is also discussed. At least 14 LQTS genes are now thought to be responsible for the disease. High-risk individuals may have multiple mutations, large gene rearrangements, C-loop mutations in KCNQ1, transmembrane mutations in KCNH2, or have certain gene modifiers present, particularly NOS1AP polymorphisms. In regards to treatment, nadolol is preferred, particularly for long QT type 2, and short acting metoprolol should not be used. Thoracoscopic left cardiac sympathectomy is valuable in those who cannot adhere to beta blocker therapy, particularly in long QT type 1. Indications for ICD therapies have been refined; and a primary indication for ICD in post-pubertal females with long QT type 2 and a very long QT interval is emerging.

Keywords: Diagnosis; Genetics; Long QT syndrome; Management; Sudden death.

Publication types

  • Letter

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • ERG1 Potassium Channel / genetics
  • Female
  • Genetic Diseases, Inborn* / diagnosis
  • Genetic Diseases, Inborn* / genetics
  • Genetic Diseases, Inborn* / therapy
  • Humans
  • KCNQ1 Potassium Channel / genetics
  • Long QT Syndrome* / diagnosis
  • Long QT Syndrome* / genetics
  • Long QT Syndrome* / therapy
  • Male
  • Mutation*
  • Polymorphism, Genetic*

Substances

  • Adaptor Proteins, Signal Transducing
  • ERG1 Potassium Channel
  • KCNH2 protein, human
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human
  • NOS1AP protein, human