Update on the Diagnosis and Management of Familial Long QT Syndrome.
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.
Green Lane Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland New Zealand; The University of Auckland, Department of Child Health, Auckland, New Zealand.
Kathryn E
KE
Waddell-Smith
Green Lane Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland New Zealand; The University of Auckland, Department of Child Health, Auckland, New Zealand. Electronic address: jskinner@adhb.govt.nz.
Jonathan R
JR
Skinner
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000072237:ERG1 Potassium Channel / Q000235:genetics; D005260:Female; D030342:Genetic Diseases, Inborn / Q000175:diagnosis / Q000235:genetics / Q000628:therapy; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000235:genetics; D008133:Long QT Syndrome / Q000175:diagnosis / Q000235:genetics / Q000628:therapy; D008297:Male; D009154:Mutation; D011110:Polymorphism, Genetic
D048868:Adaptor Proteins, Signal Transducing; D000072237:ERG1 Potassium Channel; C000606913:KCNH2 protein, human; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; C488081:NOS1AP protein, human
Diagnosis; Genetics; Long QT syndrome; Management; Sudden death