Review article

Long QT syndrome — a cause of sudden death.

Maja Dembić ; Statens Serum Institut, Copenhagen, Denmark
Sandro Brusich ; Clinical Hospital Center Rijeka, Rijeka, Croatia
Paula Louise Hedley ; Faculty of Health Sciences, University of Stellenbosch, Cape Town, South Africa
Carin Pamela de Villiers ; Faculty of Health Sciences, University of Stellenbosch, Cape Town, South Africa
Zlatko Čubranić ; Clinical Hospital Center Rijeka, Rijeka, Croatia
Jorgen Kim Kanters ; University of Copenhagen, Copenhagen, Denmark
Luka Zaputović ; Clinical Hospital Center Rijeka, Rijeka, Croatia
Michael Christiansen ; Statens Serum Institut, Copenhagen, Denmark

Abstract

Long QT syndrome (LQTS) is a primary arrhythmic disorder that may lead to the precipitation of torsades de pointe (TdP) and sudden death. Electrocardiogram (ECG) features include prolongation of the corrected QT interval and T-wave abnormalities. The genetic basis of LQTS identified to date includes thirteen susceptibility genes for LQTS: KCNQ1, KCNH2, SCN5A, ANK2, KCNE1, KCNE2, KCNJ2, CACNA1C, CAV3, SCN4B, AKAP9, SNTA1, and KCNJ5. Mutations in KCNQ1 are by far the most frequent genotype with nearly half of the patients carrying KCNQ1 mutations. These genes code for ion channels and regulatory proteins that are involved in the modulation of the currents of the cardiac action potential (AP). Acquired forms of LQTS may also have underlying genetic mutations, in these cases mutation carriers develop arrhythmias only under certain conditions (e.g. use of certain medications). Current therapies include use of beta-blockers, implantable cardioverter defibrillators (ICD) and left cardiac sympathetic denervation. LQTS mutations have been associated with sudden death in the young and very young; and postmortem genetic testing in LQTS genes can be useful when assessing the cause of a sudden unexplained death. Cascade screening is also useful to identify asymptomatic family members that may be at risk of sudden death. Here we have reviewed the genes associated with LQTS along with the description of the related pathophysiological mechanisms.

Keywords

long QT sindrome; arrhythmia; sudden cardiac death

Hrčak ID:

94688

URI

https://hrcak.srce.hr/94688

Publication date:

4.12.2012.

Article data in other languages: croatian

Visits: 4.605 *