1. Long QT syndrome — a cause of sudden death
- Author
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Dembić, Maja, Brusich, Sandro, Louise Hedley, Paula, De Villiers, Carin Pamela, Čubranić, Zlatko, Kanters, Jorgen Kim, Zaputović, Luka, and Christiansen, Michael
- Subjects
BIOMEDICINA I ZDRAVSTVO. Kliničke medicinske znanosti. Interna medicina ,sindrom dugog QT intervala ,aritmije srca ,iznenadna srčana smrt ,long QT sindrome ,iznenadna srcana smrt ,sudden cardiac death ,arrhythmia ,BIOMEDICINE AND HEALTHCARE. Clinical Medical Sciences. Internal Medicine - Abstract
Sindrom dugog QT intervala (LQTS) je primarni aritmijski poremeÊaj koji moæe dovesti do pojave malignih ventrikularnih aritmija tipa torsades de pointes (TdP) i iznenadne srËane smrti. Obiljeæja u elektrokardiogramu (EKG) ukljuËuju produljenje korigiranog QT intervala i abnormalnosti T-vala. Do danas identificirana genetska osnova za LQTS ukljuËuje trinaest podloænih gena: KCNQ1, KCNH2, SCN5A, ANK2, KCNE1, KCNE2, KCNJ2, CACNA1C, CAV3, SCN4B, AKAP9, SNTA1, i KCNJ5. NajËeπÊi genotip su mutacije KCNQ1 te gotovo polovica pacijenata ima tu vrstu mutacije. Navedeni geni kodiraju ionske kanale i regulatorne proteine koji su ukljuËeni u modulaciju struja srËanog akcijskog potencijala. SteËeni oblici LQTS-a mogu takoer biti uzrokovani genetskim mutacijama, u tim sluËajevima nositelji mutacija razvijaju aritmije iskljuËivo u odreenim uvjetima (npr. uporaba odreenih lijekova). Trenutna terapija ukljuËuje primjenu beta-blokatora, ugradnju implantabilnog kardioverter defibrilatora (ICD) te simpatiËku denervaciju srca. LQTS mutacije povezane su s iznenadnom srËanom smrti kod mladih i veoma mladih; a post-mortem genetska testiranja LQTS gena mogu biti korisna kod procjene uzroka iznenadne neobjaπnjive smrti (sudden unexplained death). Kaskadni probir koristan je za identificiranje asimptomatskih Ëlanova obitelji koji mogu biti pod poveÊanim rizikom od iznenadne smrti. U ovom preglednom Ëlanku prikazali smo gene povezane s LQTS-om zajedno s opisom povezanih patofizioloπkih mehanizama., Long QT syndrome (LQTS) is a primary arrhythmic disorder that may lead to the precipitation of torsades de pointes (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: 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
- Published
- 2012