Skip to main content

The Long QT Syndrome

  • Chapter
  • First Online:
Clinical Approach to Sudden Cardiac Death Syndromes

Abstract

The hereditary long QT syndrome (LQT) is a disease characterized by lengthened ventricular repolarization, diagnosed by the presence of a prolongation of the QT interval on the electrocardiogram (ECG) (Fig. 9.1) and associated with sudden cardiac death (SCD). The prevalence of the disease is thought to be around 1/5,000 of the general population. While the majority of patients with the LQT syndrome are at present asymptomatic, mainly due to the identification of family members during familial screening, the phenotype is varied and can range from asymptomatic individuals to syncopal episodes, seizures, malignant ventricular arrhythmias, and ventricular fibrillation. Approximately 1/3 of individuals present with syncope or aborted malignant ventricular arrhythmias, including torsades de pointes, which is the most typical ventricular arrhythmia in LQT syndrome. Symptoms in the LQT syndrome are limited to the cardiac system with the exception of individuals with the recessive form or Jervell and Lange-Nielsen who also present with neural deafness.1-6

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 84.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 149.00
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 109.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. Marijon E, Combes N, Albenque JP. Long-QT syndrome. N Engl J Med. 2008;358(18):1967; author reply 1968

    Google Scholar 

  2. Moss AJ, Schwartz PJ, Crampton RS, Locati E, Carleen E. The long QT syndrome: a prospective international study. Circulation. 1985;71(1):17-21

    CAS  PubMed  Google Scholar 

  3. Moss AJ, Schwartz PJ, Crampton RS, et al. The long QT syndrome. Prospective longitudinal study of 328 families. Circulation. 1991;84(3):1136-1144

    CAS  PubMed  Google Scholar 

  4. Romano C. Congenital cardiac arrhythmia. Lancet. 1965; 1(7386):658-659

    Article  CAS  PubMed  Google Scholar 

  5. Schwartz PJ, Malliani A. Electrical alternation of the T-wave: clinical and experimental evidence of its relationship with the sympathetic nervous system and with the long Q-T syndrome. Am Heart J. 1975;89(1):45-50

    Article  CAS  PubMed  Google Scholar 

  6. Ward OC. A new familial cardiac syndrome in children. J Ir Med Assoc. 1964;54:103-106

    CAS  PubMed  Google Scholar 

  7. Lehnart SE, Ackerman MJ, Benson DW Jr, et al. Inherited arrhythmias: a National Heart, Lung, and Blood Institute and Office of Rare Diseases workshop consensus report about the diagnosis, phenotyping, molecular mechanisms, and therapeutic approaches for primary cardiomyopathies of gene mutations affecting ion channel function. Circulation. 2007;116(20):2325-2345

    Article  CAS  PubMed  Google Scholar 

  8. Zareba W. Drug induced QT prolongation. Cardiol J. 2007; 14(6):523-533

    PubMed  Google Scholar 

  9. Bazett HC. The time relations of the blood-pressure changes after excision of the adrenal glands, with some observations on blood volume changes. J Physiol. 1920;53(5):320-339

    CAS  PubMed  Google Scholar 

  10. Goldenberg I, Moss AJ, Zareba W. QT interval: how to measure it and what is “normal”. J Cardiovasc Electrophysiol. 2006;17(3):333-336

    Article  PubMed  Google Scholar 

  11. Moss AJ, Robinson JL. Clinical aspects of the idiopathic long QT syndrome. Ann N Y Acad Sci. 1992;644:103-111

    Article  CAS  PubMed  Google Scholar 

  12. Benatar A, Decraene T. Comparison of formulae for heart rate correction of QT interval in exercise ECGs from healthy children. Heart. 2001;86(2):199-202

    Article  CAS  PubMed  Google Scholar 

  13. Schwartz PJ, Moss AJ, Vincent GM, Crampton RS. Diagnostic criteria for the long QT syndrome. An update. Circulation. 1993;88(2):782-784

    CAS  PubMed  Google Scholar 

  14. Vincent GM, Timothy KW, Leppert M, Keating M. The spectrum of symptoms and QT intervals in carriers of the gene for the long-QT syndrome. N Engl J Med. 1992;327(12): 846-852

    Article  CAS  PubMed  Google Scholar 

  15. Moss AJ, Zareba W, Benhorin J, et al. ECG T-wave patterns in genetically distinct forms of the hereditary long QT syndrome. Circulation. 1995;92(10):2929-2934

    CAS  PubMed  Google Scholar 

  16. Clancy CE, Tateyama M, Kass RS. Insights into the molecular mechanisms of bradycardia-triggered arrhythmias in long QT-3 syndrome. J Clin Invest. 2002;110(9):1251-1262

    CAS  PubMed  Google Scholar 

  17. Priori SG, Napolitano C, Schwartz PJ. Low penetrance in the long-QT syndrome: clinical impact. Circulation. 1999; 99(4):529-533

    CAS  PubMed  Google Scholar 

  18. Ackerman MJ, Khositseth A, Tester DJ, Hejlik JB, Shen WK, Porter CB. Epinephrine-induced QT interval prolongation: a gene-specific paradoxical response in congenital long QT syndrome. Mayo Clin Proc. 2002;77(5):413-421

    Article  CAS  PubMed  Google Scholar 

  19. Shimizu W, Noda T, Takaki H, et al. Epinephrine unmasks latent mutation carriers with LQT1 form of congenital long-QT syndrome. J Am Coll Cardiol. 2003;41(4):633-642

    Article  CAS  PubMed  Google Scholar 

  20. Swan H, Viitasalo M, Piippo K, Laitinen P, Kontula K, Toivonen L. Sinus node function and ventricular repolarization during exercise stress test in long QT syndrome patients with KvLQT1 and HERG potassium channel defects. J Am Coll Cardiol. 1999;34(3):823-829

    Article  CAS  PubMed  Google Scholar 

  21. Jervell A, Lange-Nielsen F. Congenital deaf-mutism, functional heart disease with prolongation of the Q-T interval and sudden death. Am Heart J. 1957;54(1):59-68

    Article  CAS  PubMed  Google Scholar 

  22. Priori SG, Schwartz PJ, Napolitano C, et al. Risk stratification in the long-QT syndrome. N Engl J Med. 2003;348(19): 1866-1874

    Article  PubMed  Google Scholar 

  23. Schwartz PJ, Priori SG, Spazzolini C, et al. Genotype-phenotype correlation in the long-QT syndrome: gene-specific triggers for life-threatening arrhythmias. Circulation. 2001;103(1):89-95

    CAS  PubMed  Google Scholar 

  24. Splawski I, Shen J, Timothy KW, et al. Spectrum of mutations in long-QT syndrome genes. KVLQT1, HERG, SCN5A, KCNE1, and KCNE2. Circulation. 2000;102(10): 1178-1185

    CAS  PubMed  Google Scholar 

  25. Zareba W, Moss AJ, Schwartz PJ, et al. Influence of genotype on the clinical course of the long-QT syndrome. International Long-QT Syndrome Registry Research Group. N Engl J Med. 1998;339(14):960-965

    Article  CAS  PubMed  Google Scholar 

  26. Keating M, Atkinson D, Dunn C, Timothy K, Vincent GM, Leppert M. Linkage of a cardiac arrhythmia, the long QT syndrome, and the Harvey ras-1 gene. Science. 1991;252(5006):704-706

    Article  CAS  PubMed  Google Scholar 

  27. Keating M, Dunn C, Atkinson D, Timothy K, Vincent GM, Leppert M. Consistent linkage of the long-QT syndrome to the Harvey ras-1 locus on chromosome 11. Am J Hum Genet. 1991;49(6):1335-1339

    CAS  PubMed  Google Scholar 

  28. Barhanin J, Lesage F, Guillemare E, Fink M, Lazdunski M, Romey G. K(V)LQT1 and lsK (minK) proteins associate to form the I(Ks) cardiac potassium current. Nature. 1996;384(6604):78-80

    Article  CAS  PubMed  Google Scholar 

  29. Sanguinetti MC, Curran ME, Zou A, et al. Coassembly of K(V)LQT1 and minK (IsK) proteins to form cardiac I(Ks) potassium channel. Nature. 1996;384(6604):80-83

    Article  CAS  PubMed  Google Scholar 

  30. Anderson CL, Delisle BP, Anson BD, et al. Most LQT2 mutations reduce Kv11.1 (hERG) current by a class 2 (trafficking-deficient) mechanism. Circulation. 2006;113(3): 365-373

    Article  CAS  PubMed  Google Scholar 

  31. Jiang C, Atkinson D, Towbin JA, et al. Two long QT syndrome loci map to chromosomes 3 and 7 with evidence for further heterogeneity. Nat Genet. 1994;8(2):141-147

    Article  CAS  PubMed  Google Scholar 

  32. Warmke JW, Ganetzky B. A family of potassium channel genes related to eag in Drosophila and mammals. Proc Natl Acad Sci USA. 1994;91(8):3438-3442

    Article  CAS  PubMed  Google Scholar 

  33. Bennett PB, Yazawa K, Makita N, George AL Jr. Molecular mechanism for an inherited cardiac arrhythmia. Nature. 1995;376(6542):683-685

    Article  CAS  PubMed  Google Scholar 

  34. George AL Jr, Varkony TA, Drabkin HA, et al. Assignment of the human heart tetrodotoxin-resistant voltage-gated Na+ channel alpha-subunit gene (SCN5A) to band 3p21. Cytogenet Cell Genet. 1995;68(1-2):67-70

    Article  CAS  PubMed  Google Scholar 

  35. Wang Q, Shen J, Splawski I, et al. SCN5A mutations associated with an inherited cardiac arrhythmia, long QT syndrome. Cell. 1995;80(5):805-811

    Article  CAS  PubMed  Google Scholar 

  36. Mohler PJ, Schott JJ, Gramolini AO, et al. Ankyrin-B mutation causes type 4 long-QT cardiac arrhythmia and sudden cardiac death. Nature. 2003;421(6923):634-639

    Article  CAS  PubMed  Google Scholar 

  37. Mohler PJ, Splawski I, Napolitano C, et al. A cardiac arrhythmia syndrome caused by loss of ankyrin-B function. Proc Natl Acad Sci USA. 2004;101(24):9137-9142

    Article  CAS  PubMed  Google Scholar 

  38. Bianchi L, Shen Z, Dennis AT, et al. Cellular dysfunction of LQT5-minK mutants: abnormalities of IKs, IKr and trafficking in long QT syndrome. Hum Mol Genet. 1999;8(8): 1499-1507

    Article  CAS  PubMed  Google Scholar 

  39. Krumerman A, Gao X, Bian JS, Melman YF, Kagan A, McDonald TV. An LQT mutant minK alters KvLQT1 trafficking. Am J Physiol Cell Physiol. 2004;286(6): C1453-C1463

    Article  Google Scholar 

  40. van den Berg MH, Wilde AA, de Medina EO Robles, et al. The long QT syndrome: a novel missense mutation in the S6 region of the KVLQT1 gene. Hum Genet. 1997;100(3-4):356-361

    Article  PubMed  Google Scholar 

  41. Isbrandt D, Friederich P, Solth A, et al. Identification and functional characterization of a novel KCNE2 (MiRP1) mutation that alters HERG channel kinetics. J Mol Med. 2002;80(8):524-532

    Article  CAS  PubMed  Google Scholar 

  42. Larsen LA, Andersen PS, Kanters J, et al. Screening for mutations and polymorphisms in the genes KCNH2 and KCNE2 encoding the cardiac HERG/MiRP1 ion channel: implications for acquired and congenital long Q-T syndrome. Clin Chem. 2001;47(8):1390-1395

    CAS  PubMed  Google Scholar 

  43. Lu Y, Mahaut-Smith MP, Huang CL, Vandenberg JI. Mutant MiRP1 subunits modulate HERG K+ channel gating: a mechanism for pro-arrhythmia in long QT syndrome type 6. J Physiol. 2003;551(Pt 1):253-262

    Article  CAS  PubMed  Google Scholar 

  44. Tawil R, Ptacek LJ, Pavlakis SG, et al. Andersen’s syndrome: potassium-sensitive periodic paralysis, ventricular ectopy, and dysmorphic features. Ann Neurol. 1994;35(3): 326-330

    Article  CAS  PubMed  Google Scholar 

  45. Tsuboi M, Antzelevitch C. Cellular basis for electrocardiographic and arrhythmic manifestations of Andersen-Tawil syndrome (LQT7). Heart Rhythm. 2006;3(3):328-335

    Article  PubMed  Google Scholar 

  46. Plaster NM, Tawil R, Tristani-Firouzi M, et al. Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen’s syndrome. Cell. 2001;105(4):511-519

    Article  CAS  PubMed  Google Scholar 

  47. Splawski I, Timothy KW, Sharpe LM, et al. Ca(V)1.2 calcium channel dysfunction causes a multisystem disorder including arrhythmia and autism. Cell. 2004;119(1):19-31

    Article  CAS  PubMed  Google Scholar 

  48. Vatta M, Ackerman MJ, Ye B, et al. Mutant caveolin-3 induces persistent late sodium current and is associated with long-QT syndrome. Circulation. 2006;114(20):2104-2112

    Article  CAS  PubMed  Google Scholar 

  49. Medeiros-Domingo A, Kaku T, Tester DJ, et al. SCN4B-encoded sodium channel beta4 subunit in congenital long-QT syndrome. Circulation. 2007;116(2):134-142

    Article  PubMed  Google Scholar 

  50. Chen L, Marquardt ML, Tester DJ, Sampson KJ, Ackerman MJ, Kass RS. Mutation of an A-kinase-anchoring protein causes long-QT syndrome. Proc Natl Acad Sci USA. 2007; 104(52): 20990-20995

    Article  CAS  PubMed  Google Scholar 

  51. Ueda K, Valdivia C, Medeiros-Domingo A, et al. Syntrophin mutation associated with long QT syndrome through activation of the nNOS-SCN5A macromolecular complex. Proc Natl Acad Sci USA. 2008;105(27):9355-9360

    Article  CAS  PubMed  Google Scholar 

  52. Cronk LB, Ye B, Kaku T, et al. Novel mechanism for sudden infant death syndrome: persistent late sodium current secondary to mutations in caveolin-3. Heart Rhythm. 2007;4(2): 161-166

    Article  PubMed  Google Scholar 

  53. Hobbs JB, Peterson DR, Moss AJ, et al. Risk of aborted cardiac arrest or sudden cardiac death during adolescence in the long-QT syndrome. JAMA. 2006;296(10):1249-1254

    Article  CAS  PubMed  Google Scholar 

  54. Moss AJ, Zareba W, Kaufman ES, et al. Increased risk of arrhythmic events in long-QT syndrome with mutations in the pore region of the human ether-a-go-go-related gene potassium channel. Circulation. 2002;105(7):794-799

    Article  CAS  PubMed  Google Scholar 

  55. Moss AJ, Shimizu W, Wilde AA, et al. Clinical aspects of type-1 long-QT syndrome by location, coding type, and biophysical function of mutations involving the KCNQ1 gene. Circulation. 2007;115(19):2481-2489

    Article  CAS  PubMed  Google Scholar 

  56. Schwartz PJ, Priori SG, Locati EH, et al. Long QT syndrome patients with mutations of the SCN5A and HERG genes have differential responses to Na+ channel blockade and to increases in heart rate. Implications for gene-specific therapy. Circulation. 1995;92(12):3381-3386

    CAS  PubMed  Google Scholar 

  57. Goldenberg I, Moss AJ, Bradley J, et al. Long-QT syndrome after age 40. Circulation. 2008;117(17):2192-2201

    Article  PubMed  Google Scholar 

  58. Kaufman ES, McNitt S, Moss AJ, et al. Risk of death in the long QT syndrome when a sibling has died. Heart Rhythm. 2008;5(6):831-836

    Article  PubMed  Google Scholar 

  59. Moss AJ, Zareba W, Hall WJ, et al. Effectiveness and limitations of beta-blocker therapy in congenital long-QT syndrome. Circulation. 2000;101(6):616-623

    CAS  PubMed  Google Scholar 

  60. Windle JR, Geletka RC, Moss AJ, Zareba W, Atkins DL. Normalization of ventricular repolarization with flecainide in long QT syndrome patients with SCN5A:DeltaKPQ mutation. Ann Noninvasive Electrocardiol. 2001;6(2):153-158

    Article  CAS  PubMed  Google Scholar 

  61. Fan K, Lee K, Lau CP. Dual chamber implantable cardioverter defibrillator benefits and limitations. J Interv Card Electrophysiol. 1999;3(3):239-245

    Article  CAS  PubMed  Google Scholar 

  62. Groh WJ, Silka MJ, Oliver RP, Halperin BD, McAnulty JH, Kron J. Use of implantable cardioverter-defibrillators in the congenital long QT syndrome. Am J Cardiol. 1996;78(6): 703-706

    Article  CAS  PubMed  Google Scholar 

  63. Zareba W, Cygankiewicz I. Long QT syndrome and short QT syndrome. Prog Cardiovasc Dis. 2008;51(3):264-278

    Article  PubMed  Google Scholar 

  64. Udo EO, Baars HF, Winter JB, Wilde AA. Not just any ICD device in patients with long-QT syndrome. Neth Heart J. 2007;15(12):418-421

    Article  CAS  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Oscar Campuzano .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2010 Springer-Verlag London

About this chapter

Cite this chapter

Brugada, R., Campuzano, O. (2010). The Long QT Syndrome. In: Brugada, R. (eds) Clinical Approach to Sudden Cardiac Death Syndromes. Springer, London. https://doi.org/10.1007/978-1-84882-927-5_9

Download citation

  • DOI: https://doi.org/10.1007/978-1-84882-927-5_9

  • Published:

  • Publisher Name: Springer, London

  • Print ISBN: 978-1-84882-926-8

  • Online ISBN: 978-1-84882-927-5

  • eBook Packages: MedicineMedicine (R0)

Publish with us

Policies and ethics