creators_name: Vincent, G. Michael editors_name: Singh, Balbir editors_name: Lokhandwala, Yash editors_name: Francis, Johnson editors_name: Gupta, Anup type: journalp datestamp: 2005-05-02 lastmod: 2011-03-11 08:56:01 metadata_visibility: show title: The Long QT Syndrome ispublished: pub subjects: ipej full_text_status: public keywords: cardiac ion channelopathies; Long QT syndrome abstract: The Long QT syndrome (LQTS) can be inherited or acquired and is of particular interest and concern at present. Patients with LQTS are predisposed to the ventricular tachyarrhythmia torsade de pointes (TdP) which causes syncope and sudden death. Inherited LQTS is the prototype of the “primary cardiac arrhythmias” or “cardiac ion channelopathies”. The study of inherited LQTS has provided enormous insight into the molecular basis of cardiac electrophysiology and arrhythmogenesis in general. Drug induced LQTS is the most common cause of acquired LQTS, and is a pressing public health issue. Considerable attention has been focussed on this form of LQTS following the withdrawal from the USA market of a number of prescription medications, including terfenedine in 2000 and cisapride in 2001. This review will discuss both forms, but with more emphasis on inherited LQTS. date: 2002-10 date_type: published publication: Indian Pacing and Electrophysiology Journal volume: 2 number: 4 publisher: Indian Pacing and Electrophysiology Group pagerange: 127-142 refereed: TRUE referencetext: 1. Jervell A, Lange-Nielsen F: Congenital deaf-mutism, functional heart disease with prolongation of the QT interval, and sudden death. Am Heart J 1957;54:59-68 2. Romano C, Genrme G, Pongiglione R.: Aritmie cardiache rare dell'eta pediatrica. Clin Pediatr 1963;45:656-683 3. Ward OC: A new familial cardiac syndrome in children. J Ir Med Assoc 1964;54:103-106 4. Splawski I, Shen J, Timothy KW, Lehmann MH, Priori S, Robinson JL, Moss AJ, Schwartz PJ, Towbin JA, Vincent GM, Keating MT: Spectrum of Mutations in Long-QT Syndrome Genes KVLQT1, HERG, SCN5A, KCNE1, and KCNE2. Circulation 2000;102:1178-1185 5. Schott JJ, Charpentier F, Peltier S, Foley P, Drouin E, Bouhour JB, Donnelly P, Vergnaud G, Bachner L, Moisan JP, et al: Mapping of a gene for long QT syndrome to chromosome 4q25-27. Am J Hum Genet 1995;57:1114-1122 6. Barhanin J, Lesage F, Guillemare E, Fink M, Lazdunski M, Romey G: KvLQT1 and IsK (minK) proteins associate to form the IKs cardiac potassium current. Nature 1996;384:78-80 7. Sanguinetti MC, Curran ME, Zou A, Shen J, Spector PS, Atkinson DL, Keating MT: Co-assembly of KvLQT1 and minK (IsK) proteins to form cardiac Iks potassium channel. Nature 1996;384:80-83 8. Splawski I, Shen J, Timothy KW, Vincent GM, Lehmann MH, Keating MT: Genomic structure of three long QT syndrome genes: KVLQT1, HERG, and KCNE1. Genomics 1998;51:86-97 9. Sanguinetti MC, Jiang C, Curran ME, Keating MT: A mechanistic link between an inherited and an acquired cardiac arrhythmia: HERG encodes the IKr potassium channel. Cell 1995;81:299-307 10. Sanguinetti MC, Curran ME, Spector PS, Keating MT: Spectrum of HERG K+-channel dysfunction in an inherited cardiac arrhythmia. Proc Natl Acad Sci U S A 1996;93:2208-2212 11. Curran ME, Splawski I, Timothy KW, Vincent GM, Green ED, Keating MT: A molecular basis for cardiac arrhythmia: HERG mutations cause long QT syndrome. Cell 1995;80:795-803 12. Splawski I, Shen J, Timothy KW, Vincent GM, Lehmann MH, Keating MT: Genomic structure of three long QT genes: KVLQT1, HERG and KCNE1. Circulation 1998;98:(Abstract) 13. Abbott GW, Sesti F, Splawski I, Buck ME, Lehmann MH, Timothy KW, Keating MT, Goldstein SA: MiRP1 forms IKr potassium channels with HERG and is associated with cardiac arrhythmias. Cell 1999;97:175-187 14. Wang Q, Shen J, Splawski I, Atkinson D, Li Z, Robinson JL, Moss AJ, Towbin JA, Keating MT: SCN5A mutations associated with an inherited cardiac arrhythmia, long QT syndrome. Cell 1995;80:805-811 15. Wang Q, Shen J, Li Z, Timothy KW, Vincent GM, Priori SG, Schwartz PJ, Keating MT: Cardiac sodium channel mutations in patients with long QT syndrome, an inherited cardiac arrhythmia. Hum Mol Genet 1995;4:1603-1607 16. Wang Q, Li Z, Shen J, Keating MT: Genomic organization of the human SCN5A gene encoding the cardiac sodium channel. Genomics 1996;34:9-16 17. Splawski I, Timothy KW, Vincent GM, Atkinson DL, Keating MT: Molecular basis of the long-QT syndrome associated with deafness. Proc Assoc Am Physicians 1997;109:504-511 18. Neyroud N, Tesson F, Denjoy I, Leibovici M, Donger C, Barhanin J, Faure S, Gary F, Coumel P, Petit C, Schwartz K, Guicheney P: A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome. Nat Genet 1997;15:186-189 19. Schulze-Bahr E, Haverkamp W, Wedekind H, Rubie C, Hordt M, Borggrefe M, Assmann G, Breithardt G, Funke H: Autosomal recessive long-QT syndrome (Jervell Lange-Nielsen syndrome) is genetically heterogeneous. Hum Genet 1997;100:573-576 20. Schulze-Bahr E, Wang Q, Wedekind H, Haverkamp W, Chen Q, Sun Y: KCNE1 mutations cause Jervell and Lange-Nielsen syndrome. Nat Genet 1997;17:267-268 21. Duggal P, Vesely MR, Wattanasirichaigoon D, Villafane J, Kaushik V, Beggs AH: Mutation of the gene for IsK associated with both Jervell and Lange-Nielsen and Romano-Ward forms of Long-QT syndrome. Circulation 1998;97:142-146 22. Vetter DE, Mann JR, Wangemann P, Liu J, McLaughlin KJ, Lesage F, Marcus DC, Lazdunski M, Heinemann SF, Barhanin J: Inner ear defects induced by null mutation of the isk gene. Neuron 1996;17:1251-1264 23. Splawski I, Timothy KW, Vincent GM, Atkinson DL, Keating MT: Molecular basis of the long-QT syndrome associated with deafness. N Engl J Med 1997;336:1562-1567 24. Vincent GM, Timothy KW, Leppert M, Keating MT: The spectrum of symptoms and QT Intervals in the carriers of the gene for the long-QT syndrome. N Engl J Med 1992;327:846-852 25. Moss AJ, Zareba W, Benhorin J, Locati EH, Hall WJ, Robinson JL, Schwartz PJ, Towbin JA, Vincent GM, Lehmann MH: ECG T-wave patterns in genetically distinct forms of the hereditary long QT syndrome. Circulation 1995;92:2929-2934 26. Zhang L, Timothy KW, Vincent GM, Lehmann MH, Fox J, Giuli LC, Shen J, Splawski I, Priori S, Compton SJ, Yanowitz F, Benhorin J, Moss AJ, Schwartz PJ, Robinson J, Wang Q, Zareba W, Keating M, Towbin JA, Napolitano C, Medina A: The spectrum of ST-T wave patterns and repolarization parameters in congenital long QT syndrome: ECG findings identify genotype. Circulation 2000;102:2849-2855 27. Schwartz PJ, Priori SG, Spazzolini C, Moss AJ, Vincent GM, Napolitano C, Denjoy I, Guicheney P, Breithardt G, Keating MT, Towbin JA, Beggs AH, Brink P, Wilde AAM, Toivonen L, Zareba W, Robinson J, Timothy KW, Corfield V, Wattanasirichaigoon D, Corbett C, Haverkamp W, Schulze-Bahr E, Lehmann MH, Schwartz K, Coumel P, Bloise R: Genotype-phenotype correlation in the long QT syndrome. Gene-specific triggers for life-threatening arrhythmias. Circulation 2001;103:89-95 28. Vincent GM: The heart rate of Romano-Ward long QT syndrome patients. Circulation 1985;72:III-44(Abstract) 29. Shimizu W, Antzelevitch C: Cellular basis for the ECG features of the LQT1 form of the long-QT syndrome: effects of beta-adrenergic agonists and antagonists and sodium channel blockers on transmural dispersion of repolarization and torsade de pointes. Circulation 1998;98:2314-2322 30. Wilde AA, Jongbloed RJ, Doevendans PA, Duren DR, Hauer RN, van Langen IM, van Tintelen JP, Smeets HJ, Meyer H, Geelen JL: Auditory Stimuli as a Trigger for Arrhythmic Events Differentiate HERG-Related (LQTS2) Patients from KVLQT1-Related Patients (LQTS1). J Am Coll Cardiol 1999;33:327-332 31. Bennett PB, Yazawa K, Makita N, George AL, Jr.: Molecular mechanism for an inherited cardiac arrhythmia. Nature 1995;376:683-685 32. Chandra R, Starmer CF, Grant AO: Multiple effects of KPQ deletion mutation on gating of human cardiac Na+ channels expressed in mammalian cells. Am J Physiol 1998;274 (5 Pt 2):H1643-H1654 33. Dumaine R, Wang Q, Keating MT, Hartmann HA, Schwartz PJ, Brown AM, Kirsch GE: Multiple mechanisms of Na+ channel-linked long QT syndrome. Circ Res 1996;78:916-924 34.Schwartz PJ, Moss AJ, Vincent GM, Crampton RS: Diagnostic criteria for the long QT syndrome: an update. Circulation 1993;88:782-784 35. Keating MT, Atkinson D, Dunn C, Timothy KW, Vincent GM, Leppert M: Linkage of a cardiac arrhythmia, the long QT syndrome, and the Harvey ras-1 gene. Science 1991;252:704-706 36. Zareba W, Moss AJ, Schwartz PJ, Vincent GM, Robinson JL, Priori SG, Benhorin J, Locati EH, Towbin JA, Keating MT, Lehmann MH, Hall WJ: Influence of genotype on the clinical course of the long-QT syndrome. International Long-QT Syndrome Registry Research Group. N Engl J Med 1998;339:960-965 37. Moss AJ: Clinical management of patients with the long QT syndrome: drugs, devices, and gene-specific therapy. [Review]. Pacing Clin Electrophysiol 1997;20:2058-2060 38. Moss AJ: Management of patients with the hereditary long QT syndrome. J Cardiovasc Electrophysiol 1998;9:668-674 39.. Priori SG, Barhanin J, Hauer RN, Haverkamp W, Jongsma H, Kleber AG, McKenna WJ, Roden DM, Rudy Y, Schwartz K, Schwartz PJ, Towbin JA, Wilde AM: Genetic and molecular basis of cardiac arrhythmias: Impact on clinical management part III. Circulation 1999;99:674-681 40.. Priori SG, Barhanin J, Hauer RN, Haverkamp W, Jongsma HJ, Kleber AG, McKenna WJ, Roden DM, Rudy Y, Schwartz K, Schwartz PJ, Towbin JA, Wilde AM: Genetic and molecular basis of cardiac arrhythmias: Impact on clinical management. Parts I and II. Circulation 1999;99:518-528 41. Moss AJ, Zareba W, Hall WJ, Schwartz PJ, Crampton RS, Benhorin J, Vincent GM, Locati E, Priori SG, Napolitano C, Medina A, Zhang L, Robinson J, Timothy K, Towbin JA, Andrews ML: Effectiveness and limitations of beta-blocker therapy in congenital long QT syndrome. Circulation 2000;101:616-623 42. Vincent GM, Zhang L, Timothy KW: Beta-blockers markedly reduce risk and syncope in KVLQT1 long QT patients. Circulation 1996;94:I-204(Abstract) 43. Eldar M, Griffin JC, Van Hare GF, et al: Permanent cardiac pacing in patients with the long QT syndrome. J Am Coll Cardiol 1987;10:600-607 44. Eldar M, Griffin JC, Van Hare GF, Witherell C, Bhandari A, Benditt D, Scheinman MM: Combined used of beta-adrenergic blocking agents and long term cardiac pacing for patients with the long QT syndrome. J Am Coll Cardiol 1992;20:830-837 45. Viskin S: Cardiac pacing in the long QT syndrome: review of available data and practical recommendations. J Cardiovasc Electrophysiol 2000;11:593-600 46. Levin SE: Long QT syndrome associated with syndactyly in a female. [letter; comment]. Am J Cardiol 1996;78:380 47. Marks ML, Trippel DL, Keating MT: Long QT syndrome associated with syndactyly identified in females. Am J Cardiol 1995;76:744-745 48. Marks ML, Whisler SL, Clericuzio C, Keating MT: A new form of long QT syndrome associated with syndactyly. [Review]. J Am Coll Cardiol 1995;25:59-64 49. Compton SJ, Lux RL, Ramsey MR, Strelich KR, Sanguinetti MC, Green LS, Keating MT, Mason JW: Genetically defined therapy of inherited long-QT syndrome. Correction of abnormal repolarization by potassium. Circulation 1996;94:1018-1022 50. Etheridge SP, Compton SJ, Pursley M, Kurkhardt J, Shepperd T, Mason JW: Chronic potassium shortens QTc in long QT patients with IKr defects. Pacing Clin Electrophysiol 2001;24:606(Abstract) 51. Tan HL, Alings M, Van Olden RW, Wilde AA: Long-term (subacute) potassium treatment in congenital HERG-related long QT syndrome (LQTS2). J Cardiovasc Electrophysiol 1999;10:229-233 52. Priori SG, Napolitano C, Cantu F, Brown AM, Schwartz PJ: Differential response to Na+ channel blockade, beta-adrenergic stimulation, and rapid pacing in a cellular model mimicking the SCN5A and HERG defects present in the long QT syndrome. Circ Res 1996;78:1009-1015 53. Priori SG, Napolitano C, Schwartz PJ: A molecular basis for the therapy of the long QT syndrome. Arch Mal Coeur Vaiss 1996;89:1185-1187 54. Schwartz PJ, Priori SG, Locati EH, Napolitano C, Cantu F, Towbin JA, Keating MT, Hammoude H, Brown AM, Chen LS: 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;92:3381-3386 55. Shimizu W, Antzelevitch C: Sodium channel block with mexiletine is effective in reducing dispersion of repolarization and preventing torsade de pointes in LQT2 and LQT3 models of the long-QT syndrome. Circulation 1997;96:2038-2047 56. Sicouri S, Antzelevitch D, Heilmann C, Antzelevitch C: Effects of sodium channel block with mexiletine to reverse action potential prolongation in in vitro models of the long term QT syndrome. J Cardiovasc Electrophysiol 1997;8:1280-1290 57. Reynolds E, Vander-Ark CR: Quinidine syncope and the delayed repolarization syndromes. Mod Concepts Cardiovasc Dis 1976;45:117-122 58. Roden DM: Current status of class III antiarrhythmic drug therapy. [Review]. Am J Cardiol 1993;72:44B-49B 59. Spector PS, Curran ME, Keating MT, Sanguinetti MC: Class III antiarrhythmic drugs block HERG, a human cardiac delayed rectifier K+ channel. Open channel block by methanesulfonanilides. Circ Res 1996;78:499-503 60. Roden DM, Lazzara R, Rosen M, Schwartz PJ, Towbin JA, Vincent GM: Multiple mechanisms in the long-QT syndrome: current knowledge, gaps, and future directions. For the SADS Foundation Task Force on LQTS. Circulation 1996;94:1996-2012 61. Roden DM: Taking the "idio" out of "idiosyncratic": predicting torsades de pointes. [editorial]. Pacing Clin Electrophysiol 1998;21:1029-1034 62. Priori SG, Napolitano C, Schwartz PJ, Ballabio A, Paganini V, Cantu F, Pinnavaia A, Aquaro G, Casari G: KvLQT1 mutation in drug induced torsade de pointes. Eur Heart J 1997;18:324(Abstract) 63. Donger C, Denjoy I, Berthet M, Neyroud N, Cruaud C, Bennaceur M, Chivoret G, Schwartz K, Coumel P, Guicheney P: KVLQT1 C-terminal missense mutation causes a forme fruste long-QT syndrome. Circulation 1997;96:2778-2781 64. Sesti F, Abbott GW, Wei J, Murray KT, Saksena S, Schwartz PJ, Priori SG, Roden DM, George AL, Jr., Goldstein SA: A common polymorphism associated with antibiotic-induced cardiac arrhythmia. Proc Natl Acad Sci U S A 2000;97:10613-10618 65. Wei J, Wathen M, Murray K, Daw R, Roden D, George AL, Jr.: Absence of HERG and SCN5A mutations in acquired long QT syndrome. Circulation 1995;92:I-275(Abstract) 66. Makkar RR, Fromm B, Steinman RT, Meissner MD, Lehmann MH: Female gender as a risk factor for torsade de pointes associated with cardiovascular drugs. JAMA 1993;270:2590-2597 67. Mitcheson JS, Chen L, Lin M, Culberson C, Sanguinetti MC: A structural basis for drug-induced long QT syndrome. PNAS 2000;10: 68. Grossman MA: Cardiac arrhythmias in acute central nervous system disease. Arch Intern Med 1976;136:203-207 69. Ewing DJ: Diabetic autonomic neuropathy and the heart. [Review]. Diabetes Res Clin Pract 1996;30 Suppl:31-36 70. Kahn JK, Sisson J, Vinik A: QT interval prolongation and sudden cardiac death in diabetic autonomic neuropathy. J Clin Endocrinol Metab 1987;64:751-754 71. Yanowitz F, Preston JB, Abildskov JA: Functional distribution of right and left stellate innervation to the ventricles. Production of neurogenic electrocardiographic changes by unilateral alterations of sympathetic tone. Circ Res 1966;18:416 72. Abildskov JA, Vincent GM: The autonomic nervous system in reltaion to electrocardiographic waveform and cardiac rhythm., in Randall WC (ed): Neural Regulation of the Heart. Boston, Oxford University Press, 1977, pp 409-424 73. Schwartz PJ, Stramba-Badiale M, Segantini A, Austoni P, Bosi G, Giorgetti R, Grancini F, Marni ED, Perticone F, Rosti D, Salice P: Prolongation of the QT interval and the sudden infant death syndrome. N Engl J Med 1998;338:1709-1714 citation: Vincent, G. Michael (2002) The Long QT Syndrome. [Journal (Paginated)] document_url: http://cogprints.org/4302/1/vincent.htm