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Long QT syndrome 2(LQT2)

MedGen UID:
462293
Concept ID:
C3150943
Disease or Syndrome
Synonym: LQT2
 
Genes (locations): ALG10B (12q12); KCNH2 (7q36.1)
 
Monarch Initiative: MONDO:0013367
OMIM®: 613688

Authors:
Alexander J Groffen  |  Hennie Bikker  |  Imke Christiaans   view full author information

Additional descriptions

From GeneReviews Overview
Long QT syndrome (LQTS) is a cardiac electrophysiologic disorder, characterized by QT prolongation and T-wave abnormalities on the EKG that are associated with tachyarrhythmias, typically the ventricular tachycardia torsade de pointes (TdP). TdP is usually self-terminating, thus causing a syncopal event, the most common symptom in individuals with LQTS. Such cardiac events typically occur during exercise and emotional stress, less frequently during sleep, and usually without warning. In some instances, TdP degenerates to ventricular fibrillation and causes aborted cardiac arrest (if the individual is defibrillated) or sudden death. Approximately 50% of untreated individuals with a pathogenic variant in one of the genes associated with LQTS have symptoms, usually one to a few syncopal events. While cardiac events may occur from infancy through middle age, they are most common from the preteen years through the 20s. Some types of LQTS are associated with a phenotype extending beyond cardiac arrhythmia. In addition to the prolonged QT interval, associations include muscle weakness and facial dysmorphism in Andersen-Tawil syndrome (LQTS type 7); hand/foot, facial, and neurodevelopmental features in Timothy syndrome (LQTS type 8); and profound sensorineural hearing loss in Jervell and Lange-Nielson syndrome.
From OMIM
Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death (Jongbloed et al., 1999). For a discussion of genetic heterogeneity of long QT syndrome, see LQT1 (192500).  http://www.omim.org/entry/613688

Clinical features

From HPO
Sudden cardiac death
MedGen UID:
38841
Concept ID:
C0085298
Pathologic Function
The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset).
Cardiac arrest
MedGen UID:
5456
Concept ID:
C0018790
Finding
An abrupt loss of heart function.
Syncope
MedGen UID:
21443
Concept ID:
C0039070
Sign or Symptom
Syncope is a syndrome in which loss of consciousness is of relatively sudden onset, temporary (usually less than 1 to 2 minutes), self-terminating, and of usually rapid recovery. Syncope leads to a generalized weakness of muscles with loss of postural tone, inability to stand upright, and loss of consciousness. Once the patient is in a horizontal position, blood flow to the brain is no longer hindered by gravitation and consciousness is regained. Unconsciousness usually lasts for seconds to minutes. Headache and drowsiness (which usually follow seizures) do not follow a syncopal attack. Syncope results from a sudden impairment of brain metabolism usually due to a reduction in cerebral blood flow.
Torsades de pointes
MedGen UID:
21214
Concept ID:
C0040479
Disease or Syndrome
A type of ventricular tachycardia characterized by polymorphioc QRS complexes that change in amplitue and cycle length, and thus have the appearance of oscillating around the baseline in the EKG.
Ventricular fibrillation
MedGen UID:
21844
Concept ID:
C0042510
Disease or Syndrome
Uncontrolled contractions of muscles fibers in the left ventricle not producing contraction of the left ventricle. Ventricular fibrillation usually begins with a ventricular premature contraction and a short run of rapid ventricular tachycardia degenerating into uncoordinating ventricular fibrillations.
Prolonged QT interval
MedGen UID:
57494
Concept ID:
C0151878
Finding
Increased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG).
Prolonged QTc interval
MedGen UID:
294666
Concept ID:
C1560305
Pathologic Function
A longer than normal interval (corrected for heart rate) between the Q and T waves in the heart's cycle. Prolonged QTc can cause premature action potentials during late phase depolarizations thereby leading to ventricular arrhythmias and ventricular fibrillations.
Notched T wave
MedGen UID:
416962
Concept ID:
C2347367
Finding
A bifid T-wave with a notch duration between the 2 peaks at least 0.04 sec and an amplitude at least 0.05 mV.

Professional guidelines

PubMed

Shimizu W, Moss AJ, Wilde AA, Towbin JA, Ackerman MJ, January CT, Tester DJ, Zareba W, Robinson JL, Qi M, Vincent GM, Kaufman ES, Hofman N, Noda T, Kamakura S, Miyamoto Y, Shah S, Amin V, Goldenberg I, Andrews ML, McNitt S
J Am Coll Cardiol 2009 Nov 24;54(22):2052-62. doi: 10.1016/j.jacc.2009.08.028. PMID: 19926013Free PMC Article

Recent clinical studies

Etiology

Marstrand P, Almatlouh K, Kanters JK, Graff C, Christensen AH, Bundgaard H, Theilade J
Heart Rhythm 2021 Feb;18(2):241-249. Epub 2020 Aug 31 doi: 10.1016/j.hrthm.2020.08.017. PMID: 32882399
Brouillette J, Nattel S
Can J Cardiol 2017 Dec;33(12):1577-1586. Epub 2017 Sep 11 doi: 10.1016/j.cjca.2017.09.001. PMID: 29173600
Ebrahim MA, Williams MR, Shepard S, Perry JC
Am J Cardiol 2017 Jul 15;120(2):256-261. Epub 2017 Apr 27 doi: 10.1016/j.amjcard.2017.04.018. PMID: 28532774
Steinberg C, Padfield GJ, Al-Sabeq B, Adler A, Yeung-Lai-Wah JA, Kerr CR, Deyell MW, Andrade JG, Bennett MT, Yee R, Klein GJ, Green M, Laksman ZW, Krahn AD, Chakrabarti S
J Interv Card Electrophysiol 2016 Nov;47(2):163-170. Epub 2016 Jul 9 doi: 10.1007/s10840-016-0161-2. PMID: 27394160
Page A, Aktas MK, Soyata T, Zareba W, Couderc JP
Heart Rhythm 2016 Jan;13(1):190-8. Epub 2015 Aug 31 doi: 10.1016/j.hrthm.2015.08.037. PMID: 26334569Free PMC Article

Diagnosis

Niaz T, Bos JM, Sorensen KB, Moir C, Ackerman MJ
Circ Arrhythm Electrophysiol 2020 Dec;13(12):e008830. Epub 2020 Nov 16 doi: 10.1161/CIRCEP.120.008830. PMID: 33198487
Porta-Sánchez A, Spillane DR, Harris L, Xue J, Dorsey P, Care M, Chauhan V, Gollob MH, Spears DA
JACC Clin Electrophysiol 2017 Apr;3(4):374-381. Epub 2016 Dec 21 doi: 10.1016/j.jacep.2016.10.013. PMID: 29759450
Ebrahim MA, Williams MR, Shepard S, Perry JC
Am J Cardiol 2017 Jul 15;120(2):256-261. Epub 2017 Apr 27 doi: 10.1016/j.amjcard.2017.04.018. PMID: 28532774
Steinberg C, Padfield GJ, Al-Sabeq B, Adler A, Yeung-Lai-Wah JA, Kerr CR, Deyell MW, Andrade JG, Bennett MT, Yee R, Klein GJ, Green M, Laksman ZW, Krahn AD, Chakrabarti S
J Interv Card Electrophysiol 2016 Nov;47(2):163-170. Epub 2016 Jul 9 doi: 10.1007/s10840-016-0161-2. PMID: 27394160
Page A, Aktas MK, Soyata T, Zareba W, Couderc JP
Heart Rhythm 2016 Jan;13(1):190-8. Epub 2015 Aug 31 doi: 10.1016/j.hrthm.2015.08.037. PMID: 26334569Free PMC Article

Therapy

Marstrand P, Almatlouh K, Kanters JK, Graff C, Christensen AH, Bundgaard H, Theilade J
Heart Rhythm 2021 Feb;18(2):241-249. Epub 2020 Aug 31 doi: 10.1016/j.hrthm.2020.08.017. PMID: 32882399
Niaz T, Bos JM, Sorensen KB, Moir C, Ackerman MJ
Circ Arrhythm Electrophysiol 2020 Dec;13(12):e008830. Epub 2020 Nov 16 doi: 10.1161/CIRCEP.120.008830. PMID: 33198487
Mehta A, Ramachandra CJA, Singh P, Chitre A, Lua CH, Mura M, Crotti L, Wong P, Schwartz PJ, Gnecchi M, Shim W
Eur Heart J 2018 Apr 21;39(16):1446-1455. doi: 10.1093/eurheartj/ehx394. PMID: 29020304
Brouillette J, Nattel S
Can J Cardiol 2017 Dec;33(12):1577-1586. Epub 2017 Sep 11 doi: 10.1016/j.cjca.2017.09.001. PMID: 29173600
Steinberg C, Padfield GJ, Al-Sabeq B, Adler A, Yeung-Lai-Wah JA, Kerr CR, Deyell MW, Andrade JG, Bennett MT, Yee R, Klein GJ, Green M, Laksman ZW, Krahn AD, Chakrabarti S
J Interv Card Electrophysiol 2016 Nov;47(2):163-170. Epub 2016 Jul 9 doi: 10.1007/s10840-016-0161-2. PMID: 27394160

Prognosis

Mattivi CL, Ye D, Tester DJ, Clemens DJ, Zhou W, Giudicessi JR, Ackerman MJ
Heart Rhythm 2020 Feb;17(2):315-323. Epub 2019 Sep 5 doi: 10.1016/j.hrthm.2019.08.014. PMID: 31493592
Platonov PG, McNitt S, Polonsky B, Rosero SZ, Kutyifa V, Huang A, Moss AJ, Zareba W
Circ Arrhythm Electrophysiol 2018 Jul;11(7):e005918. doi: 10.1161/CIRCEP.117.005918. PMID: 30012873Free PMC Article
Koponen M, Havulinna AS, Marjamaa A, Tuiskula AM, Salomaa V, Laitinen-Forsblom PJ, Piippo K, Toivonen L, Kontula K, Viitasalo M, Swan H
BMC Med Genet 2018 Apr 5;19(1):56. doi: 10.1186/s12881-018-0574-0. PMID: 29622001Free PMC Article
Sugrue A, Rohatgi RK, Noseworthy PA, Kremen V, Bos JM, Qiang B, Sapir Y, Attia ZI, Scott CG, Brady P, Asirvatham SJ, Friedman PA, Ackerman MJ
Circ Arrhythm Electrophysiol 2017 Nov;10(11) doi: 10.1161/CIRCEP.117.005648. PMID: 29141844
Ebrahim MA, Williams MR, Shepard S, Perry JC
Am J Cardiol 2017 Jul 15;120(2):256-261. Epub 2017 Apr 27 doi: 10.1016/j.amjcard.2017.04.018. PMID: 28532774

Clinical prediction guides

Marstrand P, Almatlouh K, Kanters JK, Graff C, Christensen AH, Bundgaard H, Theilade J
Heart Rhythm 2021 Feb;18(2):241-249. Epub 2020 Aug 31 doi: 10.1016/j.hrthm.2020.08.017. PMID: 32882399
Mattivi CL, Ye D, Tester DJ, Clemens DJ, Zhou W, Giudicessi JR, Ackerman MJ
Heart Rhythm 2020 Feb;17(2):315-323. Epub 2019 Sep 5 doi: 10.1016/j.hrthm.2019.08.014. PMID: 31493592
Porta-Sánchez A, Spillane DR, Harris L, Xue J, Dorsey P, Care M, Chauhan V, Gollob MH, Spears DA
JACC Clin Electrophysiol 2017 Apr;3(4):374-381. Epub 2016 Dec 21 doi: 10.1016/j.jacep.2016.10.013. PMID: 29759450
Sugrue A, Rohatgi RK, Noseworthy PA, Kremen V, Bos JM, Qiang B, Sapir Y, Attia ZI, Scott CG, Brady P, Asirvatham SJ, Friedman PA, Ackerman MJ
Circ Arrhythm Electrophysiol 2017 Nov;10(11) doi: 10.1161/CIRCEP.117.005648. PMID: 29141844
Steinberg C, Padfield GJ, Al-Sabeq B, Adler A, Yeung-Lai-Wah JA, Kerr CR, Deyell MW, Andrade JG, Bennett MT, Yee R, Klein GJ, Green M, Laksman ZW, Krahn AD, Chakrabarti S
J Interv Card Electrophysiol 2016 Nov;47(2):163-170. Epub 2016 Jul 9 doi: 10.1007/s10840-016-0161-2. PMID: 27394160

Recent systematic reviews

Lawley CM, Tester M, Sanatani S, Prendiville T, Beach CM, Vinocur JM, Horie M, Uhm JS, Khongphatthanayothin A, Ayers MD, Starling L, Yoshida Y, Shah MJ, Skinner JR, Turner C
Heart Rhythm 2022 Nov;19(11):1826-1833. Epub 2022 Oct 11 doi: 10.1016/j.hrthm.2022.08.003. PMID: 37850595

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