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Pediatric Long QT Syndrome Differential Diagnoses

  • Author: Sreekanth S Raghavan, MBBS, , FACC; Chief Editor: Stuart Berger, MD  more...
 
Updated: Jun 26, 2014
 
 

Diagnostic Considerations

As previously mentioned, long-QT syndrome can be mistaken for palpitations, neurocardiogenic syncope, and epilepsy.[1] Other conditions to consider in the differential diagnosis of long QT syndrome include the following:

  • Brugada syndrome
  • Short QT syndrome
  • Other causes of sudden cardiac death - Including hypertrophic cardiomyopathy and coronary artery anomalies
 
 
Contributor Information and Disclosures
Author

Sreekanth S Raghavan, MBBS, , FACC Consulting Pediatric Cardiologist, Head and Director of Pediatric Cardiac Services, Manipal Heart Institute, India

Sreekanth S Raghavan, MBBS, , FACC is a member of the following medical societies: American College of Cardiology, American Society of Echocardiography, Pediatric Cardiac Society of India

Disclosure: Nothing to disclose.

Chief Editor

Stuart Berger, MD Medical Director of The Heart Center, Children's Hospital of Wisconsin; Associate Professor, Department of Pediatrics, Section of Pediatric Cardiology, Medical College of Wisconsin

Stuart Berger, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American College of Chest Physicians, American Heart Association, Society for Cardiovascular Angiography and Interventions

Disclosure: Nothing to disclose.

Acknowledgements

John W Moore, MD, MPH Professor of Clinical Pediatrics, Section of Pediatric Cardiology, Department of Pediatrics, University of California San Diego School of Medicine; Director of Cardiology, Rady Children's Hospital

John W Moore, MD, MPH is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, and Society for Cardiac Angiography and Interventions

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

References
  1. Taggart NW, Haglund CM, Tester DJ, Ackerman MJ. Diagnostic miscues in congenital long-QT syndrome. Circulation. 2007 May 22. 115(20):2613-20. [Medline].

  2. Schwartz PJ, Moss AJ, Vincent GM, Crampton RS. Diagnostic criteria for the long QT syndrome. An update. Circulation. 1993 Aug. 88(2):782-4. [Medline].

  3. Gupta A, Lawrence AT, Krishnan K, Kavinsky CJ, Trohman RG. Current concepts in the mechanisms and management of drug-induced QT prolongation and torsade de pointes. Am Heart J. 2007 Jun. 153(6):891-9. [Medline].

  4. 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 Sep 13. 296(10):1249-54. [Medline].

  5. Goldenberg I, Moss AJ, Zareba W, et al. Clinical course and risk stratification of patients affected with the Jervell and Lange-Nielsen syndrome. J Cardiovasc Electrophysiol. 2006 Nov. 17(11):1161-8. [Medline].

  6. Albertella L, Crawford J, Skinner JR. Presentation and outcome of water-related events in children with long QT syndrome. Arch Dis Child. 2011 Aug. 96(8):704-7. [Medline].

  7. Hintsa T, Keltikangas-Jarvinen L, Puttonen S, et al. Depressive symptoms in the congenital long QT syndrome. Ann Med. 2009 Jun 23. 1-6. [Medline].

  8. Vyas H, Ackerman MJ. Epinephrine QT stress testing in congenital long QT syndrome. J Electrocardiol. 2006 Oct. 39(4 Suppl):S107-13. [Medline].

  9. Monnig G, Eckardt L, Wedekind H, et al. Electrocardiographic risk stratification in families with congenital long QT syndrome. Eur Heart J. 2006 Sep. 27(17):2074-80. [Medline].

  10. Cuneo BF, Strasburger JF, Yu S, Horigome H, Hosono T, Kandori A. In utero diagnosis of long QT syndrome by magnetocardiography. Circulation. 2013 Nov 12. 128(20):2183-91. [Medline].

  11. Mitchell JL, Cuneo BF, Etheridge SP, Horigome H, Weng HY, Benson DW. Fetal heart rate predictors of long QT syndrome. Circulation. 2012 Dec 4. 126(23):2688-95. [Medline].

  12. 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 May 15. 115(19):2481-9. [Medline].

  13. Arnestad M, Crotti L, Rognum TO, et al. Prevalence of long-QT syndrome gene variants in sudden infant death syndrome. Circulation. 2007 Jan 23. 115(3):361-7. [Medline].

  14. Tester DJ, Ackerman MJ. Postmortem long QT syndrome genetic testing for sudden unexplained death in the young. J Am Coll Cardiol. 2007 Jan 16. 49(2):240-6. [Medline].

  15. [Guideline] Epstein AE, DiMarco JP, Ellenbogen KA, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices) developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. J Am Coll Cardiol. 2008 May 27. 51(21):e1-62. [Medline]. [Full Text].

  16. Bar-Cohen Y, Silka MJ. Congenital Long QT Syndrome: Diagnosis and Management in Pediatric Patients. Curr Treat Options Cardiovasc Med. 2006 Sep. 8(5):387-395. [Medline].

  17. Vohra J. The Long QT Syndrome. Heart Lung Circ. 2007. 16 Suppl 3:S5-12. [Medline].

  18. Hamang A, Solberg B, Bjorvatn C, Greve G, Oyen N. [Genetic counseling in congenital long QT syndrome]. Tidsskr Nor Laegeforen. 2009 Jun 11. 129(12):1226-9. [Medline].

  19. Johnson JN, Ackerman MJ. Return to play? Athletes with congenital long QT syndrome. Br J Sports Med. 2013 Jan. 47(1):28-33. [Medline].

  20. Maron BJ, Chaitman BR, Ackerman MJ, et al. Recommendations for physical activity and recreational sports participation for young patients with genetic cardiovascular diseases. Circulation. 2004 Jun 8. 109(22):2807-16. [Medline].

  21. Chockalingam P, Crotti L, Girardengo G, Johnson JN, Harris KM, van der Heijden JF. Not all beta-blockers are equal in the management of long QT syndrome types 1 and 2: higher recurrence of events under metoprolol. J Am Coll Cardiol. 2012 Nov 13. 60(20):2092-9. [Medline].

  22. Seth R, Moss AJ, McNitt S, et al. Long QT syndrome and pregnancy. J Am Coll Cardiol. 2007 Mar 13. 49(10):1092-8. [Medline]. [Full Text].

  23. Barsheshet A, Moss AJ, McNitt S, Polonsky S, Lopes CM, Zareba W. Risk of syncope in family members who are genotype-negative for a family-associated long-QT syndrome mutation. Circ Cardiovasc Genet. 2011 Oct. 4(5):491-9. [Medline].

  24. Hofman N, Wilde AA, Tan HL. Diagnostic criteria for congenital long QT syndrome in the era of molecular genetics: do we need a scoring system?. Eur Heart J. 2007 Jun. 28(11):1399. [Medline].

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Marked prolongation of QT interval in a 15-year-old male adolescent with long QT syndrome. Abnormal morphology of repolarization can be observed in almost every lead (ie, peaked T waves, bowing ST segment). Bradycardia is a common feature in patients with long QT syndrome. R-R = 1 s; QT interval = 0.56 s; QT interval corrected for heart rate (QTc) = 0.56 s.
Genetically confirmed long QT syndrome with borderline values of QT corrected for heart rate (QTc) duration in a 12-year-old girl. Note the abnormal morphology of the T wave (notches) in leads V2-V4. R-R = 0.68 s; QT interval = 0.36 s; QTc = 0.44 s.
ECG of a 13-year-old female who had a syncopal event while running to a school bus. She awoke after a few seconds, and her subsequent clinical course was uneventful.
Table 1. Genetic Basis of Long QT Syndrome, Including Jervell and Lang-Nielsen (JLN) Syndrome
Type of Long QT Syndrome Chromosomal Locus Mutated Gene Ion Current Affected
LQT111p15.5KVLQT1or KCNQ1 (heterozygotes)Potassium (IKs)
LQT27q35-36HERG, KCNH2Potassium (IKr)
LQT33p21-24SCN5ASodium (INa)
LQT44q25-27ANK2, ANKBSodium, potassium and calcium
LQT521q22.1-22.2KCNE1 (heterozygotes)Potassium (IKs)
LQT621q22.1-22.2MiRP1, KNCE2Potassium (IKr)
LQT7 (Andersen syndrome)17q23KCNJ2Potassium (IK1)
LQT8 (Timothy syndrome)12q13.3CACNA1CCalcium (ICa-Lalpha)
JLN111p15.5KVLQT1or KCNQ1 (homozygotes)Potassium (IKs)
JLN221q22.1-22.2KCNE1 (homozygotes)Potassium (IKs)
Table 2. Genetic Basis of Long QT Syndrome
Group Prolonged QTc (s) Borderline QTc (s) Reference Range (s)
Children and adolescents (< 15 y)>0.460.44-0.46< 0.44
Men>0.450.43-0.45< 0.43
Women>0.460.45-0.46< 0.45
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