Long QT Syndrome Medication
- Author: Ali A Sovari, MD, FACP; Chief Editor: Jeffrey N Rottman, MD more...
Medication Summary
No treatment addresses the cause of long QT syndrome (LQTS). Antiadrenergic therapeutic measures (eg, use of beta-blockers, left cervicothoracic stellectomy) and device therapy (eg, use of pacemakers, ICDs) aim to decrease the risk and lethality of cardiac events.
As previously mentioned, the protective effect of beta-blockers is related to their adrenergic blockade, which diminishes the risk of cardiac arrhythmias. They may also reduce the QT interval in some patients. Beta-blockers used in patients with LQTS include the following:
- Propranolol
- Nadolol
- Metoprolol
- Atenolol
Beta-Adrenergic Blocking Agents
Class Summary
Antiadrenergic therapy effectively protects most patients with long QT syndrome (LQTS). Beta-blockers, especially propranolol, are the drugs most frequently used in patients with LQTS. Inform patients and their family members that beta-blockers should be continued indefinitely. Interruption in beta-blocker therapy may increase the risk of cardiac events.
Propranolol (Inderal, InnoPran XL)
Propranolol decreases the effect of sympathetic stimulation on the heart. It decreases conduction through the atrioventricular (AV) node and has negative chronotropic and inotropic effects. Consult a cardiologist because dosing varies and is individualized in patients with LQTS. Patients with asthma should use cardioselective beta-blockers. Patients with LQTS who cannot take beta-blockers may require an ICD as first-line therapy.
Nadolol (Corgard)
Nadolol is frequently prescribed because of its long-term effect. This agent decreases the effect of sympathetic stimulation on the heart. Nadolol decreases conduction through the AV node and has negative chronotropic and inotropic effects. Consult a cardiologist because dosing varies and is individualized in patients with LQTS. Patients with asthma should use cardioselective beta-blockers. Patients with LQTS who cannot take beta-blockers may require an ICD as first-line therapy.
Metoprolol (Lopressor, Toprol XL)
Metoprolol is a selective beta1-adrenergic receptor blocker that decreases the automaticity of contractions. During intravenous (IV) administration, carefully monitor blood pressure, heart rate, and ECG. Consult a cardiologist because dosing varies and is individualized in patients with LQTS. Patients with LQTS who cannot take beta-blockers may require an ICD as first-line therapy.
Atenolol (Tenormin)
Atenolol selectively blocks beta1-receptors with little or no effect on beta2 types. Consult a cardiologist because dosing varies and is individualized in patients with LQTS. Patients with LQTS who cannot take beta-blockers may require an ICD as first-line therapy.
Vatta M, Ackerman MJ, Ye B, Makielski JC, Ughanze EE, Taylor EW, et al. Mutant caveolin-3 induces persistent late sodium current and is associated with long-QT syndrome. Circulation. Nov 14 2006;114(20):2104-12. [Medline].
Rajab A, Straub V, McCann LJ, Seelow D, Varon R, Barresi R, et al. Fatal cardiac arrhythmia and long-QT syndrome in a new form of congenital generalized lipodystrophy with muscle rippling (CGL4) due to PTRF-CAVIN mutations. PLoS Genet. Mar 12 2010;6(3):e1000874. [Medline].
Border WL, Benson DW. Sudden infant death syndrome and long QT syndrome: the zealots versus the naysayers. Heart Rhythm. Feb 2007;4(2):167-9. [Medline].
Medeiros A, Kaku T, Tester DJ, et al. Sodium channel B4 subunit mutation causes congenital long QTsyndrome. Heart Rhythm. 2006;3:S34.
Wu G, Ai T, Kim JJ, et al. Alpha-1-Syntrophin Mutation and the Long QT Syndrome: a disease of sodium channel disruption. Circulation. May 28, 2008;Online, ahead of print.
Buber J, Mathew J, Moss AJ, et al. Risk of Recurrent Cardiac Events After Onset of Menopause in Women With Congenital Long-QT Syndrome Types 1 and 2. Circulation. Jun 21 2011;123(24):2784-91. [Medline].
Schwartz PJ, Moss AJ, Vincent GM. Diagnostic criteria for the long QT syndrome: an update. Circulation. 1993;88:782-4. [Medline].
Viskin S, Postema PG, Bhuiyan ZA, Rosso R, Kalman JM, Vohra JK, et al. The Response of the QT Interval to the Brief Tachycardia Provoked by Standing A Bedside Test for Diagnosing Long QT Syndrome. J Am Coll Cardiol. Jan 22 2010;[Medline].
Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation. Sep 5 2006;114(10):e385-484. [Medline].
Roden DM. Long QT Syndrome. N Engl J Med. Jan 2008;358(2):169-76. [Medline].
Goldenberg I, Thottathil P, Lopes CM, et al. Trigger-specific ion-channel mechanisms, risk factors, and response to therapy in type 1 long QT syndrome. Heart Rhythm. Jan 2012;9(1):49-56. [Medline].
Zareba W, Moss AJ, Daubert JP, Hall WJ, Robinson JL, Andrews M. Implantable cardioverter defibrillator in high-risk long QT syndrome patients. J Cardiovasc Electrophysiol. Apr 2003;14(4):337-41. [Medline].
Goldenberg I, Moss AJ, Peterson DR, McNitt S, Zareba W, Andrews ML, et al. Risk factors for aborted cardiac arrest and sudden cardiac death in children with the congenital long-QT syndrome. Circulation. Apr 29 2008;117(17):2184-91. [Medline].
Goldenberg I, Moss AJ. Long QT syndrome. J Am Coll Cardiol. Jun 17 2008;51(24):2291-300. [Medline].
Goldenberg I, Moss AJ, Zareba W, McNitt S, Robinson JL, Qi M, et al. Clinical course and risk stratification of patients affected with the Jervell and Lange-Nielsen syndrome. J Cardiovasc Electrophysiol. Nov 2006;17(11):1161-8. [Medline].
Ruan Y, Denegri M, Liu N, Bachetti T, Seregni M, Morotti S, et al. Trafficking Defects and Gating Abnormalities of a Novel SCN5A Mutation Question Gene-Specific Therapy in Long QT Syndrome Type 3. Circ Res. Mar 25 2010;Epub-ahead of print. [Medline].
Kim JA, Lopes CM, Moss AJ, McNitt S, Barsheshet A, Robinson JL, et al. Trigger-specific risk factors and response to therapy in long QT syndrome type 2. Heart Rhythm. Dec 2010;7(12):1797-805. [Medline].
Ackerman MJ. Genotype-phenotype relationships in congenital long QT syndrome. J Electrocardiol. Oct 2005;38(4 Suppl):64-8. [Medline].
Ali RH, Zareba W, Moss AJ, et al. Clinical and genetic variables associated with acute arousal and nonarousal-related cardiac events among subjects with long QT syndrome. Am J Cardiol. Feb 15 2000;85(4):457-61. [Medline].
Antzelevitch C. Arrhythmogenic mechanisms of QT prolonging drugs: is QT prolongation really the problem?. J Electrocardiol. 2004;37 Suppl:15-24. [Medline].
Antzelevitch C, Oliva A. Amplification of spatial dispersion of repolarization underlies sudden cardiac death associated with catecholaminergic polymorphic VT, long QT, short QT and Brugada syndromes. J Intern Med. Jan 2006;259(1):48-58. [Medline].
Chiang CE, Roden DM. The long QT syndromes: genetic basis and clinical implications. J Am Coll Cardiol. Jul 2000;36(1):1-12. [Medline].
Ching CK, Tan EC. Congenital long QT syndromes: clinical features, molecular genetics and genetic testing. Expert Rev Mol Diagn. May 2006;6(3):365-74. [Medline].
Gowda RM, Khan IA, Wilbur SL, Vasavada BC, Sacchi TJ. Torsade de pointes: the clinical considerations. Int J Cardiol. Jul 2004;96(1):1-6. [Medline].
[Best Evidence] Hinterseer M, Beckmann BM, Thomsen MB, Pfeufer A, Dalla Pozza R, Loeff M, et al. Relation of increased short-term variability of QT interval to congenital long-QT syndrome. Am J Cardiol. May 1 2009;103(9):1244-8. [Medline].
Kao LW, Furbee RB. Drug-induced q-T prolongation. Med Clin North Am. Nov 2005;89(6):1125-44, x. [Medline].
Lankipalli RS, Zhu T, Guo D, Yan GX. Mechanisms underlying arrhythmogenesis in long QT syndrome. J Electrocardiol. Oct 2005;38(4 Suppl):69-73. [Medline].
Modell SM, Lehmann MH. The long QT syndrome family of cardiac ion channelopathies: a HuGE review. Genet Med. Mar 2006;8(3):143-55. [Medline].
Moss AJ, Robinson J. Clinical features of the idiopathic long QT syndrome. Circulation. Jan 1992;85(1 Suppl):I140-4. [Medline].
Moss AJ, Schwartz PJ, Crampton RS, et al. The long QT syndrome. Prospective longitudinal study of 328 families. Circulation. Sep 1991;84(3):1136-44. [Medline].
Moss AJ, Zareba W, Benhorin J, et al. ECG T-wave patterns in genetically distinct forms of the hereditary long QT syndrome. Circulation. Nov 15 1995;92(10):2929-34. [Medline].
Moss AJ, Zareba W, Hall WJ, et al. Effectiveness and limitations of beta-blocker therapy in congenital long-QT syndrome. Circulation. Feb 15 2000;101(6):616-23. [Medline].
Napolitano C, Bloise R, Priori SG. Long QT syndrome and short QT syndrome: how to make correct diagnosis and what about eligibility for sports activity. J Cardiovasc Med (Hagerstown). Apr 2006;7(4):250-6. [Medline].
Rashba EJ, Zareba W, Moss AJ, et al. Influence of pregnancy on the risk for cardiac events in patients with hereditary long QT syndrome. LQTS Investigators. Circulation. Feb 10 1998;97(5):451-6. [Medline].
Roden DM. Acquired long QT syndromes and the risk of proarrhythmia. J Cardiovasc Electrophysiol. Aug 2000;11(8):938-40. [Medline].
Roden DM. Long QT syndrome: reduced repolarization reserve and the genetic link. J Intern Med. Jan 2006;259(1):59-69. [Medline].
Schwartz PJ. The congenital long QT syndromes from genotype to phenotype: clinical implications. J Intern Med. Jan 2006;259(1):39-47. [Medline].
Schwartz PJ, Locati EH, Moss AJ, et al. Left cardiac sympathetic denervation in the therapy of congenital long QT syndrome. A worldwide report. Circulation. Aug 1991;84(2):503-11. [Medline].
Schwartz PJ, Priori SG, Spazzolini C, et al. Genotype-phenotype correlation in the long-QT syndrome: gene-specific triggers for life-threatening arrhythmias. Circulation. Jan 2 2001;103(1):89-95. [Medline].
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. Sep 17 1992;327(12):846-52. [Medline].
Zareba W, Moss AJ, le Cessie S, et al. Risk of cardiac events in family members of patients with long QT syndrome. J Am Coll Cardiol. Dec 1995;26(7):1685-91. [Medline].
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. Oct 1 1998;339(14):960-5. [Medline].
| Type of LQTS | Chromosomal Locus | Mutated Gene | Ion Current Affected |
| LQT1 | 11p15.5 | KVLQT1 or KCNQ1 (heterozygotes) | Potassium (IKs) |
| LQT2 | 7q35-36 | HERG, KCNH2 | Potassium (IKr) |
| LQT3 | 3p21-24 | SCN5A | Sodium (INa) |
| LQT4 | 4q25-27 | ANK2, ANKB | Sodium, potassium and calcium |
| LQT5 | 21q22.1-22.2 | KCNE1 (heterozygotes) | Potassium (IKs) |
| LQT6 | 21q22.1-22.2 | MiRP1, KNCE2 | Potassium (IKr) |
| LQT7 (Anderson syndrome) | 17q23.1-q24.2 | KCNJ2 | Potassium (IK1) |
| LQT8 (Timothy syndrome) | 12q13.3 | CACNA1C | Calcium (ICa-Lalpha) |
| LQT9 | 3p25.3 | CAV3 | Sodium (INa) |
| LQT10 | 11q23.3 | SCN4B | Sodium (INa) |
| LQT11 | 7q21-q22 | AKAP9 | Potassium (IKs) |
| LQT12 | SNTAI | Sodium (INa) | |
| JLN1 | 11p15.5 | KVLQT1 or KCNQ1 (homozygotes) | Potassium (IKs) |
| JLN2 | 21q22.1-22.2 | KCNE1 (homozygotes) | Potassium (IKs) |
| Criterion | Points | |
| ECG findings * | ||
| QTc, ms† | >480 | 3 |
| 460-469 | 2 | |
| 450-459 in male patient | 1 | |
| Torsade de pointes‡ | 2 | |
| T-wave alternans | 1 | |
| Notched T wave in 3 leads | 1 | |
| Low heart rate for age§ | 0.5 | |
| Clinical history | ||
| Syncope║ | With stress | 2 |
| Without stress | 1 | |
| Congenital deafness | 0.5 | |
| Family history ¶ | ||
| A. Family members with definite LQTS# | 1 | |
| B. Unexplained sudden cardiac death < 30y in an immediate family member | 0.5 | |
| *In the absence of medications or disorders known to affect these electrocardiographic features. †QTc calculated by Bazett's formula ‡Mutually exclusive §Resting heart rate below the second percentile for the age. ||Mutually exclusive ¶The same family member cannot be counted in A and B. #Definite LQTS is defined by an LQTS score of more than 3 (≥4). | ||
| Group | Prolonged QTc, s | Borderline QTc, s | Reference Range, s |
| Children and adolescents (< 15 y) | >0.46 | 0.44-0.46 | < 0.44 |
| Men | >0.45 | 0.43-0.45 | < 0.43 |
| Women | >0.46 | 0.45-0.46 | < 0.45 |

