LQT5: Difference between revisions

Jump to navigation Jump to search
Line 26: Line 26:


===Therapy===
===Therapy===
*[[Beta-blockers]] are the first line treatment in LQTS along with electrolyte repletion.
*[[Beta-blockers]] are the first line treatment in LQTS, even in asymptomatic carriers, as they reduce the incidence of [[syncope]] and [[sudden cardiac death]].  
*Other [[medications]] to control non-malignant [[arrhythmias]].
*Other [[medications]] to control non-malignant [[arrhythmias]].
*Electrolytes should be repleted as neccesary.
*Avoidance of triggers (drugs, supplements, loud noises, exercise).
*Avoidance of triggers (drugs, supplements, loud noises, exercise).
* LQTs is one of the few diseases where genetic testing can provide important guidance, such as in whom to place an [[AICD]] (defibrillator) for the primary prevention of cardiac events. <ref>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 Sep 1;94(5):1018-22. PMID 8790040</ref>
* LQTs is one of the few diseases where genetic testing can provide important guidance, such as in whom to place an [[AICD]] (defibrillator) for the primary prevention of cardiac events. <ref>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 Sep 1;94(5):1018-22. PMID 8790040</ref>

Revision as of 09:41, 9 October 2012

Long QT Syndrome Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Long QT Syndrome from other Diseases

Epidemiology and Demographics

Risk Stratification

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

CT scan

MRI

Other Imaging Findings

Other Diagnostic Studies

Genetic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Case Studies

Case #1

LQT5 On the Web

Most recent articles

Most cited articles

Review articles

Programs

slides

[1]

American Roentgen Ray Society Images of LQT5

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

on LQT5

CDC onLQT5

in the news

on LQT5

Directions to Hospitals Treating Long QT Syndrome

Risk calculators and risk factors for LQT5

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]

Overview

LQT5 subtype of long QT syndrome is an autosomal dominant mutation that leads to a defect in the potassium channel. In its rare homozygous form it can cause Jervell and Lange-Nielsen syndrome.

LQT5 Subtype

Type OMIM Mutation
LQT5 176261 beta subunit MinK (or KCNE1) which coassembles with KvLQT1

Genetics and Pathophysiology

LQT5 is an autosomal dominant relatively uncommon form of LQTS. It involves mutations in the gene KCNE1 which encodes for the potassium channel beta subunit MinK. In its rare homozygous forms it can lead to Jervell and Lange-Nielsen syndrome. As in LQT1, LQT5 can lead to a decreased excretion of potassium from the cell and will show prolongation of the QT interval on EKG.

History and Symptoms

Therapy

  • Beta-blockers are the first line treatment in LQTS, even in asymptomatic carriers, as they reduce the incidence of syncope and sudden cardiac death.
  • Other medications to control non-malignant arrhythmias.
  • Electrolytes should be repleted as neccesary.
  • Avoidance of triggers (drugs, supplements, loud noises, exercise).
  • LQTs is one of the few diseases where genetic testing can provide important guidance, such as in whom to place an AICD (defibrillator) for the primary prevention of cardiac events. [1]
  • Left stellectomy is not a cure, but is a second line therapy to reduce the risk of sudden cardiac death and is indicated if the patient does not tolerate beta blockers, as well as in young patients under the age of 12 where beta blockers are not deemed protective enough and AICD is not appropriate.
  • Patients with long QT syndrome should undergo secondary prevention with AICD implantation if they sustain an aborted cardiac arrest or sudden cardiac death.

References

  1. 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 Sep 1;94(5):1018-22. PMID 8790040