0
Sign In  | Subscribe
17 December 2002, Vol 137, No. 12>
Summaries for Patients | 17 December 2002

When the Heart's Electrical System Goes Haywire: The Congenital Long QT Syndrome FREE

[+] Article and Author Information

The summary below is from the full report titled “Novel Insights in the Congenital Long QT Syndrome.” It is in the 17 December 2002 issue of Annals of Internal Medicine (volume 138, pages 981-992). The authors are XHT Wehrens, MA Vos, PA Doevendans, and HJJ Wellens.


Ann Intern Med. 2002;137(12):I-43. doi:10.7326/0003-4819-137-12-200212170-00005
Text Size: A A A

What is the problem and what is known about it so far?

The congenital long QT syndrome (LQT syndrome) is a rare inherited disorder of the heart's electrical system. It prolongs the time that the heart takes to electrically recharge after each heartbeat (known as the QT interval). The disorder is most often first detected during childhood or early adulthood.

Most patients never have symptoms of the disorder, but when they occur, symptoms include fainting, irregular heart rhythm, and sudden death; some people who die of the LQT syndrome have had no prior symptoms. In people with symptoms, half have a “cardiac event” by age 12 years; nearly all have one by age 40 years.

The LQT syndrome takes different forms depending on what inherited abnormality of the genetic material (gene) is present. Three forms of the syndrome are clinically important and are described in detail: LQT1, LQT2, and LQT3. Each has different symptoms and is diagnosed and treated differently. For example, in patients with LQT1, exercise and stress trigger cardiac events; in patients with LQT3, rest and sleep are triggers. In patients with LQT2, triggers include both rest and exercise, as well as loud noises, such as being awakened by an alarm clock. Since effective clinical management depends on the type of genetic abnormality, identifying the abnormality benefits the patients. If one family member has the LQT syndrome, all relatives should be tested since sudden death can occur in people with the gene abnormality, even if they don't have the disorder itself.

Why did the authors do this review?

Advances in genetic research in the last 10 years have provided new information on this potentially deadly disorder. Discussion of the classification, symptoms, diagnosis, and treatment of different forms of the LQT syndrome may save many lives.

How did the authors do this review?

The authors searched the PubMed database (1966–2001) and their personal databases for research about the LQT syndrome. They used 152 articles to write their review.

What did the authors find?

Patients with symptoms require treatment. Patients with LQT1 and LQT2 typically benefit from drugs called β-blockers to prevent irregular heart rhythm. Some need surgical insertion of a pacemaker or defibrillator device. Beta-blockers don't seem to help patients with LQT3, but other drugs called sodium channel–blockers and pacemaker insertion may help. The need to treat patients with no symptoms remains controversial.

What are the implications of this review?

Researchers are developing specific treatments for each form of this sometimes life-threatening condition.

Figures

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s “Cited By” API will populate this tab (http://www.crossref.org/citedby.html).
Compression-Only CPR: Pushing the Science Forward
Cone
AAM 2010;304:1493-1495.
All you need to read in the other general jounals
BMJ 2010;341:c5893-c1494.

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy This Article

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Register Now for a free account
Advertisement

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles
Novel Insights in the Congenital Long QT Syndrome
Ann Intern Med. 2002;137(12):981-992.
Topic Collections
PubMed Articles
Implantable cardioverter defibrillator therapy in pediatric and congenital heart disease patients: a single tertiary center experience in Korea.
Korean journal of pediatrics Issue date: 2013 Mar
Congenital long QT syndrome of particularly malignant course connected with so far unknown mutation in the sodium channel SCN5A gene.
Cardiology journal Issue date: 2013

Annals of Internal Medicine

Other Resources

Copyright © 2013 The American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704

Buy This Article

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Register Now for a free account
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)