CLINICAL RESEARCH: HEART RHYTHM DISORDER
Long QT Syndrome in Children in the Era of Implantable Defibrillators
Susan P. Etheridge, MD, FACC*,*,
Shubhayan Sanatani, MD ,
Mitchell I. Cohen, MD, FACC ,
Cecilia A. Albaro, MD*,
Elizabeth V. Saarel, MD, FACC* and
David J. Bradley, MD, FACC*
* University of Utah, Salt Lake City, Utah
University of British Columbia, Vancouver, British Columbia, Canada
Phoenix Children’s Hospital and Arizona Pediatric Consults/Pediatrix, Phoenix, Arizona.
Manuscript received March 16, 2007;
revised manuscript received April 25, 2007,
accepted May 5, 2007.
* Reprint requests and correspondence: Dr. Susan P. Etheridge, 100 North Medical Drive, Salt Lake City, Utah 84113. (Email: pcsether{at}ihc.com).
Objectives: We sought to assess the spectrum and outcome of young long QT syndrome (LQTS) patients, addressing treatment including device indications, risks, and benefits.
Background: Long QT syndrome has a phenotype ranging from asymptomatic electrocardiogram (ECG) abnormalities to sudden death. Treatments include beta-blockers and device implantation in high-risk individuals. Despite genetic testing, accurate risk stratification remains challenging.
Methods: A database search at 3 institutions identified all pediatric LQTS patients. Records were reviewed for demographics, criteria for diagnosis, treatment, follow-up, and ECG and device data.
Results: We identified 128 patients ages 8.0 ± 5.4 years with QTc of 487 ± 39 ms and follow-up of 4.4 ± 3.5 years. Most were diagnosed because of an abnormal ECG in a patient with a family history (53%). Genetic mutations were identified in 51 patients. Beta-blockers were used in 126 (98%) and pacemaker/implantable cardioverter-defibrillator implantation in 27 (21%) patients, usually because of symptoms despite use of beta-blockers. Pacing was common; 22% received an appropriate shock but device-related re-intervention occurred in 48%. Device patients had longer QTc intervals (p = 0.03) and more symptoms (p < 0.001). No one with an isolated KCNQ1 and all patients with an SCN5A mutation had device implantation. During the study period, there were 2 deaths.
Conclusions: Long QT syndrome without symptoms is increasingly recognized as family members are screened. Evaluation of this minimally symptomatic population offers an evolving understanding of LQTS. Previous studies of highly symptomatic patients were more worrisome. In the era of genetic testing and device implantation, overall mortality is low with treatment. Device therapy, although effective, is not without complications and should be reserved for high-risk patients.
|
Abbreviations and Acronyms
| | ECG = electrocardiogram | | ICD = implantable cardioverter-defibrillator | | LQTS = long QT syndrome | | TdP = torsades de pointes |
|
Related Article
-
Long QT Syndrome in Children: Not One Disease Anymore
- Seshadri Balaji
J. Am. Coll. Cardiol. 2007 50: 1341-1342.
[Full Text]
[PDF]
This article has been cited by other articles:
|
|
|
|
 
P. J. Schwartz, C. Spazzolini, S. G. Priori, L. Crotti, A. Vicentini, M. Landolina, M. Gasparini, A. A. M. Wilde, R. E. Knops, I. Denjoy, et al.
Who Are the Long-QT Syndrome Patients Who Receive an Implantable Cardioverter-Defibrillator and What Happens to Them?: Data From the European Long-QT Syndrome Implantable Cardioverter-Defibrillator (LQTS ICD) Registry
Circulation,
September 28, 2010;
122(13):
1272 - 1282.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. J. Schwartz
Cascades or Waterfalls, the Cataracts of Genetic Screening Are Being Opened on Clinical Cardiology
J. Am. Coll. Cardiol.,
June 8, 2010;
55(23):
2577 - 2579.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Viskin and A. Halkin
Treating the Long-QT Syndrome in the Era of Implantable Defibrillators
Circulation,
January 20, 2009;
119(2):
204 - 206.
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. M. Vincent, P. J. Schwartz, I. Denjoy, H. Swan, C. Bithell, C. Spazzolini, L. Crotti, K. Piippo, J.-M. Lupoglazoff, E. Villain, et al.
High Efficacy of {beta}-Blockers in Long-QT Syndrome Type 1: Contribution of Noncompliance and QT-Prolonging Drugs to the Occurrence of {beta}-Blocker Treatment "Failures"
Circulation,
January 20, 2009;
119(2):
215 - 221.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Atallah, F. Fynn-Thompson, F. Cecchin, D. J. DiBardino, E. P. Walsh, and C. I. Berul
Video-Assisted Thoracoscopic Cardiac Denervation: A Potential Novel Therapeutic Option for Children With Intractable Ventricular Arrhythmias
Ann. Thorac. Surg.,
November 1, 2008;
86(5):
1620 - 1625.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. M. Vincent
Genotyping Has a Minor Role in Selecting Therapy for Congenital Long-QT Syndromes at Present
Circ Arrhythm Electrophysiol,
August 1, 2008;
1(3):
227 - 233.
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. I. Berul
Congenital Long-QT Syndromes: Who's at Risk for Sudden Cardiac Death?
Circulation,
April 29, 2008;
117(17):
2178 - 2180.
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. N. DeMaria, J. J. Bax, O. Ben-Yehuda, P. Clopton, G. K. Feld, G. S. Ginsburg, B. H. Greenberg, J. D. Knoke, W. Y.W. Lew, J. A.C. Lima, et al.
Highlights of the Year in JACC 2007
J. Am. Coll. Cardiol.,
January 29, 2008;
51(4):
490 - 512.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Balaji
Long QT Syndrome in Children: Not One Disease Anymore
J. Am. Coll. Cardiol.,
October 2, 2007;
50(14):
1341 - 1342.
[Full Text]
[PDF]
|
|
|
|
