title: Risk factors for aborted cardiac arrest and sudden cardiac death in children with the congenital long-QT syndrome.
abstract: BACKGROUND
  The congenital long-QT syndrome (LQTS) is an important cause of sudden cardiac death in children without structural heart disease. However, specific risk factors for life-threatening cardiac events in children with this genetic disorder have not been identified.
  
  
  RESULTS
  Cox proportional-hazards regression modeling was used to identify risk factors for aborted cardiac arrest or sudden cardiac death in 3015 LQTS children from the International LQTS Registry who were followed up from 1 through 12 years of age. The cumulative probability of the combined end point was significantly higher in boys (5%) than in girls (1%; P<0.001). Risk factors for cardiac arrest or sudden cardiac death during childhood included corrected QT interval [QTc] duration > 500 ms (hazard ratio [HR]; 2.72; 95% confidence interval [CI], 1.50 to 4.92; P=0.001) and prior syncope (recent syncope [< 2 years]: HR, 6.16; 95% CI 3.41 to 11.15; P<0.001; remote syncope [> or = 2 years]: HR, 2.67; 95% CI, 1.22 to 5.85; P=0.01) in boys, whereas prior syncope was the only significant risk factor among girls (recent syncope: HR, 27.82; 95% CI, 9.72 to 79.60; P<0.001; remote syncope: HR, 12.04; 95% CI, 3.79 to 38.26; P<0.001). Beta-blocker therapy was associated with a significant 53% reduction in the risk of cardiac arrest or sudden cardiac death (P=0.01).
  
  
  CONCLUSIONS
  LQTS boys experience a significantly higher rate of fatal or near-fatal cardiac events than girls during childhood. A QTc duration > 500 ms and a history of prior syncope identify risk in boys, whereas prior syncope is the only significant risk factor among girls. Beta-blocker therapy is associated with a significant reduction in the risk of life-threatening cardiac events during childhood.
authors.affiliation: Cardiology Division of the Department of Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA. Ilan.Goldenberg@heart.rochester.edu
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Derick R
authors.initials: DR
authors.lastname: Peterson
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Mark L
authors.initials: ML
authors.lastname: Andrews
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Robinson
authors.forename: Emanuela H
authors.initials: EH
authors.lastname: Locati
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ackerman
authors.forename: Jesaia
authors.initials: J
authors.lastname: Benhorin
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Carlo
authors.initials: C
authors.lastname: Napolitano
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Priori
authors.forename: Ming
authors.initials: M
authors.lastname: Qi
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schwartz
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.forename: G Michael
authors.initials: GM
authors.lastname: Vincent
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004562:Electrocardiography; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008133:Long QT Syndrome / Q000151:congenital / Q000188:drug therapy / Q000235:genetics / Q000401:mortality*; D008297:Male; D010138:Pacemaker, Artificial; D010641:Phenotype; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D013575:Syncope / Q000453:epidemiology
chemical_list: D000319:Adrenergic beta-Antagonists