title: Clinical implications for patients with long QT syndrome who experience a cardiac event during infancy.
abstract: OBJECTIVE
  This study was designed to evaluate the clinical and prognostic aspects of long QT syndrome (LQTS)-related cardiac events that occur in the first year of life (infancy).
  
  
  BACKGROUND
  The clinical implications for patients with long QT syndrome who experience cardiac events in infancy have not been studied previously.
  
  
  METHODS
  The study population of 3,323 patients with QT interval corrected for heart rate (QTc) > or =450 ms enrolled in the International LQTS Registry involved 20 patients with sudden cardiac death (SCD), 16 patients with aborted cardiac arrest (ACA), 34 patients with syncope, and 3,253 patients who were asymptomatic during the first year of life.
  
  
  RESULTS
  The risk factors for a cardiac event among 212 patients who had an electrocardiogram recorded in the first year of life included QTc > or =500 ms, heart rate < or =100 beats/min, and female sex. An ACA before age 1 year was associated with a hazard ratio of 23.4 (p < 0.01) for ACA or SCD during ages 1 to 10 years. During the 10-year follow-up after infancy, beta-blocker therapy was associated with a significant reduction in ACA/SCD only in those with a syncopal episode within 2 years before ACA/SCD but not for those who survived ACA in infancy.
  
  
  CONCLUSIONS
  Patients with LQTS who experience ACA during the first year of life are at very high risk for subsequent ACA or death during their next 10 years of life, and beta-blockers might not be effective in preventing fatal or near-fatal cardiac events in this small but high-risk subset.
authors.affiliation: Section of Cardiology and Department of Cardiology and Molecular Cardiology Laboratory, Fondazione Policinico S. Matteo IRCCS and the University of Pavia, Pavia, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Spazzolini
authors.forename: Jamie
authors.initials: J
authors.lastname: Mullally
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schwartz
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Gregory
authors.initials: G
authors.lastname: Ouellet
authors.forename: Thomas
authors.initials: T
authors.lastname: Fugate
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: Christian
authors.initials: C
authors.lastname: Jons
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Robinson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ackerman
authors.forename: Jesaia
authors.initials: J
authors.lastname: Benhorin
authors.forename: Lia
authors.initials: L
authors.lastname: Crotti
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Emanuela H
authors.initials: EH
authors.lastname: Locati
authors.forename: Ming
authors.initials: M
authors.lastname: Qi
authors.forename: Carlo
authors.initials: C
authors.lastname: Napolitano
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Priori
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.forename: G Michael
authors.initials: GM
authors.lastname: Vincent
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000209:etiology*; D006801:Humans; D007223:Infant; D008133:Long QT Syndrome / Q000150:complications* / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D018570:Risk Assessment; D012307:Risk Factors
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