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Clinical implications for patients with long QT syndrome who experience a cardiac event during infancy

Carla Spazzolini1, Jamie Mullally, Arthur J Moss

  • 1Section of Cardiology and Department of Cardiology and Molecular Cardiology Laboratory, Fondazione Policinico S. Matteo IRCCS and the University of Pavia, Pavia, Italy.

Journal of the American College of Cardiology
|August 22, 2009
PubMed

Insights

Infants with long QT syndrome (LQTS) experiencing aborted cardiac arrest (ACA) face a very high risk of future cardiac events. Beta-blockers may not effectively prevent these events in this high-risk group.

Area of Science:

  • Cardiology
  • Pediatric Cardiology
  • Genetics

Background:

  • Clinical implications of cardiac events in infancy due to Long QT Syndrome (LQTS) remain understudied.
  • Previous research has not focused on the long-term prognosis of LQTS patients experiencing cardiac events within the first year of life.

Purpose of the Study:

  • To evaluate the clinical and prognostic significance of LQTS-related cardiac events occurring in infancy.
  • To identify risk factors for cardiac events in the first year of life and assess long-term outcomes.

Main Methods:

  • Analysis of data from the International LQTS Registry, including 3,323 patients with corrected QT interval (QTc) ≥450 ms.
  • Categorization of patients into groups: sudden cardiac death (SCD), aborted cardiac arrest (ACA), syncope, and asymptomatic.
  • Identification of risk factors for cardiac events in 212 patients with electrocardiograms in the first year of life.

Main Results:

  • Risk factors for cardiac events in infancy included QTc ≥500 ms, heart rate ≤100 bpm, and female sex.
  • ACA in the first year of life significantly increased the risk of ACA or SCD between ages 1-10 years (HR 23.4, p < 0.01).
  • Beta-blocker therapy showed a reduction in ACA/SCD only for those with prior syncope, not for infants surviving ACA.

Conclusions:

  • Infants with LQTS experiencing ACA are at extremely high risk for subsequent life-threatening cardiac events.
  • Beta-blocker efficacy in preventing fatal or near-fatal events in this specific high-risk infant subset may be limited.
  • Early identification and risk stratification are crucial for managing LQTS in infancy.
Abstract

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