Clinical implications for patients with long QT syndrome who experience a cardiac event during infancy.
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.
Spazzolini
Carla
C
Section of Cardiology and Department of Cardiology and Molecular Cardiology Laboratory, Fondazione Policinico S. Matteo IRCCS and the University of Pavia, Pavia, Italy.
Mullally
Jamie
J
Moss
Arthur J
AJ
Schwartz
Peter J
PJ
McNitt
Scott
S
Ouellet
Gregory
G
Fugate
Thomas
T
Goldenberg
Ilan
I
Jons
Christian
C
Zareba
Wojciech
W
Robinson
Jennifer L
JL
Ackerman
Michael J
MJ
Benhorin
Jesaia
J
Crotti
Lia
L
Kaufman
Elizabeth S
ES
Locati
Emanuela H
EH
Qi
Ming
M
Napolitano
Carlo
C
Priori
Silvia G
SG
Towbin
Jeffrey A
JA
Vincent
G Michael
GM
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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