Long QT syndrome and pregnancy.
OBJECTIVE
This study was designed to investigate the clinical course of women with long QT syndrome (LQTS) throughout their potential childbearing years.


BACKGROUND
Only limited data exist regarding the risks associated with pregnancy in women with LQTS.


METHODS
The risk of experiencing an adverse cardiac event, including syncope, aborted cardiac arrest, and sudden death, during and after pregnancy was analyzed for women who had their first birth from 1980 to 2003 (n = 391). Time-dependent Kaplan-Meier and Cox proportional hazard methods were used to evaluate the risk of cardiac events during different peripartum periods.


RESULTS
Compared with a time period before a woman's first conception, the pregnancy time was associated with a reduced risk of cardiac events (hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.10 to 0.76, p = 0.01), whereas the 9-month postpartum time had an increased risk (HR 2.7, 95% CI 1.8 to 4.3, p < 0.001). After the 9-month postpartum period, the risk was similar to the period before the first conception (HR 0.91, 95% CI 0.55 to 1.5, p = 0.70). Genotype analysis (n = 153) showed that women with the LQT2 genotype were more likely to experience a cardiac event than women with the LQT1 or LQT3 genotype. The cardiac event risk during the high-risk postpartum period was reduced among women using beta-blocker therapy (HR 0.34, 95% CI 0.14 to 0.84, p = 0.02).


CONCLUSIONS
Women with LQTS have a reduced risk for cardiac events during pregnancy, but an increased risk during the 9-month postpartum period, especially among women with the LQT2 genotype. Beta-blockers were associated with a reduction in cardiac events during the high-risk postpartum time period.
Seth
Rahul
R
Cardiology Division of the Department of Medicine, University of Rochester Medical Center, Rochester, New York 14642, USA.
Moss
Arthur J
AJ
McNitt
Scott
S
Zareba
Wojciech
W
Andrews
Mark L
ML
Qi
Ming
M
Robinson
Jennifer L
JL
Goldenberg
Ilan
I
Ackerman
Michael J
MJ
Benhorin
Jesaia
J
Kaufman
Elizabeth S
ES
Locati
Emanuela H
EH
Napolitano
Carlo
C
Priori
Silvia G
SG
Schwartz
Peter J
PJ
Towbin
Jeffrey A
JA
Vincent
G Michael
GM
Zhang
Li
L
D000328:Adult; D015331:Cohort Studies; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000209:etiology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006323:Heart Arrest / Q000401:mortality; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000401:mortality; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000175:diagnosis* / Q000401:mortality; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011336:Probability; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment