Trial: Long QT syndrome and pregnancy

Authors:  Seth R, Moss AJ, McNitt S, Zareba W, Andrews ML, Qi M, Robinson JL, Goldenberg I, Ackerman MJ, Benhorin J, Kaufman ES, Locati EH, Napolitano C, Priori SG, Schwartz PJ, Towbin JA, Vincent GM, Zhang L.

Reference:  J Am Coll Cardiol. 2007 Mar 13;49(10):1092-8. Epub 2007 Feb 27.

Purpose:  To investigate the clinical course of women with long QT syndrome (LQTS) throughout their potential childbearing years.

Number of Patients:  1084

Number of Centers:  International LQTS Registry

Design:  Cohort

Authors Conclusion:  Women with the congenital long QT syndrome 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 of cardiac events, defined as syncope, aborted cardiac arrest, or long-QT death, during this high-risk postpartum period.

Key words:  Long QT syndrome, ventricular arrhythmia, pregnancy

Comment:  Prior to this study, only limited data was available regarding the risk associated with pregnancy in women with the congenital long QT syndrome.  The current study includes female subjects of child-bearing age who were enrolled in the International LQTS Registry.  It is hypothesized that the increased risk of cardiac events occurring postpartum may be related to physiological and hemodynamic changes, alterations in adrenergic activity, or alterations in hormone levels after delivery.  With the larger number of subjects in this cohort, the benefit from beta-blocker therapy, particularly in reducing postpartum risk, is now well documented. 

Ongoing Related Studies:

1. The Long QT Syndrome in Pregnancy
2.. Long QT Syndrome-Population Genetics and Cardiac Studies
3. Linkage Study of Long QT Syndrome In An Amish Kindred

Summary written by Andrea Russo, MD