Identification of a common genetic substrate underlying postpartum cardiac events in congenital long QT syndrome.

Objectives: The aim of this study was to elucidate the genetic basis for long QT syndrome (LQTS) in patients with a personal or family history of postpartum cardiac events.

Background: The postpartum period is a time of increased arrhythmogenic susceptibility in women with LQTS.

Methods: Between August 1997 and May 2003, 388 unrelated patients (260 females, average age at diagnosis, 23 years, and average QTc, 482 ms) were referred to Mayo Clinic's Sudden Death Genomics Laboratory for LQTS genetic testing.