Long QT Syndrome
A 34-year-old female who is 4 months postpartum presents after a nocturnal seizure. She was awakened at night by an alarm clock to feed her baby, spoke briefly with her husband, and suddenly lost consciousness, appearing to have epileptic-type movements before spontaneously recovering. On further questioning, she reported several syncopal events over the past 15 years, once when standing suddenly, also thought at the time to be a seizure. Previous neurological investigations were normal. A 12-lead ECG (Figure 1A) revealed a corrected QT interval of 550 ms with low-amplitude, notched T-waves.
Background and Prevalence
Long QT syndrome (LQTS) is an inherited cardiac condition caused by genetically encoded abnormalities in cardiac ion channels, characterized clinically by palpitations, syncope, and sudden cardiac death, with varying degrees of QT prolongation and T-wave morphological …