I write this letter following the tragic death of a 10-year-old child. The child presented with a syncopal episode on a school sports day. The ensuing investigation included a detailed cardiology examination. The child's electrocardiogram (ECG) was normal, but the possibility of an intermittent pattern of long QT syndrome was considered. Holter monitoring was being organized when the child suffered another syncopal episode while swimming and died.
Family members were tested for the markers for long QT syndrome by ECG examination. The ECG of one child, who was a close relative of the index child, showed long QT abnormalities. Thus, not only was the cause of death in the index child identified more definitively but the other child was treated and what could well have been another sudden and unexpected death was prevented.
Long QT syndrome is manifested in some people who are highly vulnerable to ventricular tachycardias and may progress to ventricular fibrillation, with frequently fatal results.1 The ECGs of most patients with this pattern of polymorphic ventricular tachycardia (also known as torsades de pointes) show a long QT interval, even if the patient is in sinus rhythm at the time of testing.2
Some lives might be saved by considering the possibility of long QT syndrome in a young person presenting with syncopal symptoms.3,4 Regrettably, some deaths will inevitably occur, as this syndrome frequently presents for the first time as a sudden death.
In all situations in which long QT syndrome is diagnosed or under serious consideration, it is important that physicians consider ordering a detailed ECG examination of the patient's family members, because in a small number of cases long QT syndrome has a hereditary component. Testing of asymptomatic family members may identify other children at risk for sudden death and allow preemptive intervention at low cost and with great effectiveness.
Although the death of the index child in this case was probably unavoidable, family testing did identify another child at risk of a preventable death from the same syndrome. We can make a difference if we all think about the possibility of long QT syndrome whenever a child dies suddenly and unexpectedly.