Abstract 1053: Contribution of Inherited Diseases to (aborted) Sudden Cardiac Death in Childhood
Background In adults, sudden cardiac death (SCD) is most often secondary to coronary artery disease. In children an inherited cause is more likely, and investigation of relatives may yield the diagnosis, when the cause of death in the SCD victim remains unresolved. In addition, relatives of the victim may also be at risk of life-threatening events due to these inherited cardiac diseases. We aimed to investigate the contribution of inherited diseases to SCD in children.
Methods and Results We counseled 24 consecutive, unrelated families after SCD of a child aged 1–18 years, who was disease-free during lifetime and in whose family there was no known inherited heart disease. We performed cardiac investigation (ECG, X-ECG, echo) of first (n=83) and second (n=9) degree relatives and performed diagnosis-directed DNA analysis. Autopsy was performed in 19 cases. We identified a diagnosis in 12/24 families: Long QT syndrome (LQTS, n=7), catecholaminergic polymorphic ventricular tachycardia (CPVT, n=3) and hypertrophic cardiomyopathy (HCM, n=2, diagnosed by autopsy). For comparison, we also studied nine children after aborted SCD; in five, a diagnosis was made: LQTS (n=3) and CPVT (n=2). In 15 of the 17 (12=5) families with a diagnosis, a disease-causing mutation in either a first degree family member or the index patient confirmed the diagnosis. (LQTS, n=9/10; CPVT, n=4/5; HCM, n=2/2).
Conclusions Cardiac examination of relatives and/or postmortem analysis after SCD of a child has a high diagnostic yield (12/24 = 50%), comparable to analysis in a surviving victim of SCD (5/9 = 56%). As CPVT and LQTS can both be very successfully managed, these results warrant active family screening after unexplained SCD of a child.