Febrile seizures prior to sudden cardiac death: a Danish nationwide study

Febrile seizure (FS) is a common disorder affecting 2–5% of children up to 5 years of age. The aim of this study was to determine whether FS in early childhood are over-represented in young adults dying from sudden cardiac death (SCD).

We included all deaths (n = 4595) nationwide and through review of all death certificates, we identified 245 SCD in Danes aged 1–30 years in 2000–09. Through the usage of nationwide registries, we identified all persons admitted with first FS among SCD cases (14/245; 5.7%) and in the corresponding living Danish population (71 027/2 369 785; 3.0%) and also in victims of transport accidents (26/917; 2.8%). The frequency of FS among SCD cases was significantly increased by an odds ratio of 1.96 [95% confidence interval (CI) 1.14–3.36; P = 0.021] compared with the living Danish population and with an odds ratio of 2.08 (95% CI 1.07–4.04; P = 0.046) compared with transport accident victims. SCD cases did not differ statistically in birth year (P = 0.272), age at SCD (P = 0.667) or prior medical conditions, except for epilepsy (P < 0.001), when comparing SCD with and without prior FS. The most common cause of death in autopsied SCD cases with FS was sudden arrhythmic death syndrome (5/8; 62.5%).

In conclusion, this study demonstrates a significantly two-fold increase in the frequency of FS prior to death in young SCD cases compared with the two control groups, suggesting that FS could potentially contribute in a risk stratification model for SCD and warrant further studies.