People with epilepsy may die suddenly and unexpectedly without a structural 
pathological cause. Most SUDEP cases are likely to be related to seizures. SUDEP 
incidence varies and is <1:1,000 person-years among prevalent cases in the 
community and approximately 1:250 person years in specialist centres. 
Case-control studies identified certain risk factors, some potentially amenable 
to manipulation, including uncontrolled convulsive seizures and factors relating 
to treatment and supervision. Both respiratory and cardiac mechanisms are 
important. The apparent protective effect of lay supervision supports an 
important role for respiratory factors, in part amenable to intervention by 
simple measures. Whereas malignant tachyarrhythmias are rare during seizures, 
sinus bradycardia/arrest, although infrequent, is well documented. Both types of 
arrhythmias can have a genetic basis. This article reviews SUDEP and explores 
the potential of coexisting liability to cardiac arrhythmias as a contributory 
factor, while acknowledging that at present, bridging evidence between cardiac 
inherited gene determinants and SUDEP is lacking.