Heart rate and blood pressure in sudden unexpected death in epilepsy (SUDEP)

Epilepsy is associated with interictal and ictal autonomic dysfunction. Seizures can immediately cause increases in blood pressure (BP) and heart rate (HR). However, it is unknown whether uncontrolled seizures, particularly when frequent, might chronically elevate the BP or HR. Additionally, it is unknown whether the interictal BP and HR is altered in individuals who are at risk for SUDEP, compared with other individuals with epilepsy. SUDEP often occurs in patients with highly refractory epilepsy. Such individuals might be at risk for a state of chronically heightened sympathetic tone, which might affect the HR and BP interictally. This study compared the resting awake interictal HR and BP in individuals who subsequently died due to SUDEP and compared these to HR and BP in two control epilepsy groups (refractory and controlled). While the overall HR and BP are similar between groups, there is a trend toward a higher diastolic BP and more stable HR in individuals who subsequently died due to SUDEP, compared with epilepsy controls. These data suggest that there may be specific types of interictal autonomic dysfunction in individuals at risk for SUDEP. Such abnormalities might serve as markers for those at elevated risk for SUDEP.