Heart rate variability and sudden unexpected death in epilepsy


  • Quantifying heart rate variability (HRV) may help stratify the risk of sudden unexpected death in epilepsy (SUDEP) in patients with epilepsy.

Why this matters

  • In patients with epilepsy, a common cause of mortality is SUDEP, which is often triggered by nocturnal tonic-clonic seizures (TCS).

  • The risk of SUDEP is increased by TCS because TCS can impair cardiorespiratory and autonomic dysfunction; however, there is currently no method of stratifying an individual’s risk for SUDEP.

  • HRV is an accepted measure of neural cardiac control, where low HRV is strongly predictive of an increased risk of sudden death in patients with heart disease.

  • Reduced interictal HRV has also been associated with drug-resistant, chronic epilepsy, and can predict a more severe outcome after epilepsy surgery.

  • Therefore, altered HRV may be a risk factor for SUDEP, which is yet to be validated.