Association of Short-term Heart Rate Variability and Sudden Unexpected Death in Epilepsy

Area of Science:

• Neurology
• Cardiology
• Epilepsy Research

Background:

• Sudden unexpected death in epilepsy (SUDEP) is a critical concern in epilepsy management.
• Heart rate variability (HRV) analysis offers insights into autonomic nervous system function.
• Previous research suggests a potential link between HRV and SUDEP, but further investigation is needed.

Purpose of the Study:

• To compare HRV parameters between SUDEP cases and living epilepsy controls.
• To identify specific HRV components associated with SUDEP risk and survival duration.

Main Methods:

• A retrospective, nested case-control study involving patients who underwent video-EEG monitoring (VEM).
• Analysis of 5-minute interictal electrocardiogram (ECG) recordings during sleep and wakefulness.
• Extraction and comparison of time and frequency domain HRV components, including normalized low-frequency power (LFP) and high-frequency power (HFP).

Main Results:

• SUDEP cases exhibited significantly lower normalized LFP during wakefulness compared to controls (p=0.015).
• A multivariable model confirmed lower normalized LFP in SUDEP cases (p=0.020).
• Reduced normalized LFP correlated with shorter latency to SUDEP, and increased HFP was associated with longer survival.

Conclusions:

• Reduced short-term LFP, a validated biomarker for sudden death, is associated with SUDEP.
• Increased HFP may be cardioprotective and is linked to longer survival in SUDEP.
• HRV quantification, particularly LFP and HFP, shows potential for stratifying SUDEP risk in epilepsy patients.