Abstract 17733: Some Epilepsy Patients Die Suddenly Without a Preceding Seizure Episode: What are the Mechanisms?
Introduction: Epilepsy is associated with a significantly increased risk of sudden cardiac arrest (SCA), and we have previously reported that this devastating outcome does not always require a preceding seizure. Based on the hypothesis that the pathophysiology of SCA for epilepsy patients may be heterogeneous, we compared the clinical profile of epilepsy patients with and without seizure activity prior to SCA.
Methods: Subjects of all ages with SCA occurring in the setting of prior documented epilepsy were identified from a large, ongoing, population-based study of SCA in the Northwest US (community pop. approx. 1 million). We explored the relationships between baseline demographics, lifetime medical history and SCA circumstances among those who had a witnessed seizure within 24 hours of the SCA event (seizure-dependent) and those who did not (seizure-independent). Data were obtained from multiple sources (first responders, medical practitioners and medical examiner) between 2002 and 2015. Patients with terminal illnesses and non-cardiac causes of arrest were excluded, as well as those with infantile febrile seizures or alcoholic withdrawal seizures.
Results: Among 142 subjects with SCA and seizure disorder, 64 (45.1%) were witnessed during the event and, among these, 26 (40.6%) were seizure-dependent while 38 (59.4%) were seizure-independent. The seizure-independent subjects were significantly older (mean age 61.9 years; 95% CI, 43.1 to 80.7 years; vs 47.6 years; 95% CI, 27.0 to 68.2 years; p=0.006). However the younger seizure-dependent group had higher prevalence of cardiac arrest due to pulseless electrical activity (PEA) or asystole (81.0% vs 58.3%; p=0.081). There was no notable difference in the burden of comorbidities (Charlson index 1.92 vs 2.37; p=0.941), periarrest characteristics, ECG and echo parameters.
Conclusions: Seizure-independent SCA occurs at an older age, supporting the hypothesis that over time, neuro-cardiac remodeling may lead to cardiac arrest in the absence of hypoxia. In younger, seizure-dependent patients hypoxia may be a pre-requisite, but both hypotheses warrant further detailed investigation.
Author Disclosures: E.C. Stecker: Research Grant; Significant; NIH. K. Chua: None. A. Uy-Evanado: None. C. Teodorescu: None. K. Reinier: None. K. Gunson: None. J. Jui: None. S.S. Chugh: Research Grant; Significant; NIH.
- © 2015 by American Heart Association, Inc.