Background: Approximately 1 in 1000 patients with epilepsy dies suddenly and unexpectedly with no obvious medical cause.The purpose of this study was to determine if the hearts of such individuals harbor occult cardiac pathology.Design: Followingacomprehensiveprotocol,weperformed careful pathologic evaluations of the hearts of 7 patients with epilepsywhodiedsuddenlyand13previouslyhealthypeople who died by hanging or a drug overdose.Hearts were studied only when there was no history or gross anatomical evidence of heart disease or the use of adrenergic drugs.Methods: Multiple sections of each heart were evaluated independently by 2 cardiac pathologists who were blinded to patient group.Results: Pathologic conditions were found in 5 hearts in the group with epilepsy and in none of the hearts in the comparison group.Four of the 7 hearts in the group with epilepsy had evidence of irreversible pathology in the form of perivascular and interstitial fibrosis.These 4 hearts plus a fifth had evidence of reversible pathology in the form of myocyte vacuolization.Lesions occurred predominantly in the subendocardium. Conclusion:Our results support the hypothesis that patients with epilepsy who die suddenly and unexpectedly have cardiac pathologic conditions that may be responsible for their deaths.