Pacemakers could play a future role in protecting epilepsy patients

Results of a UK study in this week’s issue of THE LANCET highlight how interruptions to the heart’s rhythm is an under-reported consequence of epileptic seizures, and that the use of cardiac pacemakers by some epilepsy patients could play a future role in protecting against sudden unexplained death.

Patients with epilepsy are at risk of sudden unexplained death. Irregular heart rhythm as a result of neurological dysfunction during seizures is thought to be a possible cause.

John Duncan (Institute of Neurology UCL and National Society for Epilepsy, London) and colleagues studied 20 patients with epilepsy who received an implantable device which monitored heart rhythms. These devices were programmed to record automatically for very slow heart beat (bradycardia, 40 beats per minute or less) or very fast beats (tachycardia, 140 beats or more per minute) were detected.

Patients were studied for up to 22 months; ECG patterns monitored heart rhythms during 377 seizures. Heart rate during habitual seizures exceeded 100 beats per minute among 16 patients. Four patients had bradycardia or periods of asystole (cardiac inactivity) and were given permanent pacemaker insertion. Three of these four patients had potentially fatal asystole.

Professor Duncan comments: “We have shown that implantable loop recorders can identify potentially fatal cardiac abnormalities in patients with epilepsy, and suggest that the incidence of bradycardia and asystole has previously been under-reported. Asystole underlies a proportion of sudden unexpected deaths in epilepsy, which could be prevented by cardiac-pacemaker insertion.”

In an accompanying commentary, Lawrence J Hirsch and W Allen Houser (Mailman School of Public Health, Columbia University, New York City, USA) consider the present study an important step forward but caution that it is too early to change clinical practice until larger confirmatory studies are conclusive.