New device spots potentially fatal heart problems during epileptic seizures
17 December 2004
A new implant could significantly reduce the risk of cardiac arrest from an epileptic seizure, according to a University College London (UCL) study published in today's Lancet .
In a pilot trial funded by the National Society for Epilepsy, 20 epilepsy patients were implanted with a device which monitored their heart rhythms for up to 22 months. The implants picked up eight incidences of serious drops in heart rate during seizures. Four of the patients went on to have permanent pacemakers inserted. Potentially fatal pauses in heart rhythms were detected during a seizure in three of these patients.
A number of people with epilepsy are at risk of sudden death from a seizure, but identifying these high-risk patients can be difficult. Routine electrocardiography (ECG) and in-patient monitoring, which typically lasts one week, can spot potential problems but will only capture a limited number of seizures over this period.
The implant, a loop recorder inserted just above the heart, can monitor cardiac rhythms continuously for over 18 months, enabling doctors to spot the occasional abnormality of heart rate - known as a cardiac arrhythmia - that might otherwise be missed in routine check-ups.
In the trial, the implant was programmed to automatically record an exceptionally slow or fast rate - known as a bradycardia (below 40 beats per minute) or a tachycardia (above 140 beats per minute). Additionally, in the event of a seizure, patients or their relatives could trigger the ECG recording using a remote activating device.
In the study, heart rhythms were recorded during 377 of a total of 3377 seizures reported by patients, and the four patients who were subsequently given pacemakers all experienced periods in which the heart beat ceased temporarily or went very slowly.
More than 350,000 people are affected by epilepsy in the UK , with 30,000 new cases diagnosed every year. Each year there are around 1,000 epilepsy-related deaths, around half of which are due to sudden unexpected death in epilepsy (SUDEP).
Professor John Duncan of UCL's Institute of Neurology and Medical Director of the National Society for Epilepsy says: "A small number of people with epilepsy are at risk from sudden death, particularly young adults who continue to have seizures despite taking a mix of anti-epileptic medication. This device not only offers them a much longer period of monitoring, but it enables them to continue with their everyday activities rather than spending a week in a hospital.
"Most of the cardiac events detected by the device would not have been picked up during routine ECG monitoring, meaning these loop recorders offer a substantial improvement in spotting potentially fatal heart arrhythmias in these patients."
The Reveal Plus implantable loop recorder, designed by Medtronic, can also be used to diagnose whether the cause of sudden blackouts is linked to abnormal heart rhythms.
Professor Duncan and his team plan to run a larger study of patients with different forms of epilepsy to assess those at high risk who might benefit from having a pacemaker.
Notes for Editors
For more information or to set up an interview, please contact Jenny Gimpel at the UCL Media Relations Office on +44 (0)20 7679 9739, mobile: + 44 (0)7990 675 947 or e-mail email@example.com.
Press enquiries can also be directed to Margaret Thomas at the National Society for Epilepsy on +44 (0)1494 601401, mobile: +44 (0)7970 117 954 or e-mail Margaret.Thomas@epilepsynse.org.uk . The study was funded by the NSE (website http://www.epilepsynse.org.uk/)