Pacemakers Can Avert Fatal Attack in Some Epilepsy Patients

Study found slowed or stopped heartbeats during seizures

THURSDAY, Dec. 16, 2004 (HealthDayNews) -- Cardiac pacemakers could help reduce the high incidence of sudden death among those with epilepsy, a British study indicates.

Four of 20 patients monitored for up to 22 months were found to have episodes of either bradycardia, an abnormally slow heartbeat, or asystole, a complete cessation of heartbeat, the researchers said. In three of the patients, the asystole episodes were potentially fatal. All four had pacemakers implanted.

The report appears in the Dec. 17 issue of The Lancet.

About one in every 1,000 persons with epilepsy dies each year of what is called SUDEP, sudden unexplained death in epilepsy, and the incidence of sudden death increases with the severity of the condition. For patients whose epilepsy is severe enough to require surgery, the annual SUDEP death rate is 1 percent.

The 20 British participants were all in that high-risk group, said Dr. John S. Duncan, professor of neurology at the Institute of Neurology in London and leader of the study. They were outfitted with an implantable device, developed by Medtronics, an American company, which was programmed to detect episodes of abnormally slow heart rhythm, less than 40 beats a minute, or abnormally fast rhythm, more than 140 beats a minute.

A total of 377 seizures was recorded. Abnormally fast, but not life-threatening, heartbeats were common in 16 of the participants during their seizures, but the episodes of slower or no heartbeat in the other four patients were clearly more important.

"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 asysteole has previously been underreported," Duncan said in a statement.

A larger study with Medtronics is being planned in Great Britain. It will include 200 people with epilepsy, Duncan said.

The new study "provides the first real hope that some cases of SUDEP might be prevented," said an accompanying editorial in the journal by neurologists at the Columbia University College of Physicians and Surgeons in New York City.

But long-term monitoring with implanted recorders would be needed, the editorial said, and "additional studies should be done before we apply these findings to routine care of people with epilepsy."

One reason for caution is that "there are multiple mechanisms of sudden death" in epilepsy, said Dr. W. Allen Houser, professor of neurology at the Columbia University Mailman School of Public Health. "Cardiac cases are among the most important, but there are also pulmonary [lung] causes."

The study "probably will lead to a more critical investigation of the possibility that this is a possible cause of sudden death," said Dr. Gregory L. Barkley, head of the comprehensive epilepsy program at Henry Ford Hospital in Detroit, and chairman of the Epilepsy Foundation's clinical advisory committee.

"With a report like this, neurologists would take a look to see whether this is something they would consider for a patient," Barkley said.

It's necessary to determine which patients might benefit from a pacemaker, he said, but occasionally the need is obvious.

"I have one patient who, whenever he has a seizure that lasts four or five seconds, his heart stops completely as well," Barkley said. "So I put in a pacemaker."

He said he would go over the British report thoroughly "to figure out how it applies to my practice."

More information

An overview of epilepsy is given by the Epilepsy Foundation.

SOURCES: John S. Duncan, M.D., professor of neurology, Institute of Neurology, London, England; Gregory L. Barkley, M.D., director, comprehensive epilepsy program, Henry Ford Hospital, Detroit: Dec. 17, 2004, The Lancet
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