Like an estimated three million Americans, Nancy Guthrie, the 84-year-old mother of the NBC News anchor Savannah Guthrie, has a pacemaker implanted in her chest.
Law enforcement officials who are investigating her kidnapping are reported to have contacted the company that made Ms. Guthrie’s device to find out what they can learn from the information it yields.
Experts in heart health and digital forensics say the answer may be “not much.”
A pacemaker constantly records a person’s heart rate, and uses that data to prevent it from dropping too low. If a person’s lowest heart rate is set to 50, for example, the pacemaker will send painless electronic pulses when the rate drops lower in order to drive it back up (unlike an implanted defibrillator, which shocks a stopped heart).
But while the device monitors a person’s heart rate, a pacemaker “would not help” find someone who was kidnapped, said Dr. Michael Mack, a heart surgeon at Baylor Scott & White Health in Dallas.
He and the other experts emphasized that they were not commenting directly on Nancy Guthrie.
Pacemakers are constantly recording data, but they do not provide information on a patient’s location, said Dr. Roderick Tung, director of the cardiac electrophysiology program at the Banner — University Medical Center Phoenix in Arizona.
A vast majority of patients use remote monitoring, which involves a device that’s typically placed on a bedside table. In some cases, it is an app on a smartphone. The monitor checks on data stored in the pacemaker throughout the day. Investigators did not say which company made Ms. Guthrie’s device, nor if it uses that method of monitoring.
Dr. Kenneth Stein, global chief medical officer at Boston Scientific, which makes pacemakers, explained that periodically, such a remote monitoring instrument “wakes up” and transmits data, often at night when a patient is sleeping.
That data tells whether the battery is good, and if the pacemaker is functioning the way it should. The device also transmits alerts if something is going wrong with the patient’s heart.
In order for pacemaker data to be sent to the monitor, the person needs to be close by — typically no more than about 10 feet away, Dr. Tung said.
Suppose someone is away from the monitor and that person’s heart rhythm becomes erratic? Then, Dr. Tung said, that event would be stored in the pacemaker and relayed only when the person gets close to the monitor.
It’s like writing emails on a plane when there is no Wi-Fi, he explained. The emails are stored and then sent when you reconnect to the internet.
Dr. Stein added that the reason the pacemaker only occasionally transmitted data was that companies wanted to prolong the device’s battery life, which, for modern devices, is at least 10 years.
Data from the monitor is transmitted to the company, which then sends it to a doctor or clinic.
“There is a lot of cybersecurity to make sure it is protected,” Dr. Stein said, limiting the risk of a patient’s private information being exposed.
He added that having the company analyze the data was akin to having a lab test company draw a person’s blood, analyze it and send the results to the doctor.
Doctors check on the pacemaker data only occasionally, unless they receive an alert.
If a patient does not have remote monitoring, the doctor will see data only when the patient goes in for a visit.
There is, though, a way to learn something from a pacemaker after a person dies. The information in a pacemaker will show the time the heart stopped beating. It can reveal an event, like a sudden irregular heartbeat, that might have led to death. It can also point to a sudden death — a heart rate that was regular then dropped to zero.
“It’s kind of like a black box on an airplane,” said Dr. Michael Lauer, a cardiologist who is a former deputy director at the National Institutes of Health.
A pacemaker ended up being a key aid in solving a different mystery one year ago, when the actor Gene Hackman and his wife, Betsy Arakawa, were found dead in their home near Santa Fe, N.M.
Because there were no witnesses, the examination of Mr. Hackman’s cardiac device allowed a pathologist to determine when the actor had died in the home, which was about a week after his wife had died.
Nicholas Bogel-Burroughs contributed reporting.
Gina Kolata reports on diseases and treatments, how treatments are discovered and tested, and how they affect people.
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