THURSDAY, May 10, 2007 (HealthDay News) -- Listening to tunes on an iPod may be great for putting a skip in your step, but it can also play havoc with a heart pacemaker, a new study found.
The portable music players caused pacemakers to malfunction in 50 percent of patients, according to the study by a Michigan high school senior that was expected to be presented Thursday at the Heart Rhythm Society's annual meeting, in Denver.
The biggest concern is that pacemakers store the history of a heart's rhythms, said Jay Thaker, the Okemos High School student, who worked with several doctors on the research. "If a physician was to go back and look at that (history), the physician might think that the patient was having abnormal heart rhythms," he added.
One danger is that heart patients might be treated for conditions that aren't really present, Thaker said. "In addition, if an iPod stopped a pacemaker from working in a patient who was totally dependent on their pacemaker, it could cause the heart to stop," he said.
Many electric devices -- such as cell phones, appliances, microwave ovens and high tension wires -- can produce the same effect. That's why doctors tell their patients not to put any electric device over their pacemaker.
For the study, Thaker and his research team -- which included doctors from Michigan State University and the University of Michigan -- held an iPod two inches from the chests of 83 patients for five to 10 seconds. The result: So-called "telemetry interference" occurred in 29 percent of the patients, and "over sensing" (a pacemaker misreading the heart's function) occurred in 20 percent of patients. In one patient, the pacemaker stopped working. In some cases, interference was detected even when the iPods were held as far as 18 inches from the chest, the study found.
Thaker acknowledged that pacemaker patients aren't the typical iPod user. But because the music players are so common, people with pacemakers need to be aware of the risk, he said.
"People commonly strap their iPod to the arm right next to their pacemaker or put it in a shirt pocket. There are quite a few situations where they come in proximity to the pacemaker -- closer than we would like them to," said Thaker, whose father is an electrophysiologist and whose mother is a doctor, and who hopes to attend medical school.
Dr. Edwin Kevin Heist, a cardiac electrophysiologist at Massachusetts General Hospital, agrees that iPods can be a danger to patients with pacemakers.
"It's clear that iPods can affect pacing function," said Heist. "There is a possibility for a severe reaction, such as loss of consciousness."
Heist said he tells his patients that they can use any household device, including cell phones and iPods, but not to put them over their pacemaker. "Patients with a pacemaker could safely use an iPod, just don't put it over the device," he said.
iPods could also pose a problem for patients with implanted pacemaker defibrillators, Heist said. "The possibility would be there for inappropriate shock," he said. "The shocks are quite painful and traumatic for patients."
For more information on pacemakers, visit the American Heart Association.