Portable music players called iPods interfered with pacemakers in 30 percent of patients tested in a new study, though none of the interference was life-threatening. The study was presented here by a high school student who worked with a University of Michigan and Michigan State University team; the presentation took place at the Heart Rhythm Society's 28th Annual Scientific Sessions.
When held two inches from the patients' chests for five to 10 seconds, iPods interfered with telemetry equipment monitoring the heart, caused implantable pacemakers to misread the heart's pacing, and, in one case, caused the device to stop functioning.
"For people depending on these pacing devices, iPod interference can lead physicians to misdiagnose the actual heart function," said Jay Thaker, lead author and a high school senior at Okemos High School in Okemos, MI. "Our findings are disconcerting because although the typical pacemaker patient may not be an iPod user, they are often in close contact with grandchildren and other young people who are avid users."
The study tested iPods on 83 patients at the Thoracic and Cardiovascular Institute and Michigan State University with dual chamber and single chamber pacemakers. Telemetry interference was found in 29 percent of patients, over sensing (pacemakers misreading the heart's function) in 20 percent, and pacemaker inhibition (pacemaker stopped functioning) in one patient. In some cases, interference was detected even when iPods were held as far as 18 inches from the chest.
After reading news stories about studies involving cell phones and pacemakers, Thaker approached Krit Jongnarangsin, M.D., at the University of Michigan Cardiovascular Center about doing a similar study using iPods.
"At first I was surprised when Jay contacted me with the idea. He seemed genuinely interested in doing the research and had a real curiosity about the subject," said Dr. Jongnarangsin, senior author and an assistant professor in the Division of Cardiovascular Medicine at the University of Michigan. "I felt comfortable with Jay doing the research. Besides Jay, this study was performed by physicians including an electrophysiologist and fellows in electrophysiology at Michigan State University."
Thaker, whose parents are physicians, has not yet decided where to attend college next year, but is leaning toward Michigan State. He plans to go onto medical school.