According
to a recent study published in the journal Heart Rhythm, the magnets in
portable headphones may cause temporary malfunction of some cardiac
devices. Therefore, the researchers suggest that patients with
implantable cardioverter-defibrillators or pacemakers should not place
headphones from MP3 players too close to their chests. The interference
that can be caused by the headphones includes inhibition of
tachyarrhythmia detection in ICDs and asynchronous pacing in
pacemakers. Patients with these devices don't need to avoid portable
headphones, they should just keep them at least 3 centimeters (1.2
inches) from their chests. Cardiac arrhythmia specialists have long
told patients not to place electronic equipment directly over their
devices.
According to the study's researchers, the FDA has already concluded
that digital music players are unlikely to interfere with implanted
devices, but not much was known about potential interference from
portable headphones. In the recent study, electromagnetic levels from
portable headphones exceeded levels sufficient to disable sensing in an
implanted device, when the headphones were less than 2 centimeters from
the chest. Most of the devices returned to normal functioning once the
headphones were moved away. Patients with ICDs were more likely to have
an interaction, than patients with pacemakers. The headphones' magnetic
fields were the same whether the MP3 player was turned on, or the
headphones were plugged in.
SOURCE: Jamie Sheller, Injury Board