A new study shows that music headphones or earbuds can interfere with pacemakers and implanted heart defibrillators if the items are held together closely.
The findings could be a warning to those who hang headphones around their neck or keep them in their shirt pockets.
"Headphones contain magnets, and some of these magnets are powerful," said the study's leader, Dr. William Maisel, a cardiologist at Beth Israel Deaconess Medical Center in Boston and a heart device consultant to the federal Food and Drug Administration. '
Maisel's findings were presented Sunday at a conference of the American Heart Association in New Orleans.
The study tested eight models of earbuds and over-ear headphones on 60 people with heart devices. When headphones were about 1inch from the device, interference was detected 25 percent of the time in four of the 27 pacemaker patients and 10 of the 33 defibrillator patients. One defibrillator reset itself in one of the patients.
The study showed that patients may not feel any difference, but the interference could temporarily deactivate the defibrillator, keeping it from working when its most needed. Nearly 2 million people worldwide have pacemakers, defibrillators or other devices to help their hearts beat faster, slower or more regularly.
Dr. Kenneth Ellenbogen, a heart device expert at Virginia Commonwealth University and a spokesman for the heart association, said the solution is simple: "Keep your headphones on your ears, and when they're not on your ears, you shouldn't put them over your chest or your pacemaker."