Heart Beat: Fatal attraction?
That magnetic brooch or necklace may set off more than your eyes or sweater "" it could also set off, or turn off, your pacemaker or implanted cardioverter/defibrillator (ICD).
Jewelry, reading glasses, name tags, and even some clothing sport a new breed of magnet. Called rare earth or neodymium-iron-boron magnets, they are more powerful than the traditional magnets used to stick things to a refrigerator or found inside stereo speakers.
Swiss researchers tested two jewel-sized pieces as well as a necklace and a name tag "" all made of neodymium-iron-boron magnets "" in 70 volunteers with a pacemaker or ICD. All four pieces interfered with the heart device at a distance of an inch or so. They made the pacemakers generate "beat now" signals at a fixed rate regardless of the heart's activity. More worrisome, they turned off the ICDs' ability to detect and stop a potentially deadly heart rhythm.