Even though most electromagnetic fields in the home environment will rarely affect the function of a pacemaker or ICD, it is recommended you keep any item containing magnets at least 15cm (6 inches) away from your device.
The reason for this is that there is a small magnetically activated switch built into pacemakers and ICDs. This internal switch is designed to close when a magnet of sufficient strength is placed over it.
When the switch closes in a pacemaker, the device paces the heart at a fixed pre-set rate (which may differ from your programmed settings).
When the switch closes in an ICD, it prevents the device from delivering treatment therapies.
You may not always know whether an item contains a magnet. However, if household items are used as intended and properly maintained, they should have no effect on your heart device. This includes microwaves, kitchen appliances, cordless phones, radios, televisions, computers, hair dryers, electric shavers, electric toothbrushes, electric blankets, and small power tools.
If you accidentally place a magnet too close to your device, simply move the item away. The pacemaker or ICD will return to its normal programmed settings once the magnet is removed.
The use of magnetic mattress pads and pillows is not recommended as it would be difficult to maintain a 15cm (6 inch) separation from your device at all times.