Have you recently purchased a new item
for your home or received a gift that contains magnets? You may
begin to question whether the item could possibly affect the function
of your pacemaker or ICD (implantable cardioverter defibrillator).
You are not alone and that is why we consulted the engineers at
Medtronic for information about magnets and your implantable device.
Do magnets affect pacemakers/ICDs?
First, it may be helpful to review a known fact about magnets. Maybe
you remember in science class learning that items that have electric
and magnetic components have an "electromagnetic" energy field around
them. 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 away (at least 6 inches/ 15
centimeters) from your pacemaker/ICD.
The reason for this is because there is a small magnetically activated
switch built into the electronics of pacemakers and ICDs. This internal
switch is designed to close when a magnet of sufficient strength
is placed over it.
- When the internal switch is closed in
the pacemaker, the pacemaker paces the heart at a continuous pre-set
rate (which could be different then the rate your doctor programmed).
- When the internal switch is closed in
an ICD, it prevents the ICD from delivering treatment therapies.
Removing the magnet returns the pacemaker/ICD
back to its previous, normal programming.
Aren't magnets used as part of a pacemaker/ICD monitoring?
Yes, the programmer head containing a magnet (or other powerful
magnet) could be applied over your pacemaker/ICD as part of your
device monitoring. Holding a magnet over a pacemaker/ICD closes
the internal switch so monitoring and testing can begin. For example,
data stored in your device since the last clinic visit can then
be retrieved for analysis, or the battery can be tested. The switch
opens back up again when the magnet is removed without any permanent
effect to your pacemaker/ICD.
What are the guidelines for using items with magnets around the
home?
As a general rule, maintain a minimum distance of 6 inches/15
centimeters between any household item with magnets and your implantable
device. (An industrial work environment may require a further
separation than 6 inches/15centimeters). By maintaining a 6 inch/15
centimeter separation, you can use that new gift or household item
even when you know it has magnets in it, including items such as:
- Decorative refrigerator magnets
- Large home stereo speakers
- Small gas engines
- Hand-held massagers or massage chair
cushions
- Magnetic therapy products such as massagers,
chair pads, bracelets, knee wraps, back supports, slippers, or
shoe insoles. The use of magnet mattress pads and pillows is
not recommended since it would be difficult to keep a 6 inch/15
centimeter separation from your implantable device.
You may not always know if an item has
a magnet in it. However, if you use household items as they are
intended, and they are properly maintained, they will have no effect
on your pacemaker/ICD. This includes microwaves, kitchen appliances,
cordless phones, radios, televisions, video games, CD players, hair
dryers, electric shavers, electric toothbrushes, electric blankets,
leaf blowers, lawn mowers, garage door openers, computers and small
shop tools.
If you mistakenly place a magnet item too close to your pacemaker/
ICD, simply move the item away. Your pacemaker/ICD will immediately
return to its previous normal programming. There will be no damage
or re-programming effects to your implantable device.
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