What is an artificial pacemaker?
An "artificial pacemaker" is a small, battery-operated device that helps the heart
beat in a regular rhythm. Some are permanent (internal) and some are temporary (external).
They can replace a defective natural pacemaker or blocked pathway.
A pacemaker uses batteries to send electrical impulses to the heart to help it pump
properly. An electrode is placed next to the heart wall and small electrical charges
travel through the wire to the heart. Most pacemakers have a sensing device that
turns itself off when the heartbeat is above a certain level. It turns back on when
the heartbeat is too slow. These are called demand pacemakers. AHA Recommendation
If you have an artificial pacemaker, be aware of your surroundings and the devices
that may interfere with pulse generators:
Home appliances
CB radios, electric drills, electric blankets, electric shavers, ham radios, heating
pads, metal detectors, microwave ovens, TV transmitters and remote control TV changers,
in general, have not been shown to damage pacemaker pulse generators, change pacing
rates, or totally inhibit pacemaker output.
Several of these devices have a remote potential to cause interference by occasionally
inhibiting a single beat. However, most people can continue to use these devices
without significant worry about damage or interference with their pacemakers. Power-generating
equipment, arc welding equipment and powerful magnets (as in medical devices, heavy
equipment or motors) can inhibit pulse generators. Patients who work with or near
such equipment should know that their pacemakers may not work properly in those
conditions.
Cellphones
Cellphones available in the United States (less than 3 watts) don't appear to damage
pulse generators or affect how the pacemaker works.
Technology is rapidly changing as the Federal Communications Commission (FCC) is
making new frequencies available. Newer cellphones using these new frequencies might
make pacemakers less reliable. A group of cellphone companies is studying that possibility.
Medical equipment
Carry a wallet I.D. card with you. Equipment used by doctors and dentists can affect
your pacemaker, so tell them you have one.
Magnetic resonance imaging (MRI) uses a powerful magnet to produce images of internal
organs and functions. Metal objects are attracted to the magnet and are normally
not allowed near MRI machines. The magnet can interrupt the pacing and inhibit the
output of pacemakers. If MRI must be done, the pacemaker output in some models can
be reprogrammed. Discuss with your doctor the possible risks and benefits before
you undergo MRI scanning.
Extracorporeal shock-wave lithotripsy (ESWL) is a noninvasive treatment that uses
hydraulic shocks to dissolve kidney stones. This procedure may be done safely in
most pacemaker patients, with some reprogramming of the pacing. You'll need careful
follow-up after the procedure and for several months to be sure the unit is working
properly. Patients with certain kinds of pacemakers implanted in the abdomen should
avoid ESWL. Discuss your specific case with your doctor before and after the treatment.
Radiofrequency (RF) ablation uses radio waves to manage a wide variety of arrhythmias.
Recent studies of patients with implanted pacing systems measured the units before,
during and after RF catheter ablation. They showed that most permanent pacemakers
aren't adversely affected by radio frequencies during catheter ablation. A variety
of changes in your pacemaker can occur during and after the treatment. Your doctor
should carefully evaluate your pacing system after the procedure.
Transcutaneous (tranz"ku-TA'ne-us) electrical nerve stimulation (TENS) is used to
relieve acute or chronic pain. Several electrodes are placed on the skin and connected
to a pulse generator. Most studies have shown that TENS rarely inhibits bipolar
pacing. It may sometimes briefly inhibit unipolar pacing. This can be treated by
reprogramming the pulse generator. Diagnostic radiation (such as screening X-ray)
appears to have no effect on pacemaker pulse generators. However, therapeutic radiation
(such as for treating cancerous tumors) may damage the circuits of the pacemaker.
The degree of damage is unpredictable and may vary with different systems. But the
risk is significant and builds up as the radiation dose increases. The American
Heart Association recommends that the pacemaker be shielded as much as possible,
and moved if it lies directly in the radiation field. If you depend on your pacemaker
for normal heart pacing, the electrocardiogram (ECG) should be monitored during
the treatment, and your pulse generator should be tested often after and between
radiation sessions.
Dental equipment doesn't appear to affect pacemakers adversely. Some patients may
feel an increase in pacing rates during dental drilling.
Electroconvulsive therapy (such as for certain mental disorders) appears to be safely
used in patients with pacemakers. Short-wave or microwave diathermy uses high-frequency,
high-intensity signals. These may bypass your pacemaker's noise protection and interfere
with or permanently damage the pulse generator. Related AHA publications
Heart and Stroke Facts
Living With Your Pacemaker
Abnormal Heart Rhythms
Detailed Research
Heart and Stroke Facts
2001 Heart and Stroke Statistical Update
"Interference With Cardiac Pacing," Kenneth A. Ellenbogen, M.D., Intelligence Reports in Cardiac Pacing and Electrophysiology, HealthScan Inc., 1995
ACC/AHA Practice Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices (Executive Summary, #71-0136 Circulation. 1998;97;1325-1335; Full Text, #71-0137 JACC. 1998;31:1175-1209)
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