Devices that may Interfere with Implantable Cardioverter Defibrillators (ICDs)

Updated:Dec 21,2016

Modern Implantable Cardioverter Defibrillators (ICDs) have built-in features to protect them from most types of interference produced by other electrical devices you might encounter in your daily routine.  However, since they are implanted to prevent sudden cardiac arrest and can deliver therapeutic shocks, it is prudent to pay attention to your physician’s instructions and try to avoid sources of disruption.

ICDIf you have an artificial ICD, always:

  • Be aware of your surroundings and the devices that may interfere with pulse generators.
  • Carry your ICD ID card to prove that you have an ICD. Download the ICD Wallet ID card
  • Tell healthcare professionals you have an ICD before they start any test or procedure using medical or electronic devices.
  • Notify the doctor or nurse where you work that that you have an ICD.
  • Move away from or turn off any equipment you suspect of interfering with your ICD. Your ICD will rarely be permanently damaged and will resume its normal activity. Inform your healthcare provider of any concerns regarding your device.
  • When in doubt, consult your doctor.

Learn more about devices that may interfere with ICDs:

Anti-theft systems (also called electronic article surveillance or EAS): Interactions with EAS systems are unlikely to cause clinically significant symptoms in most patients. However, the American Heart Association recommends that you:

  • Be aware that EAS systems may be hidden or camouflaged in entrances and exits in many businesses.
  • Don't stay near the EAS system longer than is necessary.
  • Don't lean against the system.

Metal detectors for security: Interactions with metal detectors are unlikely to cause clinically significant symptoms in most patients. However, the American Heart Association recommends that you:
  • Don't stay near the metal detector any longer than is necessary.
  • Don't lean against the system.
  • If scanning with a hand-held metal detector is necessary, tell the security personnel that you have an ICD and request an alternative form of inspection. Ask them not to hold the metal detector near the device any longer than is absolutely necessary.

Cell phones: Currently, phones available in the United States (less than 3 watts) present a very small risk to ICDs due to wireless transmissions from the antennae.
  • Technology is rapidly changing as the Federal Communications Commission (FCC) makes new frequencies available.
  • Newer cellphones using these new frequencies might make ICDs less reliable.
  • A group of cellphone companies is studying that possibility.
  • Keep your cell phones at least 6 inches away from your ICD by using them on the ear opposite your ICD site and avoid keeping them in your front chest pocket.
  • Keep walkie-talkies ( 3 watts or less) at least 6 inches away from your ICD site

MP3 players/headphones: MP3 players do not pose the risk; the headphones do. Most contain a magnetic substance, and research has documented that placing the headphones too close to the ICD caused interference. That same research showed that ICDs were twice as likely to have interference as pacemakers were.
  • Keep your headphones at least 6 inches away from your ICD.
  • Never rest your head on the chest of a person with an ICD while you're wearing headphones.
  • Both the earbud and clip-on types of headphones can cause interference.
  • Do not place headphones in a breast pocket or drape them over your chest.

Radios: Can possibly affect how the ICD works.
  • CB radios or amateur ("ham") radios under 3 watts should be kept 6 inches away from the implanted device. CB and “ham” radios (3-15 watts) should be kept at least 12 inches from your ICD. CB and “ham” radios (15-30 watts) should be kept at least 2 feet from your device.
  • CB radios (under 5 watts) should be kept at least 12 inches from your ICD site.

Extracorporeal shock-wave lithotripsy (ESWL): A noninvasive treatment that uses hydraulic shocks to dissolve kidney stones.
  • ESWL should be avoided in patients with ICDs.
  • Discuss your specific case with your doctor before and after the treatment.

Magnetic resonance imaging (MRI): A noninvasive diagnostic tool that uses a powerful magnet to produce images of internal organs and functions.
  • MRIs are not recommended for people with ICDs. Discuss options with your physician. Some types of ICDs may be OK for an MRI; however, your doctor and technician will need to review your ID card and consult to make sure.

Radiofrequency ablation (RFA) or microwave ablation: A medical procedure that uses waves to manage a wide variety of arrhythmias.
  • Your doctor should carefully evaluate the risk; the procedures may be acceptable with certain precautions taken.

High-frequency, short-wave or microwave diathermy: A medical procedure that uses high-frequency, high-intensity signals for physical therapy. These may interfere with or permanently damage the pulse generator.
  • Not recommended for people with ICDs.

Therapeutic radiation (such as for cancer treatment): May damage the device’s circuits.
  • The degree of damage is unpredictable and may vary with different systems.
  • The risk is significant and builds up as the radiation dose increases.
  • The American Heart Association recommends that the ICD be shielded as much as possible and moved if it lies directly in the radiation field.
  • ICDs have been shown to be more sensitive to radiation therapy interference than pacemakers.

Transcutaneous electrical nerve stimulation (TENS): A medical device used to relieve acute or chronic pain with electrodes placed on the skin and connected to a pulse generator.
  • Most studies have shown that TENS rarely interferes with some types of ICDs; however, TENS can interfere with other types and can interfere on subsequent TENS treatment even after showing no interference on initial treatments.
  • TENS may be acceptable with precautions taken such as careful evaluation and extended cardiac monitoring.
  • Not recommended for use on the torso.

CT and CAT Scans: Diagnostic specialized x-rays called computed tomography (CT scan) or computed axial tomography (CAT scan) that combined with computers create multiple images of areas inside the body that are being examined.
  • Depending on the scanner being used, some ICDs may receive interference so be certain to have your doctor, electrophysiologist or technician discuss the procedure first.
Electrolysis: A procedure for removing unwanted hair.
  • Be prepared to provide a note from your physician before electrolysis can be performed.
  • Certain precautions may be recommended by your doctor and device manufacturer.

Electrocauterization: A procedure used in surgery to stop bleeding.
  • Your doctor should carefully evaluate the risk; the procedures may be acceptable with certain precautions taken.

Other medical procedures that may be possible when the necessary precautions have been taken:
  • Acupuncture with electrical stimulus
  • Ultrasound
  • Hyperbaric Oxygen Therapy
  • External defibrillation including use of AEDs
  • Stereotaxis

Power-generating equipment, arc welding equipment, jumper cables, and powerful magnets: Such as found in some medical devices, heavy equipment or motors can inhibit pulse generators.
  • Stay at least 2 feet away.
  • Working with this equipment is not recommended for people with ICDs.
  • Follow your healthcare provider's instructions about being around such equipment.

Magnets: Magnets in general may or may not affect your ICD operation so it is best to avoid close and prolonged contact with any of them. Magnets can activate a switch which can prevent the ICD from delivering treatment therapies such as life-saving shocks.
  • Keep magnets at least 6 inches (15 cm) from the ICD site.
  • Avoid magnet therapy such as used in bracelets and necklaces that may be worn for extended periods of time near the ICD.
  • You may not know what does or doesn’t have a magnet in it. If you feel any interference, move away from the source or turn it off if possible.

Electric power tools and electronic devices: Most household equipment in good condition poses little if any risk to your ICD when they are used properly. However, it is best to keep them at least 6 inches (15 cm) away from your ICD site. Primarily keep the motors and antennae 6 inches from your ICD.

  • Drill (battery and electric)
  • Hedge trim
  • Weed whacker
  • Router
  • Circular/skill saws
  • Leaf blower
  • Electric lawn mower
  • Sander
  • E-readers
  • Electronic tablets
  • Video game wireless controllers
  • Remote car starters and remote key entry
  • Security badge wall scanner
  • Home wireless devices such as modems, Bluetooth®, routers, headsets
  • Speakers
  • Radio-controlled toys and other products
  • Hair dryer
  • Hand-held back massager

Ab stimulators, electronic body fat scales, magnetic mattress pads or pillows: Are likely to interfere and are NOT recommended for use if you have an ICD.

Gas-powered equipment, car battery charger and gasoline ignition systems: Components within ignition systems of gas-powered engines can cause interference in some cases.

  • Keep at least 12 inches (30cm) away from your ICD site

Electric fences, electrical pet containment systems, transformer boxes: Like most of the potentially disruptive items, the risk increases with extended periods of time and close proximity to them.

  • Keep at least 12 inches (30cm) away from your ICD site

Also in this Section:
This content was last reviewed September 2016.


Subscribe to Heart Insight magazine and monthly e-newsletter
Heart Insight logo
Our digital magazine delivers helpful articles and the latest news on keeping your heart healthy. Sign up today!



By clicking submit below you agree to the Terms and Conditions and Privacy Policy