Electromagnetic Interference

Dealing With Electromagnetic Interference (EMI)

When you live with a CRT-P, CRT-D or pulmonary artery (PA) pressure sensor, it is important to be aware of electromagnetic interference, or EMI. EMI happens when the electromagnetic field generated by certain household objects, pieces of heavy equipment and medical equipment/procedures interferes with the way an implantable device or PA sensor works.

EMI can potentially:

  • Disrupt the function of a CRT-P or DRT-D
  • Cause a CRT-D to falsely sense an irregular heart rhythm, sending a shock that is not needed 
  • Interfere with a PA sensor reading

Ask your doctor about the best way to avoid EMI, and for answers to any questions you may have about how specific equipment can affect your device. 

EMI and pulmonary artery (PA) pressure sensors

If you have a pulmonary artery (PA) pressure monitoring system, EMI from theft detection or airport security systems could make it difficult for you to take sensor readings. However, it is unlikely that you would be taking readings when you are near this type of equipment. Electric blankets or waterbeds could cause interference. If you have a waterbed or electric blanket, take the reading in another room.

EMI and other implantable devices

Some surgeries and medical procedures can interfere with your device, as can some industrial equipment. Use caution with some household and personal equipment.

Medical procedures to avoid

Always inform hospital, clinic and dental staff that you have a CRT-P or CRT-D. The following procedures produce EMI and are not considered safe for people with implantable devices.

  • Microwave diathermy
  • MRI/MRA scans for people with certain CRT-Ps and CRT-Ds

If you have a CRT-P or CRT-D that was not designed to allow you to safely undergo an MRI scan under certain conditions, you should not have an MRI scan. The extremely strong magnetic fields used in the diagnostic procedure could impair the devices normal function.

Always consult with a physician before undergoing an MRI scan.

Medical procedures to consult your doctor about

Ask your doctor before undergoing:

  • Acupuncture with electrical stimulus
  • Cardioversion
  • Electrocautery
  • Electroconvulsive therapy
  • Electrolysis
  • Endoscopic procedures: colonoscopy/gastroscopy
  • Hyperbaric therapy
  • Iontophoresis
  • Interferential current therapy
  • Laser/lasik eye surgery
  • Lithotripsy
  • Radiation therapy
  • Radio frequency ablation
  • Ultrasound, therapeutic
  • Transcutaneous electrical nerve stimulation (tens)
  • Transurethral prostate therapy

Medical procedures with no known risk

Medical procedures that you can safely have if you have a pacemaker or an implantable cardioverter defibrillator include:

  • Acupuncture with no electrical stimulus
  • Bone density scan
  • CT scan
  • Dental drills and ultrasonic scalers
  • Electrocardiogram
  • External counter pulsation
  • Fluoroscopy
  • Mammography (position emission tomography(PET))
  • Ultrasound, diagnostic
  • X-ray, diagnostic

Industrial equipment 

Some industrial equipment can produce EMI that interferes with pacemakers. These include:

  • Arc welders
  • Induction furnaces
  • Very large or defective electric motors
  • Very large internal combustion engines with poorly shielded ignition systems

Ask your doctor before working with or near these machines.

Home and office technology to avoid:

  • Magnetic mattresses or chairs
  • Electrical equipment in poor condition
  • Electrical equipment that is improperly grounded

Home and office technology with no known risks

These items carry no known risk to implantable devices. Use caution with items marked with an asterisk.



  • AM/FM radios
  • Bingo game magnetic wands
  • CB and Ham radio
  • CD/DVD players
  • Cell phones*
  • Copy machines
  • Cordless phones*
  • Hand-held massagers*
  • Hearing aids
  • Electric blankets
  • Electric toothbrushes
  • Electric razors*
  • Electric invisible fences
  • Fax machines
  • Global positioning system (GPS)
  • Hair dryer*
  • Heart rate monitors
  • Heating pads
  • iPods and MP3 players
  • Laser tag games
  • Pagers
  • Patient alert devices
  • Laptop/desktop computers
  • Personal digital assistants
  • Printers
  • Remote controls - TV, garage door, stereo, camera/ video equipment
  • Scuba Diving (up to 200 feet)
  • Slot machines
  • Stereo speakers*
  • Tanning beds
  • TVs and VCRs
  • Video games
  • Air purifiers
  • Battery-powered cordless power tools
  • Blenders
  • Clothes dryers
  • Convection ovens
  • Corded drills and power tools**
  • Electric can openers
  • Electric knives
  • Electric ovens and stoves
  • Food processors
  • Gas ovens and stoves
  • Gas-powered tools**
  • Hot tubs/whirlpool baths
  • Lawn mowers**
  • Laser level
  • Leaf blowers
  • Microwave ovens
  • Portable space heaters  
  • Snow blowers
  • Soldering irons
  • Stud finders
  • Vacuum cleaners
  • Washing machines
* Do not place directly over device ** Keep 12 inches from device