Modern ICDs have built-in protection from interference by most current technologies. But do you know which ones could be problematic for your patients?
Implantable cardioverter defibrillators are at very low risk of interference from the majority of electrical devices your patients encounter and employ in daily life. But there are a number of popular personal devices (eg, cell phones, MP3 players and headphones) as well as medical instruments (eg, MRI, TENS) that could be a problem.
Click through the slides above for a quick look at 10 devices you'll want to discuss with any patient who has an ICD.
Cell phones: Phones now available in the United States (less than 3 watts) present minimal risk to ICDs as transmission is wireless. Patients should understand that as the FCC makes new frequencies available, built-in ICD protection may become less reliable. Remind patients to keep cell phones at least 6 inches away from the ICD (use on opposite ear) and not to keep the phone in a front chest pocket.
CB/Ham Radios: These radios can possibly affect ICD function so the following guidance should be offered to your patients who are enthusiasts:
Metal Detectors (for security): Even though interactions with metal detectors shouldn’t cause clinically significant symptoms in most patients with ICDs, the American Heart Association recommends that:
MP3 players/headphones: The MP3 player is not a problem, but headphones do pose a risk because they contain a magnetic substance that has been shown to cause interference when an ICD is too close. (ICDs are twice as susceptible to interference as pacemakers.) A few pointers for patients:
Computed Axial Tomography: Some ICDs are safe during CT scan, others are not. Before proceeding with the test, consultation is advised with an electrophysiologist and/or technician.
Magnetic Resonance Imaging: Evaluation via MRI is Not Recommended for people with ICDs because of the power of the magnet; be prepared to discuss options with a patient who requires this type of imaging. Some ICD models are appropriate for MRI but the patient’s ID card should be reviewed and consultation with the manufacturer is advised.
Radio Frequency (or microwave) Ablation: The procedure may be appropriate for some patients with appropriate precautions taken; the risk needs to be carefully evauated and discussed with the patient.
Therapeutic Radiation (eg, for cancer): An ICD can be seriously damaged by radiation and some are more vulnerable than others. Damage to the unit increases as radiation dose goes up. The AHA recommends shielding the ICD as much as possible during treatment and that it be moved if it lies in the radiation field.
Transcutaneous Electrical Nerve Stimulation: Most research shows that TENS rarely interferes with some ICDs, but it can disrupt others; and, it can interfere on subsequent treatments after remaining stable on initial treatment. With careful evaluation and precautions (eg, extended cardiac monitoring) it may be appropriate. TENS should not be used on the torso.
Electric Power Tools/Electronic Devices: When in good condition and used properly, most household equipment poses little if any risk to an ICD. It is important to remind patients that it is always best to keep these devices at least 6 inches (15 cm) away from the site of the ICD.
And Keep in Mind: Ab stimulators, electronic body fat scales, magnetic mattress pads or pillows; gas-powered equipment, car battery charger and gasoline ignition systems; electric fences, electrical pet containment systems, transformer boxes.
Source: American Heart Association. Devices that may Interfere with Implantable Cardioverter Defibrillators (ICDs).