While there has always been concern about the potential for electromagnetic interference with pacemaker, implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) function, due to interaction between the device and an electromagnetic field, the risk is quite low (table 1) [1,2]. Electromagnetic interference (EMI) can occur in a variety of settings, but overall is more likely in the hospital environment than in the non-hospital environment .
There have been occasional reports of cardiac implantable electronic devices (CIEDs) being impacted by sources of EMI in the non-hospital environment (eg, slot machines, laptop computers, etc). There are also disclaimers that wireless sources could be the source of EMI with CIEDs, even though no published data exists (eg, automobile manufacturers providing "caution" for device patients purchasing automobiles with "keyless" entry mechanisms, etc). Nonetheless, there are few sources of EMI in the non-hospital environment which are truly concerning. However, with the proliferation of wireless technology, any new device which operates on a new frequency or new technology platform should be assessed in order to determine whether there is indeed any significant potential for EMI with any CIED.
Electromagnetic interference with medical sources is discussed separately. (See "Pacing system malfunction: Evaluation and management", section on 'Electromagnetic interference' and "Implantable cardioverter-defibrillators: Complications", section on 'Electromagnetic interference'.)
Although there are no studies that have systematically evaluated the effect of household microwave ovens on implanted devices, it is widely accepted that contemporary pacemakers and ICDs are adequately shielded from microwave energy produced by modern appliances . Pacemaker manufacturers do not recommend any special precautions when using common household appliances, such as televisions, radios, toasters, microwave ovens, and electric blankets. As new appliances reach the market that use a new or different energy source, the appliances need to be tested to determine whether there is any potential for device interference.
There are circumstances in which a device may be affected by specific sources of energy under narrow circumstances. This was illustrated in a study assessing the potential for induction cook tops to interfere with pacemaker function. Patients with a unipolar, left-sided implant could experience interference if the pot was not concentrically placed on the induction coil and if the patient stood as close as possible to the cook top. The most common response to interference was a reset to an asynchronous interference mode . Most contemporary devices utilize bipolar pacing and sensing configuration, which minimizes the chance of device malfunction.