Electromagnetic interference in patients with implanted pacemakers or cardioverter-defibrillators

Electromagnetic radiation may interact adversely with implanted pacing systems and implantable cardioverter-defibrillators (ICDs).1-4 Modern life exposes us all to an ever increasing number of potential sources of electromagnetic interference (EMI) and patients with implanted pacemakers or ICDs often ask about the use of microwave ovens, walking through airport metal detectors, and the use of cellular phones. This article gives an overview of the current knowledge of the effects of EMI on pacemakers and ICDs. Although no recent studies have been performed which test the effect of household microwave energy on pacemakers and ICDs, it is widely believed and accepted that all modern pacemakers are adequately shielded from microwave energy produced by modern appliances.5 Pacemaker manufacturers therefore recommend that patients with implanted devices do not need to take special precautions in the use of microwaves or other common household equipment such as televisions, radios, toasters, and electric blankets. The effect of metal detector gates on implanted pacemakers was studied more than 10 years ago.6 In 103 patients who were monitored as they passed through typical metal detectors, alarms invariably were activated when the patients walked through the gates. In none of the patients was the pacemaker function affected. None of the devices was reset to the programmed noise protection mode (most often V00) or spontaneous fixed rate mode of function, nor were any of the devices' outputs inhibited in paced patients, or inappropriately delivered in patients who had normal cardiac rhythm. It is therefore accepted practice to advise patients that while airport screening devices may detect the pacemaker or ICD metal case the device will not be adversely affected. Patients should carry their device identification card for the purpose of obtaining security clearance. Several studies have shown that cellular phones might cause EMI with complex medical equipment7 …