Interference in implanted cardiac devices, Part I.

摘要: Sensing intrinsic cardiac electrical activity is essential for the function of pacemakers and implantable cardioverter defibrillators (ICDs). Examples undesired triggering or inhibition pacemaker output by extraneous signals were identified early after introduction noncompetitive, “ demand” pacemakers. Hermetic shielding in metal cases, filtering, interference rejection circuits, together with a preference (much more marked United States 1 than Europe 2 ) bipolar sensing, made contemporary ICDs relatively immune to electromagnetic energy sources homes workplaces. Sources (EMI) remained ubiquitous medical environment. However, they predictable avoidable. New technologies that use spectrum (i.e., wireless telephones, electronic article surveillance [EAS] devices) have rekindled interest EMI risks patients implanted devices. Although these do not constitute major public health threat, adverse interactions can occur. The counterpart compatibility, science aimed at avoiding potential adding redesigning circuits against specific sources. There are three elements any compatibility problem. must be an source, receptor victim (in our case device) cannot properly due phenomenon, path between them allows source interfere receptor. Each present, although may readily every situation. Identifying least two eliminating (or attenuating) one generally solves problems. Collaboration among industry, physicians, regulatory agencies, consumer groups will hopefully achieve full devices other technologies. This require adoption international standards establishing upper limit permissible field intensities whole spectrum. Implanted should react fields below this limit; intense prohibited. two-part review discusses first part addresses general concepts everyday life workplace. second focuses on EMI, highlighting preventive measures.