How does electromagnetic interference (EMI) affect the perioperative management of permanent pacemakers (PPMs) and automatic implantable cardioverter-defibrillators (AICDs)?

Updated: Oct 29, 2018
  • Author: Albert H Tsai, MD; Chief Editor: Sheela Pai Cole, MD  more...
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Answer

Answer

After the properties of the patient’s CIED properties are determined (see above), perioperative management of the device is largely driven by the potential for EMI.

There are various potential sources of EMI in the perioperative setting (eg, radiofrequency ablation [RFA], magnetic resonance imaging [MRI], lithotripsy, radiation therapy, and electroconvulsive therapy [ECT]), but the most common cause for concern is electrocauterization above the level of the umbilicus. CIEDs set to synchronous modes (ie, with the sensing function turned on) are susceptible to misinterpretation of electrocautery use as native cardiac rhythm. This may result in inappropriate sensing, shocking, or both, as illustrated by the following examples:

  • Inappropriate sensing - A pacer-dependent patient with a PPM set to DDD for complete heart block presents for excision of a chest-wall tumor; if the pacemaker remains in synchronous pacing mode, it may interpret Bovie artifact as native QRS waves and become inhibited, thereby exposing the patient to the underlying heart block and resulting in inadequate cardiac output
  • Inappropriate shocking - A non-pacer-dependent patient with an AICD for a history of dilated cardiomyopathy presents for excision of a chest-wall tumor; if the defibrillator function remains on, the AICD may interpret Bovie artifact as ventricular fibrillation (VF) and defibrillate the patient inappropriately

In cases where there is concern about EMI affecting the CIED, appropriate interventions must be employed to avoid inappropriate sensing and shocking. Close attention must be paid to the ECG, pulse oximetry, and the arterial waveform (when applicable) in the presence of EMI to ensure the preservation of perfusing rhythms. Various measures may be employed to mitigate EMI and ensure appropriate CIED function (see below).


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