Electromagnetic Interference

by Chris Nickson, Last updated August 11, 2014

OVERVIEW

electromagnetic interference can affect the function of implanted eletronic devices such as pacemakers and ICDs

CAUSES

diathermy (monopolar & bipolar)
mobile phones (don’t place over pacemaker)
MRI
shivering
faciculations
alterations in heart size
positive pressure ventilation
peripheral nerve stimulators
TENS machine
defibrillation

EFFECTS ON PACEMAKERS AND ICDs

inappropriate triggering or inhibition of output
asynchronous pacing
reprogramming
damage to device circuitry
pacing wires may acts as aerials and cause heating of endocardium

PREVENTION

use bipolar diathermy
if conventional diathermy required → position plate so that most of current passes away from the pacemaker, use short, sharp bursts and watch SpO2 or art line.
ensure all devices are not in the same vector as the pacemaker current (between pacemaker and heart)
if reason for pacemaker severe heart failure where loss of AV synchrony may precipitate haemodynamic compromise -> have a telemetric programmer and cardiac technician close @ hand
keep lithotripter atleast 6 inches away from pacemaker (should be timed with ECG and rate modulation deactivated)
if have to defibrillate keep pads as far from pace maker as possible
avoid sux c/o faciculations (if used in a patient with a sensing mode activated -> use defaciculating dose of NDNMBD)
avoid using defibrillation if at all possible (high level of EMI) -> if required use AP pad configuration and keep pad’s 10cm away from pacemaker

MAGNETS

no longer recommended to place magnet over pacemakers, only applicable to older non-reprogrammable pacemakers
placement of a magnet would default mode to an asynchronous mode or a fixed rate
all modern pacemakers are reprogrammable

MANAGEMENT OF PACEMAKER MALFUNCTION

get help
remove electromagnetic interference
praecordial thumps (percussive pacing)
isoprenaline
adrenaline
transthoracic external pacing (capture around 80mA)
trans-venous pacing
trans-oesophageal pacing

References and Links

CCC — Pacemakers

About Chris Nickson

FCICM FACEM BSc(Hons) BHB MBChB MClinEpid(ClinTox) DipPaeds DTM&H GCertClinSim

Chris is an Intensivist at the Alfred ICU in Melbourne and is an Adjunct Clinical Associate Professor at Monash University. He is also the Innovation Lead for the Australian Centre for Health Innovation and the Chair of the Australian and New Zealand Intensive Care Society (ANZICS) Education Committee. He has a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia's Northern Territory, Perth and Melbourne. He has since completed further training in emergency medicine, clinical toxicology, clinical epidemiology and health professional education. He coordinates the Alfred ICU's education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the 'Critically Ill Airway' course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of Lifeinthefastlane.com, the RAGE podcast, the Resuscitology course, and the SMACC conference. His one great achievement is being the father of two amazing children. On Twitter, he is @precordialthump.

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