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
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