Magnet
Reviewed and revised 7 May 2014
OVERVIEW
- a magnet is a device that creates its own magnetic field
USES
- assessment of pacemakers and implantable cardioverter-defibrillators
METHOD OF USE
- place magnet near device
Pacemaker
- will default to asynchronous mode or a fixed rate (turns off sensing)
- Rate depends on battery life (usually 70-90/min)
- can be used to identify oversensing
- help identify battery failure as a cause of failure to capture
ICD
- will turn off the antiarrhythmic programme (potentially dangerous!) -> need to have a defibrillator nearby
- no effect on backup pacemaker
- inactivate during CPR (compressionist may feel the 40J shocks from the ICD -> transient discomfort, minimal risk of harm)
- inactivate after death in non-coroner’s cases
- inactivate during transcutaneous pacing
- inactivate when inappropriate shocks occurring
COMPLICATIONS
- may prevent ICD from cardioverting a dangerous dysrhythmia
References and Links
Journal articles
- Jacob S, Panaich SS, Maheshwari R, Haddad JW, Padanilam BJ, John SK. Clinical applications of magnets on cardiac rhythm management devices. Europace. 2011 Sep;13(9):1222-30. doi: 10.1093/europace/eur137. Epub 2011 May 26. PMID: 21616944.
- Rodriguez-Blanco YF, Souki F, Tamayo E, Candiotti K. Magnets and implantable cardioverter defibrillators: what’s the problem? Ann Card Anaesth. 2013 Jan-Mar;16(1):54-7. PMID: 23287088.
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
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