Implantable Cardioverter Defibrillators (ICDs)
OVERVIEW
- implantable device defibrillator +/- pacemaker (counter shock vector is from RV -> both SVC)
INDICATIONS
- VF or sudden cardiac death survivors
- VT-associated syncope not caused by MI or other correctable cause
- minimally symptomatic VT with EF <35%
- previous MI, LVEF ‘monitor only’ mode
- dysrhythmia resistant to anti-arhythmics or if anti-arrhythmics contra-indicated
INTRAOPERATIVE
- ideally have the cardiac technician present to enable the defibrillation function
- have defibrillator close to hand (attach prior to surgery)
- place pads at cardiac apex and below right clavicle
POSTOPERATIVE
- nurse in HDU/ ICU with resuscitation equipment close by
- cardiac technician interrogation and reprogramming post surgery
- check medications as they may change threshold
- monitor for infection
- look for lead displacement or fracture
- check with cardiologist/technician for programming and idiosyncracies of unit
- monitor ECG
- have an external defibrillator available
MAGNETS AND AICDs
- no longer recommended to place magnet over AICDs — only applicable to older non-reprogrammable pacemakers
- magnet placement turns off antiarrhythmic program but has no affect on backup pacemaker
- all modern AICDs are reprogrammable
PROBLEMS WITH ICDs
- battery depletion
- lead fracture or displacement (by surgery, defibrillation or CVL/PAC placement)
- lead or box infection (e.g. due to bacteremia)
- multiple shocks due to algorithm error, sensing failure, oversensing of physiological signals and lead failure
- EMF interference from shaver, TV remote, MRI and also possible
- ICD may be switched off intra-operatively because of interference from diathermy (need to turn back on!)
- threshold may be changed by medications
References and Links
- Aguilera AL, Volokhina YV, Fisher KL. Radiography of cardiac conduction devices: a comprehensive review. Radiographics. 2011 Oct;31(6):1669-82. doi: 10.1148/rg.316115529. PubMed PMID: 21997988.
- Atlee JL, Bernstein AD. Cardiac rhythm management devices (part I): indications, device selection, and function. Anesthesiology. 2001 Nov;95(5):1265-80. PMID: 11684999.
- Atlee JL, Bernstein AD. Cardiac rhythm management devices (part II): perioperative management. Anesthesiology. 2001 Dec;95(6):1492-506. PMID: 11748411.
FOAM and web resources
- FEMT — Pacemakers and AICDs by Annie Sadosty (2004)
- PacerICD.com
Medmastery
- Course: ICD Essentials
- What is an Implantable Cardioverter Defibrillator (ICD)?
- Who qualifies for an ICD?
- What is ATP (anti-tachycardia pacing)?
- Defibrillation for VF and VT when ATP fails
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.
| INTENSIVE | RAGE | Resuscitology | SMACC