Implantable Cardioverter Defibrillator
What is an ICD?
ICD stands for Implantable Cardioverter
Defibrillator. If your doctor has suggested that
you need an ICD you may have experienced
or may be at risk of experiencing an
abnormal, fast heart rhythm. An ICD can
recognise and monitor your heart rhythm
and can deliver various electrical treatments if
needed. It is made up of a small, slim,
box-shaped device which contains a battery
and electronic circuits, usually placed under
the skin below your collarbone, normally on
the left-hand side.
Most modern ICDs have three
If your heart rhythm is too slow, the device can
give your heart extra support by working as a
normal pacemaker (anti-bradycardia pacing).
If your heart beats too fast, the ICD can give you
a burst of extra beats at a slightly faster rate
which should return your heart back to a normal
rhythm (anti-tachycardia pacing or ATP).
If the anti-tachycardia pacing doesn’t bring
your heart back to a normal rhythm,
or if the ICD senses a faster, dangerous
rhythm called Ventricular Fibrillation, the
ICD can then give a shock (defibrillation).
attrubutte: Blausen.com staff. "Blausen gallery 2014". Wikiversity Journal of Medicine.DOI:10.15347/wjm/2014.010. ISSN 20018762. (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons
How is the ICD fitted?
This procedure is performed under a general
anaesthetic or a local anaesthetic and sedation.
The ICD generator is connected to either one
or two leads which pass through a vein into the
heart. The doctor may test the device during
the procedure to ensure it is working correctly.
The implant should take between one and two
hours and any stitches that may need to be
subsequently removed will be done at your
What happens after the ICD has
You will probably be allowed to go home the
next day provided your ICD is checked and there
are no complications. You will be given an ICD
identity card, emergency information and
instructions at this point. You will also be given
a helpline number should you have any queries
Normally an ICD battery lasts between six
and nine years and the replacement procedure
will usually involve changing the ICD
generator, not having new leads implanted.
Will I feel anything different?
Some patients have reported that having
shocks can feel like they have been suddenly
kicked or punched in the chest. These shocks
can be quite painful but the pain will only last
for a few econds, others may not feel anything.
If you do feel unwell after a shock, or if
your device has given you veral shocks,
please dial 999 for an ambulance. Show the
paramedics your identity card long with any
mergency instructions; this will inform them
of exactly which type of device you have
and what the best course of action will be.
You should always contact us
if you think you have had a shock. Any
further questions please contact the Arrhythmia Nurse Specialist on 01273 696955 Ext 4071.
Courtesy of Arrhtyhmia Alliance. Registered Charity No. 1107496 ©2010