Livewires Northern Ireland Patient Support Group

Information about ICDs (implantable cardioverter defibrillators)

People with an ICD can live a normal life with very few restrictions, but have the reassurance that, IF they get another fast heart rhythm, they will have a built-in 'lifesaver'.

An ICD system is made up of:

• a pulse genorator, and
• an electrode lead (or sometimes two leads).

A modern pulse generator is much smaller than a small matchbox and weighs about 75 grams (3 ounces). It contains a battery-powered electronic circuit in a sealed unit. This unit is uaually connected to the inside of the heart by one or more electrode leads which pass through a vein. These are very fine, flexible wires, covered in plastic or silicone.

The ICD constantly monitors your heart rhythm. If it senses that a rhythm disturbance is beginning, it can deliver one of the following treatments:

• If the rhythm disturbance is not too serious, the ICD delivers a short series of electrical impulses which will often correct the heartbeat without the need for any further action, This is called pacing.
  
  
• If this dosen't work, or if the ICD series senses a more serious rhythm disturbance, the ICD will deliver a bigger electrical shock to your heart in order to stop the abnomal beating and get the heart rhythm back to normal. There is usually a delay of between 3 and 12 seconds between the ICD detecting an abnormal heart rhythm and delivering the electrical shock. In a small number of cases, more than one shcok is needed.

Taken from a publication by the British Heart Foundation - Implantable cardioverter defibrillators (ICDs): Information for people with an ICD and for their family and friends

The National Institute for Clinical Excellence (NICE) - Information for patients: Guidance on inplantable cardioverter defibrillators for arrhythmias

ELA Medical - An ICD : a life jacket for my heart...

Guidant - Defibrillator (ICD) Patients (includes video of how ICDs are made)

Biotronick - Getting a new lease on life with an implantable cardioverter defibrillator Patient information

Heart Rythm Society - Public and Patients - Implantable Cardioverter Defibrillators (ICDs)

Family Doctor - Implantable Cardioverter Defibrillator

British Cardiac Society - Implantable Cardioverter Defibrillator (ICD)

Your Heart - Implantable Cardioverter Defibrillator (ICD)

Ohio Health - Implantable cardioverter-defibrillators: Controlling a chaotic heart

Multimedia resources

Medtronic - Article about ICD's - from the New York Times (includes multimedia illustration)

Medtronic - video available to provide reporters with visual resource can be found at the following page: Video News Release: New England Journal of Medicine SCD-HeFT Results

Heart1.com - Guidant Video - Learn more about ICDs