An ICD is an electrical device implanted under the skin, usually by the collar bone, connected to leads that go inside the heart. The ICD continuously monitors the heart rhythm. The ICD is designed to detect rapid life threatening heart arrhythmias and treat them either with anti-tachycardia pacing or delivery of an electrical shock to the heart muscle which causes it to be converted to a normal rhythm.  The ICD also has the ability to pace the heart to prevent it from going too slowly, just like a conventional pacemaker.  (See pacemaker section).

An ICD has two parts. The generator houses the battery and the computerized electronics.  Leads are wires that are passed from the generator thru the veins to the inside of the heart.  The leads carry impulses sent from the pulse generator to the heart muscle and also send information from the heart muscle back to the generator.  The computer continuously monitors the heart rhythm from the information obtained by the leads. If a fast life threatening heart rhythm is detected, the generator directs the delivery of electrical energy to convert the heart rhythm to normal either by overdrive pacing or delivery of an electrical shock

ICDs are recommended in people who have:

  *Survived a cardiac arrest

  *Have severe heart dysfunction and are at risk for sudden cardiac death

  *Have had an episode of ventricular tachycardia or ventricular fibrillation

  *Have hypertrophic cardiomyopathy

  *Genetic abnormality of the electrical system of the heart that can cause sudden

    cardiac death. Examples of conditions like these are Long QT Syndrome and    

    Brugada‚Äôs Disease 


close (X)