What is an implantable cardioverter defibrillator?

An implantable cardioverter defibrillator (ICD) is a battery-powered device which is implanted into the body.

 

Image of an ICD. 

It monitors your heart rhythm to see if it is fast and abnormal and so needs to be corrected. If the ICD detects an abnormal heart rhythm, it delivers electrical impulses (shocks) to the heart muscle to correct the rhythm. An ICD can also stop the heart from beating too slowly. It does this by sending small electrical impulses to the heart muscle to make it contract and pump blood.