Implantable cardioverter-defibrillators (ICDs)

Implantable cardioverter-defibrillators (ICDs)is a small battery powered device that is placed in the chest to detect and stop irregular heartbeats (arrhythmias).

November 8, 2022

Implantable cardioverter-defibrillators (ICDs)is a small battery powered device that is placed in the chest to detect and stop irregular heartbeats (arrhythmias).

Some facts about Implantable cardioverter-defibrillators (ICDs):

  • The heartbeat is continuously monitored by an ICD and electric shocks is delivered when needed, to restore a regular heart rhythm.
  • An ICD is required if you have a dangerously fast heartbeat that keeps your heart from supplying enough blood to the rest of your body.
  • An ICD is also required if you are at high risk of a heart rhythm problem (arrhythmia), usually because of a weak heart muscle.

Types of ICD:

An ICD is a type of cardiac therapy device, which are available in two basic types. These include:

  • Traditional ICD: This ICD is implanted in the chest, and the wires are attach to the heart. An invasive surgery is required to implant a traditional ICD.
  • Subcutaneous ICD (S-ICD): This is another option which is implanted under the skin at the side of the chest below the armpit.  It is generally attached to an electrode that runs along the breastbone.

Preparation for Implantable cardioverter-defibrillators (ICDs):

  • Several tests may be done by your health care provider before you get an ICD. 
  • The test may include: Electrocardiography (ECG or EKG), Echocardiography, Holter monitoring, Event recorder, and Electrophysiology study (EP study).
  • You will be asked to avoid food and drinks for at least 8 hours before the procedure if you are having an ICD implanted..
  • Talk to your doctor about all the medications you are taking and whether you should continue to take them before the procedure to implant an ICD.

Procedure for Implantable cardioverter-defibrillators (ICDs):

  • An IV will be inserted into your forearm or hand and you may be given a medication called a sedative to help you relax.
  • You will likely receive general anesthesia.
  • The doctor guides one or more flexible, insulated wires (leads) into veins near the collarbone to the heart during surgery to implant the ICD, using X-ray images as a guide
  • The ends of the leads will be attached to the heart and the other ends will be attached to a device (shock generator) that's implanted under the skin beneath the collarbone.
  • Usually, the procedure to implant an ICD takes a few hours.
  • Your doctor will test the ICD and program it for your specific heart rhythm needs once it is in place.
  • Speeding up the heart and then shocking it back into a regular rhythm may be required in testing the ICD.
  • An ICD could be programmed for low-energy pacing or a higher energy shock depending on the problem with the heartbeat.
  • You may a painless fluttering in your chest or feel nothing when your ICD responds to mild changes in your heartbeat.
  • The ICD may deliver a higher energy shock for more-serious heart rhythm problems which can be painful, possibly making you feel as if you have been kicked in the chest.
  • Although, only one shock is generally needed to restore a regular heartbeat, some people might have two or more shocks during a 24 hour period.
  • Having three or more shocks in a short amount of time is called an electrical or arrhythmia storm for which you need emergency medical help to see if your ICD is working properly.
  • The ICD can be adjusted to reduce the number and frequency of shocks if necessary.
  • Medications may be provided to make the heart beat regularly and decrease the risk of an ICD electrical storm.