Implantable Cardioverter-Defibrillator (ICD) - Topic Overview
An implantable cardioverter-defibrillator (ICD) is a battery-powered device that can fix an abnormal heart rate or rhythm and prevent sudden death. The ICD is placed inside the chest. It's attached to one or two wires (called leads) that go into the heart through a vein.
An ICD is also known as an automatic implantable cardioverter-defibrillator (AICD).
Who needs an ICD?
You might need an ICD if you have had a serious episode of an abnormally fast heart rhythm or are at high risk for having one. If you have coronary artery disease, heart failure, or a problem with the structure or electrical system of the heart, you may be at risk for an abnormal heart rhythm.
An example of a life-threatening heart rhythm is ventricular tachycardia.
- Heart Failure: Should I Get an Implantable Cardioverter-Defibrillator (ICD)?
- Heart Problems: Should I Get an Implantable Cardioverter-Defibrillator (ICD)?
How does an ICD work?
An ICD is always checking your heart rate and rhythm. If the ICD detects a life-threatening rapid heart rhythm, it tries to slow the rhythm to get it back to normal. If the dangerous rhythm does not stop, the ICD sends an electric shock to the heart to restore a normal rhythm. The device then goes back to its watchful mode.
An ICD also can fix a heart rate that is too fast or too slow. It does so without using a shock. It can send out electrical pulses to speed up a heart rate that is too slow. Or it can slow down a fast heart rate by matching the pace and bringing the heart rate back to normal.
Whether you get pulses or a shock depends on the type of problem that you have and how the doctor programs the ICD for you.
How is an ICD placed?
Your doctor will put the ICD in your chest during minor surgery. You will not have open-chest surgery. You probably will have local anesthesia. This means that you will be awake but feel no pain. You also will likely have medicine to make you feel relaxed and sleepy.