Implantable Defibrillator
An implantable defibrillator, also known as an ICD (implantable cardioverter defibrillator), is a small, life-saving device placed under the skin of the chest and connected to the heart. It uses electrical impulses to monitor and correct dangerous heart rhythms.
The ICD detects abnormal heartbeats (arrhythmias) and delivers electrical signals or shocks when necessary to restore a normal rhythm. It also stores data about your heart’s activity, which can be reviewed by your doctor to help guide your treatment.
ICDs are most commonly used in patients at risk of ventricular tachycardia or ventricular fibrillation—fast, life-threatening arrhythmias that can lead to sudden cardiac arrest if not treated.
What does it do?
An ICD has two main functions:
- Pacing – If your heart is beating too fast, the ICD first sends small, painless electrical impulses to try to slow it down.
- Defibrillation – If the fast rhythm continues, the ICD delivers a stronger electric shock to reset the heart’s rhythm.
Additionally, ICDs can act as pacemakers, helping to correct slow heart rhythms when necessary. The device monitors your heartbeat continuously and only activates when needed, ensuring your heart maintains a safe rhythm at all times.
How does it work?
The ICD is implanted just beneath the skin, usually below the collarbone. Thin electrode wires are guided through veins into the heart and connected to the device. These leads allow the ICD to:
- Monitor your heart rhythm
- Detect arrhythmias
- Deliver electrical therapy when needed
The device works around the clock to detect dangerous rhythms like ventricular tachycardia or fibrillation, which could lead to cardiac arrest if untreated. It ensures that if an irregular pattern is detected, appropriate therapy is delivered within seconds.
Why is it performed?
Your doctor may recommend an ICD if you are at risk of, or have already experienced, dangerous arrhythmias. This includes:
- A history of ventricular tachycardia or fibrillation
- A previous cardiac arrest
- Certain types of heart failure or cardiomyopathy
- Arrhythmias that haven’t responded to medications or other treatments
ICDs are designed to prevent sudden cardiac death in high-risk patients.
The procedure
ICD implantation is usually done under local anaesthesia with mild sedation. It typically takes 1 to 3 hours and involves:
- Making a small incision just below the collarbone
- Creating a pocket under the skin for the device
- Threading one or more electrode leads through a vein to the heart
- Connecting the leads to the ICD and positioning it with guidance from X-ray imaging
- Testing the device and then closing the incision with stitches or surgical glue
Your heart’s activity will be monitored during the entire procedure.
Recovery
After the procedure:
- You’ll be taken to a recovery area for monitoring
- Your arm will be dressed with a special bandage, which must stay in place for about a week
- You’ll receive clear instructions on wound care, activity restrictions, and what to do if you receive a shock from your ICD
- Avoid tight-fitting clothing near the implant site and heavy lifting for the first month
Most patients return home the same day or the following day and resume regular activities within a few weeks. Your care team will also help you create an action plan for living safely with your ICD.