An implantable cardioverter defibrillator (ICD) is a small, battery-operated device that monitors the heart’s rhythm and provides appropriate treatment. Most ICDs have both pacemaker and defibrillator functions.
If the heart beats too slowly, the ICD can help the heart beat at a normal pace. If the heart begins to beat unnaturally, the device provides a shock to restore a normal rhythm. ICD implantation refers to the surgical insertion of an ICD.
Types of ICDs
Medtronic Evera MRI SureScan® ICD System
This new device is FDA-approved in the MRI environment, so it allows patients to undergo routine MRIs. Our validated monitoring protocol allows us to provide advanced MRI options for patients with older pacemakers and ICDs that were not specifically tested for use in the MRI environment.
Subcutaneous Implantable Defibrillator (S-ICD)
Most ICDs have leads that go through chest veins and touch the heart to provide treatment of dangerous heart rhythms. However, the S-ICD uses a defibrillation wire that goes under the skin in the chest rather than through the veins.
These devices don't have the capacity to pace the heart and can only treat dangerous heart rhythms with shocks as opposed to painless pacing. Young patients or those on hemodialysis for end-stage kidney disease may prefer them.
Do You Need an ICD?
Certain heart rhythms are extremely dangerous and can lead to sudden cardiac death or cardiac arrest. Some irregular rhythms that may require an ICD implant include:
- Bradycardia — heart beating too slowly
- Ventricular tachycardia — heart beating too rapidly
- Ventricular fibrillation — heart muscle not pumping, but just quivering
You may need an ICD if you:
- Have had one or more episodes of serious irregular heart rhythms
- Have had a heart attack and are at high risk for arrhythmias
- Have a high risk of dangerous arrhythmias
- Have a weakened heart muscle
- Have a high likelihood of developing an arrhythmia
- Have the condition known as hypertrophic cardiomyopathy, which is an enlarged heart muscle that does not function properly
Description of the Procedure
We use light sedation and a local anesthesia to help you relax.
Your doctor makes a small incision below the collarbone on the left or right side. A wire, called a lead, is threaded through a vein in the upper chest to the heart. An X-ray monitor watches the lead move through the vein to the heart. The signals between the heart and the ICD are carried on this lead.
Your doctor implants the ICD in a pocket created under the skin at the incision site. When in place, we increase the sedation. We then test the ICD to make sure that it shocks the heart appropriately. When in the right place and working properly, we close the incision with stitches.
Immediately After Procedure
Chest X-rays ensure the ICD and leads are in the proper place. The average hospital stay is one to three days.
Postoperative Care at the Hospital
The day after your implant, you will have an ECG and blood tests. Your doctor may check the ICD function again. You’ll be sedated during the procedure.
When the Device is Active
If your heart requires a shock from your ICD, you may be able to feel it like a light thump or a strong kick in the chest. You may feel lightheaded before the shock. Try to stay calm and sit or lie down. If someone is with you, ask him or her to stay.
If you feel OK after the shock, contact your doctor’s office to let them know. This is not an emergency. Your doctor may want you to come in for a check-up, particularly if this is the first shock you have received. If you receive multiple shocks in a row or in a day, you should go to the emergency room.
Risk Factors for ICD Implants
Possible complications may include:
- Damage to the heart or lungs
- Damage to blood vessels
- Inappropriate shocks or device malfunction
Some factors that may increase the risk of complications include:
- History of smoking
- History of excess alcohol consumption
- Bleeding or blood-clotting problems
- Use of some medicines
- Chronic diseases such as diabetes
Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.
ICDS From a UVA Cardiologist
ICDs can both restore normal rhythm with painless pacing and, if necessary, provide an electric shock to prevent patients from dying suddenly from very fast heart rhythms. View Transcript.