Information on having an implanted cardioverter defibrillator (ICD)

What is an ICD?

An ICD is an implantable device which consists of a small battery-operated generator connected to one, two or three leads implanted into the heart via a vein in your chest.

ICDs are designed to monitor, detect, and treat abnormally fast heart rhythms. When these are detected, the ICD will deliver electrical pulses to the heart. It will also deliver an electric shock to reset abnormal rhythms if needed.

Why do I need an ICD?

Your consultant has referred you for an ICD implant as they feel you are at an increased risk of dangerously fast heart rhythms. If these rhythms were left untreated, it could result in you losing consciousness and your heart stopping (cardiac arrest).

There can be many reasons that a person may be at increased risk of these types of rhythms; it may be due to a previous heart attack, genetic risk factors or coronary artery disease. Your consultant will have discussed your reason for device implant during your consultation.

How is an ICD implanted?

When having your ICD implanted, you will be given local anaesthetic and may also be given some sedation to help you relax during your procedure as you will be awake. The leads that will sit in the heart and send electrical impulses are implanted via a vein in your left shoulder.

The generator that generates the electrical impulses is then connected to the leads and placed under the skin. The skin will then be closed using dissolvable sutures and a dressing will be placed over the wound. You will be able to remove the dressing after five days.

Risks and side-effects

All surgical procedures carry a risk, but ICD implants are relatively straight forward. The procedure is reasonably short, and any risks will be fully explained by the doctor before your procedure when you are asked to sign a consent form.

Will I have a scar?

You will be left with a small scar over the wound site. This should fade with time.

Will I be in pain after the procedure?

You might feel a little sore and bruised the first few days after your device is implanted. The nurses will advise you about pain relief before you are discharged. The nurses will also give you some information about looking after your wound when you get home.

A cardiac physiologist will check your device before you are discharged. They will also advise you to keep arm movement to below shoulder-level for the first 4-6 weeks. This is to ensure that the leads that have been implanted into the heart are not displaced.

You will also be given a patient identification card with your new device details and a home monitor information pack before you go home, explaining how your device can be monitored from home.

How often will my new device be checked?

You will have a follow-up appointment with the physiologists in the cardiac device clinic four to six weeks after your implant. You will have a check-up every six to 12 months either in clinic or via your home monitor.

How often will my ICD fire?

Many patients never experience a shock from their device and those that do only experience shocks infrequently.

Some patients may experience inappropriate shocks from their device, due to the device misinterpreting fast rhythms, however this is very rare. If this occurs, it may be necessary to adjust your medications and, in some cases, make programming changes to your device settings.

Do ICD shocks hurt?

Patients that have had shocks from their devices describe it as a thump in the chest that lasts a couple of seconds. Some people have been unaware that they have had a shock. Your device will alert you with an audible alert if you have received a shock.

What do I do if I get a shock?

If you receive a shock from your device, try to stay calm. If you receive one shock and you feel well, call the device clinic, and let them know that you have had a shock.

The physiologists may ask you to come into the department for a check of your device or send them a download of your device recordings through your home monitor.

If you receive one shock from your device and feel unwell, or you receive more than one shock in quick succession, dial 999 and tell the operator that you have received a shock, or more than one shock, from your ICD.

Do I need to make any lifestyles changes after my ICD is implanted?

Once you are fully recovered from your procedure, you can return to your normal daily activities. We advise that you should avoid placing your mobile phone over your device (e.g., in your shirt pocket) as strong magnets can interfere with devices.

Most new devices are MRI compatible, so it is safe for you to go into an MRI scanner. You should make sure that the hospital that you attend for your MRI is aware that you have an ICD and show them your patient ID card with your device details.

If you drive, you will need to notify the DVLA that you have had an ICD implanted. If you receive an appropriate shock from your ICD, you will need to notify the DVLA of this and will not be permitted to drive for 6 months.

Will exercise trigger my ICD to fire?

If you are very active, we can programme your device accordingly. In some cases, patients are advised to reduce their exercise. This should be discussed with your consultant before your implant procedure.

What will happen when I die?

Your device will stop working when your heart stops working. If, at some point in the future, you opt for a ‘Do Not Attempt Cardiopulmonary Resuscitation’ (DNACPR) it may be necessary to deactivate your device. This will enable you to die naturally without your device delivering inappropriate shocks.

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