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Why do I need to have a Implantable Cardiac Defibrillator (ICD) or Cardiac Resynchronisation Therapy (CRT) Pacemaker? 

Your doctor has recommended that you have a small device called an Implantable Cardiac Defibrillator (ICD) or Cardiac Resynchronisation Therapy (CRT) Pacemaker fitted under your skin. This document gives you information about the device and how we fit it, including the risks.

What is a Implantable Cardiac Defibrillator (ICD) or Cardiac Resynchronisation Therapy (CRT) Pacemaker? 

It is a small box fitted under the skin (and occasionally under the muscle), usually near the left shoulder. It is connected to thin leads (one or two leads or three leads depending on the type of device you need). The leads are placed through your veins and into the heart. There, the leads monitor your heart, producing a small electrical impulse to help your heart to beat normally. 

If you have an ICD implanted it will notice abnormal heart rhythms, especially ones that could be dangerous and can give electrical pulses (known as a shock) to help your heart beat normally again. 

Pre-procedure assessment and care 

  • You will be asked to attend for a short pre-assessment appointment (approximately half an hour) a few days before the procedure. This is to ensure you are suitable for the procedure, do blood test and take an ECG. Also, is an opportunity for you to ask questions.
  • During your pre-assessment appointment, the nurse will give you specific instructions about food intake prior to your procedure.
  • On the day of the procedure, we recommend you have only light meals and avoid caffeine-containing drinks 24 hours prior to procedure. Take usual morning tablets with sips of water then strictly nothing by mouth afterwards.
  • Always bring all your medication with you. The nurses will review your tablets and explain which tablets you can or cannot take before the procedure. If you take Warfarin or Direct Oral Anti-Coagulants such as Apixaban, Rivaroxaban, Dabigatran or Edoxaban you will be given advice for managing your medication prior to your procedure.
  • Please make sure you have a shower, bath or wash the night before or on the day of your procedure. This helps to make sure your skin is clean and reduces the risk of infection.
  • If applicable and if needed, please shave your chest prior to procedure.
  • Avoid applying cream or lotion on your chest.
  • Please make sure that nails are free form nail polish.
  • Please bring your dressing gown and slippers (or slip on shoes) with you. You will be given a gown to wear for the procedure.
  • Please remember to bring your reading glasses with you and something to read or occupy you. 
  • Do not bring any valuables or cash with you, other than small change for a newspaper, as they may be left unattended while you are undergoing your test. 

On the day of your procedure

  • Before the procedure, a small tube (cannula) is inserted into your arm so that we can give you medicines during the procedure
  • You will be asked to put on a hospital gown, the gown opens at the back
  • You will be given intravenous antibiotics prior to going to procedure room, the team will discuss any allergies you have before giving the antibiotics
  • When it is time for your procedure time you will be taken to the specialised treatment area which is called the cardiac catheter labs.

During the procedure

  • The procedure is carried out by a trained specialist Doctor, supported by other specialist cardiac staff including nurses, cardiac physiologists and radiographers. 
  • The procedure typically takes about 1 hour, but occasionally may take longer than this.
  • We will clean your skin with an antiseptic solution which may feel cold, and your chest will be covered in sterile drapes.
  • You may be given medication to help you feel relaxed and help you stay still during the procedure. If so, you may feel sleepy but will still be awake. You are then given a local anaesthetic as a small injection under the skin.
  • A small incision will be made in the skin to allow the pacemaker and its wires to be placed. This is done using X-rays to help guide the positioning.
  • During the procedure you will feel some soreness and pressure whilst the device is implanted. You may feel other sensations including fluttering of your heartbeat. If this is the case please let the team know.
  • At the end of the procedure, the Doctor will use stitches to close the wound, and cover this with a layer of glue.

After the procedure

  • We will observe you including your blood pressure and breathing until you are fully awake. You will then be offered refreshments. You might be asked to remain in hospital overnight for further observation. 
  • You may experience some discomfort at the site - please ask for painkillers if this is the case.
  • Before going home a cardiac physiologist will check the pacemaker by putting an electronic ‘wand’ over the area, and a doctor will come to see you to ensure that you are recovering well from the procedure. After this, you will be able to go home. This is usually on the same day, but in some cases, you may have to stay in overnight.
  • You should travel home with a friend or relative and should travel by car (not public transport). This is to ensure you will be able to return more quickly if there are problems on the way home.
  • Once you have a pacemaker implanted, you must NOT drive for at least 1 week. If you drive for a living, drive trucks or lorries, or hold a special license (DVLA Group II), you MUST NOT DRIVE until you have spoken to the DVLA.
  • As with any surgical procedure, there will be a scar, there will also be a bump at the site where the device has been implanted.

What happens when I get home?

  • The stitches used will usually dissolve by themselves.
  • If a dressing was used to cover the wound, this should be left in place for 7 days. Please keep it as dry as possible in that time. After 7 days, you can remove it and wash as usual.
  • If you notice redness, swelling, or a discharge at the site of your implant please contact us on the same day, these could be signs of infection. We are available during weekdays from 8am to 6pm. After working hours please contact the Coronary Care Unit (CCU) or go to the Emergency Department (ED). 
  • You should avoid lifting your arm on the side the device was implanted above the shoulder for a few weeks. We may provide you with a sling to help you.
  • We will provide you with a card stating which type of pacemaker you have and when you had it fitted. You should show this to any doctor or dentist who treats you in future, or if you need to through a security at the airport.
  • You will receive an appointment to come back to the Pacemaker clinic after 6 weeks, and will have a pacing check every year. 

What are the benefits of having the procedure? 

The benefits depend on the type of device you have fitted: 

  • A pacemaker helps to protect you from the symptoms and dangers of having a heartbeat that is too slow.
  • A CRT can help people whose heart muscle does not work well. It can reduce the symptoms they feel, improve the amount of activity they can do, and reduce the chance of their heart stopping altogether. You may experience more or less benefits than expected, it is not possible to predict accurately how much benefit you will feel before the procedure.
  • An ICD helps to protect you from dangerous heart rhythms. If these heart rhythms were not treated they could cause your heart to stop beating altogether.

What are the risks involved? 

All procedures on the heart carry some risk. Common or unavoidable complications are:

  • Bruising and discomfort at the area of insertion, which usually settles within a few days.
  • About 5 in 100 cases people develop a large collection of blood at the site, which usually resolves itself, but may occasionally require further treatment.

There are other complications you should be aware of. The risk of complications depends on the type of device you have. All devices carry the following risks: 

  • Damage or collapse of a lung because of a needle making a hole in the lung (about 1 in 100 people). This often requires no treatment but may require the insertion of a chest drain which would be used to help re-inflate the lung.
  • A tear in the wall of heart, resulting in blood collecting around the heart (about 1 in every 100 people). Emergency treatment might be required if this happened including drainage of collected blood, or some form of heart surgery and transfer to another hospital. 
  • The needle may puncture the wrong vessel (about 2 in 100 people), which may lead to excess bleeding. This often requires no treatment, but sometimes you may require a blood transfusion, or further emergency treatment.
  • The leads may slip out of place (about 2 in 100 people for each lead). This would mean you need a repeat procedure to put the leads back in the correct position. Making sure you do not lift your arm above your shoulder after the procedure will help with this risk.
  • The leads may not work (about 2 in 100 chance for each lead). This would mean you need a repeat procedure to replace the lead.
  • An infection around the pacemaker or its leads (about 2 in 100 people). This risk is minimised by giving antibiotics but if infection still occurs; you would need another procedure to remove the pacemaker.

There are extra risks for specific devices:

  • For CRT or CRT-D devices, there is a chance we may be able to implant leads on one side of the heart, but not on the other (about 4 in 100 people). We would still fit the box, but you would not get the specific benefits of a CRT device. 
  • For ICD or CRT-D devices, there is a chance the device can deliver electrical impulses known as a shock when it is not supposed to (about 5 in 100 chance). 

Overall risks

  • The overall risk of complications in the first 30 days is about 5%.
  • For CRT or CRT-D devices, there is a chance that you may experience less benefit than expected, or no benefit at all. It is not possible to predict this will apply to. 
  • In the case that a serious complication occurs, your doctors may arrange for emergency procedures to save your life or save you from significant harm. If you are unwell at the time, it may not be possible to discuss these with you, and your doctors will act in your best interests. The risks under these circumstances are not predictable in advance. If needed, you may be transferred to another hospital where more specialist services are available.
  • The risk of death is about at 1 in 1000 people, this risk would be higher if you experience a serious complication, or if this procedure is done as an emergency.

What alternatives do I have? 

Your doctor has recommended this procedure as the most appropriate treatment for your condition, when deciding on your treatment it has been deemed that the benefits outweigh the risks. There may be alternative ways to manage your condition, and if you would like to discuss alternative options, please let us know before you sign the consent form. In this situation the procedure would be deferred, and you would be referred back to your usual doctor.

Further reading

Pacemakers BHF

Implantable cardioverter defibrillator (ICD) - BHF

Further information

If there is anything you do not understand or if you would like further information after you have read this information, please contact us using the details below, depending on where you are having your procedure:

Wexham Park Cardiac Catheter Labs 03006 139572

Frimley Park Hospital Cardiac Catheter Labs 03006 133339

For queries relating to you appointment contact the Cardiology Appointment Team on 03006 133344

Contact us

If you have any queries relating to this information, please contact the Cardiology service.

About this information

Service:
Cardiology

Reference:
C/048

Approval date:
1 February 2026

Review date:
1 February 2029

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Important note 

This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.