❤️Pacemakers and Surgery
Having a pacemaker or implanted cardiac defibrillator (ICD) does not usually prevent you from having a knee replacement. The anaesthetic and surgical teams simply need some extra information beforehand so your device works safely during your operation.
What a pacemaker or ICD is
A pacemaker is a small device implanted under the skin that sends gentle electrical signals to keep your heart beating regularly.
An ICD does the same job and can also deliver a stronger shock to correct a dangerous rhythm. Some devices do both.
Why the anaesthetic team needs to know
Some equipment used in surgery — particularly a device called diathermy that seals small blood vessels — can briefly interact with pacemakers and ICDs.
Knowing about your device means the team can put simple precautions in place, including sometimes adjusting settings before and after surgery. This keeps both your heart and your device working exactly as they should.
Device checks before surgery
The team will usually want to see a recent device check — often from the last 12 months. If your last check was a while ago, one may be arranged before your operation.
If you have any device symptoms, an ICD shock or concerns about the battery, please tell your team as soon as possible.
What to bring to hospital
Bring your device identification card if you have one — this shows the make, model and settings.
Bring the contact details of the clinic that looks after your device (often called pacing clinic or cardiac physiology). This helps the hospital team liaise directly if needed.
Frequently asked questions
Will my device need to be turned off? Not usually. In some cases the shock function of an ICD is briefly paused during the operation and switched back on straight afterwards. A specialist stays involved throughout.
Will I feel anything different? No. Any adjustments are made by the specialist team using an external programmer — you don't feel it.
Do I need to stop my heart medicines? Only if you are specifically told to. Most heart medicines are continued as normal.
Practical tips
- Bring your device ID card and pacing-clinic contact details.
- Tell the team about any device symptoms or recent shocks.
- Continue your heart medicines unless told otherwise.