Patient Information

Implantable loop recorders


This explains why we have recommended an implantable loop recorder for you, and how it will be fitted.

What is an implantable loop recorder (ILR)?

An ILR is a monitor which is implanted just under your skin on your chest wall. The ILR allows your heart’s electrical activity to be recorded. Your doctor or Cardiac Nurse Specialist (CNS) can review the information to help diagnose and manage your condition.

Why do I need an ILR?

Your doctor or CNS may recommend an ILR if you have one or more of the following symptoms or health conditions.

Symptom or conditionWhy do we monitor?
Unexplained fainting: A transient (temporary) loss of consciousness, also known as “passing out”. This can occur due to a number of reasons, including low blood pressure and abnormal heart rhythms.Fainting can be serious when caused by an abnormal heart rhythm.
Heart palpitations: A usually harmless condition in which the heart feels as if it is pounding, racing or fluttering.Palpitations may indicate a serious underlying heart
Atrial fibrillation: A common condition when the upper chambers of the heart beat fast and irregularly. Also called AF or AFib.AFib requires treatment because it is strongly linked to stroke.
Unexplained stroke: A stroke of unknown cause that may be triggered by AFib, causing a blood clot to form and block oxygen to the brain.Detecting AFib after stroke may help healthcare professionals to prevent a second stroke.

How long will I have my ILR inserted?

You may need the ILR for a few days, a few months, or possibly longer. It will depend on your condition and the information the ILR gives us. Your doctor or CNS will decide when it is safe to remove the ILR and discuss this with you.

How is an ILR fitted?

The ILR is inserted under the skin on your chest. We give you a local anaesthetic. A small cut of about 2 centimetres is made to allow us to insert the device. The procedure normally takes 15 to 30 minutes.

Who will perform my procedure?

Most ILRs are implanted by a CNS trained by a cardiology consultant. Occasionally a doctor carries out the procedure.

What happens at my pre assessment appointment?

We will give you a pre assessment appointment about 7 days before your procedure.

Your appointment letter will explain where you need to go. It is likely that we will give you an appointment for an ECG before you see the CNS.

Following this we will also give you a blood test and take some swabs. You will probably be in the hospital for around 1 hour.

During your pre assessment appointment, the CNS will explain what you should bring to hospital with you on the day of the procedure. They will also tell you how to prepare for the procedure.

What happens on the day of my procedure?

You can expect the following on the day of your procedure.

  • We will ask you to remove your shirt or top and give you a hospital gown to change into.
  • A nurse will go through pre admission checks with you.
  • We will ask you to sign a consent form if you have not already done this.
  • We will clean the area of your skin where we will insert the ILR.
  • We will cover you in a blue sterile sheet with an opening over your chest. We will fold the sheet so that your face is not covered.
  • We will inject you with a local anaesthetic on your chest where we plan to insert the ILR. The anaesthetic will take a few minutes to take effect. We will make a small cut and insert the ILR.
  • We will monitor your heart during the procedure.

Will the procedure hurt?

The injection of the local anaesthetic may sting and be a little uncomfortable. You may feel a slight pushing sensation when we insert the ILR.

Once the ILR is implanted, we will close the small cut with steri strips.

What happens after the procedure?

You can expect the following after the procedure.

  • A member of the cardiology team will programme the ILR and ensure is it working properly. They will explain how you can use the ILR device and give you written information about how to use it.
  • We will ask you to rest for 20 minutes and offer you a hot drink and a biscuit.
  • The CNS will see you before you go home and discuss next steps in your care. They will give you a discharge summary that explains the ILR procedure, how to take your medication and follow up steps.
  • We will send a copy of your discharge summary to your GP.
  • Before you leave we will give you a date and time for a 6 week follow up check.

After care

You may feel some mild discomfort around the ILR insertion site, but once it has healed most people do not notice the ILR. The steri strips used to close the wound will fall off after a few weeks. If this does not happen, visit your GP to have them removed.

Do not rub or massage your skin on the site of the ILR, because this can move the ILR and cause it to stop working.

If the skin around the ILR becomes red, sore, more swollen or inflamed, contact the Cardiology Pacing Team (see Contacts section).Mobile phone image
Go to your nearest ED (A&E) if you become unwell, develop a high temperature or notice changes to the skin around the ILR and cannot get hold of the Cardiology Pacing Team.hospital

What are the benefits and risks of the procedure?

The benefits of having an ILR fitted far outweigh risks of the procedure.

An ILR alerts the cardiac team to changes in your heart rhythm that may cause your symptoms. This enables us to give you prompt treatment for potentially serious conditions.

As with any kind of surgery, there are small risks associated with the procedure. These include:

  • infection
  • bleeding
  • discomfort during the procedure.

On rare occasions, these factors may cause us to remove the ILR.

More information

Arrhythmia Alliance logo
Home – Arrhythmia Alliance – UK (heartrhythmalliance.org)
Information and advice for arrhythmia patients
Welcome to British Heart Foundation – BHF
British Heart Foundation
Information on using an ILR home monitor


Kingston Hospital Cardiology Department Admin Team, Monday to Friday 9am to 5pm 020 8934 2321 option 1
Kingston Hospital Cardiac Nurse Specialists (CNS), Monday to Friday 9am to 5pm 020 8934 6453
Kingston Hospital Device Clinic, Monday to Friday 9am to 5pm 020 8934 3854 or 3104
Kingston Hospital Cardiology Pacing team, Monday to Friday 9am to 5pm 020 8934 3872

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