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Implantable loop recorder (ILR)

Read our guide below about how we fit an implantable loop recorder and how you can prepare for it.

You can also download a PDF version of this patient information by following the link on the right.

Implantable loop recorder (ILR)

This information will help you understand how we fit an implantable loop recorder and how you can prepare for it.

What is an implantable loop recorder (ILR)?

It’s a small device placed under the skin, usually on the left side of the chest. It continuously monitors the electrical activity of the heart and can automatically record any abnormally fast or slow heart rhythm.

You can also start a manual recording when you feel symptoms using a small hand-held activator or a mobile phone app.

The device’s internal memory stores this information. Usually, our team can access the information remotely by a bedside monitor that we’ll give you during your initial appointment. We may ask you to visit the hospital so we can download the results.

Why do you need an ILR?

A loop recorder can identify the cause of symptoms you may have such as dizzy spells, unexplained fainting or palpitations. These might happen randomly and infrequently.

We normally recommend an ILR when other heart rhythm monitors can’t explain the cause of your symptoms. Other heart rhythm monitors include small devices placed outside of the chest for one or two days.

For some people who have had a stroke, an ILR might detect an abnormal heart rhythm (atrial fibrillation) that other tests haven’t identified. In some cases, it can also monitor patients who have other abnormal heart rhythms such atrial fibrillation or ventricular tachycardia.

Are there any alternatives?

Your doctor recommended an ILR as the best way to monitor your heart. We normally only recommended it when other tests fail to identify the cause of your symptoms. Other alternatives don’t allow for a prolonged period of monitoring. Talk to your specialist if you want to discuss any other alternatives.

How do we fit an implantable loop recorder?

You’ll stay awake but we’ll give you a local anaesthetic to numb the area so you don’t feel any pain. You may feel an initial stinging sensation for a short period before the area becomes numb.

We’ll make a small cut (incision) of around 1 cm and inject the loop recorder under the skin. You may feel some pushing but it shouldn’t be painful. We’ll then close the cut with a special type of glue and/or steri-strips (paper-like sticky bandage strips). In rare occasions you may need stitches.

Are there any risks?

This is a common simple procedure. The risks are low and generally not serious. There’s a chance of bleeding, bruising, discomfort and infection.

The device can move slightly under the skin as it isn’t secured in a set position. This generally doesn’t cause problems but if it feels uncomfortable or you’re concerned, contact us.

The device can also come out through the skin (called erosion). If this happens tell us straight away.

How should I prepare for the procedure?

Do not eat anything the morning of your procedure. You can drink water normally.

Bring a list of all your medication. If you do not take insulin, diabetes medication or blood thinning medication, you can take your medication as normal during the morning of your procedure.

If you take insulin or diabetes medication do not take them until you have eaten after the procedure.

If you take blood thinning medication (Rivaroxaban, Apixaban, Edoxaban or Dabigatran)

Do not take it on the morning of the procedure but bring it with you to take after. If you take warfarin, aim for a blood clotting measure INR of around 2.5 the week before the procedure. Your anticoagulation clinic will help you with this.

Only bring essential items and avoid wearing jewellery or other valuables. You can bring a book to read or earphones to listen to music while you wait.

What can I expect from my recovery?

If you feel well, you can normally go home within an hour of the procedure and can continue the day as you would normally. Your chest may feel bruised or sore and you can take painkillers that you normally use at home to help if needed.

We may ask you to limit the movement of your upper body and avoid heavy lifting for a few days to allow the wound to heal.

Before discharge home, a cardiac physiologist will explain how to use the loop recorder and the home remote monitoring device. A cardiology nurse will advise you on post-procedure wound aftercare.

You’ll get an ID card for the device that you must always carry with you.

Looking after your wound

The wound dressing can be removed 3 days after your procedure.

Keep the wound area clean and dry. You can shower when the wound appears completely healed (normally around 7 days). Pat dry with a clean towel.

The steri-strips can be removed in 7 to 10 days but normally fall off on their own when you start showering. The skin glue will fall off on its own. Please don’t pick at it.

If you had stiches they will either absorb naturally or we’ll tell you when they need removing.

Infection would normally happen within the first few weeks. Look out for any pain, swelling and redness or oozing at the wound site. Contact the clinic or your GP if that happens.

What should I do if I have any unexplained symptoms such as dizziness, fainting and palpitations?

Use your patient assistant (symptom activator) to manually record the heart rhythm during symptoms. Write down why you used the symptom activator each time.

If you’re well and don’t need immediate help, contact the Pacemaker Clinic to check the recording. The device is only a monitor. Call 999 first in an emergency.

If you’re unwell contact your GP or 111.

How to use the patient assistant

  1. Press and release the blue button (1). The searching light (2) will start to flash blue.
  2. Hold the activator flat against your chest over the device.
  3. When a symptom is successfully recorded, you’ll hear a sound and the success light (3) will turn green. If this doesn’t happen within 20 seconds, repeat steps 1 and 2.

If you can’t get to the patient assistant within 5 minutes of your symptoms, write down the date and time they happened. Tell the team at your next appointment.

What follow-up will I have?

The Pacemaker Clinic will send you an appointment within around 6 weeks.

The 6-week check happens remotely via the Carelink monitor. Follow the instructions on your letter and inside your Carelink monitor to do this.

If you don’t send a Carelink transmission, we’ll rebook your appointment which may mean a delay in results. You’ll also get a call on the day to check on your wellbeing and ILR wound site.

We’ll tell you about your next follow up by post. Usually this is via Carelink. Most patients have 6-monthly follow ups but this can vary on a patient basis.

Looking after your Carelink device and ILR

Do not send Carelink transmissions in between appointments unless the Pacemaker Clinic asks you to. Excessive Carelink transmissions cause a drain in the ILR battery life and reduces the monitoring period.

The device has limited memory and will delete the oldest recordings. To try and avoid this contact the device clinic when you’ve used the activator four times.

If you have a black out

Get urgent medical help. When you’re well enough, contact the pacemaker clinic so we can check your ILR.

How long does the monitor last?

The device has an internal battery that lasts approximately 3 to 4 years. After that, we can replace the device if you still need one or remove it if you don’t need it. We remove the device in a similar way to how we fit it.

Can I have MRI and x-rays?

Tell healthcare professionals before any procedure or investigation that you have a loop recorder.

You must not have an MRI scan without talking to the Pacemaker Clinic. Although it’s safe to have an MRI with your ILR, the stored information may be lost during the scan and needs to be saved before your appointment.

CT scans, x-rays and mammograms are safe.

Can I travel?

Your ILR may alert security scanners so you must tell airport security staff. These scanners won’t damage your loop recorder. You may need to show staff your device identification card. If you’re away for a longer period (over 1 month) you can take the remote Carelink monitor with you.

What activities or exercise can I do?

You can continue to do any activities or sports as normal, but we’ll ask you to limit some activities until your wound has healed. We may tell some patients to limit certain activities because of their underlying heart problem.

Can I drive?

There are no driving restrictions with this device and you don’t need to notify the DVLA. But, depending on your condition, you may have been told not to drive and to inform DVLA.

Discuss your specific circumstances with your cardiologist. You can find out more about driving regulations on the DVLA website.

More information

Search online for the British Heart Foundation or Arrhythmia Alliance.

Contact us

Pacemaker Clinic, Ward 3A, Wycombe Hospital
01494 425471
Monday to Friday 8.30am to 4.30pm 

Cardiac Day Unit, Wycombe Hospital
01494 425278
Monday to Friday 8am to 6pm