Heart test
Implantable Loop Recorder
An implantable loop recorder is a small device placed under the skin of the chest to continuously monitor your heart rhythm for months or years.
Quick answer
Implantable Loop Recorder: what it is and what the results mean
An implantable loop recorder (ILR) is a small device, about the size of a memory stick, inserted just under the skin near the heart. It continuously records the heart’s electrical activity and stores abnormal rhythms for review.
- Why it is done: It is used to investigate infrequent symptoms such as unexplained fainting, palpitations or dizziness, or to detect intermittent abnormal rhythms (such as atrial fibrillation), when shorter monitors have not captured the problem.
- Understanding results: The recorded rhythms are downloaded and reviewed by the cardiology team.
What it is
An implantable loop recorder (ILR) is a small device, about the size of a memory stick, inserted just under the skin near the heart. It continuously records the heart’s electrical activity and stores abnormal rhythms for review.
Why it is done
It is used to investigate infrequent symptoms such as unexplained fainting, palpitations or dizziness, or to detect intermittent abnormal rhythms (such as atrial fibrillation), when shorter monitors have not captured the problem.
What to expect
It is inserted in a quick procedure under local anaesthetic through a small cut in the chest, often taking only a few minutes. Afterwards it records automatically and when you activate it during symptoms, with data reviewed remotely or at clinic visits.
Understanding the results
The recorded rhythms are downloaded and reviewed by the cardiology team. Capturing your heart rhythm during a symptom helps confirm or rule out a rhythm problem and guides treatment such as a pacemaker or medicines.
Good to know
Risks and limitations
It is a low-risk procedure; occasional issues include minor bleeding, bruising or infection at the site. It monitors rhythm but does not treat problems, and can stay in place for up to a few years before removal.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Implantable Loop Recorder: frequently asked questions
How long does an implantable loop recorder stay in?
It can remain in place for up to about three years, depending on the device, and is removed once it has captured the needed information or the battery ends. Removal is another minor procedure.
Can I go through airport security with it?
Yes. The device is safe with everyday equipment, though you should carry your device identification card and mention it if asked. Your team will advise on any specific precautions.
Related tests
Other heart test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- British Cardiovascular Society / relevant professional body
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