What it is
A Holter monitor is a portable . Sticky patches (electrodes) on your chest are wired to a small battery-powered recorder, worn on a belt or in a pouch, which records your heartbeat continuously. A hospital ECG lasts a few minutes. This one follows your heart through a normal day, and usually a night.
Why it is done
A doctor may ask for it to find the cause of palpitations, dizzy spells or fainting, which may not happen while you are in the clinic. It helps to find rhythm problems such as , and a heartbeat that is too fast or too slow. It is also used after a heart attack, and when a new heart medicine is started.
What it helps with
- Atrial fibrillation
- Heart attack
Palpitations
How to prepare
No special preparation is needed.
Do
- Bathe or shower before you start, as you cannot while wearing it
- Tell the team if you are allergic to tape or plasters, or have sensitive skin
- Tell the team about every medicine you take. The team will tell you which medicines to take or stop
Do not
- Do not let the recorder get wet
- Do not go near magnets, metal detectors or electric blankets while wearing it
What happens
- Your chest is cleaned, and some hair may be shaved so the patches stick.
- Sticky patches go on your chest, and the wires are taped down.
- The wires connect to the recorder, worn on a belt at your waist or in a pouch around your neck.
- You go home and carry on with your day. You write down what you do and any symptoms, with the time, so they can be matched to the recording.
- When the time is up, you take the recorder back to the hospital, where the recording is analysed.
If your symptoms come on with exercise, you may be asked to exercise while wearing it. If you wear it for more than a day you may be shown how to disconnect and reconnect it. If a patch loosens or the recorder switches off, contact the team for advice.
Afterwards
Once the patches are off you can bathe as usual. The skin may be red or itchy where they were, and the patches can tug a little as they come off. A specialist studies the recording, and you may be called back to talk about it. This can take a few weeks. If you have heard nothing after a few weeks, contact the doctor who sent you.
Risks and side effects
A Holter monitor is safe and painless. The sticky patches can irritate the skin, and a few people are allergic to the adhesive, so report a skin reaction to the team. The recorder has to stay close to your body, which can make it harder to sleep.
Results and what comes next
A heart specialist reads the recording alongside your diary. A normal result shows your heart rate changing as it should with activity, with no important rhythm changes and no heartbeat that is too fast or too slow. A result that is not normal can show a rhythm problem, and some changes can mean the heart is not getting enough oxygen. You may then need more tests or treatment.
What it cannot show: it only covers the time you wear it, so a problem that happens rarely may be missed. For rare symptoms a recorder worn for longer, or switched on when symptoms occur, may be used, or a small device placed under the skin of the chest. It records rhythm, not pictures. An shows the heart's structure and pumping.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Does a Holter monitor hurt?
No. It is safe and painless. Some of the patches are very sticky and can irritate the skin, so tell the team if your skin is sensitive. Taking the patches off can tug a little.
Can I bathe or sleep with a Holter monitor on?
You cannot bathe or shower while wearing it, so wash beforehand. You can sleep with it on, but it must stay close to your body and must not get wet, and some people find it harder to sleep.
What if my symptoms do not happen while I wear it?
Then the recording may look normal even though a problem exists. Tell your doctor, who may suggest a longer recording with an event recorder, or a small device placed under the skin of the chest (an implantable loop recorder).
How is a Holter monitor different from an ECG?
A resting ECG records your heart for a few minutes in the clinic. A Holter monitor records continuously for a day or two while you go about your life, so it can catch rhythm problems that come and go.
