Holter Monitor: What the 24-Hour Heart Rhythm Test Involves
A Holter monitor is a small portable device that records the heart's rhythm for 24 to 48 hours. This article explains why it is used, how to wear it and what to expect.
Scientist and Chief Medical OfficerDr. Ambed Mishra, PharmD, PhDEducational information only, not medical advice. Always ask a qualified doctor about your own health. In an emergency call 112 (India) or 911 (US). Read the full disclaimer.
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Some heart rhythm problems come and go, so a short test in a clinic can miss them. A Holter monitor solves this by recording your heart rhythm while you go about your day. This article explains what MedlinePlus and the NHS say about it.
What is a Holter monitor?
MedlinePlus describes a Holter monitor as a portable device that continuously records the heart's rhythm for 24 to 48 hours during normal activities. The NHS calls a similar test a portable ECG. It says electrodes are taped to your chest and connected to a recorder worn on a waist belt, usually for 24 to 48 hours and up to 7 days.
Why is it used?
MedlinePlus says a Holter monitor may be used:
- To see how the heart responds to everyday activity
- After a heart attack
- To diagnose rhythm problems that cause palpitations or fainting
- When starting a new heart medicine
It can detect rhythm problems such as atrial fibrillation or flutter, fast or slow heart rates, paroxysmal supraventricular tachycardia and ventricular tachycardia.
How it is worn
The monitor is small and light enough to be carried around during the day. Electrodes are attached to the chest and joined by wires to a small, battery-powered recorder. MedlinePlus says the recorder is carried in a pocket or in a pouch worn around the neck or waist. You keep a diary of your activities and symptoms, because these are matched against the recording. If your symptoms have previously happened during exercise, you may be asked to exercise.
Tips while wearing it
According to MedlinePlus:
- Keep the electrodes firmly attached, and you will be told how to replace them if they come loose
- Avoid electric blankets, high-voltage areas, magnets and metal detectors
- Keep the monitor dry
- Shower before the test, because you cannot shower while wearing the monitor
- Tell your provider if you have an allergy to tape or adhesives
The NHS also notes that you cannot bathe or shower while wearing a portable ECG.
What to expect
Many people worry that a monitor will get in the way of daily life. In general, MedlinePlus says you carry on with your normal activities, because the aim is to capture what your heart does in everyday situations. No special preparation is needed, and the test is painless. Some people need their chest shaved for the electrodes. The monitor must stay close to the body, which can make sleeping difficult. The adhesive may occasionally cause an uncomfortable skin reaction, which you should report to the provider's office. Apart from this, MedlinePlus lists no risks.
Results
After the recording period you return the monitor, and your provider checks it for abnormal rhythms. MedlinePlus says a normal result shows no significant changes in rhythm or pattern and a heart rate that is not abnormally fast or slow, remembering that heart rate varies with activity. An abnormal result may show various arrhythmias, and some changes may suggest the heart is not getting enough oxygen. The NHS says results for portable ECGs can take a few weeks and that a follow-up appointment may be needed. If you have heard nothing after a few weeks, contact the doctor who referred you.
When to see a doctor
See a doctor if you have palpitations, dizziness or fainting, so they can decide whether a Holter monitor or other test is needed. Tell your doctor if you keep a symptom diary and bring it to your appointment.
Call emergency services at once for fainting with chest pain, severe breathlessness, or palpitations that do not go away, or palpitations with chest pain or breathlessness. Do not drive yourself to hospital.
In an emergency, call your local emergency number (112 in India, 911 in the United States).
Common questions
How long do I wear a Holter monitor?
MedlinePlus says it records for 24 to 48 hours. The NHS says a portable ECG is usually worn for 24 to 48 hours and up to 7 days.
Can I shower with a Holter monitor?
No. MedlinePlus says to shower before the test and keep the monitor dry, and the NHS says you cannot bathe or shower while wearing it.
Why do I need to keep a diary?
MedlinePlus says you record your activities and symptoms so they can be matched against the recording.
Is a Holter test painful?
MedlinePlus says it is painless, though the adhesive may occasionally cause a skin reaction and some people need their chest shaved.
Important: please read
- Educational information only. This article is general health education. It is not medical advice, diagnosis or treatment. Reading it does not create a doctor–patient relationship with MyDoctor or with anyone else.
- Ask a qualified doctor. Always talk to a qualified, registered doctor about your own health. In India, that means a doctor registered with the National Medical Commission (NMC) or a State Medical Council. In the United States, a licensed physician. Elsewhere, a doctor licensed where you live.
- Never ignore or delay professional advice because of something you read here. Do not start, stop or change any medicine or treatment without your doctor.
- Emergencies: call 112 in India, 911 in the United States, or your local emergency number. Do not wait for an online answer.
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- About the sources. This article summarises, in our own words, information from the public health bodies named under Sources. Health knowledge changes, and this summary may not reflect the latest research or your personal situation.
- Liability. To the extent permitted by law, MyDoctor (MODERNUS HEALTH TECHNOLOGIES PRIVATE LIMITED) accepts no liability for any decision made on the basis of this content.
Sources
- NIH MedlinePlus. Holter monitor (24 h) - MedlinePlus medlineplus.gov
- NHS. Electrocardiogram (ECG) - NHS www.nhs.uk
Dr. Ambed Mishra, PharmD, PhD
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Dr. Ambed Mishra is a clinical (patient care) scientist, author and former professor. He is Group CEO and Chief Medical Officer of MODERN US HEALTH (MODERN US GROUP), Austin, Texas, the group behind MyDoctor, and a senior consultant who teaches and trains MD/DO physicians, PharmD and PhD professionals, nurses and other healthcare professionals in patient care in the United States and India.
More about Dr. Ambed Mishra
- More than ten years of full-time leadership in United States healthcare, building patient care services that improve medication adherence and bring doctors, pharmacists and nurses together around each patient.
- Leads the MD and engineering teams behind MyDoctor: clinic and hospital management software, electronic health records and telehealth for hospitals and physician groups in the United States and India.
- Former Assistant Professor and Clinical Preceptor at Rajiv Gandhi University of Health Sciences, Bangalore, and senior researcher with hospitals, universities and patient care groups in India and the United States.
- More than 30 published research and review articles and case reports, and more than 15 international conference presentations in India, Australia, Canada, the United States, Spain and other countries.
- Chief Medical Officer and Global Program Head of a nonprofit mission that helps cover hospital and doctor visit bills for patients in need in India, Nepal, the United States and other countries.
The author's office answers questions about articles, research, speaking and collaboration. It cannot give personal medical advice.