Quick answer
What Is Holter Monitoring?
Holter monitoring is continuous recording of the heart rhythm, usually for 24 to 48 hours, with a small recorder connected to electrodes on the chest. Fitting takes about 15 to 20 minutes, then you go about your usual activities and note your symptoms. The results help find the cause of palpitations, dizziness, or fainting that occur almost every day.
Sources01 / Understanding the procedure
About Holter Monitoring
What Is Holter Monitoring
A Holter is a small ECG recorder worn on the body and connected to several electrodes on the chest. Unlike a standard ECG, which only records for a few seconds, a Holter records every heartbeat for 24 to 48 hours while you go about your daily activities, including while you sleep. This way, your doctor can see your heart rhythm at the exact moment symptoms occur. The standard ECG is covered on the Electrocardiogram (ECG) page.
How It Works in Brief
The electrodes pick up the heart's electrical signals and the recorder stores them continuously, about 100,000 beats every day. During the recording, you press a marker button or write in a diary each time you feel palpitations, dizziness, or other symptoms. After the device is returned, a computer analyzes the entire recording, then your doctor reviews the results and matches the time of your symptoms with your heart rhythm at that moment.
What Is Assessed
- Heart rate: the maximum, minimum, and average heart rate, both day and night.
- Rhythm problems: for example atrial fibrillation, tachycardia, long pauses, or heart block.
- Extra beats: the number of extra beats from the upper or lower chambers of the heart in a day.
- Match with symptoms: whether the symptoms you noted occur at the same time as a rhythm problem.
When a Holter Is Chosen
A Holter is suitable if symptoms occur almost every day, so they are likely to be captured within one to two days. A Holter is also used to assess the results of heart rhythm treatment, count extra beats, or monitor the rhythm in certain heart diseases. If symptoms are rare, for example once a month or less often, a recording of 24 to 48 hours is often not enough. Your doctor may choose a recorder that is worn for longer or placed under the skin, which is covered on the Long-Term Heart Rhythm Monitoring and Implantable Loop Recorder (ILR) pages.
After the Results Are Out
Holter results help your doctor decide the next steps: no specific treatment if the rhythm is normal, medicines or ablation if the heartbeat is too fast, a pacemaker if the heartbeat is too slow or has long pauses, and blood thinners if atrial fibrillation is found. A normal rhythm while symptoms occur is also a useful result, because it helps your doctor look for other causes outside rhythm problems. Further treatment is covered on the Arrhythmia Management page.
02 / Understanding the procedure
When Is This Procedure Considered?
A doctor may consider this procedure in the situations below. The decision is always made after a thorough assessment.
- Palpitations Almost Every DayTo see your heart rhythm at the exact moment palpitations occur.
- Frequent Dizziness or Near FaintingMay be caused by a heartbeat that is too slow, long pauses, or a heartbeat that is too fast.
- Counting Extra BeatsFor example extra beats from the lower chambers of the heart, whose number in a day needs to be assessed.
- Assessing Rhythm Treatment ResultsFor example after ablation or a change in medicines to control the heart rate.
- Looking for Atrial FibrillationFor example after a stroke or with an irregular heartbeat that a standard ECG has not yet captured.
- Heart Disease with a Risk of ArrhythmiaFor example hypertrophic cardiomyopathy, to look for dangerous rhythms that you cannot feel.
Situations to Consider First
- Fainting with Injury, Chest Pain, or Shortness of BreathThis is an emergency; go to the emergency room right away instead of waiting for a scheduled Holter test.
- Very Rare SymptomsThe chance of capturing them within 24 to 48 hours is small; a recorder worn for longer is more suitable.
- Adhesive Allergy or Sensitive SkinThe staff can adjust the type or position of the electrodes.
- Planned MRI ScanThe recorder must be removed before an MRI; tell the staff so the schedule can be adjusted.
03 / Before the procedure
How Should You Prepare?
The Holter is fitted at the clinic, then you take it home for the recording period.
Shower before you come. The majority of Holter recorders must not get wet, so you cannot shower during the recording. Avoid lotion, oil, or powder on your chest.
Clothing. Wear a loose top that buttons at the front so the wires and recorder are not pulled.
Medicines. Take your medicines as usual unless your doctor tells you otherwise. Bring a list of your medicines, especially heart rhythm medicines.
Plan your recording days. Choose days with your usual activities, including activities that often trigger your symptoms, and make sure you can come back to have the device removed.
Unsure about the preparation instructions? Ask our team before the procedure.
04 / During the procedure
How Is the Procedure Done?
Fitting a Holter is done in an examination room without anesthesia and takes about 15 to 20 minutes. The recording lasts 24 to 48 hours, sometimes up to 7 days, while you go about your usual activities.
Attaching the Electrodes
The skin of your chest is cleaned and, if needed, some hair is shaved. Several electrodes are attached to the chest, then connected with wires to the recorder, which is clipped to your belt or hung on a strap.
During the Recording
You go about your usual activities, including working, walking, and sleeping. Each time symptoms occur, press the marker button if there is one, then write down the time, activity, and symptoms in your diary.
Removing the Device
When the recording period is over, you return to the clinic to have the device removed and hand in your diary. For some devices, you can remove it yourself following the staff's instructions.
Analysis and Reading
The recording is analyzed by computer, then reviewed and read by your doctor. Results are usually ready within a few days and discussed at your next visit.
05 / Benefits and risks
Benefits and Risks Should Be Discussed Together.
Every medical procedure has benefits and risks. Your doctor will explain both for your situation before the procedure.
Benefits You Can Expect
- Symptoms Matched with Heart RhythmYour doctor sees your heart rhythm at the exact time you feel symptoms.
- Records Day and NightRhythm problems during sleep or activity, which often go unnoticed, are also recorded.
- Done While You Go About Your Day at HomeNo needles and no hospital stay; you go about your daily activities as usual.
- Helps Choose TreatmentThe results form the basis for decisions about medicines, ablation, a pacemaker, or blood thinners.
The benefits of a procedure are not a promise of a cure. Ask how the results will affect your care plan.
Risks You Should Know
- Skin IrritationItching or redness from the electrode adhesive, usually mild and temporary.
- Symptoms That Do Not Occur During the RecordingIf symptoms are rare, a recording of 24 to 48 hours may not capture them.
- Disrupted RecordingElectrodes that come off or excessive movement can make part of the recording hard to read.
- Not an Emergency DeviceA Holter only records and does not call for help; severe symptoms still require a visit to the emergency room.
- Less Comfortable During SleepThe wires and recorder can feel bothersome, especially on the first night.
Risks can differ from person to person. A full explanation and consent are given after an individual assessment.
06 / After the procedure
What Is Recovery Like?
There is no recovery period. You can go about your usual activities during and after the recording.
While wearing the device. Do not shower, swim, or get the recorder wet. Avoid electric blankets and keep the recorder away from strong magnets. You may use your mobile phone, but do not place it directly against the recorder.
If an electrode comes off. Reattach it in the same place if you have been shown how, then note the time.
Skin. Mild itching or redness from the adhesive usually goes away within a few days.
Results and follow-up visit. Come to your next visit to discuss the results. If your symptoms were not captured, your doctor may suggest a longer recording.
Warning signs to watch for. A Holter only records and does not call for help. Go to the emergency room right away if you experience:
- Fainting, especially during activity or with injury
- Chest pain or severe shortness of breath
- A very fast heartbeat with severe dizziness or weakness
Know the Signs That Need Prompt Care.
Follow the team's guidance on warning signs. If severe or sudden symptoms appear after the procedure, go to the nearest emergency department right away or call Heart Attack Center 1500 258.
07 / Team and support
Doctors and Procedure Support
The doctors below are listed for this procedure. Listed by name, not by ranking.
Dr. dr. Dicky A. Hanafy, Sp.JP(K)
Arrhythmia and Electrophysiology
Arrhythmia and Device Center +1 center
Clinical focusElectrophysiology and Arrhythmia Ablation · Pacemaker and ICD Implantation
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Dr. dr. Faris Basalamah, Sp.JP(K)
Interventional Cardiology
Coronary Intervention Procedures +1 center
Clinical focusComplex Coronary Intervention · Cardiac Electrophysiology
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dr. Sunu B. Raharjo, Sp.JP(K), Ph.D.
Arrhythmia and Electrophysiology
Arrhythmia and Device Center
Clinical focusClinical and Interventional Electrophysiology · Cardiac Arrhythmia Ablation
View ProfileHolter Monitoring System
A small ECG recorder that you wear during daily activities to monitor your heart rhythm continuously for 24 to 48 hours or…
The availability of technology and test support is confirmed with the team. Technology is chosen according to clinical need.
08 / Common questions
Before You Plan the Procedure.
Frequently asked questions about Holter monitoring.
Can I shower while wearing a Holter?
Generally not, because the majority of Holter recorders are not waterproof. Shower before the fitting and after the device is removed. If you need to freshen up, you can wipe your body with a damp towel while avoiding the electrodes and recorder. Some wireless patch recorders are splash-resistant; ask about the rules for the device you are using.
Can I work, exercise, and sleep as usual?
Yes, and this is actually encouraged. A Holter aims to record your heart rhythm during a typical day, including activities that often trigger your symptoms. Avoid exercise that makes you sweat heavily or activities in water, because the electrodes can come off. When sleeping, place the recorder beside your body so the wires are not pulled.
Why do I need to record my symptoms?
A symptom diary makes the recording more meaningful. Your doctor matches the time of your symptoms with your heart rhythm at that moment. If symptoms occur at the same time as a rhythm problem, the cause becomes clearer. If the rhythm stays normal during symptoms, a rhythm problem is unlikely to be the cause. Note the time, activity, and what you feel, as well as when you take medicines and sleep.
What if my symptoms do not occur during the recording?
The recording is still useful because your doctor can see your rhythm throughout the day and night, including problems you cannot feel. If your symptoms have not been captured, your doctor may repeat the Holter or choose a recorder that is worn for longer, for example a patch recorder worn for 7 to 14 days, an event recorder, or a recorder placed under the skin, depending on how often your symptoms occur.
What is the difference between a Holter, a standard ECG, and an implanted recorder?
A standard ECG records a few seconds in the examination room. A Holter records continuously for 24 to 48 hours while you go about your activities, suitable if symptoms occur almost every day. An implanted recorder, or implantable loop recorder, is placed under the skin with local anesthesia and can work for about 3 years, suitable if symptoms are rare but serious, such as fainting.
When will my Holter results be ready?
The recording needs to be analyzed by computer, then its important parts are reviewed one by one by your doctor, so results are usually ready within a few days after the device is returned. Your doctor explains the results at your next visit. If you faint, have chest pain, or have severe shortness of breath during the recording, do not wait for the Holter results; go to the emergency room right away.
Sources and Medical Review
Translated from the Indonesian edition medically reviewed by Dr. dr. Dicky A. Hanafy, Sp.JP(K).
Sources as cited in the Indonesian edition.
- Steinberg JS, Varma N, Cygankiewicz I, et al. 2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry. Heart Rhythm. 2017;14(7):e55-e96.
- Brignole M, Moya A, de Lange FJ, et al. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J. 2018;39(21):1883-1948.
- Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2024;45(36):3314-3414.
- Zeppenfeld K, Tfelt-Hansen J, de Riva M, et al. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J. 2022;43(40):3997-4126.
- Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;140(8):e382-e482.
- Barrett PM, Komatireddy R, Haaser S, et al. Comparison of 24-hour Holter Monitoring with 14-day Novel Adhesive Patch Electrocardiographic Monitoring. Am J Med. 2014;127(1):95.e11-95.e17.