Holter monitoring factsheet


A Holter monitor is a 24-48 hour continuous recording of the heart's electrical activity, more commonly shown on a simple electrocardiogram (ECG).  It is a portable recording device that provides important information about the heart and its rhythm throughout the day. 

This test is painless and is taken during normal daily activity. It helps determine heart rhythm disturbance (arrhythmia), which would not necessarily be detected by a standard ECG. It can be used for infants, children or adults.

The Holter monitor is fitted with a belt that you wear around your waist. It is battery-powered and has five wires called leads. The leads are attached to electrodes (stickers), which are worn on your chest. 

Electrical impulses from every heart beat are transmitted to an amplifier which records and saves them for review and analysis on a scanner and computer.

Reasons your physician may request a Holter monitor:

  • evaluate chest pain not reproduced with exercise testing
  • evaluate other signs and symptoms that may be heart-related, such as fatigue, dizziness, or fainting
  • identify irregular heartbeats or palpitations
  • assess risk for future heart-related events in conditions such as cardiomyopathy or Wolff-Parkinson-White syndrome
  • assess the function of an implanted pacemaker
  • determine the effectiveness of therapy for complex arrhythmias
  • help exclude a cardiac cause for your symptoms.

 Before the procedure

The Holter Monitor records for 24 hours or 48 hours. Your physician will determine the best option for you.

Your physician/technician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the test.

Remember to keep a diary of your activities during the recording period. Your physician/technician will give the diary to you.

Risks associated with the Holter Monitor are rare. Prolonged application of the adhesive  electrode patches may cause skin irritation or tissue breakdown at the application site.

 During the procedure

Putting the Holter monitor on

  1. Your physician/technician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the test.
  2. Electrodes will be attached to your chest and the Holter monitor will be attached to the electrodes with the five leads. The monitor may be clipped onto a belt and worn around your waist.
  3. Once you have been hooked up to the monitor and given instructions, you can return to your usual activities, unless your physician instructs you differently. This will allow your physician to identify problems that may only occur with certain activities.
  4. You will be instructed to keep a diary of your activities during the recording period. You should write down the date and time of your activities, particularly if any symptoms, such as dizziness, palpitations, chest pain, or other previous symptoms occur.

Taking the Holter monitor off

Simply remove and discard the five adhesive electrode patches off your chest. You must return the entire device, along with the diary to the cardiac department.

 After the procedure

Three channels of recorded electrocardiograms (ECG) are analysed by sophisticated arrhythmia detection software to find and label abnormalities. 

The ECG is run through a computer, which analyses the rate and rhythm of the heart, looks for changes in the heart's electrical activity, and produces a record of every heartbeat during the 24 or 48 hours. 

Symptoms recorded in the diary can then be correlated with changes in the ECG.

Results of the test and report will be forwarded to your referring doctor.


Please take care of the monitor

  • Do not swim or shower with the monitor
  • Do not drop the monitor
Last updated Wednesday 10th July 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024

This factsheet was produced with support from John Hunter Children's Hospital.