What is the Holter?

Reading time: 3 min

The Holter study is a non-invasive scan that allows the frequency and type of heart rhythm to be studied. Unlike the electrocardiogram, which allows you to see the behavior of the heart at a given moment, the Holter does it throughout a full day.

This test usually records the heart's activity over a 24-hour period (in some cases longer Holter recordings are made, depending on the diagnostic needs). To do this, electrodes are placed on the chest and connected by cables to a recording device similar in size to a cigarette packet. This Holter monitor allows us to see how the heart rate behaves (number of beats per minute) throughout the day and night. And it also allows us to watch the heart’s rhythm over the test period. In this way, it is possible to see whether it has a normal rhythm (sinus rhythm) or if there is some kind of abnormal rhythm (arrhythmia).  

The advantage of this method over a conventional electrocardiogram (which is also capable of measuring frequency and rhythm) is that while the electrocardiogram shows the activity of the heart at a specific time, the Holter monitor allows us to see how the heart behaves over the course of a full day, so that we can assess how it works as we go about our daily lives.  

Once the device has been removed, the registered information is sent to a computer where, through a specific programme, the data is analysed and a report of the result is made, which can take up to 15 days. 

How is it done?

To take this test you must go to the hospital on two consecutive days. On the first day the recording device is put in place, and on the second day it is removed.  

To apply the electrodes, the patient must be undressed from the waist up. The electrodes are placed on the chest and have an adhesive that holds them in position during the course of the test. To ensure the electrodes remain in a stable position, a mesh is often placed over them. They are then connected to the recording unit and the patient can get dressed again. During the 24-hour test period, the person should lead a normal life. If, during the course of the test, they notice any strange sensations (like palpitations), they should make a note of these so that they can let the doctor know on the day they go to collect the test results. During the course of the test, the only daily activity that the person cannot do is shower. They may wash, but must not get the electrode area or Holter unit wet. The next day, the patient has to go to the hospital to have the device removed. 

What complications could there be?

Complications are extremely rare; skin disturbances may occur only in people who are allergic to the adhesive on the electrodes.

How do you prepare yourself?

You do not need to take any special measures before the test. The only recommendation is to wear clothing that is easy to remove and not too tight, so it does not press on the electrodes once they are in place. 

Substantiated information by:

Laura Sanchís Ruiz

Published: 9 February 2021
Updated: 9 February 2021


Receive the latest updates related to this content.

Thank you for subscribing!

If this is the first time you subscribe you will receive a confirmation email, check your inbox

An error occurred and we were unable to send your data, please try again later.