24-hour ECG monitoring

This page explains about 24-hour ECG monitoring, and what to expect when your child comes to Great Ormond Street Hospital (GOSH) to have this procedure.24-hour ECG monitoring is a type of electrocardiogram (ECG) that records your child’s heart activity over a period of time, usually 24 hours. ECGs are one of frequently used scans for diagnosing heart problems. An ECG measures electrical activity within the heart through sticky sensor pads put on your child’s chest.

An ECG is usually carried out in hospital for a short period of time, whereas 24-hour monitoring is carried out using a portable ECG recorder over a longer time.

What happens before the 24-hour ECG monitoring starts?

Your child does not need to prepare for the scan. As the scan is of your child’s chest area, it would be helpful if they could wear loose clothes they can take off easily. Please arrive at the Echo department at the time stated in your child’s appointment letter.

What does 24-hour ECG monitoring involve?

Your child will need to take off their top clothes and lie on a bed next to the ECG machine. The technician will apply some sticky sensor pads on your child’s chest, which they will then connect with wires to the portable ECG machine. Your child’s heart activity will be recorded through the sensors onto the machine for the entire period that they are wearing the sensors. The monitor is about the size of a mobile phone and is carried in a small bag around your child’s waist.

You will usually be asked to keep a brief diary of your child’s activity and any symptoms while they are wearing the monitor. This enables the doctors to match what your child was doing with their activity at the time. 

Microwave ovens can affect the recording machine, so your child should avoid close contact with them for the duration of the test.

What happens afterwards?

When the time period is up, usually 24 hours later, you should remove the sensor pads from your child’s chest and place the recorder in the postage paid envelope provided. If you are coming back to GOSH for an appointment, you may also be asked to bring this recorder with you. The technician will download the results into a computer and show the results to the doctor.

Are there any risks?

There are no risks associated with ECG monitoring. Wearing the monitor means that your child will not be able to bathe or shower or go swimming for the duration of the test, but all other activities should be possible.

Compiled by:
Walrus Investigation Suite in collaboration with the Child and Family Information Group
Last review date:
January 2015