Your child is having a 24 hour electrocardiogram

Electrocardiograms (ECG) 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. Sometimes, an ECG needed over a longer period of time, for instance for a day and a night or longer. This page from Great Ormond Street Hospital (GOSH) explains about 24 hour electrocardiograms (ECG), what is involved and what to expect when your child is fitted with the monitor.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 do not apply any lotion or ointment to your child’s chest the night before the scan as this can make it more difficult for the sensor pads to stick in place.

What does 24 hour ECG monitoring involve?

They 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 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.

Once the monitor has been fitted and we have explained about the test, you and your child will be able to go home.

We will ask you to keep a brief diary of your child’s activity and any symptoms while they are wearing the monitor. This lets the doctors to match what your child was doing with their heart activity at the time.

Are there any risks?

There are no risks associated with ECG monitoring.

Some children develop a red rash where the sensors were stuck to the skin. This is harmless and will disappear over the next day or two.

Wearing the monitor means that your child will not be able to have a bath or shower or go swimming while they are wearing the monitor, but all other activities should be possible.

Microwave ovens can affect the recording machine, so your child should avoid close contact with them while they are wearing the monitor.

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.

Compiled by:
Walrus Ward in collaboration with the Child and Family Information Group
Last review date:
May 2019