An ECG is a test that is used at Great Ormond Street Hospital (GOSH) to measure the electrical activity of the heart to check how well it is working. 

It records this activity and prints it onto paper. From the information on the paper the doctor will be able to tell if there are any problems with your heart’s rhythm which could be a sign of a heart problem.

What happens

Usually an ECG is taken whilst you are resting, though sometimes you may have to have it while on an exercise bike or treadmill. You are allowed to eat and drink before this test as it will not affect the results.

You will be asked to take your top off (girls can keep their bras on) and the technician will place 12 sticky discs onto the chest area. Next they will connect these discs to some wires which lead back to the machine which will record your heart’s activity. Once the test is done, the sticky discs are all taken off.

The test doesn't take long, once all the discs and wires are in place the recording only takes about a minute.

The doctors may want to monitor your heart rate over 24 hours to check the difference in your heart rate between night and day. Then the ECG leads will be connected to a little cassette recorder which can be kept in your pocket. All the discs and the wires will be taken off the next day.

Does it hurt?

No, it’s completely painless.


The paper will be shown to a specialist to check. He will then write a report to your doctor. This might take a few days.

Compiled by:
Great Ormond Street Hospital
Last review date:
February 2012