The electrocardiogram (ECG)

An electrocardiogram, or ECG, records the rhythm and electrical activity of your heart. Some people have an ECG before having an operation. Others have one as part of a routine health check-up, even if there is no suspicion of heart disease. Motor racing drivers, scuba drivers, marathon runners, sport person should have screening cardiac tests routinely.

What happens?

Several small patches, set in sticky plaster, are put on your arms, legs and chest and connected to a recording machine. The patches, called 'electrodes', are connected to wires which lead to the ECG recorder. This recorder picks up the electrical signals produced by each heartbeat. The machine records a few beats from each set of electrodes onto paper.

The ECG machine only records signals from your body. The whole test takes about five minutes and will not be uncomfortable at all.

What can the test show?

An electrocardiogram can detect problems with your heart rhythm. It can show if you have had a heart attack, either recently or some time ago. It can also tell if your heart has become enlarged or is working under strain.
The ECG is a simple and useful test but it has some limitations. An abnormal reading does not always mean that there is something wrong. On the other hand, some patients who have serious heart disease may have a normal ECG.