What is an ECG?

An electrocardiogram (ECG) is a test that checks for problems with the electrical activity in your heart by translating the heart's electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.

How does the electrical activity work?

The heart is a muscle pump made up of four chambers. The two upper chambers are called atria, and the two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract and pump blood through the heart to the lungs and the rest of the body.

What is the purpose of an ECG?

An ECG is a simple and valuable test that, can, at times, assist in definitively diagnosing a heart problem. However, a normal ECG does not rule out serious heart disease.

For example, you may have an irregular heart rhythm that 'comes and goes', and the recording can be normal between episodes. Also, not all heart attacks can be detected by an ECG; same goes for angina - a common heart disorder that is not usually detected by a routine ECG.

Conducting specialised ECG recordings can sometimes help to overcome some limitations.

Holter Monitor or Ambulatory EGC

This involves wearing a small monitor which constantly records your heart rhythm. This test records the electrical activity of your heart when you are walking about (ambulatory) and doing your normal activities. It aims to detect abnormal heart rhythms that may 'come and go'. The electrical activity is usually recorded for 12 to 24 hours.