ECG (Electrocardiogram)

An electrocardiogram, or ECG, is a simple test that records the electrical signals in your heart each time it beats. Small sensors called electrodes are attached to the skin and detect these signals, which are traced as a pattern of lines. The test is quick and completely painless, and it gives doctors valuable information about how your heart is working.

An ECG is used to check the rhythm and electrical activity of the heart. It can help find the cause of symptoms such as chest pain, palpitations, dizziness, or breathlessness, and detects cardiac arrhythmias, acute myocardial infarction (heart attack), ischemic heart disease, and structural heart changes. It is also used in routine check-ups, before surgery, and to monitor the effects of heart medicines.

A standard ECG needs very little preparation. You can usually eat and drink as normal and take your medicines unless told otherwise. It helps to wear clothing that is easy to remove from the upper body, since electrodes are placed on the chest. Let staff know about any medicines you take, as some can affect the heart's electrical activity.

You lie down while several small, sticky electrodes are attached to your chest, arms, and legs and connected to a recording machine. You need to stay still and relaxed for a short time while the machine records your heart's activity, which takes only a few minutes. The test does not send any electricity into your body, so it is entirely safe and painless.

The electrodes are removed and you can return to normal activities immediately. The ECG trace is reviewed by a doctor, who looks at your heart's rhythm and the pattern of electrical signals. The results can show whether your heart rhythm is normal, reveal signs of strain or damage, or point to a specific condition. Your doctor will explain the findings and whether any further tests are needed.