An electrocardiogram (ECG) is used to detect abnormal heart rhythms and to investigate the cause of chest pait.

An ECG records the electrical activity of the heart. The heart produces tiny electrical impulses which spread through the heart muscles to make the heart contract. These impulses can be detected by the ECG machine. Any ECG may help you discover the cause of symptoms such as abnormal palpitation or chest pain. Sometimes, it is done as part of a routine test, for example, before an operation. The ECG test is painless and harmless. The ECG machine records electrical impulses coming from your body and does not put any electricity into your body.



Small metal electrodes are attached to your arms, legs and chest. Wires from the electrodes are connected to the ECG machine. The machine detects and amplifies the electrical impulses that occur at each heartbeat and records them on to a piece of paper or computer. A few heartbeats are recorded from different sets of electrodes. The test is only five minutes long.