An electrocardiogram or ECG, records the electrical activity of your heart. Small sticky patches called ‘electrodes’ are put on your arms, legs and chest. These are connected, by wires, to an ECG recording machine. The recording machine picks up the electrical signals that make the heart pump blood. It records a few beats from each set of electrodes onto paper.
The ECG machine only records the signals from your heart. It does not give electric shocks and does not damage your heart. The whole test takes about five minutes and is not painful or uncomfortable.