To find out how well your heart is working, you may need to have an electrocardiogram (ECG). An ECG is a simple and painless test that measures the electrical activity of your heart. Before an ECG, you may have your hair shaved or skin cleaned so the electrodes stick on your body properly. During an ECG, leads are attached to electrodes - sticky dots - that are placed on your arms, legs and chest.
The leads connect to a machine, which takes the reading. The results of your ECG will be interpreted by a trained doctor or nurse.