ECG (EKG, electrocardiogram, or electrocardiograph) is a simple painless test which measures the rhythm and electrical activity of your heart.
During an ECG small sticky pads are placed on your body connected to wires that link up to the ECG machine. The machine reads and records, on paper, the electrical signals from your heart.
An ECG records the rhythm of your heart and can detect abnormal patterns which can help diagnose various heart conditions.
It can help tell if you are having a heart attack or if you have had one in the past. It can also detect irregularities in your heart rhythm. It can sometimes detect if your heart is enlarged or if there is any strain on your heart pumping.
An ECG is often the first heart test you will have, however it is just a snapshot so you may need other tests too.
An ECG is a safe test. It records the electrical activity of your heart but does not produce electricity itself so there is no risk of electrocution.
Small sticky pads called electrodes are placed on your arms, legs and chest. These are connected to wires that link up to the ECG machine. Your heart’s electrical activity is picked up by the electrodes and the machine prints out the pattern. You will need to lie still because movement can affect the recording.
When the test is finished the ECG machine prints a tracing of the recording. Depending on your heart problem you may or may not need any other tests. If the result shows there is a problem, the treatment and further management will depend on what is causing your signs and symptoms.
An ECG on its own may not be enough to diagnose your heart condition but it will show if your heart is beating too fast, too slow or with an abnormal rhythm. Sometimes your ECG can be normal but you may need more tests to definitely rule out a heart problem.
An ECG can also provide clues to how your heart is pumping and if it is enlarged. An ECG done while you are having symptoms can often be more informative.
Heart & Stroke Conditions A-Z – see our range of guides.
Step by Step through Heart Attack – our patient information booklet
Step by Step through Stroke – our patient information booklet
Step by Step through Heart Medicines – our patient information booklet
Step by Step through Inherited Heart Disease – our patient information booklet
Step by Step through Heart Failure – our patient information booklet
Angina – our guide from symptoms to treatment
AF and You – our information booklet for people living with Atrial Fibrillation