An electrocardiogram (ECG) is a simple test. It is used to check your heart’s rhythm and electrical activity.

Sensors attached to the skin detect the electrical signals produced by your heart each time it beats.

These signals are recorded by a machine and are looked at by a doctor to see if they’re unusual.

When an ECG is used

An ECG is often used to help diagnose and check conditions affecting the heart.

It can be used to investigate symptoms of a possible heart problem. These could be chest pains, palpitations, dizziness and shortness of breath. Palpitations are suddenly noticeable heartbeats.

An ECG can help detect:

• arrhythmias – where the heart beats too slowly, too quickly, or irregularly
• coronary heart disease – where the heart’s blood supply is blocked or interrupted by a build-up of fatty substances
• heart attacks – where the supply of blood to the heart is suddenly blocked
• cardiomyopathy – where the heart walls become thickened or enlarged

A series of ECGs can also be taken to check a person already diagnosed with a heart condition. It’s also used to check on someone taking medication that is known to affect the heart.