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An electrocardiogram (ECG) is a test which measures the electrical activity of your heart to show whether or not it is working normally.
An ECG records the heart’s rhythm and activity on a moving strip of paper or a line on a screen. Your doctor can read and interpret the peaks and dips on paper or screen to see if there is any abnormal or unusual activity.
What can an ECG (electrocardiogram) show?
An electrocardiogram can be a useful way to find out whether your high blood pressure has caused any damage to your heart or blood vessels. Because of this, you may be asked to have an ECG when you are first diagnosed with high blood pressure.
Some of the things an ECG reading can detect are:
- cholesterol clogging up your heart’s blood supply
- a heart attack in the past
- enlargement of one side of the heart
- abnormal heart rhythms
How is an ECG carried out?
An ECG (electrocardiogram) is a safe and painless test which normally only takes a few minutes.
Leads from an electrocardiograph machine are attached to the skin on your arms, legs and chest using sticky patches. These leads read signals from your heart and send this information to the electrocardiograph. The machine then prints the reading on a paper strip or on a screen.
There are three main types of ECG:
- Resting ECG – if your doctor is interests in how your heart is working while you are at rest, you will be asked to lie down and relax while the heartbeat is being recorded.
- Exercise ECG – your doctor may be interested in how your heart reacts to activity and you will be asked to walk or run on a treadmill or cycle on an exercise bike while your heartbeat is recorded.
- 24-hour ECG – sometimes it can be helpful to monitor your heartbeat throughout the day, in which case you will be asked to wear a small electrocardiograph machine. The recordings from the machine are then read by your doctor when you return the machine.
Who will carry out my electrocardiogram?
You may be able to have your ECG in your GP surgery. However not all surgeries have this equipment so you may be referred to a local hospital to carry out the test.
Is there anything I need to do before an ECG (electrocardiogram)?
If you are having a resting ECG, there is no need to do anything different before having the test.
If you are having an exercise ECG, make sure that you are wearing comfortable clothes and shoes that you can exercise in. It is also helpful to avoid eating a meal or drinking a caffeinated drink for two hours before the test because these can affect your heart’s rhythm.