What it is
A treadmill test is an recorded while you exercise, which is why it is also called an exercise ECG or a stress test. You walk on a treadmill while the speed and slope slowly increase, and the machine records how your heart, pulse and respond. Some problems show only when the heart is working hard.
Why it is done
A doctor may ask for it to find out whether chest pain, breathlessness, palpitations or dizziness could be caused by narrowed heart arteries, or to look for rhythm changes during exercise. It is also used after a heart attack or a procedure to open the arteries, and to check certain valve problems.
What it helps with
How to prepare
Ask the team for exact instructions, as they differ. Usually:
Do
- Wear comfortable clothes and shoes, ideally trainers
- Ask whether to take your usual medicines on the day. The team will tell you which medicines to take or stop
- Tell the team about every medicine you take, including any tablet for erection problems taken in the last day or two
Do not
- Do not have a heavy meal, tea or coffee, or smoke for some hours before. The team will tell you how long
- Do not put body lotion, oil or talcum powder on your chest
What happens
- You take off your top. Your chest may be shaved and cleaned so the sticky patches (electrodes) hold.
- The patches are wired to an machine, and a cuff goes on your arm.
- You start walking slowly on the treadmill. Every few minutes the speed and slope go up.
- Staff watch your ECG, pulse and blood pressure throughout. Say at once if you feel chest pain, great tiredness, dizziness or severe breathlessness. You will not be asked to do more than you can.
- The test stops when you reach a target heart rate, when your ECG or blood pressure changes, when symptoms start or when you are too tired. You are watched for some minutes afterwards.
If you cannot walk on a treadmill, you may cycle instead, or be given a medicine through a vein that makes the heart work harder. Sometimes a scan such as an is added.
Afterwards
You can go home once your heart rate has settled and your breathing is back to normal. The patches may tug as they come off, and the skin can be slightly sore or have a mild rash. Your doctor receives the result and will discuss it with you, which can take a few days to a few weeks. If you have heard nothing after a few weeks, contact the doctor who sent you.
Risks and side effects
A treadmill test is generally safe. Chest pain or fainting can happen. A heart attack or a dangerous heart rhythm is rare. People at higher risk are usually spotted beforehand and are not given the test, so tell the team about your symptoms and any heart problem.
Results and what comes next
A normal result means you exercised as long as most people your age and sex, with no worrying symptoms or changes in your or .
A result that is not normal may point to blocked heart arteries or a rhythm problem, but it means more tests are needed, not a certain diagnosis. Next steps can include a stress , a nuclear scan or .
What it cannot show: it cannot always give a clear answer on its own, and exercise results can be hard to read in some people, which is why a scan is sometimes added. A rhythm problem that comes and goes may need a longer recording, such as a Holter monitor.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Is a treadmill test safe?
It is generally safe, and it is done in hospital with staff watching you all the time. Chest pain or fainting can happen, but a heart attack or a dangerous heart rhythm is rare. People at higher risk are usually spotted beforehand and are not given the test.
What if I cannot walk on a treadmill?
You may be asked to cycle on an exercise bike instead, or be given a medicine through a vein that makes the heart work harder. Tell the team beforehand if you have trouble walking.
Is a treadmill test the same as an ECG?
It is an ECG recorded while you exercise, so it is also called an exercise ECG. A resting ECG is recorded while you lie still. Doctors use the two for different questions.
How long does it take, and when do I get the result?
Allow anything from about 15 minutes to an hour, including preparation. The exercise itself is often 10 to 15 minutes. The doctor will discuss the result with you, which can take a few days to a few weeks, so ask when you will hear.
