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Oxford University Hospitals NHS Foundation Trust
Cardiothoracic Services

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Exercise tolerance testing (ETT)

An exercise tolerance test assesses the heart under stress.

There are two ways to perform this test; via a treadmill, or a bike (ergometer).

Both methods make the heart work under an increasing workload, to see if there are any changes in heart rate, heart rhythm or blood pressure, and if any symptoms manifest.

The treadmill starts at a walking pace on a slight incline and gets steeper and faster every three minutes, until either the patient or the supervising member of staff ends the test. The test is unlikely to progress to a running speed, but on occasion this is needed to stress the heart to an appropriate level.

On the bike the resistance of the pedals increases at a timed interval, until the patient cannot pedal any longer.

During the test the patient is closely monitored by two members of staff (usually a Cardiac Physiologist and a Healthcare Scientist Assistant) and has an ECG (electrocardiogram) and blood pressure cuff attached to monitor the heart in detail.

During the test the members of staff will monitor your ECG and Blood pressure closely to ensure patient safety and to make sure that the test has been completed to an appropriate level.

After the test patients are monitored for several minutes until fully recovered.

It is best to wear comfortable shoes and clothing for this test so you can exercise to your full capacity.

Cardio-pulmonary exercise testing (CPET)

A CPET is a test that uses exercise to monitor a patients' overall cardiac and respiratory health. The test is performed whilst on a bike (ergometer) that increases in resistance constantly throughout the test. There is no fixed protocol for this test and each patient will have a customized protocol created for them based on their exercise capacity.

Before starting the test you will have your height and weight recorded, ECG wires, a blood pressure cuff and a oxygen saturation finger probe attached to you and you will perform a basic lung function test called spirometry.

Once these preliminary test have been completed you will then go on the bike where you will have mask attached to your face to record the gases you breath in and breath out. You will then be asked to sit still on the bike for 2 minutes, followed by pedaling against minimal resistance for a further 2 minutes and after this a resistance will be applied to the pedals continually and gradually from that point onwards until you cannot pedal any further.

During the test the members of staff will monitor your ECG, blood pressure, oxygen saturations and oxygen and carbon dioxide consumption and production closely, to ensure patient safety and to make sure that the test has been completed to an appropriate level.

Once the test is complete, you will be monitored for several minutes until you are fully recovered.

It is advised to wear comfortable shoes and wear comfortable clothing for this test as we want to enable you to exercise to your full capacity.