ETT - exercise tolerance test

Basic cardiovascular stress test for assessment of exercise tolerance and diagnosis of coronary artery disease


Stress testing

A resting ECG is a useful tool but even normal findings cannot exclude the possibility of significant ischaemic heart disease. If angina is suspected, a more suitable test is an exercise tolerance test (exercise ECG or treadmill test); a recording of your heartbeat while your heart is working harder than normal. It is similar to an ECG except that you are walking on a treadmill while the recording is taken. To start with, the treadmill will move relatively slowly, and as you become used to the pace, the workload will be gradually increased. You will be under close supervision and your heart rate, blood pressure and ECG will be carefully monitored. You will be asked to report any chest discomfort.

Indications

  • Diagnosis of coronary artery disease, particularly in patients with cardiovascular risk factors, such as smoking, family history of coronary artery disease, hypertension, diabetes and high cholesterol.
  • Assessment of fitness / exercise tolerance in certain conditions and occupations, e.g. DVLA criteria for drivers, the police force and some cardiomyopathies.
  • Diagnosis and assessment of arrhythmias provoked by exercise.

Risks and complications

The treadmill test can be associated with some degree of discomfort, including palpitations, chest pain, shortness of breath, headache or nausea. The risk of serious complications, such as significant arrhythmias or heart attack, is extremely small. Dr Ruzicka and the technicians are very experienced with this procedure and all the necessary resuscitation equipment to deal with any emergency is available.

Before the procedure

It is important not to eat heavily before the test. You should also avoid strenuous exercise for several hours prior to the test and refrain from smoking for 24 hours. Please stop any of the medication listed below for 48 hours before the test: beta-blockers, e.g. Atenolol, Bisoprolol, Carvedilol, Labetalol, Metoprolol, Nebivolol, Propranolol, Timolol, calcium channel blockers, e.g. Diltiazem, Verapamil and Ivabradine. Some of these drugs may be known by different brand names. If in doubt, check with your pharmacist or GP. Please bring also the list of medication.

The test will be supervised by Dr Ruzicka and performed by a cardiac physiologist. Just before the procedure, Dr Ruzicka will again explain the test to you and answer all your questions. The physiologist will ask you to remove your clothing above the waist. Electrodes will be put on your chest, your blood pressure will be taken and women will be offered a gown. Since we need direct access to the chest women are advised to wear trousers or a skirt rather than a dress and it is important that you bring sensible shoes that you can walk in safely.

During the procedure

You will be asked to step on the treadmill and to start walking at a slow pace up a gentle incline. The speed and slope will increase slightly every three minutes and your blood pressure will be taken regularly. You should keep the physiologist informed of how you are feeling, if you are experiencing any pain or if you are starting to feel short of breath or just getting tired. If you feel you cannot continue, the test will be stopped but it is important that you do as much exercise as you possibly can in order for the results to be meaningful. Once the exercise section of the test has finished, you will be be able to lie down and your heart will be monitored with an ECG and a blood pressure machine until it returns to its resting rate. The whole test takes approximately 30 minutes.

Dr Ruzicka will review and analyse your exercise test to see if the ECG tracings show any arrhythmias or signs of ischaemic heart disease. The effect of exercise on the blood pressure will also be assessed.

After the procedure

Dr Ruzicka will explain the results to you and arrange further tests, treatment and follow-up as appropriate. A letter with relevant information will be sent to your GP.

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