Cardiopulmonary Exercise Testing (CPX, CPET, CPEX)
What is Cardiopulmonary testing?
Cardiopulmonary exercise testing, often abbreviated as CPX, CPEX or CPET, is now the ‘gold standard’ objective tool for the evaluation of cardiopulmonary function and fitness. It is an entirely non-invasive and objective method of assessing integrative exercise responsesinvolving the pulmonary, cardiovascular and skeletal musclesystems, which are not adequately reflected through the measurementof individual organ system function. Hence, CPX evaluates the way in which your heart, lungs and circulation simultaneously respond to exercise.
Why is it done?
Diseases that affect the heart, lungs, circulation or blood may cause an abnormal response to exercise. CPX is used to simultaneously measure many parameters that can then be used to help with a diagnosis or to reassure you as to the cause of your symptoms.
If you are awaiting surgery, CPX may be used to assess your risk of complications and identify any special precautions that may need to be taken to reduce the risk.
Why not perform a simple treadmill testing rather than CPX testing?
Cardiopulmonary exercise testing adds important additional information to that provided by the standard exercise test. Due to the ability of a CPX to objectively assess breath by breath gas analysis (via a facemask or a fitted mouthpiece a multitude of objective exercise indicators can be collected that simply cannot be ascertained using a normal treadmill or alternative forms of exercise testing.
Why Refer to AZ Heart RHYTHM CENTER for CPX Testing?
At the Arizona Heart Rhythm Center we use the market leading Ultima CardiO2™ CPX system which uses an all digital data acquisition to MedGraphics’ patented breath by breath gas exchange system (see Figure below). ECG data is displayed on the right hand screen with gas analysis data simultaneously displayed on the left hand screen. This service is not available in most hospitals and is the only Cardiac led service in the South West. Additionally, we have a top grade exercise treadmill to provide a full range of exercise stress options.
How is the test performed?
The test will be performed by trained technologist and/or a doctor, who will explain the test and answer any questions. They will ask you to remove items of clothing above the waist, and sticky electrodes will be applied to your chest to monitor your heart rate and rhythm. Your height and weight will be recorded and a few baseline questions will be asked to assess your background history. You will then undergo baseline spirometry which is a baseline non invasive breathing test to assess your resting lung function. Following this your breathing will then subsequently be assessed through a tube attached to the CPX machine. The tube is held in place by a mouthpiece, which you hold between your teeth, or a face mask, which is held against your face by some straps.
Once you are ready, you will be assisted onto the exercise machine. Your resting breathing will then be assessed. You will then be required to exercise whilst breathing through the facemask / mouthpiece whilst still breathing in room air. The exercise will begin very easy, and become progressively harder. You will be encouraged to continue for as long as you can. The test will probably last for fifteen minutes with the exercise component lasting for 7-12 minutes depending on your level of fitness.
When you indicate that you want to stop, the exercise will rapidly become very easy again so that you can ease down. Measurements will continue to be taken until they have returned to normal. On occasions, it may be necessary to stop the test earlier than you feel you need, if all the important information has been acquired. Equally, if you feel unwell or there are changes on your heart tracings the physiologist/doctor may decide to stop the test.
Should I stop any Medications for the Test?
You should continue to take all of your prescribed medications unless otherwise specifically notified. You should bring your medications list with you
Are there any special precautions I should take before the test?
- Do not eat or drink (water is acceptable) for two hours prior to your appointment. Avoid caffeine for 4 hours prior.
- Wear comfortable, loose fitting clothes and flat, suitable walking shoes.
- If you have any doubts or worries, please discuss them with the physiologist or doctor. They are there to help you.
How do I pay for my test?
All of the major insurance companies recognise CPX testing as a valid method to assess Cardio-pulmonary fitness. However, it is advised that you check with your insurance company prior to your appointment. We are also happy to facilitate those patients who wish to self pay or are self referred.
When is CPX useful
Here are just a few recognised examples
Evaluation of exercise tolerance.
Evaluation of undiagnosed exercise intolerance.
Evaluation of patients with cardiovascular disease.
Evaluation of patients with respiratory disease/symptoms.
Exercise evaluation and prescription for cardio pulmonary rehabilitation.
Evaluation of impairment/disability.
Evaluation of lung, heart and heart–lung transplantation.
Healthy subjects wishing to assess their fitness prior to training, in order to help meet personal fitness goals and or weight loss targets.
Athletes at all levels needing expert guidance to titrate training programs.