Cardiopulmonary exercise test (CPET)
1 Introduction
CPET = CPX (cardiopulmonary exercise test) we are going to see what the body’s response to
exercise is.
measurement of:
VO2: oxygen uptake
VCO2: output CO2
VE: ventilation
Derived parameters
The directly measured parameters are measured with the mask: it measures the O 2 and CO2
concentration.
1.1 Fick equation
IMPORTANT
VO2 = Q * (a-v)O2
Q = cardiac output = HR * SV = HR * EDV-ESV = amount of litres that leaves the left ventricle every
minute.
(a-v)O2 = the artery-venous difference in oxygen.
Normal situation: O2 % in blood is 90% and around 11-12% goes back to the heart (right part)
Only a fraction of what goes inside, also goes outside (there will always stay blood in the heart =
afterload). This depends on the amount of stretch of the ventricle and the amount of force the
ventricle needs to overcome the blood pressure in the peripheral system (the aorta). The normal
afterload can be increased when there is for example a higher blood pressure.
A lot of heart patients take beta blockers they have a higher HR when you stop taking these meds
higher VO2 max and it can have an effect on the cells as well.
In heart patients, there are often other problems as well: compensations in the muscles (atrophia) or
lung problems. A normal breathing frequency is 12-16x/min but in this test, we speak about a normal
breathing freq. when it is <20x/min
1
, 1.2 When to perform a CPET?
Evaluati on of exercise capacity (for training in pati ents as well as sports men)
Functional capacity
Indication of the limiting systems
Contribution of cardiac, muscular and pulmonary etiology
Evaluati on of cardiovascular disease
Functional evaluation and prognosis in Chronic Heart Failure (CHF)
Selection of heart transplantation
Monitoring in case of cardiac rehabilitation
Evaluati on of respiratory disease
COPD and exercise related asthma
Interstitial pulmonary disease
Pulmonary vascular disorder
Cystic fibrosis
Monitoring in case of pulmonary rehabilitation
Specifi c clinical implicati ons
Preoperative evaluation
Evaluation in case of limitation or handicap
e.g. patients with morbid obesity who will undergo surgery
There are different systems that can limit the exercise: cardiovascular system, pulmonary system
and muscles. This test gives you insight in cardiovascular and pulmonary problems.
In some patients, the whole body adapts to the chronic heart failure.
1.3 Contra-indication to CPET
Before you do a CPET, you need to do an anamnesis and look at the medical file. Other tests will be
performed in advance as well (such as the lung function test). Sometimes, the test is stopped sooner
than expected, e.g. because of a rhythm disorder
“absolute” contra-indications:
Unstable angor, unstable after using medication
Acute myocardial infarct 3-5 days
Fever
Uncontrolled arrhythmia
Symptomatic severe aorta stenosis
Uncontrolled symptomatic heart failure (in case of decompensation)
Acute lung emboli
Acute endocarditis, myocarditis or pericarditis (inflammation of the heart, without proper
medication use)
Uncontrolled asthma and lung oedema
2
1 Introduction
CPET = CPX (cardiopulmonary exercise test) we are going to see what the body’s response to
exercise is.
measurement of:
VO2: oxygen uptake
VCO2: output CO2
VE: ventilation
Derived parameters
The directly measured parameters are measured with the mask: it measures the O 2 and CO2
concentration.
1.1 Fick equation
IMPORTANT
VO2 = Q * (a-v)O2
Q = cardiac output = HR * SV = HR * EDV-ESV = amount of litres that leaves the left ventricle every
minute.
(a-v)O2 = the artery-venous difference in oxygen.
Normal situation: O2 % in blood is 90% and around 11-12% goes back to the heart (right part)
Only a fraction of what goes inside, also goes outside (there will always stay blood in the heart =
afterload). This depends on the amount of stretch of the ventricle and the amount of force the
ventricle needs to overcome the blood pressure in the peripheral system (the aorta). The normal
afterload can be increased when there is for example a higher blood pressure.
A lot of heart patients take beta blockers they have a higher HR when you stop taking these meds
higher VO2 max and it can have an effect on the cells as well.
In heart patients, there are often other problems as well: compensations in the muscles (atrophia) or
lung problems. A normal breathing frequency is 12-16x/min but in this test, we speak about a normal
breathing freq. when it is <20x/min
1
, 1.2 When to perform a CPET?
Evaluati on of exercise capacity (for training in pati ents as well as sports men)
Functional capacity
Indication of the limiting systems
Contribution of cardiac, muscular and pulmonary etiology
Evaluati on of cardiovascular disease
Functional evaluation and prognosis in Chronic Heart Failure (CHF)
Selection of heart transplantation
Monitoring in case of cardiac rehabilitation
Evaluati on of respiratory disease
COPD and exercise related asthma
Interstitial pulmonary disease
Pulmonary vascular disorder
Cystic fibrosis
Monitoring in case of pulmonary rehabilitation
Specifi c clinical implicati ons
Preoperative evaluation
Evaluation in case of limitation or handicap
e.g. patients with morbid obesity who will undergo surgery
There are different systems that can limit the exercise: cardiovascular system, pulmonary system
and muscles. This test gives you insight in cardiovascular and pulmonary problems.
In some patients, the whole body adapts to the chronic heart failure.
1.3 Contra-indication to CPET
Before you do a CPET, you need to do an anamnesis and look at the medical file. Other tests will be
performed in advance as well (such as the lung function test). Sometimes, the test is stopped sooner
than expected, e.g. because of a rhythm disorder
“absolute” contra-indications:
Unstable angor, unstable after using medication
Acute myocardial infarct 3-5 days
Fever
Uncontrolled arrhythmia
Symptomatic severe aorta stenosis
Uncontrolled symptomatic heart failure (in case of decompensation)
Acute lung emboli
Acute endocarditis, myocarditis or pericarditis (inflammation of the heart, without proper
medication use)
Uncontrolled asthma and lung oedema
2
