Dr .Samiaa Hamdy Sadek

1. By
Dr. Samiaa Hamdy Sadek
Assiut University
Interpretation of Cardio-Pulmonary
Exercise Testing (CPET)

3. Maximal exercise testing

5. This is the highest attainable oxygen consumption
achieved during an incremental exercise test
VO2 is defined by the Fick equation:
VO2 = CO* C (a – v)O2
where CO is cardiac output and C (a – v)O2 is the
arterio-venous O2 content difference.

6.  O2 pulse = VO2/HR
ml O2 consumed per beat
taken to reflect stroke volume
assuming PaO2 and C(a-v)O2 respond
normally
O2 pulse < 80% predicted is abnormal

12. Pco2 of respired gas, determined at the end of an
exhalation.
This is commonly the highest Pco2 measured during the
alveolar phase of the exhalation.
 It is expressed in units of millimeters of mercury (or
kilopascals).

13. Normal resting end tidal CO2 ranges between 36 – 44
mmHg, approximating arterial PaCO2.
With exercise end tidal CO2 should increase 3 -8
mmHg from rest to AT and then slightly decline at
maximal exercise secondary to the anaerobically
induced increase in VE (minute ventilation).

14. Po2 of respired gas, determined at the end
of an exhalation.
End tidal O2 normaly at rest 90mmHg or greater and
increases with exercise 10-30 mmHg for exercise
above the anaerobic threshold because of metabolic
acidosis induced hyperventilation and rising R
(respiratory exchange ratio) at maximal exercise.

16. the ratio of VE at peak exercise to the estimated
maximal voluntary ventilation (MVV) represents the
assessment of the ventilatory limitation or of the
prevailing ventilatory constraints. Ventilatory
limitation is judged to occur when VE /MVV exceeds
85%.
In lung diseases, the increase in VE /MVV may reflect
either the reduction in ventilatory capacity (reduction
in MVV), the increase in ventilatory demand
(increase in VE ), or both.

17. Achievement of age-predicted maximal HR during
exercise is often used as a reflecion of maximal or
near maximal effort and presumably signals the
achievement of VO2max.
The difference between the age maximal HR and the
maximal HR achieved during exercise is referred to
as the HR reserve (HRR). Normally, at maximal
exercise, there is little or no HRR.

19. Anaerobic threshold

23. VE/VO2VE/VO2
VE/VCO2
50 -
0 -
AT
RC AT RC
Normal Obstructive Restrictive/PVD
(Efficiency of ventilation)
Normal values at AT: VE/VO2: 25 (22-27) VE/VCO2: 28 (26-30)
Ventilatory Equivalents