Case 1

Clinical Findings

This 22-year-old shipyard apprentice machinist was evaluated because of complaints of dyspnoea. He stated that he had been unable to play a full game of football (soccer) for the last 3 years and that he gets out of breath and has to stop after climbing three to four flights of stairs on shipboard. He never smoked. He denied cough, chest pain, oedema, or other symptoms. Physical, X-rays, and laboratory examinations were normal.

Exercise Findings:

The patient performed exercise on a cycle ergometer. He pedalled at 60rpm without added load for 3minutes. The work rate was then increased 20W per minute to his symptom-limited maximum. He stopped exercise because of general fatigue. Resting and exercise ECGs were normal.

Selected Respiratory Function Data – were all within normal limits

Measurement Predicted Measured
Age, yr   22
Sex   Male
Height, cm   189
Weight, kg   76
Hb, g/L [130-165 g/L] 154
VC, L 3.30 4.30
IC, L 2.20 2.80
TLC, L 4.52 5.30
FEV1, L 2.66 3.52
FEV1/VC, % 81 80
MVV, L/min 127 124
DLCO, ml/mm HG/Min 22.4 29.8

 

Selected Exercise Data

Measurement Predicted Measured
Exercise duration   13:09
Peak workload 262 254
RER at end   1.22
VO2peak (max) (mL/kg/min) 42.5 46.3 (109%)
VO2 at AT   28.4 (67%)
VE/VCO at AT   25
Maximum VE, L.min 209.0 108.4 (52%)
Breathing Reserve   48%
BP (rest, max)   110/70; 180/60
ECG (rest, max)   82; 194  (98%)
Vd/Vt   0.28 – 0.09
VE/VCO2 slope   26.34
O2 pulse   14 – 18

 

9-panel

 

 Answer:

Is the exercise capacity reduced?

No, when looking at panel 3: VO2 and VCO2 vs work rate.
Assess VO2 max/peak first?
– low, normal, high?

Assess VO2 response
– normal = linear increase with work rate @ 20ml/min/watt

Assess VCO2 response
– increases linearly (y=1<) with VO2 up to lactic acidosis (AT)
– More rapid increase after AT

If it was reduced it could have been any disorder, yet it wasn’t and all was within normal limits.

Wasserman et al: Chapter 8 refer to the Principles of Interpretation: A flowchart Approach.
Principles of Exercise Testing and Interpretation: including Pathophysiology and Clinical Applications; p. 183.

Referring to flowchart 1,

Peak VO2 and the anaerobic threshold are within normal limits.

See Flowchart 2, the ECG and O2 pulse at peak are normal, the patient is NOT obese, the results for this patient are all normal, and his symptoms could be related to a lack of fitness.

 

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