This 49 yr old female had been exposed to sandblasting and 25yrs of cigarettes. On questioning, she admitted to a grinding chest pain, originating in the mid-back and radiating around the left chest into the sub-sternal area. The pain, brought on when walking the dog on cold days and relieved in a few minutes by rest, had not previously been treated or diagnosed. She denied shortness of breath. A physical examination revealed no evidence of peripheral vascular disease, heart murmurs or abnormal heart sounds. The resting 12 lead- ECG was within normal limits.
The patient performed exercise on a cycle ergometer. She pedalled at 60rpm without added load for 3 min. The work rate was then increased 10W per minute to his symptom-limited maximum. The patient stopped exercising due to sub-scapular pain and right anterior chest pain. No significant ECG changes. The chest pain resolved within 1 minute of cessation of exercise.
Selected Respiratory Function Data – were all within normal limits
|Hb, g/L||[130-165 g/L]||110|
|VC, L||2.56 – 3.92||3.63|
|VC, % Predicted||112|
|PEF, L||300.84 – 477.96||476|
|FEV1, L||2.06 – 3.31||2.73|
Selected Exercise Data
|RER at end||1.31|
|VO2peak (max) (mL/kg/min)||20.9||14.5 (50%)|
|VO2 at AT||7.5 (36%)|
|VE/VCO at AT||34|
|Maximum VE, L.min||118||38.2 (32%)|
|BP (rest, max)||110/70; 190/90|
|ECG (rest, max)||91; 178 (104%)|
|Vd/Vt||0.19 – 0.15|
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 the VO2 is reduced, whereas the anaerobic threshold in normal, which directs us to flowchart 3.
The breathing reserve branch is high and although the ECG is not abnormal, the 9 panel plot directs us the diagnosis of myocardial ischeamia.