Tuesday, August 22, 2006

CPET

What do you think of this CPET data?
61 y/o obese woman (BMI: 37.3), S/P remote CABG with patent grafts and normal LVEF on recent angiography with persistent DOE. Very remote smoking Hx with only a mild restrictive defect (FVC~70% with FEV1/FVC>80), normal DLCO and normal HRCT. Negative methacholine challenge.
DATA (predicted values and/or percentages):
VO2max (ml/kg/min): 14.4 (25.4/56%)
AT: 0.749 (>0.698) - 43% predicted VO2max (>40%)
Max HR 73% predicted with still good reserve: 44. O2 pulse 11.5 (8.4)
VE max: 50.7 (65.9 / 77%)
Vt: 1.28 (0.563)
Respiratory rate: 36 (<50)
Breathing reserve: 2% (20-40%)
Vd/Vt at rest: 0.51 (0.30)
Vd/Vt at peak: 0.26 (0.18)
RQ: 0.93 (1.1-1.3)
No desat.
FVC at peak declined by 19% and FEV1 at peak did not change.

5 comments - CLICK HERE to read & add your own!:

Arenberg said...

To my eyes there is a respiratory limitatin, but normal dead space changes with exercise (i.e probably no COPD or pulmonary arterial disease).

I wonder if she doesn't have a neuromuscular defect...myasthenia, other myoptahy (is she on a statin?), or just profound deconditioning.

Do you have any muscle enzymes?

Baleeiro said...

CKs (haven't checked aldolase) are normal. Clinically I have favored deconditioning/obesity.

Baleeiro said...

Incidentally, she had been given a trial of bronchodilators but could not tell any difference...
What do you make of the high Vd/Vt at baseline?

Anonymous said...

What was the VE/VCO2 at AT?
Also, I don't see any blood gas results, so I assume the Vd/Vt was calculated by some other method. If so, the exercise Vd/Vt results are inaccurate and should not be used in diagnosis (Lewis et al. Chest 1994).

Baleeiro said...

Thank you for the comment on the Vd/Vt. It was indeed estimated and not directly measured with ABGs. It also did go down anyway with exercise.
The VE/VCO2 at AT was 43.