Lecture 7 practise questions

Question 1

How is the breathing reserve assessed and what is the implication of a lower than normal breathing reserve?

Answer 1

Assessed using a CPET.

Breathing reserve is calculated by- MVV - VEmax

Abnormal BR = ventilatory limitation to exercise

Question 2

Describe the V-slope method of assessing the anaerobic threshold from CPET results.

Answer 2

In the V-slope method, the VCO2 is plotted against VO2

The AT is the point where the slope of the relationship between VCO2 and VO2 becomes steeper than 1.0

This represents the time when the rate of increase in VCO2 exceeds the rate of increase of VO2

Question 3

What does an abnormal O2 pulse progression during a CPET tell us about the possible cause of unexplained dyspnoea?

Answer 3

O2 pulse measures stroke volume.

Abnormal values or trajectory (early plateau or double slope) during the CPET indicate myocardial ischaemia