Question 1

How does a cardiopulmonary exercise test separate cardiac from pulmonary limitation?

Accepted Answer

Mainly through the breathing reserve, the ventilation left unused at peak exercise. In cardiac limitation it is preserved, usually with a low threshold, a raised ventilatory efficiency slope and a flattening oxygen pulse. In pulmonary limitation it is exhausted. Trained athletes are an exception: they can exhaust their breathing reserve while reaching a supranormal peak oxygen uptake.

Question 2

What does a fall in systolic blood pressure during exercise testing mean?

Accepted Answer

A fall of more than 10 mmHg from baseline despite a rising workload suggests cardiac output is not rising as it should. Verify it at once. With other evidence of ischaemia it is an absolute reason to stop the test; without it, it is a relative reason needing clinical judgement. Candidates often miss it, because instinct expects a high pressure to be the dangerous finding.

Question 3

Why is the respiratory exchange ratio reported on a test result?

Accepted Answer

It helps judge whether the effort was high enough to interpret the rest of the report. European respiratory guidance treats a peak above roughly 1.05 as supporting high effort, but it does not prove it alone: read it with symptoms, heart rate, workload and the ventilatory response. A lower peak suggests a reduced peak oxygen uptake may reflect effort rather than genuine limitation.

Question 4

When is a functional test more useful than laboratory exercise testing?

Accepted Answer

In older or frailer patients, where the question is usually what the person can do rather than which system limits them. 5-times sit-to-stand, handgrip strength and gait speed are quick, need little equipment, and relate directly to transfers, falls risk and probable sarcopenia. Know what each is confounded by before acting on the result.

Investigating Exertional Symptoms

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