How is CPX (CPET) Testing Performed?

A cardiopulmonary exercise  test is performed at our hospital to a set protocol as described in...
"Chapter 5: Principles of Exercise Testing and Interpretation. K. Wasserman, J. Hansen, D. Sue, R. Casaburi, B. Whipp. Third edition 1999. Lippincott Williams & Wilkins, Philadelphia . Baltimore . New York . London. Buenos Aires . Hong Kong . Sydney . Tokyo."

The subject is connected to computerised 12 lead ECG and breathes in and out of a small mouthpiece whilst seated on a bicycle ergometer. The inspired and expired gases are sampled and analysed for oxygen consumption and carbon dioxide production. The subject is then asked to pedal the ergometer against a continuously increasing resistance. The short movie below shows how this is done.

The ECG, the bicycle ergometer and the metabolic cart are all connected to the on board computer. The test is planned to last around 10 minutes in total and the data is then analysed by bivariate analysis.

The ECG is artifact free and is programmed to detect ischaemia as defined by ST segment depression. The AT is determined by gas exchange as described elsewhere. No blood tests are performed routinely.