Oxygenation
Abstract
Abstract Key Points: • A fall in SpO2 of >4% from resting values is abnormal during a CPET. • Disorders of the lung and pulmonary circulation are the most common reason for O2 desaturation. • Understanding the causes of hypoxaemia provides a foundation on which to interpret CPET. • In health, lung ventilation to perfusion matching improves during exercise. • Subjects with heart disease tend not to desaturate on exercise, but some cardiac septal defects, such as patent foramen ovale (PFO), are fairly common and can open during a CPET to cause a right-to-left shunt and desaturation.
Fields of Study & Subjects
Cardiovascular and exercise physiology
Cardiovascular and Diving-Related Complications
Chronic Obstructive Pulmonary Disease (COPD) Research
Publication details
- Journal / source
- Oxford University Press eBooks
- Pages
- 109–118
- Publication date
- 1 February 2026
- Language
- EN
- Document type
- Book chapter