Right ventricular performance during exercise in chronic obstructive pulmonary disease. The effects of oxygen

Radionuclide ventriculography allows non-invasive assessment of right ventricular performance. This study has confirmed that there is a modest reduction in right ventricular ejection fraction (RVEF) in patients with chronic obstructive pulmonary disease (COPD), as compared to normal subjects. However, occult right ventricular dysfunction also becomes apparent in these patients during exercise. The change in RVEF during exercise is related to the corresponding fall in arterial oxygen saturation in patients with COPD. Oxygen improves the response of the right ventricle to exercise, although the mechanism remains unclear. Long-term oxygen therapy, in patients with respiratory failure, does not appear to have any significant effect on RVEF.