Investigation on the relation of impedance rheopneumogram with pulmonary hemodynamics and right ventricular function in patients with chronic obstructive pulmonary disease.

In order to investigate the relation of impedance rheopneumogram with pulmonary hemodynamics and right ventricular function in patients with chronic obstructive pulmonary disease (COPD), we measured impedance rheopneumogram and performed right heart catheterization on 150 COPD patients simultaneously both at rest and during exercise test. The results showed that impedance rheopneumogram was mainly influenced by right ventricular after-load while the influences of right ventricular pre-load, right ventricular contractivity, right ventricular work index and cardiac output were rather slight. These results also suggest that in COPD patients impedance rheopneumogram is of great value when used to predict pulmonary arterial pressure but of little value when used to measure the right ventricular function.