Right ventricular function and pulmonary hypertension]

Background: Hypothetically the right ventricular function measured by Equilibrium Radionuclide Ventriculography (RNV) is determined by the right ventricular ejection fraction and depends on the afterload. We investigated the possibility to evaluate the increased pulmonary artery pressure (PAP) by using this method. Patients and Method: We examined 109 patients (54,6 +/- 11 years) with chronic obstructive pulmonary disease (COPD). Lung function test, analysis of blood gases, pulmonary artery catheterisation and RNV were done within one week. Results: There are 52 patients with non, 37 with labile and 20 with fixed pulmonary hypertension. Patients with normal PAP and nearly normal RVEF (49,2 +/- 8) were used as control group. Patients with pulmonary hypertension have had a lower mean RVEF, but there was no significant difference to the control group. Furthermore there was no significant correlation between mean PAP and RVEF detectable. By using RNV we diagnosed fixed pulmonary hypertension with a sensitivity of 95% and a specificity of 33% reduced RVEF and partial respiratory failure as a second noninvasive parameter achieved a more precise but not sufficient prediction of pulmonary hypertension, tested in Chi-Square-Test. Obviously the RVEF depends not only on the afterload but also on the preload and contractility. However, influences on contractility are multidimensional and difficult to assess and to determine. Conclusion: Eventually it is not possible to use the RNV for measuring RVEF to diagnose pulmonary hypertension in COPD.