RIGHT-VENTRICULAR FUNCTION AND PULMONARY- HYPERTENSION

Background: Hypothetically the right ventricular function measured by Equilibrium Radionuclide Ventriculography (RNV) is determined by the r ight ventricular ejection fraction and depends on the afterload. We in vestigated 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 di sease (COPD). Lung function test, analysis of blood gases, pulmonary a rtery catheterisation and RNV were done within one week. Results: Ther e 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 t o 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 noninvasi ve 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 contract ility. However, influences on contractility are multidimensional and d ifficult to assess and to determine. Conclusion: Eventually it is not possible to use the RNV for measuring RVEF to diagnose pulmonary hyper tension in COPD.