[Active and passive factors in the genesis of pulmonary arterial hypertension in various cardiopathies and pneumopathies].

The role of active and passive factors involved in the genesis of Pulmonary Arterial Hypertension (PAH) is analyzed in a group of eighty patients with several cardiopathies and pneumopathies. The group include: 20 patients with Chronic Obstructive Lung Disease (NODC), 20 with Diffuse intersticial pneumopathy (NI), 12 with Cardiorespiratory Syndrome of the grossly obese (OB), 6 with Pulmonary Embolism (TEP), 6 with Mitral Stenosis (CRI), 5 with Hypertensive Ventricular Septal Defect (CIV + HAP) and 11 patients with Pulmonary Arterial Hypertension of Unknown etiology (HAP-ED). For the analysis, the Harvey and Enson's formulas were used. The conclusions of the study are: 1) The compliance of the elastic arteries of the lung in the groups of NOC, NI and OB is normal but in the other groups seems to be modified. 2) In the groups of NI and OB the interrelationship of factors such as alveolar hypoxia and pulmonary wedge pressure (PWP) play the major role in the genesis of PAH, although the role of the PaCO2 in the OB group remains to be established. 3) In the groups of NOC, CRI and TEP the PWP is not determinant. The absence of a significant correlation between arterial oxygen unsaturation and pulmonary diastolic pressure in the NOC group suggests other factors. 4) The vascular structural damage seems to be the most important factor in the genesis of PAH in the HAP-ED and CIV + HAP groups.