EFFECTS OF PULMONARY HYPERTENSION ON PULMONARY FUNCTION



Abnormalities of pulmonary function in pa­tients with pulmonary vascular disease are usu­ally a consequence of the underlying lung disease rather than an intrinsic effect of the pulmonary vascular disease. An exception is the decreased diffusing capacity due to capillary obliteration. In addition, pulmonary vascular occlusion and ob­literation cause shunt and ventilation-perfusion inequality by undefined mechanisms. The result­ing hypoxemia is further exaggerated by the as­sociated reduction of cardiac output and low mixed venous Po2.