ABSTRACT
Primary or secondary pulmonary vascular diseases are significant entities in the etiology of interstitial lung diseases. The salient facts of pulmonary vascular histology and their alterations with age must be kept in mind when reviewing lung tissue biopsied for possible vascular abnormalities. Abnormalities of pulmonary vasculature may be considered from different angles. The congenital cardiovascular abnormalities that lead to the development of hyperkinetic pulmonary hypertension are enumerated in a table. Conditions of aortic stenosis, myocardial dysfunction secondary to atherosclerotic cardiovascular disease, cardiomyopathies, or essential hypertension all result in decreased cardiac output and increased left atrial pressure which, in turn, produces the pulmonary arterial changes as described under the section of mitral stenosis. From the clinical standpoint, a patient presenting with pulmonary hypertension and right heart failure in the absence of intrinsic cardiac disease or extrapulmonary obstruction to venous return and normal wedge pressures should suggest veno-occlusive disease as a probable diagnosis.
