Pulmonary Hemodynamics in Symptomatic Coal Miners1

Forty-seven coal miners, selected because they were symptomatic, underwent studies of pulmonary hemodynamics at rest and during exercise. They were divided into two groups depending on the absence or presence of airway obstruction. Of the 23 in the group without airway obstruction, one had a high mean pulmonary artery pressure at rest and another 3 showed increase of this pressure during exercise. All 4 had the pinpoint type of simple pneumoconiosis. Of the subjects with obstruction, 7 of 24 had pulmonary arterial hypertension that could be accounted for by airway obstruction or complicated pneumoconiosis, whereas one with less severe obstruction had pinpoint opacities on his chest radiograph. Abnormalities of alveolar-arterial oxygen gradient, arterial oxygen tension, and dead space ventilation were common in both groups, but were only significantly related to pulmonary artery pressure in the group with obstruction. These results indicate that pulmonary arterial hypertension can occur in the pinpoint typ...