The right ventricle and the small pulmonary arteries in coalworkers.

In previous work (Thomas, 1951; James and Thomas, 1956), we have been made aware of some problems of pulmonary heart disease that needed further elucidation. Further consideration of the method of assessment of right ventricular hypertrophy and its relation to emphysema and pneumoconiosis when present, separately or together, was needed. Jaffe (1934), referred to the lesion of pneumoconiosis as including obliterative changes in the branches of the pulmonary artery. Other workers (Gough, 1952; Wells, 1954; James and Thomas, 1956), have referred to the presence of arterial lesions in the vessels of the lungs in pneumoconiosis. It seemed important to examine the relationship of these vascular changes to the right ventricular hypertrophy. The nature of the changes in the vessels is also in question. Pulmonary thrombosis has been regarded as a relatively rare happening, but we have found that in pulmonary heart disease, especially in coalworkers, it is much commoner than is thought. Other workers have seen differing kinds of arterial lesions in the lungs in other forms of pulmonary hypertension (McKeown, 1952; Wade and Ball, 1957), and it seemed important to try and assess the nature of the change in pneumoconiosis. Heart failure and lung disease has been reviewed by Hecht (1956), and from this review it is clear that forms of heart failure can differ in different pulmonary diseases.