A study of the etiological basis of primary pulmonary hypertension

Clinical and autopsy findings are discussed in 9 patients in whom a diagnosis of "primary" pulmonary hypertension was made. In 6 of these cases, pulmonary emboli and thrombi provided the etiological basis for pulmonary hypertension. The difficulty of differentiating cases of recurrent pulmonary embolization from cases of "primary" pulmonary hypertension is discussed. The possibility that all cases of primary pulmonary hypertension represent recurrent embolization is considered. Therapy with anticoagulation and venous ligation is recommended for all cases of "primary" pulmonary hypertension.