Bronchoconstriction in the presence of pulmonary embolism.

I MPRESSIVE pathologic evidence has accumulated that suggests that recurrent showers of small pulmonary emboli are commonly undetected clinically.1 3 The eventual development of obstructive pulmonary hypertension and cor pulmnonale in some cases is well known, but effective therapy of this late stage of the disease is not available. It has been reported, however, that prompt treatment can result in reversal of pulmonary hypertelnsion.4 Ulnfortunately, the early detection of pulmonary emboli is difficult, especially when not associated with overt pulmonary infaretion. In the course of a recenlt study in dogs in which autologous venous thrombi were released to the lungs, changes in pulmonary mechanics indicative of bronchoconstriction and increased pulmonary resistance were found.5 These observations prompted an investigation of comparable nmeasures of pulmonary function in patients whose clinical findings suggested a diagnosis of pulmonary thromboembolism. It is the purpose of this communication to document the existence of bronchoconstrietion in seven patients with pulmonary embolism, and to indicate the clinical and theoretical implications of this relationship. Our observations suggest that the measurement of bronehoconstriction may be a useful aid to the early detection of pulmonary emboli.