Fatal pulmonary embolism.

Massive pulmonary embolism is a dramatic, often fatal, event. If death is not immediate, embolectomy using cardiopulmonary bypass is feasible, and a num ber of reports have appeared in recent years attest ing to its value (1-3). However, emergency em bolectomy is not practical on a wide scale. In over 300 cases of pulmonary embolism with positive lung-scan findings, we have observed that major or fatal embolization rarely is the first evi dence of a thromboembolic process. Most patients have symptoms or signs of small emboli antedating the catastrophic episode by 5-7 days or more. Lung scanning is an effective and widely applicable test for identifying occlusion of lobar, segmental and some subsegmentai pulmonary arteries (6,7), while adequate anticoagulation is known to definitely re duce the incidence and mortality from recurrent emboli (8). Detection of these minor or "signal" emboli by lung-perfusion scanning followed by in tensive anticoagulation is a potentially effective means of preventing massive embolization. This paper describes the clinical course and autopsy findings in seven patients with massive pul monary embolism and suggests that lung scanning may play an important role in reducing the incidence of fatal attacks.