Syncope is a well-known initial manifestation of pulmonary embolism (PE)1. However, given the varied causes of syncope, determining the prevalence of PE among patients hospitalized for syncope is important.
A recent NEJM study furthers our understanding of PE and syncope2. This multicenter prospective study enrolled 560 patients not already on anticoagulation who were hospitalized for a first episode syncope. Of 230 patients who had either a high pretest probability for PE, positive D-dimer assay or both, PE was diagnosed in 97 (17%, or nearly 1 of 6 of enrolled patients) based on CT or ventilation/perfusion scan. PE was found more frequently among patients with syncope of undetermined cause than those with an alternative explanation (25.4% vs 12.7%).
The results of this study should make us consider, perhaps more frequently, the possibility of PE in patients hospitalized for first episode syncope not on anticoagulants, particularly those without an alternative explanation.
- Thames MD, Alpert JS, Dalen JE. Syncope in patients with pulmonary embolism. J Am Med Assoc 1977;238:2509-2511.
- Prandoni P, Lensing AWA, Prins MH, et al. Prevalence of pulmonary embolism among patients hospitalized for syncope. N Engl J Med 2016;375:1524-31.
Contributed by Rebecca Berger MD, Department of Medicine, Mass General Hospital, Boston, MA.