By Matthew E. Fink, MD

Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital

Dr. Fink reports he is a retained consultant for Procter & Gamble and Pfizer.

SOURCE: Prandoni P, Lensing AW, Prins MH, et al. Prevalence of pulmonary embolism among patients hospitalized for syncope. N Engl J Med 2016;375:1524-1531.

Syncope is a chief complaint for which neurologists often are consulted. In most cases, the neurological concern is possible stroke or an epileptic seizure. However, a variety of cardiopulmonary problems are most often the underlying cause of syncope, including cardiac arrhythmias and pulmonary embolism. The investigators of this study reviewed the clinical records of 560 patients (mean age of 76 years) who were admitted to the hospital with syncope. Diagnosis of pulmonary embolism was ruled out in 330 of the 560 patients on the basis of a negative D-dimer assay and low pretest clinical probability. Of the remaining 230 patients, pulmonary embolism was identified in 97 (42.2%). In the entire cohort, prevalence of pulmonary embolism was 17.3% and there was evidence of an embolus in a main pulmonary or lobar artery larger than 25% of the total area of both lungs in 61 patients.

Based on this careful and detailed review of clinical features of patients with syncope, it appears that pulmonary embolism may be one of the most common causes, and should be considered by all physicians who are evaluating such patients, including neurologists.