Pulmonary embolism (PE) is a known and potentially serious cause of syncope but the prevalence of PE in patients presenting with syncope remains unclear. In particular, while PE is reported as a rare cause of syncope in some studies, with a frequency below 1.5 % [1–5], its prevalence was as high as 10–17 % in others [6,7]. These broad differences highlight the need for a standardized approach to identify patients at high risk of PE that warrant further evaluation.
