Medicine: Pulmonary embolism as a cause of syncope

Pulmonary embolism is a sudden blockage in the major blood vessel of your lung, the pulmonary artery.
Syncope (fainting): Doctors and many patients who had syncope can list a number of causes. Pulmonary embolism is not among these causes.
Yet, when we look at a new study with 230 patients hospitalised with their first syncope: Surprisingly, pulmonary embolism was the cause of the syncope in 17% of the patients.
A well-known professor read this study with regard to weaknesses and strengths. He found 4 caveats. Despite these 4 caveats, he recommends:
Keep pulmonary embolism as a cause for syncope in mind, should ever a patient have syncope.