Syncope.

Syncope, which can be defined as a transient loss of consciousness caused by transient global cerebral hypoperfusion and characterised by rapid onset, short duration, and spontaneous complete recovery, is a common condition. This definition is useful for differentiating syncope from other clinical conditions that also involve real or apparent transient loss of consciousness, but in which the mechanism is not global cerebral hypoperfusion, such as epilepsy, falls, or psychiatric pseudosyncope. We reviewed the etiological classification of syncope and found that reflex syncope is the most common etiology in the general population, with a good prognosis, whereas cardiac syncope increases with age and has a worse prognosis. We also reviewed the role and limitations of different tests, specifically referring to the interpretation of the results of carotid sinus massage, the role of tilt-table testing, the diagnostic strategy in patients with syncope and bundle branch block, the adenosine test, and the emerging role of prolonged electrocardiographic monitoring. Furthermore, we reviewed the different therapeutic options available. The importance of establishing syncope units with the aim of improving the diagnostic process and optimizing resources is also emphasized.