In evaluating a patient who has suffered syncope, the most sensitive and specific tests are:
Complete blood count and basic metabolic panel.
Electrocardiogram and echocardiogram.
Head CT and carotid Doppler ultrasound.
History and physical examination.
Cardiac monitor and postural (orthostatic) vital signs.
The cause of syncope can be determined by thorough history and physical examination in 50–85% of patients. No other laboratory examination has greater diagnostic efficacy. A detailed account of the event must be obtained from the patient. This must include the circumstances surrounding the episode, precipitant factors, activity, and position. Head CT is not part of the workup in a patient with simple syncope.