Postural syncope: mechanisms and management

• Postural syncope is a transient loss of consciousness secondary to a reduction in cerebral blood flow and is typically precipitated by standing. It is the commonest cause of recurrent transient loss of consciousness. • Recurrent unexplained postural syncope is most often due to one of the five disorders of circulatory control: vasovagal syncope, postural tachycardia syndrome, chronic autonomic failure, initial orthostatic hypotension, or persistently low supine systolic blood pressure. • Failure to identify the underlying cause of postural syncope can result in ongoing morbidity, impaired quality of life and high health care costs. • With a detailed history, examination, blood pressure assessment and electrocardiography, most disorders of circulatory control can be diagnosed. • In difficult cases, analysis of sympathetic nervous system and circulatory responses during head-up tilting can aid diagnosis. • Treatment is challenging and compounded by a lack of evidence. Most patients can be managed in an outpatient setting, and hospital admission or emergency department