Role of autonomic evaluation in the diagnosis and management of syncope.

There are many causes of syncope that include neurological (autonomic and non-autonomic), cardiac and psychiatric causes, amongst others. Disorders of the autonomic nervous system, either intermittent or fixed, are increasingly recognised as contributing to a large proportion of syncope. However, the majority of guidelines focus on cardiological and neurological evaluation in these disorders. In this overview we focus specifically on the role of autonomic evaluation. This has dual purposes; to aid the diagnosis and cause of syncope, and furthermore to provide information to understand the pathophysiological basis of syncope and thus improve management of such disorders.