What is the Value of Clinical History in Establishing the Cause of Syncope

It is commonly accepted that the clinical history is important in the diagnosis of the cause of syncope. For example, pallor, nausea, and diaphoresis are believed to be specific for vasovagal syncope. However, the value of clinical history in the diagnosis of the type of syncope has been little investigated. Wayne et al. [1] analyzed the clinical features of 510 patients with a wide variety of causes of syncope. Particular emphasis was placed on the nature of the prodromal and recovery symptoms, the position prior to syncope and the duration of prodromal and recovery symptoms. Although this study represented the first attempt to critically examine the clinical history in patients with syncope, it was not possible to draw conclusions, because there were several important limitations. In fact, the histories were retrospectively obtained from medical records and precise details were often unavailable. Moreover, many of the diagnoses were established on a presumptive basis due to the absence of clear diagnostic criteria.