History taking as a diagnostic test in patients with syncope: developing expertise in syncope

Transient loss of consciousness (T-LOC) is very common and caused by many disorders spanning multiple specialties with consequences varying from benign to lethal, necessitating an accurate, efficient diagnostic work-up. The European Society of Cardiology Guidelines on Syncope recommends that the initial work-up of suspected syncope consists of history taking, a physical examination, and ECG. The emphasis on taking a history is justified by its high diagnostic yield.1,2 Surprisingly, there is relatively little research on how data from the medical history are collected and analysed in syncope patients. While a few studies have described evidence-based point scores for diagnosing patients with syncope, the added value of expert history taking in syncope has received less attention.2 The diagnostic yield of the initial work-up by non-expert physicians in patients with T-LOC according to the ESC guidelines is reported to be 60–70% with history taking as the main factor,3 while after standardized evaluation in dedicated units (syncope units) ∼85% of patients are reported to be diagnosed.4,5 The diagnostic yield of expert history taking in patients who remain undiagnosed after standardized approaches according to the management model proposed by the ESC is unknown. The focus of this current opinion is on the roles of evidence-based point scores and expert history taking in diagnosing suspected syncope. An effective diagnostic strategy for syncope requires knowledge of other causes of T-LOC and hence requires training or experience in relevant aspects of cardiology, neurology, internal medicine, emergency medicine, paediatrics, geriatrics, and psychiatry. These specialties are all within general internal medicine, which has become fragmented leading to decrease in the broad skills of history taking and physical examination. The majority of patients with suspected syncope have vasovagal or other types of reflex syncope like situational or carotid sinus syncope. In the emergency …