Recurrent syncope: differential diagnosis and management

### Learning objectives Syncope is defined as a transient loss of consciousness (TLOC) due to global cerebral hypoperfusion characterised by rapid onset, short duration and spontaneous recovery.1 Syncope is common, affecting more than 35% of the general population at least once in their lifetime and many of these people will have recurrent syncope.w1 Syncope is associated with significant healthcare utilisation as it accounts for 3–5% of emergency departments (EDs), up to 6% of hospital admissionsw2–w4 and results in many investigations.w2 w5 Achieving an accurate diagnosis is essential to determine prognosis and appropriate treatment. The causes of syncope are broad and many conditions can mimic syncope by also causing TLOC. Furthermore, a large proportion of patients is discharged from hospital without a clear diagnosis.w2 This can often result in significant patient anxiety and unnecessary driving/occupation restrictions. In addition, without a clear diagnosis, treatment may not be commenced or appropriate and an accurate prognosis cannot be provided. The prognosis of syncope is dependent on the specific cause and presence of underlying heart disease, and can range from benign in the case of vasovagal syncope, to life threatening in the case of ventricular arrhythmias.w6 Discriminating benign from life-threatening causes of syncope can be difficult and frequently results in unnecessary and often costly investigations. Understanding how to comprehensively, yet succinctly, investigate the patient with syncope will allow the clinician to arrive at a diagnosis, start targeted treatment and accurately estimate patient’s prognosis, and to do so with …