Characterization of reflex syncope in Brugada syndrome: a literature review

In Brugada syndrome (BrS), syncope is considered a sign of increased risk for sudden cardiac death (SCD) due to ventricular tachycardia/ventricular fibrillation (VT/VF) episodes. However, arrhythmic syncope in BrS is extremely rare, while nonarrhythmic syncope may occur as in the general active population, mostly from reflex events. Symptomatic patients with BrS show a higher risk profile, requiring a watchful risk stratification. In this scenario, a clinical misjudgment could determine to overlook the risk of SCD as well as to pursue inappropriate therapeutic approaches. Therefore, understanding the correct mechanism of the syncope in BrS is mandatory representing a real sign of increased risk only if linked to VT/VF episodes. This review focuses on the BrS population considering the role of the autonomic nervous system, the issue of a correct syncope classification, the potential link between reflex and arrhythmic syncope, and diagnostic work flow in patients with a concomitant reflex mechanism, with a specific focus on the head-up tilt test and implantable loop recorder roles.