Diagnosis and treatment of vasovagal syncope

Syncope is a complaint that is commonly seen in adolescence and early adulthood. An episode of unconsciousness is seen at least once during lifespan in 12%-48% of population (1). Vasovagal syncope (VS) is one the most important causes of syncope in children, which is diagnosed by ruling out other provable causes of syncope, positive response to tilt table test and a typical history. Despite the studies performed in recent years, the pathophysiological mechanisms underlying the VS have not been explained completely, especially in children. Cardio-inhibition and/or vasodepression caused by vagal activation during a syncope forms the last step of the pathophysiological mechanism. Many studies have used spectral and time domain heart rate variation (HRV) analyses during tilt table test in order to reveal the effect of autonomic nervous system in the pathophysiological mechanism of VS (2,3). Although these studies agreed that the autonomous nervous system plays an important role in pathophysiological mechanism of VS, definite etiology and parasympathetic response mechanism have not been fully recognized. This may be because of differences between the patient and control groups, usage of different tilt table procedures, different syncope categories, and inadequate number of patients. In this review, our aim is to investigate the up-to-date approaches in the etiology, physiopathology, diagnosis and treatment of VS, which is the most frequent cause of syncope in children, by the help of the literature.