Abstract: 　Vasovagal syncope (VVS) is the most common cause of unexplained syncope in children. The etiology of VVS is complex, and its diagnosis is mainly based on clinical manifestations and head-up tilt test (HUT). It has been pointed out that neuroendocrine system plays an important role in the pathogenesis of syncope. HUT-induced syncope is accompanied by abnormal neurohumoral activation. The changes of plasma concentration of endothelin-1 and nitric oxide secreted by endothelial system before and after VVS syncope in children suggest that endothelial system is involved in the occurrence of VVS in children. This article reviews the research on the involvement of vascular endothelial system in the pathogenesis of VVS in children.

Key words: vasovagal syncope;　vascular endothelial system;　child