血管迷走性晕厥是儿科的常见疾病,表现为站立时视、听觉下降,恶心、呕吐、大汗,站立不稳,伴血压或心率下降,甚至突发短暂的意识丧失伴肌张力下降,严重影响小儿的身心健康,其发病机制迄今还不清楚。QT离散度(QTd)是体表心电图各导联间的QT间期变异程度,代表心室肌复极不同步性和 Vasovagal syncope is a common pediatric disease, manifested as standing, hearing loss, nausea, vomiting, sweating, standing instability, with blood pressure or heart rate decreased, and even sudden short-term loss of consciousness associated with decreased muscle tension, seriously affected Children’s physical and mental health, its pathogenesis is still unclear. QT Dispersion (QTd) is the degree of QT interval variation between the leads of the body surface electrocardiogram, representing the asynchrony of ventricular repolarization and