晕厥指由各种原因引起的一过性脑血流灌注降低或能量供应不足 ,导致脑缺氧或神经元能量代谢障碍所引起的临床症状 ,表现为意识障碍 ,同时伴有肌张力降低或消失 ,严重时有惊厥发作 ,晕厥发作持续几秒钟至几分钟自行恢复 ,醒后不能回忆。对晕厥的诊断主要依据病史、临床表现及相 Syncope refers to a variety of reasons caused by transient cerebral perfusion decreased or insufficient energy supply, leading to cerebral hypoxia or neuronal energy metabolism caused by clinical symptoms, manifested as disturbance of consciousness, accompanied by reduced or disappeared muscle tone , Severe seizures, seizures continued for a few seconds to several minutes to recover, wake up can not recall. The diagnosis of syncope mainly based on history, clinical manifestations and phase