7岁男孩,发作性晕厥7年。患儿系足月顺产,生后未见异常。半月后突哭闹,面色苍白,意识丧失、无抽搐,约数分钟自行缓解。以后每年均有类似发作1～2次。无明显诱因。85年1～8月共发作6～7次,发作时间较前延长。发作前患儿述头昏、“心”内不适、恶心,随之面色苍白,睡倒,神志 7-year-old boy, paroxysmal syncope 7 years. Children with full-term follow-up, no abnormalities after birth. Half a month after sudden crying, pale, loss of consciousness, no convulsions, about a few minutes to ease themselves. After a similar attack every year 1 or 2 times. No obvious incentive. 85 years from January to August a total of 6 to 7 episodes, the attack time longer than before. Before the attack, the child described dizziness, “heart” discomfort, nausea, followed by pale, fall asleep, consciousness