Methods The HRV was analyzed in children with unexplained syncope (n=27),who had positive head-up tilt table test (HUTT)results and were diagnosed as VVS. Healthy children were matched as controls (n=29).

• 方法对27例不明原因晕厥患儿经直立倾斜试验(HUTT)检查阳性并诊断为VVS的HRV进行分析(研究组),并将29例健康儿童作为对照(对照组)。