血清铁在鉴别儿童血管迷走性晕厥和体位性心动过速综合征中的意义

目的：分析血清铁在儿童血管迷走性晕厥（vasovagal syncope，VVS）和体位性心动过速综合征（postural orthostatic tachycardia syndrome，POTS）鉴别诊断中的意义。方法：2009年8月至2012年9月间就诊于北京大学第一医院儿科晕厥专业门诊或住院的年龄4~17岁的患儿共57例，其中确诊为POTS的患儿40例，VVS患儿17例。采用血清铁及其受试者操作特征（receiver operating characteristic，ROC）曲线分析不同血清铁值对鉴别儿童VVS和POTS的预测价值。结果：POTS患儿血清铁值中位数为17.4 μmol/L（四分位数间距13.5~21.8 μmol/L），VVS患儿血清铁值中位数为8.9 μmol/L（四分位数间距7.5~17.6 μmol/L），两组间比较差异有统计学意义（P<0.01）。以血清铁11.8 μmol/L作为界值对VVS和POTS患儿进行鉴别的灵敏度为92.5%，特异度为64.7%。结论：血清铁可能作为临床上鉴别VVS和POTS的初步方法。

Significance of serum iron in the differential diagnosis between vasovagal syncope and postural orthostatic tachycardia syndrome in children

To explore the predictive value of serum iron in differentiating between vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children. Methods: Totally 57 children (aged 4-17 years, POTS 40 cases, and VVS 17 cases) who were at the syncope clinic or admitted to the Department of Pediatrics, Peking University First Hospital from August 2009 to September 2012 were included in the study. The diagnoses were analyzed by the value of serum iron and receiver operating characteristic (ROC) curves used to explore the predictive value of different serum iron in differential diagnosis between VVS and POTS. Results: There were significant differences in the median value of POTS ［17.4 (interquartile range 13.5-21.8) μmol/L］ and VVS ［8.9 (interquartile range 7.5-17.6) μmol/L］ (P<0.01). When the value of serum iron was 11.8 μmol/L, the sensitivity and specificity of the differential diagnosis between VVS and POTS were 92.5% and 64.7%, respectively. Conclusion: The serum iron might be used as an initial diagnostic method in differential diagnosis between VVS and POTS, based on the history of the patients.