Abstract: 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.

Key words: Iron, Syncope, vasovagal, Postural orthostatic tachycardia syndrome, Diagnosis, differential, Children