Plasma hydrogen sulfide in differential diagnosis between vasovagal syncope and postural orthostatic tachycardia syndrome in children.

To explore the predictive value of plasma hydrogen sulfide (H(2)S) in differentiating between vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children. Patients were divided between the POTS group (n=60) and VVS group (n=17) by using either the head-up test or head-up tilt test. Twenty-eight healthy children were selected for the control group. Plasma concentrations of H(2)S were determined for children in all groups (POTS, VVS, and control). Plasma levels of H(2)S were significantly higher in children with VVS (95.3±3.8 μmol/L) and POTS (100.9±2.1 μmol/L) than in children in the control group (82.6±6.5 μmol/L). Compared with the VVS group, the POTS group had plasma levels of H(2)S that were significantly increased. The receiver operating characteristic curve for the predictive value of H(2)S differentiation of VVS from POTS showed a H(2)S plasma level of 98 μmol/L as the cutoff value for high probability of distinction. Such a level produced both high sensitivity (90%) and specificity (80%) rates of correctly discriminating between patients with VVS and patients with POTS. H(2)S plasma level has both high sensitivity and specificity rates to predict the probability of correctly differentiating between patients with VVS and patients with POTS.

Zhang F ，Li X ，Stella C ，Chen L ，Liao Y ，Tang C ，Jin H ，Du J ... -  《-》

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

Li JW ，Zhang QY ，Gao J ，Jin HF ，Du JB ... -  《-》

[Diagnosis of vasovagal syncope in children with postural orthostatic tachycardia syndrome].

Wu LJ ，Wang C ，Lin P ，Yuan HL ，Jin L ，Kang MH ，Zhu LP ... -  《-》

Body mass index is decreased in children and adolescents with postural tachycardia syndrome.

Lin J ，Zhao H ，Ma L ，Jiao F ... -  《-》

Postural orthostatic tachycardia syndrome with increased erythrocytic hydrogen sulfide and response to midodrine hydrochloride.

To evaluate the use of erythrocytic hydrogen sulfide (H2S) in predicting the therapeutic efficacy of midodrine hydrochloride for children with postural orthostatic tachycardia syndrome (POTS). Fifty-five children were included in this study, involving 28 children with POTS (POTS group) and 27 healthy children (control group). Children in the POTS group received midodrine hydrochloride treatment. Erythrocytic H2S production was measured; a receiver operating characteristic curve was used to assess if erythrocytic H2S could predict the therapeutic response to midodrine hydrochloride treatment. H2S production from erythrocytes was significantly higher in the POTS group than in the control group (P < .01). H2S production was also significantly higher in responders to midodrine hydrochloride than in non-responders (P < .05). The change in symptom score and baseline erythrocytic H2S production had a positive linear relationship (P < .01). There was also a positive correlation with the change in heart rate (P < .05). The receiver operating characteristic curve showed an area under curve value of 0.813. Erythrocytic H2S production yielded a sensitivity of 78.9% and a specificity of 77.8% in predicting the efficacy of midodrine hydrochloride therapy for children with POTS. Erythrocytic H2S could serve as a useful predictor of therapeutic response to midodrine hydrochloride in children with POTS.

Yang J ，Zhao J ，Du S ，Liu D ，Fu C ，Li X ，Chen S ，Tang C ，Du J ，Jin H ... -  《-》