title: Postural orthostatic tachycardia syndrome with increased erythrocytic hydrogen sulfide and response to midodrine hydrochloride.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Erythrocytic H2S could serve as a useful predictor of therapeutic response to midodrine hydrochloride in children with POTS.
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, PR China.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Yang
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.forename: Shuxu
authors.initials: S
authors.lastname: Du
authors.forename: Die
authors.initials: D
authors.lastname: Liu
authors.forename: Chunhin
authors.initials: C
authors.lastname: Fu
authors.forename: Xueying
authors.initials: X
authors.lastname: Li
authors.forename: Stella
authors.initials: S
authors.lastname: Chen
authors.forename: Chaoshu
authors.initials: C
authors.lastname: Tang
authors.forename: Junbao
authors.initials: J
authors.lastname: Du
authors.forename: Hongfang
authors.initials: H
authors.lastname: Jin
mesh_terms: D019540:Area Under Curve; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006339:Heart Rate; D006801:Humans; D006862:Hydrogen Sulfide / Q000097:blood*; D008297:Male; D008879:Midodrine / Q000627:therapeutic use*; D054972:Postural Orthostatic Tachycardia Syndrome / Q000097:blood* / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013566:Sympathomimetics / Q000627:therapeutic use
chemical_list: D013566:Sympathomimetics; D008879:Midodrine; D006862:Hydrogen Sulfide
keywords: AUC; Area under curve; H(2)S; HR; HUT; Head-up test; Heart rate; Hydrogen sulfide; OI; Orthostatic intolerance; POTS; Postural orthostatic tachycardia syndrome