title: alpha-Adrenoceptor agonists for the treatment of vasovagal syncope: a meta-analysis of worldwide published data.
abstract: OBJECTIVE
  The present study was aimed at evaluating present randomized controlled trials (RCTs) regarding the effect of alpha-adrenoceptor agonists on vasovagal syncope (VVS).
  
  
  METHODS
  According to inclusion and exclusion criteria, articles were selected from medical electronic databases. RCTs were then assessed based on the Juni assessment, and meta-analysis was completed using the Review Manager 4.2 software. Indication to further evaluate effects was the recurrence of syncope during follow-up treatment or a response in the head-up tilt test (HUT) after treatment. The results were stated as odd ratio (OR), with a 95% confidence interval (CI) and a p < 0.05 significant level.
  
  
  RESULTS
  In total, six RCTs were selected. Funnel plot analysis showed possible publication bias. Meta-analysis of the six RCTs, including all 165 patients in the treatment group and 164 patients in the control group, indicated that alpha-adrenoceptor agonists were more effective than placebos in treating VVS (OR = 0.21, 95% CI: 0.06-0.77, p = 0.02). The further, weighted independent t-test disclosed that the weighted mean percentage of responders for midodrine (76.3%+/- 7.7%) was significantly higher than that for etilefrine (65.5%+/- 15.4%) (t = 5.863, p < 0.001).
  
  
  CONCLUSIONS
  The currently published RCTs support that alpha-adrenoceptor agonists might be effective for VVS. Midodrine can be regarded as a better choice compared with etilefrine.
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liao
authors.forename: Xueying
authors.initials: X
authors.lastname: Li
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Zhang
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
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use*; D005039:Etilefrine / Q000627:therapeutic use; D006801:Humans; D008879:Midodrine / Q000627:therapeutic use; D017063:Outcome Assessment, Health Care; D016032:Randomized Controlled Trials as Topic; D019462:Syncope, Vasovagal / Q000188:drug therapy*
chemical_list: D000316:Adrenergic alpha-Agonists; D008879:Midodrine; D005039:Etilefrine