title: Randomized comparison of metoprolol versus conventional treatment in preventing recurrence of vasovagal syncope in children and adolescents.
abstract: BACKGROUND
  Previous studies that have assessed the effects of beta blockers on preventing vasovagal syncope provide conflicting results. We sought to evaluate the effectiveness of metoprolol versus conventional treatment in preventing the recurrence of syncope in children and adolescents.
  
  
  METHODS
  Twenty-eight children and adolescents (8 boys, 20 girls; mean age, 12+/-3 years; age range, 8-17 years) with vasovagal syncope were randomized to receive either metoprolol (metoprolol group; dosage range, 0.5-1.5 mg/kg/d) or conventional treatment (control group) for 1 year. The main outcome measure was the first recurrence of syncope beginning 2 weeks after the start of treatment. The mean follow-up was 22+/-10 months. Time to first recurrence of syncope was analyzed using Kaplan-Meier curves and compared with a log-rank test.
  
  
  RESULTS
  The 2 groups did not differ in terms of clinical characteristics. The number of syncopal episodes before tilt testing was 8+/-6 in patients in the metoprolol group and 9+/-6 in patients in the control group (P=0.150). Syncope recurred in 6 of 14 children in the metoprolol group and in 4 of 14 children in the control group. No significant between-group differences were found regarding the probability of freedom from a recurrent episode of syncope during follow-up (metoprolol vs controls, 43% vs 29%; P=0.389), as demonstrated by Kaplan-Meier curve analyses.
  
  
  CONCLUSIONS
  Recurrence of vasovagal syncope in children and adolescents treated with metoprolol is similar to that of patients treated with conventional therapy.
authors: Department of Pediatrics, Peking University First Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.
authors: Qingyou
authors: Q
authors: Zhang
authors: Hongfang
authors: H
authors: Jin
authors: Li
authors: L
authors: Wang
authors: Jianjun
authors: J
authors: Chen
authors: Chaoshu
authors: C
authors: Tang
authors: Junbao
authors: J
authors: Du
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology* / Q000627:therapeutic use*; D055502:Secondary Prevention; D019462:Syncope, Vasovagal / Q000517:prevention & control* / Q000628:therapy*
chemical_list: D008790:Metoprolol