The Effectiveness of Metoprolol in the Prevention of Syncope Recurrence in Children and Adolescents

The purpose of this study to evaluate the effectiveness of metoprolol versus conventional treatment in the prevention of syncope recurrence in children and adolescents.

Syncope is often a frustrating clinical problem seen in pediatric patients. Most pediatric syncope is benign, and vasovagal syncope (VVS) is the most common type of syncope seen in children . The diagnosis of VVS is established by history, often confirmed by tilt tests. A wide range of drugs has been proposed for VVS , with β-adrenergic blocking agents being first-line therapy. However, clinical studies have shown conflicting results in terms of therapy effectiveness. β-blockers have been claimed to be effective for 60% to 100% of young patients in many uncontrolled studies but not in most short- and long-term controlled studies . Sheldon et al., in a recent multicenter, double-blinded, placebo-controlled, randomized study of adult patients, reported that metoprolol was not effective in preventing VVS. To our knowledge, no pediatric randomized controlled trials with long-term follow-up have demonstrated the efficacy of β-blockers for the prevention of syncope.

Inclusion Criteria: Children with a history of syncope were included if they had had at least three syncopal episodes per year and had a positive head-up tilt test result. Exclusion Criteria: Patients were excluded if they had: Other causes of syncope; Cardiovascular and/or systemic disease; Systolic blood pressure >130 mm Hg or diastolic blood pressure >90 mm Hg； or History of asthma, impaired liver function, Ⅱ to Ⅲ degrees of atrioventricular block, sinus bradycardia < 40 beats/min, or other contraindications for β-blockers.