Practice Variation in Establishing the Adequacy of Beta Blockers as An Antiarrhythmic Agent in School Aged Children and Adolescents

Abstract Background Beta blockers (BB) are commonly prescribed to manage arrhythmias in children and adolescents without any standardised approach to establish BB adequacy. We invited all Canadian pediatric cardiologists to participate in an anonymous survey to understand practice variation in the assessment of BB adequacy in school aged children and adolescents with arrhythmia or the potential for arrhythmia. Methods An electronic survey approved by Institutional Ethics Board was distributed by e-mail to 96 Canadian pediatric cardiologists, who had been active in practice for at least one year. Incomplete surveys were excluded. Results Forty-one cardiologists (43%) responded to all questions in the survey. Thirteen cardiologists (32%) reported always assessing BB adequacy, seventeen (41%) did so only for specific arrhythmias, whereas eleven (27 %) reported never performing such an assessment. Nineteen (46%) and eighteen (44%) cardiologists reported using Holter monitoring and exercise testing, respectively, to assess beta receptor blockade adequacy. Thirteen (32%) considered BB therapy adequate if Holter demonstrated a 20% drop in heart rate (HR) from baseline and ten respondents (24%) defined adequate BB therapy using exercise test as 20% drop in maximal HR or blood pressure (BP) from baseline. Conclusion Despite wide variation in practice, Holter monitoring and exercise testing are commonly used methods to measure the adequacy of BB therapy. There are no standard criteria, but the majority (56%) reported using a 20% drop in HR or BP from the pretreatment state as a criterion for adequate BB therapy in children and adolescents with arrhythmia or potential for arrhythmia.