Safety,Efficacy, And Dose Protocol Of Metoprolol For Heart Rate Reduction In Pediatric Outpatients Undergoing Cardiac Ct Angiography

Background: Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population.Objective: Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA.Methods: We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal).Results: Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural doselength product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported.Conclusion: Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population.