Sotalol in treatment of pediatric cardiac arrhythmias

Sotalol in neonates for arrhythmias: Dosing, safety, and efficacy

INTRODUCTION

Various agents may be utilized to manage supraventricular tachycardia (SVT) in neonates and infants. Recently, sotalol has piqued interest given its reported success in managing neonates and infants with SVTs, especially with the intravenous formulation. While the manufacturer recommends using an age-related nomogram in neonates and young infants to guide doses, clinical reports describe various dosing based on weight (mg/kg) or on body surface area (BSA) in mg/m2 . Given the reported variation in clinical practice with regard to dosing in neonates, there is a gap in the literature and translation into clinical practice regarding applicability of the nomogram into clinical practice. The purpose of this study was to describe sotalol doses based on body weight and BSA in neonates for SVT.

METHODS

This is a single center retrospective study evaluating effective sotalol dosing from January 2011 and June 2021 (inclusive). Neonates who received intravenous (IV) or oral (PO) sotalol for SVT were eligible for inclusion. The primary outcome was to describe sotalol doses based on body weight and BSA. Secondary outcomes include comparison of doses to the manufacturer nomogram, description of dose titrations, reported adverse outcomes, and change in therapy. Two-sided Wilcoxon signed-rank tests were used to determine statistically significant differences.

RESULTS

Thirty-one eligible patients were included in this study. The median (range) age and weight were 16.5 (1-28) days and 3.2 (1.8-4.9) kg, respectively. The median initial dose was 7.3 (1.9-10.8) mg/kg or 114.3 (30.9-166.7) mg/m2 /day. Fourteen (45.2%) of patients required a dose increase for SVT control. The median dose required for rhythm control was 8.5 (2-14.8) mg/kg/day or 120.7 (30.9-225) mg/m2 /day. Of note, the median recommended dose per manufacturer nomogram for our patients would have been 51.3 (16.2-73.8) mg/m2 /day, which is significantly lower than both the initial dose (p < .001) and final doses (p < .001) utilized in our study. A total of 7 (22.9%) patients were uncontrolled on sotalol monotherapy using our dosing regimen. Two patients (6.5%) had reports of hypotension and one patient (3.3%) had a report of bradycardia requiring discontinuation of therapy. The average change in baseline QTC following sotalol initiation was 6.8%. Twenty-seven (87.1%), 3 (9.7%), 1 (3.3%) experienced prolongation, no change, or a decrease in QTc, respectively.

CONCLUSIONS

This study demonstrates that a sotalol strategy significantly higher than the manufacture dose recommendations are required for rhythm control in neonates with SVT. There were few adverse events reported with this dosing. Further prospective studies would be advantageous to confirm these findings.

Early experience with intravenous sotalol in children with and without congenital heart disease

BACKGROUND

Arrhythmias are common in the pediatric population. In patients unable to take oral medications or in need of acute therapy, options of intravenous (IV) antiarrhythmic medications are limited. Recently IV sotalol has become readily available, but experience in children is limited.

OBJECTIVE

The purpose of this study was to describe our initial experience with the use of IV sotalol in the pediatric population.

METHODS

A retrospective study of all pediatric patients receiving IV sotalol was performed. Patient demographic characteristics, presence of congenital heart disease, arrhythmia type, efficacy of IV sotalol use, and adverse effects were evaluated.

RESULTS

A total of 47 patients (26 (55%) male and 24 (51%) with congenital heart disease) received IV sotalol at a median age of 2.05 years (interquartile range 0.07-10.03 years) and a median weight of 12.8 kg (interquartile range 3.8-34.2 kg), and 13 (28%) received IV sotalol in the acute postoperative setting. Supraventricular arrhythmias occurred in 40 patients (85%) and ventricular tachycardia in 7 (15%). Among 24 patients receiving IV sotalol for an active arrhythmia, acute termination was achieved in 21 (88%). Twenty-three patients received IV sotalol as maintenance therapy for recurrent arrhythmias owing to inability to take oral antiarrhythmic medications; 19 (83%) were controlled with sotalol monotherapy. No patient required discontinuation of IV sotalol secondary to adverse effects, proarrhythmia, or QT prolongation.

CONCLUSION

IV sotalol is an effective antiarrhythmic option for pediatric patients and may be an excellent agent for acute termination of active arrhythmias. It was well tolerated, with no patient requiring discontinuation secondary to adverse effects.

High-dose sotalol is safe and effective in neonates and infants with refractory supraventricular tachyarrhythmias

Our objective was to assess the efficacy and safety of high-dose sotalol in neonates and infants with refractory supraventricular tachycardia (SVT). SVT in neonates and infants can be refractory to primary therapies; therefore, secondary agents, e.g., sotalol, are often required to obtain control of SVT. Age-factor nomogram dosing of sotalol is widely used; however, our institution uses greater doses based on body surface area (approximately 150-200 mg/m(2)/d). A retrospective review of 78 inpatients receiving sotalol, after failing another antiarrthymic medication, at our institution from 2001 to 2008 was performed. Corrected QT intervals (QTc), 24-h Holter-monitoring results, and outpatient records were reviewed to assess safety and efficacy for patients ≤ 2 years of age. Median patient age at the time of initiation of therapy was 24 days (range 3-728). Forty-eight patients (62%) were neonates, and 36 (46%) had congenital heart disease. The median sotalol dosage was 152 mg/m(2)/day (range 65-244). The SVT of 70 patients (90%) was controlled with sotalol. No patients experienced significant QTc prolongation or proarrhythmia. Mean duration of follow-up was 3.3 ± 0.24 years. High-dose sotalol allows for safe and rapid control of refractory tachyarrhythmias in this young age group.

Management of infants with idiopathic dilatation of the right atrium and atrial tachycardia

Idiopathic dilatation of the right atrium (IDRA) is a rare anomaly defined as isolated enlargement of the right atrium in the absence of other cardiac lesions known to cause right atrial dilatation. IDRA is a congenital anomaly with unknown pathogenesis and highly variable clinical presentation. Optimal management of severe IDRA is controversial and individualized. Literature reports of long-term follow-up have been limited. We describe a child with IDRA with rapid atrial tachycardia (AT) refractory to both medical and surgical management, and we provide long-term follow-up on our two previously reported cases, both of whom had documented AT. For infants with AT, the clinical course is unpredictable, and medical therapy is the first line of treatment. The decision to proceed with surgical resection of a giant right atrium should be made on an individual basis. Atrial resection along with a modified right atrial MAZE procedure could be considered in infants with life-threatening atrial tachyarrhythmia refractory to medical treatment. Surgical scarring of the right atrium may produce substrate for atrial arrhythmia, which may also be refractory to medical therapy. Histological examination of excised atrial tissue remains inconsistent and not contributory to the determination of the etiology of IDRA. Our three infants with IDRA illustrate unique features of their variable clinical courses, as well as continued difficulties with establishing clear guidelines with regard to surgical management of this unusual disorder.

Are 1–2 tablets dangerous? Beta-blocker exposure in toddlers

The common use and wide availability of beta-adrenergic blocking agents make them frequent ingestants for small children. Yet, there are no clear guidelines in the literature to direct the care of the toddler with the history of ingesting 1-2 tablets. With 40 years of extensive clinical experience, not one documented case of death or serious cardiovascular morbidity as a direct result of a beta-blocker exposure is to be found in an English language review for children under 6 years of age. As with children on chronic beta-blocker therapy, several cases of symptomatic hypoglycemia associated with a single acute propranolol exposure suggest a vulnerability to this complication. Though the risk to the toddler exposed to 1-2 tablets appears to be extremely small, several factors mitigate the actual risk to the child and the need for triage to a health care facility.