Medications used to manage supraventricular tachycardia in the infant a North American survey

Pediatric Beta Blocker Therapy: A Comprehensive Review of Development and Genetic Variation to Guide Precision-Based Therapy in Children, Adolescents, and Young Adults

Beta adrenergic receptor antagonists, known as beta blockers, are one of the most prescribed medications in both pediatric and adult cardiology. Unfortunately, most of these agents utilized in the pediatric clinical setting are prescribed off-label. Despite regulatory efforts aimed at increasing pediatric drug labeling, a majority of pediatric cardiovascular drug agents continue to lack pediatric-specific data to inform precision dosing for children, adolescents, and young adults. Adding to this complexity is the contribution of development (ontogeny) and genetic variation towards the variability in drug disposition and response. In the absence of current prospective trials, the purpose of this comprehensive review is to illustrate the current knowledge gaps regarding the key drivers of variability in beta blocker drug disposition and response and the opportunities for investigations that will lead to changes in pediatric drug labeling.

Pharmacological Management of Cardiac Arrhythmias in the Fetal and Neonatal Periods: A Scientific Statement From the American Heart Association: Endorsed by the Pediatric & Congenital Electrophysiology Society (PACES)

Disorders of the cardiac rhythm may occur in both the fetus and neonate. Because of the immature myocardium, the hemodynamic consequences of either bradyarrhythmias or tachyarrhythmias may be far more significant than in mature physiological states. Treatment options are limited in the fetus and neonate because of limited vascular access, patient size, and the significant risk/benefit ratio of any intervention. In addition, exposure of the fetus or neonate to either persistent arrhythmias or antiarrhythmic medications may have yet-to-be-determined long-term developmental consequences. This scientific statement discusses the mechanism of arrhythmias, pharmacological treatment options, and distinct aspects of pharmacokinetics for the fetus and neonate. From the available current data, subjects of apparent consistency/consensus are presented, as well as future directions for research in terms of aspects of care for which evidence has not been established.

Outcomes of Infant Supraventricular Tachycardia Management Without Medication

Most infants presenting with supraventricular tachycardia (SVT) are treated with an antiarrhythmic, primarily to prevent unrecognized future episodes that could lead to tachycardia-induced cardiomyopathy. A common practice at our institution is to not treat after the first presentation of infant SVT and instead educate parents on heart rate monitoring and reasons to present to care. The goal of this study was to evaluate the outcomes of non-pharmacologic treatment of infant SVT at first presentation and compare to outcomes of infants treated with an antiarrhythmic. This was a retrospective single center study of all infants presenting with a first episode of SVT from 2014 to 2021. Excluded were patients with a non-reentry type tachyarrhythmia, atrial flutter, long-RP tachycardia, congenital heart disease, or abnormal ventricular function. Sixty-four infants were included in the study. Thirty-six were managed without an antiarrhythmic. SVT recurred in 28% of the non-treatment group vs 50% in those treated with antiarrhythmics, p = 0.12. Of the patients admitted to the hospital, those in the non-treatment group had a shorter length of stay, 1(IQR 1-1) vs 3(IQR 2-4) days, p < 0.01. Non-treated patients were less likely to present to the emergency department for recurrent SVT, 6% vs 32%, p < 0.01. Neither group had a patient develop tachycardia-induced cardiomyopathy. For infants with structurally and functionally normal hearts, non-treatment combined with parental education after the first episode of SVT does not lead to worse outcomes. This approach avoids the burden of medication administration in an infant and may have the added benefit of empowering parents to feel comfortable managing clinically insignificant tachycardia at home.

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.

Outcomes in Infants with Supraventricular Tachycardia: Risk Factors for Readmission, Recurrence and Ablation

Supraventricular tachycardia (SVT) is the most common arrhythmia in infants. Once diagnosed, infants are admitted for antiarrhythmic therapy and discharged after observation. There are limited data on risk factors for readmission and readmission rates, while on medication. The objective of this study was to investigate risk factors for readmission and outcomes in infants diagnosed with SVT. This is a single-center retrospective study over a 10-year period of infants under 6 months of age with documented SVT. Infants with congenital heart disease requiring surgical or catheter intervention, gestational age less than 32 weeks or diagnosis of atrial flutter or fibrillation were excluded. The primary outcome was readmission within 31 days of hospital discharge. Long term need for ablation and eventual discontinuation of medications were assessed. Ninety patients were included. Beta blockers were the initial therapy in 66 and 28 required a medication change. Nineteen were readmitted within 31 days of discharge. The only clinical factor associated with early readmission was presence of ventricular pre-excitation (6/19 vs. 8/71, p = 0.03). Patients who were readmitted within 31 days had a longer length of treatment (12 [11.5, 22.0] vs. 10 [7.5, 12.0] months, p = 0.007) and were more likely to undergo ablation (4/19 vs. 2/71, p = 0.017). In this cohort of infants with SVT, readmission was common and ventricular pre-excitation was identified as a risk factor for readmission. Infants who were readmitted within 31 days of discharge had longer length of antiarrhythmic therapy and were more likely to undergo catheter ablation.

Clinical Predictors of Recurrent Supraventricular Tachycardia in Infancy

BACKGROUND

Data regarding recurrence risk among infants with supraventricular tachycardia (SVT) are limited.

OBJECTIVES

The purpose of this study was to determine incidence and factors associated with SVT recurrence.

METHODS

This was a retrospective single-center study (1984-2020) with prospective phone follow-up of infants with structurally normal hearts diagnosed at age ≤1 year with re-entrant SVT. Primary outcome was first SVT recurrence after hospital discharge. Classification and regression tree analysis was performed to determine a risk algorithm.

RESULTS

Among 460 infants (62% male), 87% were diagnosed at ≤60 days of age (median 13 days; IQR: 1-31 days). During a median follow-up of 5.2 years (IQR: 1.8-11.2 years), 33% had recurrence. On multivariable analysis, factors associated with recurrence included: fetal or late (>60 days) diagnosis (HR: 1.90; 95% CI: 1.26-2.86; and HR: 1.73; 95% CI: 1.07-2.77, respectively), Wolff-Parkinson-White (WPW) syndrome (HR: 2.46; 95% CI: 1.75-3.45), and need for multi-antiarrhythmic or second-line therapy (HR: 2.08; 95% CI: 1.45-2.99). Based on the classification and regression tree analysis, WPW incurred the highest risk. Among those without WPW, age at diagnosis was the most important factor predicting risk. Fetal or late diagnosis incurred higher risk, and if multi-antiarrhythmic or second-line therapy was also required, risk nearly doubled. Infants without WPW, who were diagnosed early (0-60 days), and who were discharged on propranolol were at lowest recurrence risk.

CONCLUSIONS

Infants with SVT are most likely to be diagnosed at ≤60 days and be male. Risk factors for recurrence (occurred in 33%), present at time of diagnosis, include WPW, fetal or late diagnosis, and multi-antiarrhythmic or second-line therapy. Infants with early diagnosis, without WPW, and discharged on first-line monotherapy are at lowest recurrence risk.

Effective Control of Supraventricular Tachycardia in Neonates May Requires Combination Pharmacologic Therapy

INTRODUCTION

Supraventricular tachycardia (SVT) is one of the arrhythmias that can occur in newborns. Most SVT incidents in the neonatal period are spontaneously resolved around the first year of life, but since tachycardia can frequently occur before complete resolution, appropriate medication use is required. However, no clear guidelines or consensus on the treatment of neonatal SVT have been established yet.

METHODS

From January 2011 to December 2021, demographic data and antiarrhythmic medications used were retrospectively analyzed for 18 newborns diagnosed with SVT at a single center.

RESULTS

A total of four medications (propranolol, amiodarone, flecainide, and atenolol) were used as maintenance therapy to prevent tachycardia recurrence, and propranolol was the most used, followed by amiodarone. Thirty-nine percent of the patients were controlled with monotherapy, but the remainder required two or more medications. The median period from medication initiation after diagnosis to the last tachycardia event was 15.5 days, and the median total duration of medication use was 362 days. None of the patients experienced any side effects of antiarrhythmic medications. The total duration of medication use was statistically significant according to the mechanism of SVT, and the usage time of the increased automaticity group was shorter than that of the re-entry group.

CONCLUSION

Since most neonatal SVT resolves within 1 year, it is significant to provide prophylactic medication to prevent tachycardia recurrence at least until 1 year of age, and depending on the patient, the appropriate combination of medications should be identified.

Evaluation of Clinical Course and Maintenance Drug Treatment of Supraventricular Tachycardia in Children During the First Years of Life. A Cohort Study from Eastern Germany

Supraventricular tachycardia (SVT) is considered the most common cause of arrhythmia in children and infants. Regarding the likelihood of a spontaneous resolution of SVTs during the first years of life, drug treatment aims to bridge the time until children 'grow out' out of the arrhythmia. The choice of antiarrhythmic agents and the planning of maintenance therapy are mainly based on clinical experience and retrospective single- and multi-institutional analyses and databases from all over the world approaching differently to this topic. The current study aimed to evaluate the clinical course, pharmacological treatment strategies, and constellations of risk for recurrences in the management of SVTs in children aged 3 < years. The database of the Heart Center Leipzig, Department of Pediatric cardiology, was searched for pediatric patients aged < 3 years with a clinically documented SVT between 2000 and 2019 that received pharmacologic treatment. Patients with complex congenital heart disease or arrhythmias following cardiac surgery were excluded. 69 patients were included. Pharmacologic treatment, follow-up schedule, recurrences, outcomes, and risk factors for complicated courses are reported. Drug therapy of SVTs in young children remains a controversial topic with heterogeneous treatment and follow-up strategies applied. Risk factors for recurrences and/or stubborn clinical courses are difficult rhythm control with 3 or more antiarrhythmic drugs, ectopic atrial tachycardias, and a first occurrence of the SVT in the fetal period. Prospective studies are needed to sufficiently evaluate optimal treatment strategies.

Medical Management of Infants With Supraventricular Tachycardia: Results From a Registry and Review of the Literature

Background

Several medication choices are available for acute and prophylactic treatment of refractory supraventricular tachycardia (SVT) in infants. There are almost no controlled trials, and medication choices are not necessarily evidence based. Our objective was to report the effectiveness of management strategies for infant SVT.

Methods

A registry of infants admitted to hospital with re-entrant SVT and no haemodynamically significant heart disease were prospectively followed at 11 international tertiary care centres. In addition, a systematic review of studies on infant re-entrant SVT in MEDLINE and EMBASE was conducted. Data on demographics, symptoms, acute and maintenance treatments, and outcomes were collected.

Results

A total of 2534 infants were included: n = 108 from the registry (median age, 9 days [0-324 days], 70.8% male) and n = 2426 from the literature review (median age, 14 days; 62.3% male). Propranolol was the most prevalent acute (61.4%) and maintenance treatment (53.8%) in the Registry, whereas digoxin was used sparingly (4.0% and 3.8%, respectively). Propranolol and digoxin were used frequently in the literature acutely (31% and 33.2%) and for maintenance (17.8% and 10.1%) (P < 0.001). No differences in acute or prophylactic effectiveness between medications were observed. Recurrence was higher in the Registry (25.0%) vs literature (13.4%) (P < 0.001), and 22 (0.9%) deaths were reported in the literature vs none in the Registry.

Conclusion

This was the largest cohort of infants with SVT analysed to date. Digoxin monotherapy use was rare amongst contemporary paediatric cardiologists. There was limited evidence to support one medication over another. Overall, recurrence and mortality rates on antiarrhythmic treatment were low.

Antiarrhythmic Medication in Neonates and Infants with Supraventricular Tachycardia

Supraventricular tachycardia (SVT) is the most common arrhythmia in neonates and infants, and pharmacological therapy is recommended to prevent recurrent episodes. This retrospective study aims to describe and analyze the practice patterns, effectiveness, and outcome of drug therapy for SVT in patients within the first year of life. Among the 67 patients analyzed, 48 presented with atrioventricular re-entrant tachycardia, 18 with focal atrial, and one with atrioventricular nodal re-entrant. Fetal tachycardia was reported in 27%. Antiarrhythmic treatment consisted of beta-receptor blocking agents in 42 patients, propafenone in 20, amiodarone in 20, and digoxin in 5. Arrhythmia control was achieved with single drug therapy in 70% of the patients, 21% needed dual therapy, and 6% triple. Propafenone was discontinued in 7 infants due to widening of the QRS complex. After 12 months (6-60), 75% of surviving patients were tachycardia-free and discontinued prophylactic treatment. Patients with fetal tachycardia had a significantly higher risk of persistent tachycardia (p: 0.007). Prophylactic antiarrhythmic medication for SVT in infancy is safe and well tolerated. Arrhythmia control is often achieved with single medication, and after cessation, most patients are free of arrhythmias. Infants with SVT and a history of fetal tachycardia are more prone to suffer from persistent SVT and relapses after cessation of prophylactic antiarrhythmic medication than infants with the first episode of SVT after birth.

"Second line medications" for supraventricular arrhythmias in children: In-hospital efficacy and adverse events during treatment initiation of sotalol and flecainide

INTRODUCTION

Sotalol and flecainide are used as second line agents in children for the treatment of supraventricular arrhythmias (SA) refractory to anti-beta adrenergic antiarrhythmics or digoxin. Efficacy and adverse events in this cohort have not been well described. Here, we report our institutional experience of second line treatment initiation for SA in children.

METHODS AND RESULTS

Utilizing an institutional database, 247 patients initiated on sotalol and 81 patients initiated on flecainide were identified. Congenital heart disease (CHD) was present in 40% of patients. Arrhythmia-free discharge on single or dual agent therapy (in combination with other antiarrhythmics) was 87% for sotalol and 91% for flecainide. Neither age, sex, dosing, presence of CHD nor arrhythmia subtype were associated with alterations in in-hospital efficacy. Compared to baseline, QTc intervals in sotalol patients (436 [416-452 ms] vs. 415 [400-431 ms], p < .01) and QRS intervals in flecainide patients (75 [68-88 ms] vs. 62 [56-71 ms], p < .01) were prolonged. Dose reduction or discontinuation due to QRS prolongation occurred in 9% of patients on flecainide. QTc prolongation resulting in dose reduction/discontinuation of sotalol was encountered in 9 patients (4%) and death with documented torsade de pointes in 2 patients (1%), with 9 of 11 patients having underlying CHD.

CONCLUSION

In children requiring second line agents for treatment of SA, both sotalol and flecainide appear to be highly efficacious. Although predominantly safe in otherwise healthy patients, electrocardiogram changes can occur and children with underlying cardiac disease may have an increased risk of adverse events and rhythm-related side effects during initiation.

Trends in the off-label use of β-blockers in pediatric patients

The use of US Food and Drug Administration (FDA)-approved drugs for the treatment of an unapproved indication or in an unapproved age group, or at doses or route of administration not indicated on the label is known as off-label use. Off-label use may be beneficial in circumstances when the standard-of-care treatment has failed, and/or no other FDA-approved medications are available for a particular condition. In pediatric patients, off-label use may increase the risk of adverse events as pharmacokinetic and pharmacodynamic data are limited in children. Approximately 73% of off-label drugs currently prescribed for various conditions do not have sufficient scientific evidence for safety and efficacy. For example, β-blockers are a class of drugs with FDA-approval for very few indications in pediatrics but are commonly used for various off-label indications. Interestingly, the proportion of off-label use of β-blockers in adults is at about 52% (66.2 million) of the total number of β-blockers prescribed. The frequency of off-label use of β-blockers in children is also high with limited data on the indications as well as safety and efficacy. We present trends in off-label use of β-blockers in children to discuss drug safety and efficacy and include recommendations for pediatric providers.

Neonatal supraventricular tachycardia

Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergency cardiac care in neonates. Atrioventricular reentrant tachycardia utilizing an atrioventricular bypass tract is the most common form of SVT presenting in the neonatal period. There is high likelihood for spontaneous resolution for most of the common arrhythmia substrates in infancy. Pharmacological agents remain as the primary therapy for neonates.

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.

Sustained tachyarrhythmia in children younger than 1 year of age: Six year single-center experience

BACKGROUND

The aim of this study was to evaluate the results of non-operational sustained tachyarrhythmia in patients <1 year of age at the present center.

METHODS

Between November 2010 and November 2016, the demographic characteristics, type and localization of the tachyarrhythmia, echocardiographic findings, and medical and/or ablation therapy for patients <1 year of age with sustained tachyarrhythmia were evaluated.

RESULTS

Of 99 patients, 91 had sustained supraventricular tachycardia, and eight had sustained ventricular tachycardia. The median age was 30 days (range, 1-350 days), and the median weight was 4.2 kg (range, 2-13 kg). The common symptoms were palpitation and restlessness (n = 49, 49.5%), or the tachycardia was detected during routine inspection (n = 25, 25.3%) or fetal echocardiography (n = 11, 11.1%). Nineteen individuals (19%) had left ventricular (LV) dysfunction on first echocardiography. Twenty individuals had congenital heart disease. Common diagnoses were Wolff-Parkinson-White syndrome (n = 27), focal atrial tachycardia (n = 10), permanent junctional reciprocating tachycardia(n = 6), and atrial flutter (n = 6). Seventeen patients underwent medical therapy combined with cardioversion. The most commonly used abortive and acute therapy agents were adenosine, esmolol, and amiodarone. The most common combination therapy was propranolol and amiodarone, followed by a propranolol and propafenone combination. Nine individuals were treated with catheter ablation due to either resistance to medical therapy or LV dysfunction.

CONCLUSIONS

Tachyarrhythmias in children <1 year of age are mostly caused by accessory pathways and require multidrug therapy. Catheter ablation is an effective alternative therapy in the case of resistance to medical therapy and/or LV dysfunction.

Short-term Refractive Effects of Propranolol Hydrochloride Prophylaxis on Retinopathy of Prematurity in Very Preterm Newborns

PURPOSE

Retinopathy of prematurity (ROP) is one of the major problems of surviving premature infants with several ophthalmic morbidities such as increased risk of refractive errors, strabismus, and cortical visual impairment. Use of propranolol hydrochloride (PH) for the prevention of ROP is a new promising treatment modality. However, long-term effects are still to be defined. In our study, we aimed to investigate the short-term refractive effects of PH used for ROP prophylaxis in very preterm newborns.

METHODS

This is a prospective, randomized, double-blind, placebo-controlled study. Very preterm newborns with a birthweight less than or equal to 1500 g and/or born prior to 32 gestational weeks were included in the study. The subjects were randomly divided into two groups: control group (CG, n = 37) given placebo and PH group (PHG, n = 34) given PH starting from 4 weeks after birth (27.1 ± 2.1 day). PHG patients received PH therapy for about 1 month (25.7 ± 7.8 day). Anthropometric measurements including weight, length, and head circumference were recorded before PH treatment (at birth) and during eye control (at corrected age). Cycloplegic refraction values were measured by retinoscopy at corrected age (CG: 10.3 ± 4.3 months, PHG: 11.4 ± 4.8 months).

RESULTS

Anthropometric measurements including gestational age, weight, length, and head circumference were similar at birth and corrected age in both groups. The mean level of spherical refraction was significantly less hyperopic in the PHG than in the CG (CG: 1.37 ± 1.40 D, PHG: 0.37 ± 1.44 D) (p = 0.005).

CONCLUSION

PH may lead to myopic shift by affecting the beta-adrenergic receptors in the choroid or ciliary body of the developing eye. Long-term refractive follow-up is required in order to elucidate the effects of PH on emmetropization process of these very preterm infants.

Propranolol Versus Digoxin in the Neonate for Supraventricular Tachycardia (from the Pediatric Health Information System)

Conflicting data exist for the appropriate management of a neonate with supraventricular tachycardia (SVT). We sought to assess postnatal prescribing trends for neonates with SVT and to evaluate if there were therapy-specific mortality and resource utilization benefits. Nationally distributed data from 44 pediatric hospitals in the 2004 to 2015 Pediatric Health Information System database were used to identify patients admitted at ≤2 days of age with structurally normal hearts and treated with an antiarrhythmic medication. Outcome variables were mortality, cost, and length of stay (LOS). Multivariable models and propensity score matching were used. There were 2,657 neonates identified with a median gestational age of 37 weeks (interquartile range 34 to 39). Digoxin and propranolol were most commonly prescribed; digoxin use steadily decreased to 23% of antiarrhythmic medication administrations over the study period, whereas propranolol increased to 77%. Multivariable comparisons revealed that the odds of mortality for neonates on propranolol were 0.32 times those on digoxin (95% confidence interval 0.17 to 0.59; p <0.001); hospital costs were $16,549 lower for propranolol versus digoxin (95% confidence interval $5,502 to $27,596, p = 0.003). No difference was found for LOS. Propensity score matching and subset analyses of patients with only arrhythmia diagnostic codes confirmed mortality benefits for propranolol, although longer LOS was observed. In conclusion, propranolol use for the neonate with SVT is associated with lower in-hospital mortality and hospital costs compared with digoxin.

Efficacy of Intravenous Sotalol for Treatment of Incessant Tachyarrhythmias in Children

Our objective was to evaluate the efficacy and safety of intravenous (IV) sotalol in the treatment of incessant tachyarrhythmias in children with normal cardiac function. Eighty-three children admitted to hospital from October 2011 to December 2014 were treated with IV sotalol or IV sotalol plus IV propafenone. The time to conversion to sinus rhythm and maintaining sinus rhythm were evaluated. Blood pressure, heart rate, QTc, PR intervals, and rhythm were monitored; 50 patients (60%) were converted to sinus rhythm with IV sotalol; time to conversion was 12.0 ± 18.0 hours; 12 additional patients (15%) were converted with IV sotalol combined with IV propafenone; time to conversion was 13.1 ± 17.6 hours. A total of 62 patients (75%) were converted. Success rates of IV sotalol for different tachycardias were similar, whereas the time to conversion differed. The time to conversion for atrioventricular reentrant tachycardia was shorter than atrial tachycardia or atrial flutter (p <0.05). QTc prolongation (from 253 to 486 ms and from 398 ms to 500 ms) was seen in 2 patients (2%) within 48 hours after conversion. The QTc reverted to normal range at 48 and 144 hours, respectively, after withdrawal of IV sotalol. A 1 month old with atrial flutter developed bradycardia (7:1 atrioventricular conduction) 5 minutes after IV sotalol, and heart rate increased gradually after drug withdrawal. No other adverse effects were observed. In conclusion, IV sotalol can be safely and effectively used to terminate pediatric tachycardias in patients with normal cardiac function. No proarrhythmic or significant toxicities were detected. Close monitoring of QTc and heart rate is required after IV sotalol. Adding IV propafenone to IV sotalol in resistant cases enhance conversion.

Nadolol for Treatment of Supraventricular Tachycardia in Infants and Young Children

Supraventricular tachycardia (SVT) is a common infant arrhythmia, for which beta-blockers are frequently chosen as therapy. Propranolol is a common choice though it is dosed every 6-8 h. We reviewed the clinical results of treating infant SVT with an extemporaneous preparation of nadolol. Retrospective cohort study of patients under 2 years old receiving nadolol for SVT at a single center. Patients were ascertained by patient and pharmacy databases. Twenty-eight infants received nadolol, of whom 25 had regular narrow complex tachycardia, 2 atrial flutter, and 1 focal atrial tachycardia. Patient age at initiation was a median 54 days (range 10-720). The final dose was 1 mg/kg/day in 22/28 patients (range 0.5-2). Once-daily dosing was used in 20 patients (71.4%); dosing was BID in 7, TID in 1. Among regular narrow complex tachycardia patients, 18/25 received nadolol monotherapy and 7 required additional agents; flecainide in 6, digoxin in 1. The median age of tachyarrhythmia onset was 18 days (range 1-180) with a median age of nadolol initiation of 30 days (range 11-390). Of the 20 regular narrow complex tachycardia patients initiated on nadolol monotherapy, 85% had no recurrences as of 1-year follow-up. Side effects were suspected in 3 of 28 (10.7%), including wheezing (n = 1, 3.5%), irritability and diarrhea (n = 1, 3.5%), and bradycardia (n = 1, 3.5%). Oral nadolol suspension was a successful treatment for SVT in 85% of patients with minimal adverse effects. Single daily dosing was used in the majority of patients.

Propranolol 0.1% eye micro-drops in newborns with retinopathy of prematurity: a pilot clinical trial

BACKGROUND

Oral propranolol reduces retinopathy of prematurity (ROP) progression, although not safely. This study evaluated safety and efficacy of propranolol eye micro-drops in preterm newborns with ROP.

METHODS

A multicenter open-label trial, planned according to the Simon optimal two-stage design, was performed to analyze safety and efficacy of propranolol micro-drops in newborns with stage 2 ROP. To this end, hemodynamic and respiratory parameters were monitored, and blood samples were collected weekly, for 3 wk. Propranolol plasma levels were also monitored. The progression of the disease was evaluated with serial ophthalmologic examinations.

RESULTS

Twenty-three newborns were enrolled. Since the fourth of the first 19 newborns enrolled in the first stage of the study showed a progression to stage 2 or 3 with plus, the second stage was prematurely discontinued. Even though the objective to complete the second stage was not achieved, the percentage of ROP progression (26%) was similar to that obtained previously with oral propranolol administration. However, no adverse effects were observed and propranolol plasma levels were significantly lower than those measured after oral administration.

CONCLUSION

Propranolol 0.1% eye micro-drops are well tolerated, but not sufficiently effective. Further studies are required to identify the optimal dose and administration schedule.

Variation in Antiarrhythmic Management of Infants Hospitalized with Supraventricular Tachycardia: A Multi-Institutional Analysis

Supraventricular tachycardia (SVT) is the most frequent form of symptomatic tachyarrhythmia in infants. The purposes of this study were to describe practice patterns of the management of infants hospitalized with SVT and factors associated with 30-day hospital readmission. This was a multi-institutional, retrospective review of the pediatric health information system database of SVT hospitalizations from 2003 to 2013. High-volume centers (HVC) were defined as those at the upper quartile of admissions. Infants with an ICD-9 code of paroxysmal SVT were included. Antiarrhythmics investigated included amiodarone, atenolol, digoxin, esmolol, flecainide, procainamide, propafenone, propranolol, and sotalol. Frequency of antiarrhythmic use based on center volume was the primary end point. Rate of 30-day SVT readmission was the secondary end point. Analysis of factors associated with readmission was assessed by Chi-square analysis and expressed as odds ratio and 95 % confidence interval. A total of 851 patients (60 % male, 44 % neonates) were hospitalized at 43 hospitals. Propranolol, digoxin, and amiodarone were the most frequently utilized antiarrhythmics. HVCs represented 12 hospitals comprising 494 (58 %) patients. Although HVCs were more likely to utilize propranolol (OR 2.5, CI 1.5-4.1), there was no significant difference in the 30-day readmission rate between patients treated at HVCs versus non-HVCs (p = 0.9). The majority of infants with SVT are treated with a small number of antiarrhythmic medications during index hospitalization. Although hospital-to-hospital variation in antiarrhythmic choice exists, there appears to be no difference in readmission. The remaining practice variation may be related to intrinsic patient characteristics.

Clinical research in neonates and infants: Challenges and perspectives

To date, up to 65% of drugs used in neonates and infants are off-label or unlicensed, as they were implemented in clinical care without the usual regulatory phases of pharmacological drug development. Pharmacotherapy in this age group is still mainly based on the individual clinical expertise of specialized pediatricians. Pharmacological trials involving neonates are indeed more difficult to perform: appropriate dosing is hampered by the rapid physiological changes occurring at this stage of development, and the selection of proper end-points and biomarkers is complicated by the limited knowledge of the pathophysiology of the specific diseases of infancy. Moreover, there are many ethical challenges in planning and conducting drug studies in pediatric patients (especially in newborns and infants). In the current review, we address some challenges and discuss possible perspectives to stimulate scientific and clinical pharmacological research in neonates and infants. We hereby aim to illustrate the add on value of the regulatory framework for model-based neonatal medicinal development currently used in Europe and the United States. We provide several examples of successful recent pharmacological trials performed in neonates and infants. In these examples, success was ensured by the implementation of specific pharmacokinetic assessments, thanks to accurate drug dosing achieved with a combination of dose validation, population pharmacokinetics and mathematical models of drug clearance and distribution; moreover, age-specific pharmacodynamics was considered via appropriate evaluations of drug efficacy with end-points adapted to the peculiar pathophysiology of diseases in this age group. These "pharmacological" challenges add to the ethical challenges that are always present in planning and conducting clinical studies in neonates and infants and support the opinion that clinical research in pediatrics should be evaluated by ad hoc ethical committees with specific expertise.

Efficacy of digoxin in comparison with propranolol for treatment of infant supraventricular tachycardia: analysis of a large, national database

INTRODUCTION

Digoxin or propranolol are used as first-line enteral agents for treatment of infant supraventricular tachycardia. We used a large national database to determine whether enteral digoxin or propranolol was more efficacious as first-line infant supraventricular tachycardia therapy.

MATERIALS AND METHODS

The Pediatric Health Information System database was queried over 10 years for infants with supraventricular tachycardia initiated on enteral digoxin or propranolol monotherapy. Patients were excluded for Wolff-Parkinson-White, intravenous antiarrhythmics (other than adenosine), or death. Success was considered as discharge on the initiated monotherapy. Risk factors for successful monotherapy and risk factors for readmission for supraventricular tachycardia for patients discharged on monotherapy were determined.

RESULTS

A total of 374 patients (59.6% male) met the study criteria. Median length of stay was 7 days (interquartile range of 3-16 days). Patients had CHD (n=199, 53.2%) and underwent cardiac surgery (n=123, 32.9%), ICU admission (n=238, 63.6%), mechanical ventilation (n=146, 39.0%), and extracorporeal membrane oxygenation (n=3, 0.8%). Pharmacotherapy initiation was at median 37 days of life (interquartile range of 12-127 days) and 47.3% were initiated on digoxin. Success was similar between digoxin (73.1%) and propranolol (73.5%). Initial therapy with digoxin was not associated with success (odds ratio 1.01, 95% CI 0.64-1.61, p=0.93). Multivariable analysis demonstrated hospital length of stay (odds ratio 0.98, 95% CI 0.98-1.00) and involvement of a paediatric cardiologist (odds ratio 0.46, 95% CI 0.29-0.75) associated with monotherapy failure, and male gender (odds ratio 1.66, 95% CI 1.03-2.67) associated with monotherapy success. No variables were significant for readmission on multivariable analysis.

DISCUSSION

Digoxin or propranolol may be equally efficacious for inpatient treatment of infant supraventricular tachycardia.

Treatment of supraventricular tachycardia in infants: Analysis of a large multicenter database

OBJECTIVE

Supraventricular tachycardia (SVT) is the most common arrhythmia in infants. Infants are typically treated with antiarrhythmic medications, but there is a lack of evidence guiding management, thus exposing infants to risks of both inadequate therapy and medication adverse events. We used data from a large clinical database to better understand current practices in SVT management, safety of commonly used medications, and outcomes of hospitalized infants treated for SVT.

METHODS

This retrospective data analysis included all infants discharged from Pediatrix Medical Group neonatal intensive care units between 1998 and 2012 with a diagnosis of SVT who were treated with antiarrhythmic medications. We categorized infants by the presence of congenital heart disease other than patent ductus arteriosus. Medications were categorized as abortive, acute, or secondary prevention therapies. We used descriptive statistics to describe medication use, adverse events, and outcomes including SVT recurrence and mortality.

RESULTS

A total of 2848 infants with SVT were identified, of whom 367 (13%) had congenital heart disease. Overall, SVT in-hospital recurrence was high (13%), and almost one fifth of our cohort (18%) experienced an adverse event. Mortality was 2% in the overall cohort and 6% in the congenital heart disease group (p<0.001). Adenosine was the most commonly used abortive therapy, but there was significant practice variation in therapies used for acute treatment and secondary prevention of SVT.

CONCLUSION AND PRACTICE IMPLICATION

Significant variation in SVT treatment and suboptimal outcomes warrant future clinical trials to determine best practices in treating SVT in infants.

Neonatal thyrotoxicosis with severe supraventricular tachycardia: case report and review of the literature

Neonatal thyrotoxicosis is a rare condition caused by the transplacental passage of thyroid stimulating immunoglobulins from mothers with Graves' disease. We report a case of neonatal thyrotoxicosis with concurrent supraventricular tachycardia (SVT). The female infant, who was born by section due to breech delivery and meconium in the amniotic fluid at 36 weeks of gestation, presented with tachycardia on day 7. Her heart rate was between 260 and 300 beats/min, and an electrocardiogram revealed ongoing SVT. Sotalol was effective after two cardioversions in maintaining sinus rhythm. Thyroid function studies revealed hyperthyroidism in the infant, and her mother was found to have Graves' disease. Since symptoms and signs can vary, especially in preterm infants with neonatal hyperthyroidism, we want to emphasize the importance of prenatal care and follow-ups of Graves' disease associated pregnancies and management of newborns after birth.

Efficacy and safety of high-dose propranolol for the management of infant supraventricular tachyarrhythmias

OBJECTIVE

To report our experience with high-dose propranolol monotherapy for prophylaxis and treatment of infant supraventricular arrhythmias (SAs).

STUDY DESIGN

Patients <1 year of age initiated on enteral propranolol as inpatients for management of SA were identified during a 10-year time period from the Texas Children's Hospital pharmacy database. Patients were included if they received propranolol monotherapy for SA. Propranolol therapy was considered successful when patients were initiated and discharged on monotherapy, without documented recurrence of arrhythmia or requiring additional antiarrhythmic medication. Patients discharged on propranolol were followed as outpatients until therapy was discontinued or a year from initiation, whichever came first.

RESULTS

A total of 287 patients met study criteria (59.2% male). Propranolol therapy was initiated at a median of 17 days of age (IQR 6-33 days) at a total daily dose of 3.6 ± 1.0 mg/kg/day. Propranolol was successful in controlling SA throughout the inpatient stay in 67.3% of patients. Only one patient experienced a clinically significant adverse event that required propranolol discontinuation. A multivariable logistic regression analysis identified the presence of congenital heart disease (OR 0.42, 95% CI 0.19-0.94, P = .04) and Wolff-Parkinson-White (OR 0.42, 95% CI 0.21-0.87, P = .01) as factors for nonsuccessful inpatient propranolol monotherapy. Of 190 patients discharged on propranolol monotherapy, 87.7% were recurrence free during follow-up.

CONCLUSIONS

High-dose propranolol is safe and reasonably successful in the treatment of infant SA. Inpatient control may be a predictor of continued outpatient efficacy.

Comparative effectiveness of digoxin and propranolol for supraventricular tachycardia in infants

OBJECTIVES

Supraventricular tachycardia is the most common arrhythmia in infants, and antiarrhythmic medications are frequently used for prophylaxis. The optimal prophylactic antiarrhythmic medication is unknown, and prior randomized trials have been underpowered. We used data from a large clinical registry to compare efficacy and safety of digoxin and propranolol for infant supraventricular tachycardia prophylaxis. We hypothesized that supraventricular tachycardia recurrence is less common on digoxin when compared with propranolol.

DESIGN

Retrospective cohort study.

SETTING

Pediatrix Medical Group neonatal ICUs.

PATIENTS

Infants discharged from 1998 to 2012 with supraventricular tachycardia who were treated with digoxin or propranolol. We excluded infants discharged before completing 2 days of therapy, those with Wolff-Parkinson-White syndrome, structural heart defects (except atrial/ventricular septal defects and patent ductus arteriosus), and those started on multidrug therapy.

MEASUREMENTS AND MAIN RESULTS

We used Cox proportional hazards to evaluate supraventricular tachycardia recurrence, defined as need for adenosine or electrical cardioversion while exposed to digoxin versus propranolol, controlling for infant characteristics, inotropic support, supplemental oxygen, and presence of a central line. We identified 342 infants exposed to digoxin and 142 infants exposed to propranolol. The incidence rate of treatment failure was 6.7/1,000 infant-days of exposure to digoxin and 15.4/1,000 infant-days of exposure to propranolol. On multivariable analysis, treatment failure was higher on propranolol when compared with that on digoxin (hazard ratio, 1.97; 95% CI, 1.05-3.71). Hypotension was more frequent during exposure to digoxin versus propranolol (39.4 vs 11.1/1,000 infant-days; p < 0.001). There was no difference in frequency of other clinical adverse events.

CONCLUSIONS

Digoxin was associated with fewer episodes of supraventricular tachycardia recurrence but more frequent hypotension in hospitalized infants relative to propranolol.

Amiodarone monitoring practices in pediatric hospitals in the United States

Laboratory monitoring of amiodarone therapy is recommended due to the high incidence of adverse events associated with the drug. The use of appropriate monitoring is unknown at pediatric hospitals. The Pediatric Health Information System database was queried during a 5-year period for all patients who received amiodarone while hospitalized. Use of thyroid function testing, hepatic function testing, electrocardiogram, pulmonary function testing, and chest X-ray for patients was identified. Incidence of individual monitoring tests and complete monitoring profile was identified and compared across patient demographic and clinical factors and pediatric hospital. A total of 1,703 patients met the study criteria, and the incidence of complete amiodarone monitoring for all patients was 7.6 %. The least common monitoring test performed was triiodothyronine at 19.4 %, and the most common was electrocardiogram at 89.7 %. Critically ill patients and neonates were more likely to have amiodarone monitoring. Considerable variation in monitoring practices between pediatric hospitals was identified. Monitoring of amiodarone therapy in patients admitted to pediatric hospitals is low. Future efforts to standardize care are warranted.

Radiofrequency ablation of drug-refractory arrhythmias in small children younger than 1 year of age: single-center experience

The use of radiofrequency ablation (RFA) for the management of supraventricular tachycardia (SVT) in infants and small children remains controversial. The aim of this study was to evaluate the safety and efficacy of RFA in critically ill small children (<1 year of age) with drug-resistant tachycardia accompanied by arrhythmogenic cardiomyopathy and heart failure. The study included 15 patients age 5.3 ± 3.7 months. Wolff-Parkinson-White syndrome and atrial tachycardia were detected in eight (53.3 %) and seven (46.7 %) of patients, respectively. Patients with structural heart pathology, including congenital heart diseases and laboratory-confirmed myocarditis, were excluded from the study. Indications for RFA included drag-refractory SVT accompanied by arrhythmogenic cardiomyopathy and heart failure. Unsuccessful ablation was observed in two 1-month-old patients who underwent successful ablation 3 months later. The follow-up period ranged from 0.5 to 8 years (average 3.9). Only one patient (6.7 %) had tachycardia recurrence 1 month after RFA. The short- and long-term RFA success rates were 86.7 and 93.3 %, respectively. The study did not show any procedure-related complications. Heart failure disappeared within 5-7 days. Complete normalization of heart chamber sizes was documented within 1 month after effective RFA. A three-dimensional CARTO system (Biosense Webster, Inc., USA) was used in three patients with body weight >7 kg. The use of the CARTO system resulted in a remarkable decrease of the fluoroscopy time without vascular injury or other procedure-related complications in all cases. Our study suggests that RFA may be considered the method of choice for SVT treatment in small children when drug therapy is ineffective and arrhythmogenic cardiomyopathy progresses.

Effects of landiolol hydrochloride on intractable tachyarrhythmia after pediatric cardiac surgery

BACKGROUND

While β-blockers can be effective in controlling tachyarrhythmias after pediatric cardiac surgery, a negative inotropic influence sometimes complicates their use. Landiolol hydrochloride is a novel, ultra-short-acting β-blocker recently developed in Japan. The drug has higher β1:β2 selectivity ratio and a less negative inotropic effect. This study retrospectively evaluates the efficacy and safety of landiolol in the management of tachyarrhythmias after pediatric cardiac surgery.

METHODS

A retrospective analysis was performed on 312 consecutive patients undergoing surgery for congenital heart disease. Twelve patients were treated with landiolol for critical tachyarrhythmia. The mean age of patients was 28.7 ± 10.6 months. Five junctional ectopic tachycardia, 2 atrial flutters, 1 paroxysmal supraventricular tachycardia, 1 atrial fibrillation, 1 atrioventricular reciprocating tachycardia with Wolff-Parkinson-White syndrome and 2 excessive sinus tachycardia were treated.

RESULTS

The mean loading and maintenance doses were 11.3 ± 4.0 and 6.8 ± 0.9 μg/kg per minute, respectively. Rate control was achieved in all patients. Landiolol reduced the heart rate from 169.7 ± 11.4 to 127.7 ± 7.5 beats per minute (p < 0.05) while blood pressure did not significantly change. Tachyarrhythmias were converted to sinus rhythm in 70.0% of the cases and the average time needed to achieve heart rate reduction was 2.3 ± 0.5 hours.

CONCLUSIONS

Landiolol was efficacious in treating tachyarrhythmia in pediatric cardiac surgery. The desired negative chronotropic effect was achieved without significant hemodynamic compromise. The ultra-short half-life of landiolol provided rapid dose manipulation. This study suggests that landiolol is a promising option for the management of postoperative tachyarrhythmias in pediatric patients.

Oral flecainide is effective in management of refractory tachycardia in infants

BACKGROUND

Propranolol and digoxin have been used as first line drugs for treatment of supraventricular tachycardia (SVT) in infants. Flecainide and other drugs have been effective as a second line treatment for controlling refractory SVT.

MATERIAL AND METHODS

This is a prospective study without randomization and control. The inclusion criteria were: infants (≤12 months) with tachyarrhythmia who failed to respond to first line drugs. Patients having post-surgical arrhythmias were excluded from the study.

RESULTS

A total of 8 infants were treated with flecainide for refractory tachyarrhythmia's. Diagnosis on electrocardiogram (ECG) was atrioventricular reentry tachycardia (AVRT) in 5, atrial ectopic tachycardia (AET) in 2, a combination of AVRT and atrioventricular nodal reentry tachycardia (AVNRT) in 1. All patients had failed trial of antiarrhythmic drugs prior to presentation: digoxin and propranolol in 7, amiodarone in 3, cardioversion in 1. Flecainide (80-130 mg/m(2) orally) resulted in termination of the tachycardia in all 8 patients. Acute pharmacological termination of arrhythmia occurred with oral flecainide loading in 1 and temporarily with intravenous esmolol loading in 1 patient. Adjuvant therapy in form of propranolol was used in 5 and digoxin in 2. There were no side effects noted. Four episodes of recurrence were noted in 3 patients over 2 years, all of which responded to dose increase. Mean follow up time is 24.75 months.

CONCLUSION

This small case series indicates that flecainide is an effective antiarrhythmic agent, free of side effects and when used orally is capable of terminating and controlling relatively resistant supraventricular tachycardia in children.

A multi-institutional analysis of inpatient treatment for supraventricular tachycardia in newborns and infants

This study aimed to examine practice patterns in the inpatient medical treatment of newborns and infants with supraventricular tachycardia (SVT) using the Pediatric Health Information System (PHIS) database, a large, multi-institutional administrative database. A retrospective examination of pediatric hospital discharge data was performed during the study period from January 2003 to September 2008. Data were extracted from the index hospitalization of all individuals younger than 1 year with the principal discharge diagnosis of SVT. Those with coexisting congenital or acquired structural heart disease were excluded from the study. The analysis included 171 patients. No deaths occurred, and 95 % of the infants were discharged to home. More than half (53 %) of the patients spent a portion of their hospital stay in an intensive care unit (ICU) setting. Multidrug therapy was common, with 45 % of the patients receiving two or more antiarrhythmic agents on the day of discharge. The five most commonly used antiarrhythmic drugs, in order of decreasing frequency of use, were propranolol, digoxin, amiodarone, flecainide, and sotalol. The median hospital stay for the group was 4 days, and this value increased as a function of the number of antiarrhythmic drugs used (median, 7 days for three or more agents) and the need for intensive care (median, 6 days). The information provided in this study helps to define common practice patterns and should allow caregivers to provide meaningful expectations to families regarding their potential treatment course and to anticipate the hospital length of stay.

Tachycardia-induced cardiomyopathy in a 1-month-old infant

Supraventricular tachycardia (SVT) is the most common arrhythmia in children and is especially common in infants. SVT is typically thought of as an acute condition; however, if unrecognized, a persistent tachyarrhythmia can progress to a state of cardiac contractile dysfunction known as tachycardia-induced cardiomyopathy. A high index of suspicion for an underlying arrhythmia is needed in the workup of any patient with new onset heart failure, and the 12-lead electrocardiogram can aid in the diagnosis. While this may be a rare cause of dilated cardiomyopathy and heart failure in children, the condition is usually reversible and should be considered in infants and young children.

The Study of Antiarrhythmic Medications in Infancy (SAMIS)

Background—

Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergent cardiac care in children, yet its management has never been subjected to a randomized controlled clinical trial. The purpose of this study was to compare the efficacy and safety of the 2 most commonly used medications for antiarrhythmic prophylaxis of SVT in infants: digoxin and propranolol.

Methods and Results—

This was a randomized, double-blind, multicenter study of infants <4 months with SVT (atrioventricular reciprocating tachycardia or atrioventricular nodal reentrant tachycardia), excluding Wolff-Parkinson-White, comparing digoxin with propranolol. The primary end point was recurrence of SVT requiring medical intervention. Time to recurrence and adverse events were secondary outcomes. Sixty-one patients completed the study, 27 randomized to digoxin and 34 to propranolol. SVT recurred in 19% of patients on digoxin and 31% of patients on propranolol ( P =0.25). No first recurrence occurred after 110 days of treatment. The 6-month recurrence-free status was 79% for patients on digoxin and 67% for patients on propranolol ( P =0.34), and there were no first recurrences in either group between 6 and 12 months. There were no deaths and no serious adverse events related to study medication.

Conclusions—

There was no difference in SVT recurrence in infants treated with digoxin versus propranolol. The current standard practice may be treating infants longer than required and indicates the need for a placebo-controlled trial.

Clinical Trial Registration Information—

http://clinicaltrials.gov ; NCT-00390546.

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.

The impact of 2007 infective endocarditis prophylaxis guidelines on the practice of congenital heart disease specialists

BACKGROUND

the impact of the 2007 American Heart Association endocarditis prophylaxis guidelines on clinician practice has not been well established. Our objective was to evaluate how the American Heart Association endocarditis guidelines changed the practice of cardiologists who manage congenital heart disease and to ascertain the degree of practice variation among cardiologists.

METHODS

a cross-sectional Web-based survey was e-mailed to Canadian (n = 134), Australian (n = 33), New Zealand (n = 9), and a random sample of American (n = 250) pediatric and adult congenital heart disease cardiologists in 2008. Nonrespondents received the survey 4 times by e-mail and once by regular post.

RESULTS

the response rate was 55%. The lesions for which cardiologists were most evenly divided between recommending versus not recommending prophylaxis were "rheumatic mitral stenosis of moderate severity" (45% recommended prophylaxis) and "perimembranous ventricular septal defect (VSD) status post surgical patch closure with no residual shunt 3 months post-operatively" (54% recommended prophylaxis). The lesions for which the greatest proportion of cardiologists discontinued prophylaxis were "small muscular VSD, no previous endocarditis" (80% discontinued prophylaxis) and "small audible patent ductus arteriosus" (83% discontinued prophylaxis). Only 69% recommended prophylaxis for "VSD s/p surgical patch closure with small residual shunt" despite current guidelines recommending prophylaxis for this scenario. Twenty-eight percent of respondents felt that the new guidelines leave some patients at risk, and 6% would not recounsel any low-risk patients following these guidelines.

CONCLUSIONS

the 2007 guidelines have resulted in a substantial change in endocarditis prophylaxis. There remains considerable heterogeneity among cardiologists regarding the prophylaxis of certain cardiac lesions.

Cardiovascular risk screening before starting stimulant medications and prescribing practices of canadian physicians: impact of the Health Canada advisory

OBJECTIVE

In May 2006, Health Canada released a statement advising against the use of stimulant medications for patients with cardiac disease after isolated reports of sudden death. The objectives of this study were to determine whether the Health Canada advisory has had an impact on cardiovascular screening of all children with attention-deficit/hyperactivity disorder before stimulants and the medical treatment of children with attention-deficit/hyperactivity disorder and real or potential cardiac problems.

METHODS

Two questionnaires were developed and mailed to a sample of noncardiologist physicians and pediatric cardiologists in Canada. The difference in the proportion of noncardiologist-responders who performed a "full screen" before and after the announcement of the Health Canada advisory was analyzed. Willingness to prescribe stimulant medications to children was assessed by using a series of clinical scenarios.

RESULTS

A total of 2326 questionnaires were distributed, 717 (31%) of which were returned. The proportion who performed a full screen increased for both noncardiologists and cardiologists after the advisory. There was also a dramatic increase in the use of the "modified screen" by the noncardiologist group and the pediatrician subgroup. There was a considerable decrease in the proportion of noncardiologists who were willing to prescribe stimulant medications to children with potential or actual cardiac issues after the advisory.

CONCLUSIONS

The Health Canada advisory has had an impact on clinical practice. It has resulted in an increase in the use of cardiovascular assessment tools before starting stimulants and a decrease in noncardiologists' willingness to prescribe stimulants to those with real or potential cardiac disease. These changes have occurred despite the lack of studies to address the cardiac risks of these medications. Because it will be difficult to assess the true cardiac risks of stimulants, consensus recommendations are needed to determine whether screening is required, what constitutes an appropriate screen, and which children can be treated cautiously with stimulant medications.

Supraventricular tachycardia in the pediatric primary care setting: Age-related presentation, diagnosis, and management

As many as 1 in 250 children experience supraventricular tachycardia (SVT), but its presentation is often vague and its symptoms mistakenly attributed to other common pediatric conditions. If SVT is correctly identified in a timely manner, most children will go on to live normal healthy lives. SVT is not covered in depth in most pediatric advanced practice nursing programs, but because of its prevalence, it should be familiar to all pediatric primary care providers. This article reviews common mechanisms of SVT and their age-related presentation, diagnosis, and management. A case study of an 8-year-old boy with SVT is presented.

Therapeutic Levels of Intravenous Procainamide in Neonates: A Retrospective Assessment

STUDY OBJECTIVES

To evaluate dosing and pharmacokinetic parameters of intravenous continuous-infusion procainamide in neonates, and to identify dosage regimens and factors leading to therapeutic procainamide levels and minimal adverse events.

DESIGN

Retrospective, observational study.

SETTING

Pediatric hospital.

PATIENTS

. Twenty-one patients (seven preterm, 14 full term) younger than 30 days who received continuous-infusion procainamide therapy for more than 15 hours or had two consecutive therapeutic procainamide levels obtained while receiving therapy between June 1, 2002, and December 31, 2005.

MEASUREMENTS AND MAIN RESULTS

Data on demographics, dosing, drug levels, and adverse effects were collected. Doses that achieved therapeutic levels were documented, and procainamide clearance was calculated and evaluated with regard to renal function and gestational age in patients who were at steady state. Mean clearance and mean N-acetylprocainamide (NAPA):procainamide ratios were compared between preterm and term neonates. No patients experienced hemodynamic instability or other adverse effects due to procainamide. Procainamide was given as a mean +/- SD 9.6 +/- 1.5-mg/kg bolus in 20 of 21 patients before continuous infusion. The mean +/- SD dose at which two therapeutic levels were achieved was 37.56 +/- 13.52 microg/kg/minute. Procainamide clearance was 6.36 +/- 8.85 ml/kg/minute and correlated with creatinine clearance (r=0.78, p<0.00001) and age at day of sampling (r=0.49, p<0.00001). The NAPA:procainamide ratio at steady state was 0.84 +/- 0.53; two patients were determined to be fast acetylators (ratio > 1). Preterm infants had lower mean clearance rates (p<0.001) but higher NAPA:procainamide ratios (p<0.01) than those of term infants. Five patients experienced seven supratherapeutic levels while receiving therapy; four of these patients were preterm, and all had creatinine clearances less than 30 ml/minute/1.73 m(2). Three patients had four pairs of levels obtained after discontinuation of procainamide, and elimination rate constant and half-life were calculated.

CONCLUSION

Procainamide can be safely used in neonates, with no short-term adverse effects. The dosage regimen for intravenous procainamide required to achieve therapeutic levels in neonates is similar to that of older infants and children. Doses may need to be reduced in premature infants and in those with renal dysfunction.