Acute Management of Refractory and Unstable Pediatric Supraventricular Tachycardia

What an anesthesiologist should know about pediatric arrhythmias

Identifying and treating pediatric arrhythmias is essential for pediatric anesthesiologists. Pediatric patients can present with narrow or wide complex tachycardias, though the former is more common. Patients with inherited channelopathies or cardiomyopathies are at increased risk. Since most pediatric patients present for anesthesia without a baseline electrocardiogram, the first identification of an arrhythmia may occur under general anesthesia. Supraventricular tachycardia, the most common pediatric tachyarrhythmia, represents a broad category of predominately narrow complex tachycardias. Stimulating events including intubation, vascular guidewire manipulation, and surgical stimulation can trigger episodes. Valsalva maneuvers are unreliable as treatment, making adenosine or other intravenous antiarrhythmics the preferred acute therapy. Reentrant tachycardias are the most common supraventricular tachycardia in pediatric patients, including atrioventricular reciprocating tachycardia (due to a distinct accessory pathway) and atrioventricular nodal reentrant tachycardia (due to an accessory pathway within the atrioventricular node). Patients with ventricular preexcitation, often referred to as Wolff-Parkinson-White syndrome, have a wide QRS with short PR interval, indicating antegrade conduction through the accessory pathway. These patients are at risk for sudden death if atrial fibrillation degenerates into ventricular fibrillation over a high-risk accessory pathway. Automatic tachycardias, such as atrial tachycardia and junctional ectopic tachycardia, are causes of supraventricular tachycardia in pediatric patients, the latter most typically noted after cardiac surgery. Patients with inherited arrhythmia syndromes, such as congenital long QT syndrome, are at risk of developing ventricular arrhythmias such as polymorphic ventricular tachycardia (Torsades de Pointes) which can be exacerbated by QT prolonging medications. Patients with catecholaminergic polymorphic ventricular tachycardia are at particular risk for developing bidirectional ventricular tachycardia or ventricular fibrillation during exogenous or endogenous catecholamine surges. Non-selective beta blockers are first line for most forms of long QT syndrome as well as catecholaminergic polymorphic ventricular tachycardia. Anesthesiologists should review the impact of medications on the QT interval and transmural dispersion of repolarization, to limit increasing the risk of Torsades de Pointes in patients with long QT syndrome. This review explores the key anesthetic considerations for these arrhythmias.

Synchronized cardioversion resolving refractory supraventricular tachycardia in a neonate: a case report with comprehensive analysis

Introduction and importance

Neonatal supraventricular tachycardia (SVT) poses unique challenges in diagnosis and management, with refractory cases requiring synchronized cardioversion being exceptionally rare. This case report explores the presentation and management of refractory SVT in a neonate, emphasizing the significance of sharing such clinical scenarios.

Case presentation

A 16-day-old neonate, born via emergency caesarean section, presented with respiratory distress, poor feeding, and vomiting. Initial diagnosis of SVT was made on the basis of electrocardiography (ECG) changes. Initial attempts with adenosine failed, leading to the recurrence of tachycardia. Despite amiodarone administration, the tachycardia persisted, prompting synchronized cardioversion. Post-cardioversion, the neonate was managed with oral medications, showing sustained improvement.

Clinical discussion

This case report highlights a neonate with refractory SVT, requiring synchronized cardioversion, presenting a rare and challenging scenario. The report addresses diagnostic challenges, treatment approaches, and potential mechanisms for refractory SVT, such as delayed presentation and resistance to adenosine. Emphasizing individualized care plans and vigilant monitoring, this report is a valuable resource for healthcare professionals, contributing to neonatal cardiology understanding and emphasizing the importance of early recognition and effective interventions. Ongoing follow-up and successful outcomes underscore the need for sustained management strategies.

Conclusion

This case report sheds light on the rarity of refractory SVT in neonates, emphasizing the complexities in diagnosis and management. Successful synchronized cardioversion and subsequent oral therapy highlight the need for a multifaceted approach in neonatal SVT cases. The implications for clinical practice underscore the importance of awareness and continued research in neonatal cardiology and emergency medicine.

Patient Characteristics Associated with Hospital Admission or Antiarrhythmic Medication Changes After Emergency Department Evaluation of Supraventricular Tachycardia

BACKGROUND

Supraventricular tachycardia (SVT) is a relatively frequent diagnosis in the pediatric emergency department (ED). However, there are no consensus guidelines for ED disposition, and there are limited data on ED outcomes. Better understanding of those who are admitted or have antiarrhythmic medication changes may avoid potentially unnecessary transfers or admissions. Our objective was to identify patient factors associated with discharge from the emergency department without medication initiation or modification after management of SVT in the pediatric ED.

DESIGN/METHODS

A retrospective review of children aged 0-18 years seen in the emergency department for SVT was conducted using electronic medical record data over a ten-year period at a single academic tertiary children's hospital. Patients with congenital cardiac disease or prior cardiac surgeries were excluded. Multivariable logistic regression analysis was used to determine association between patient factors of interest and the primary outcome of admission and secondary outcome of change to antiarrhythmic medications.

RESULTS

We analyzed 197 patients encounters. The mean age was 7 years. Of these 104 (52.8%) were admitted to the hospital or discharged with antiarrhythmic medication changes. This primary outcome was associated with younger age (aOR 0.77, 95% CI 0.67-0.86), history of pre-excitation (aOR 5.82, 95% CI 2.01-18.8), intercurrent illness (aOR 3.75, 95% CI 1.27-12.1), number of adenosine doses prior to arrival (aOR 5.45, 95% CI 1.55-22.3), and in-person cardiology consultation (aOR 6.42, 95% CI 2.43-19.4).

CONCLUSIONS

Nearly half of children treated in a pediatric ED for SVT are discharged without changes in medications. We identified patient factors associated with hospital admission or antiarrhythmic medication changes. These factors represent high value care and can be assessed when considering transfer from a referring facility. Risk stratification using these patient characteristics may reduce potentially avoidable transfers and admissions.

A Multicenter Retrospective Evaluation of Specialized Laboratory Investigations in the Workup of Pediatric Patients With New-Onset Supraventricular Tachycardia

INTRODUCTION

Specialized laboratory evaluation of supraventricular tachycardia in children may occur, but the utility is unknown. The study objectives are to assess the type, frequency, and results of specialized laboratory testing performed in pediatric patients presenting with new-onset supraventricular tachycardia. We hypothesized that when specialized laboratory testing occurs (particularly for cardiac failure, toxicologic, inflammatory, and thyroid diseases), the results are generally within normal limits.

METHODS

This is a retrospective descriptive study using an electronic health record database (TriNetX, Inc). We collected and evaluated the following data of subjects aged younger than 18 years with a first-time supraventricular tachycardia diagnosis: demographics, diagnostic codes, deaths, and laboratory codes/results (natriuretic peptide B, natriuretic peptide B prohormone N-terminal, troponin I, toxicology testing, inflammatory markers, and thyroid studies).

RESULTS

A total of 621 subjects (524 [84.4%] without laboratory testing, 97 [15.6%] with laboratory testing) were included. Thyroid studies (65 [10.5%]) were the most frequent laboratory study performed followed by cardiovascular specific studies (35 [5.6%]), inflammatory markers (21 [3.4%]), and toxicology tests (10 [1.6%]) (P = .002). Obtained laboratory testing was more frequent with older subjects, females, and need for emergency, hospital, and critical care services.

DISCUSSION

Cardiac-specific and noncardiac laboratory testing is frequently ordered for pediatric patients who present with supraventricular tachycardia. Thyroid studies were the most common laboratory testing ordered, but abnormal results only occurred in less than a quarter of subjects. These findings may highlight a quality improvement opportunity for emergency nurses and practitioners in the practice of obtaining laboratory tests to better reflect high-value evidence-based care for this vulnerable population.

Supraventricular Tachycardia in Infants With Congenital Diaphragmatic Hernia: Prevalence, Associations, and Outcomes

OBJECTIVES

To characterize the prevalence, associations, management, and outcomes of supraventricular tachycardia (SVT) in neonates with congenital diaphragmatic hernia (CDH).

DESIGN

Retrospective chart and cardiology code review within a cohort of patients with CDH was used to define a subpopulation with atrial arrhythmia. SVT mechanisms were confirmed by electrocardiogram analysis. Cox proportional hazard regression identified risk factors for SVT and association with clinical outcomes.

SETTING

Medical Surgical ICU in a single, tertiary center, Boston Children's Hospital.

PATIENTS

Eligible patients included neonates presenting with classic Bochdalek posterolateral CDH between 2005 and 2017, excluding newborns with Morgagni hernia or late diagnoses of CDH (>28 d).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

SVT arose in 25 of 232 neonates with CDH, (11%); 14 of 25 infants (56%) had recurrent SVT; atrioventricular node-dependent tachycardia was the most frequent mechanism (32%). The majority (71%) of SVT episodes received intervention. Nine patients (36%) received preventative antiarrhythmic medications. SVT was associated with lower Apgar score at 1 min, structural heart disease, larger defect size, extracorporeal membrane oxygenation (ECMO) support, and prostaglandin therapy for ductal patency as well as hospital stay greater than or equal to 8 weeks and use of supplemental oxygen at discharge.

CONCLUSIONS

SVT can occur in neonates with CDH and frequently requires treatment. Odds of occurrence are increased with greater CDH disease severity, ECMO, and prostaglandin use. In unadjusted logistic regression analysis, SVT was associated with adverse hospital outcomes, underscoring the importance of recognition and management in this vulnerable population.

When Adenosine Does Not Work: Apparent and Real Adenosine-Resistant Tachycardia

ABSTRACT

Supraventricular tachycardia (SVT) is the most common arrhythmia in the pediatric population. Adenosine is widely accepted as the first-line pharmacological treatment for hemodynamically stable SVT, constituting a class I recommendation in the 2020 American Heart Association guidelines for pediatric life support (2020 American Heart Association Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care). As most pediatric SVTs are dependent on the atrioventricular node (AVN) for their propagation, and adenosine acts primarily on the AVN, adenosine will frequently terminate the arrhythmia. The term "adenosine failure" is often used to describe when its administration does not result in sustained termination of the tachycardia. Because of its very short half-life, there is confusion between improper delivery, failure to have any effect on the tachycardia, or transient termination. There are some pediatric SVTs, which are not AVN dependent, and which truly are refractory to adenosine. Simultaneous electrocardiogram recording during administration can provide important information to differentiate between adenosine resistance and transient adenosine effect, thus guiding further management.

Arrhythmias Requiring ECMO in Infants Without Structural Congenital Heart Disease

Arrhythmias account for 55 per 100,000 patient evaluations in pediatric emergency departments. Most arrhythmias in children are amenable to medical management or cardioversion. Rarely, arrhythmias lead to significant hemodynamic instability requiring extracorporeal membrane oxygenation (ECMO) support. This study seeks to evaluate children under 1 year of age with a structurally normal heart requiring ECMO for an arrhythmia. This is a retrospective review of the Extracorporeal Life Support Organization Registry. All patients less than 1 year of age between 2009 and 2019 with a diagnosis of arrhythmia and without a diagnosis of structural heart malformation were included. Demographics, clinical characteristics, and outcomes were assessed with descriptive statistics and univariate and multivariable analyses. A total of 140 eligible patients were identified from the dataset. The most common arrhythmia was supraventricular tachycardia (SVT) in 70 (50%) patients. ECMO complications occurred in 106 (76.3%) patients and survival to discharge was achieved in 120 (85.7%) patients. In-hospital mortality was associated with neuromuscular blockade prior to ECMO [aOR 10.0 (95% CI 2.95-41.56), p < 0.001], neurologic ECMO complication [aOR 28.1 (95% CI 6.6-155.1), p < 0.001], and race with white race being protective [aOR 0.13, (95% CI 0.02-0.21), p = 0.002]. Similar survival and complication rates were found in subgroup analysis of SVT arrhythmias alone. Arrhythmias necessitating ECMO support in infants without structural congenital heart disease is a rare occurrence. However, survival to hospital discharge is favorable at greater than 85%. Given the favorable survival, earlier and more aggressive utilization of ECMO may result in improved outcomes.

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.

[Paediatric Life Support]

The European Resuscitation Council (ERC) Paediatric Life Support (PLS) guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations of the International Liaison Committee on Resuscitation (ILCOR). This section provides guidelines on the management of critically ill or injured infants, children and adolescents before, during and after respiratory/cardiac arrest.

Flecainide How and When: A Practical Guide in Supraventricular Arrhythmias

Transcatheter ablation was increasingly and successfully used to treat symptomatic drug refractory patients affected by supraventricular arrhythmias. Antiarrhythmic drug treatment still plays a major role in patient management, alone or combined with non-pharmacological therapies. Flecainide is an IC antiarrhythmic drug approved in 1984 from the Food and Drug Administration for the suppression of sustained ventricular tachycardia and later for acute cardioversion of atrial fibrillation and for sinus rhythm maintenance. Currently, flecainide is mostly used for sinus rhythm maintenance in atrial fibrillation (AF) patients without structural cardiomyopathy although recent studies enrolling different patient populations have demonstrated a good effectiveness and safety profile. How should we interpret the results of the CAST after the latest evidence? Is it possible to expand the indications of flecainide, and therefore, its use? This review aims to highlight the main characteristics of flecainide, as well as its optimal clinical use, delineating drug indications and contraindications and appropriate monitoring, based on the most recent evidence.

European Resuscitation Council Guidelines 2021: Paediatric Life Support

These European Resuscitation Council Paediatric Life Support (PLS) guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the management of critically ill infants and children, before, during and after cardiac arrest.

Care of Children with Supraventricular Tachycardia in the Emergency Department

Prior studies have characterized children with supraventricular tachycardia (SVT) in inpatient settings, however there is a paucity of data regarding pediatric SVT in the Emergency Department (ED) setting. We sought to describe pediatric ED visits for SVT and assess whether variability exists in care. We performed a cross-sectional study of ED visits for SVT among children < 18 years old from 2010 to 2017 at 33 pediatric hospitals. Visits were included if made for a primary International Disease Classification Ninth or Tenth Revision diagnosis code for SVT and intravenous (IV) adenosine was given on the initial or 2nd hospital day. We evaluated factors associated with hospital admission using multivariate logistic regression and described variability in frequency of rate of hospitalization, second-line IV antiarrhythmic medication usage, and diagnostic testing across sites. We included 2329 ED visits made by 1738 children and the median patient age was 6.3 years (IQR 1.5-11.9). There were 2 deaths (0.1% of visits). Marked variability existed between centers in rates of admission to the hospital (range 17-85%) and ICU (range 4-60%). Factors associated with admission included: younger age, male sex and presence of comorbid conditions. A second IV antiarrhythmic agent was used in 17% of visits (range 4-41% across hospitals). There was variability in rates of diagnostic testing between centers [chest x-ray (range 10-47%), complete blood count (range 10-72%), electrolytes (range 22-86%), echocardiography (range 3-68%)]. Management of SVT is variable across pediatric hospitals, suggesting an opportunity for standardization in care.

Performance of Emergency Medical Service Providers in Pediatric and Adult Simulation of Unstable Supraventricular Tachycardia

OBJECTIVE

The aim of the study was to compare emergency medical service resuscitation of pediatric and adult high-fidelity manikins in unstable supraventricular tachycardia. The primary objective was time to cardioversion. The secondary objective was to assess if the cardioversion was synchronized at the correct dosage for the manikin's weight.

METHODS

Emergency medical service providers were voluntarily enrolled as part of an emergency medical service training program. Participants were randomized to either a pediatric or adult resuscitation as their study scenario. They then completed the second resuscitation as part of the training program. Participants completed presurvey and postsurvey. Resuscitations were videotaped and analyzed by a blinded reviewer. The study was powered to detect a 60-second difference in performance between pediatric and adult scenarios with a β of 0.8 and 2-tailed α of 0.05 using an independent-samples t test.

RESULTS

A total of 37 participants were enrolled. Participants in the pediatric arm had a longer mean time to cardioversion, but the difference was not statistically significant. The mean delay to cardioversion in the pediatric scenario was 34 seconds (197 vs 163 seconds; difference 95% confidence interval [CI], -5 to 73 seconds; P = 0.09). There was no significant difference in the percentage of participants who administered a correct dose (32% vs 50%; difference 95% CI, -50% to 13%; P = 0.75) or regarding synchronization of cardioversion (74% vs 83%; difference 95% CI, -36% to 17%; P = 0.42).

CONCLUSIONS

Emergency medical service providers did not have a significant difference in time to cardioversion between pediatric and adult unstable supraventricular tachycardia simulations.

Pre-excitation cardiac problems in children: recognition and treatment

The prevalence of ventricular pre-excitation is 0.07-0.2% in the pediatric population. Kent bundle is the most common atrioventricular accessory pathway and Mahaim fiber is relatively rare. Approximately, 30-60% of children with ventricular pre-excitation have onset of atrioventricular reentrant tachycardia. Persistent atrioventricular reentrant tachycardia can lead to tachycardiomyopathy. The anterograde conduction of right accessory pathway might lead to ventricular systolic dyssynchrony which might result in cardiac dysfunction even in patients with no tachycardia onset. This type of dilated cardiomyopathy was named as accessory pathway-induced dilated cardiomyopathy. Antiarrhythmic drugs can be used to acutely terminate tachycardia or taken orally to decrease tachycardia recurrence in the long term. However, antiarrhythmic drugs that can be chosen for children are quite limited. Sotalol has become a new choice. With the maturation of radiofrequency catheter ablation technique, progress in three-dimensional electro-anatomic mapping, use of cryoablation, and accumulation of experience in children with small age and weight, catheter ablation has become the first choice for children with pre-excitation syndrome.Conclusion: For ventricular pre-excitation co-exists with dilated cardiomyopathy, differential diagnosis of tachycardiomyopathy or accessory pathway-induced dilated cardiomyopathy should be considered. Catheter ablation (radiofrequency and cryoablation) is a relatively safe and effective treatment option and has become the first choice to treat children with ventricular pre-excitation. What is Known: • Persistent atrioventricular reentrant tachycardia in children can lead to tachycardiomyopathy; • Antiarrhythmic drugs that can be chosen for children are quite limited. What is New: • The anterograde conduction of right accessory pathway (not related to supraventricular tachycardia) might lead to accessory pathway-induced dilated cardiomyopathy. • Catheter ablation (including radiofrequency and cryoablation) has become the first choice for children with pre-excitation syndrome.

Unmasking Adenosine: The Purinergic Signalling Molecule Critical to Arrhythmia Pathophysiology and Management

Adenosine was identified in 1929 and immediately recognised as having a potential role in therapy for arrhythmia because of its negative chronotropic and dromotropic effects. Adenosine entered mainstream use in the 1980s as a highly effective agent for the termination of supraventricular tachycardia (SVT) involving the atrioventricular node, as well as for its ability to unmask the underlying rhythm in other SVTs. Adenosine has subsequently been found to have applications in interventional electrophysiology. While considered a safe agent because of its short half-life, adenosine may provoke arrhythmias in the form of AF, bradyarrhythmia and ventricular tachyarrhythmia. Adenosine is also associated with bronchospasm, although this may reflect irritant-induced dyspnoea rather than true obstruction. Adenosine is linked to numerous pathologies relevant to arrhythmia predisposition, including heart failure, obesity, ischaemia and the ageing process itself. This article examines 90 years of experience with adenosine in the light of new European Society of Cardiology guidelines for the management of SVT.

Spontaneous Conversions of Supraventricular Tachycardia to Sinus Rhythm in Children After Premedication With Intranasal Dexmedetomidine: A Case Report

Intranasal dexmedetomidine administered as premedication before anesthesia and cardioversion appears to have the potential to facilitate the return of sinus rhythm. Two children, 3.5 and 1.5 years old, with recurrent supraventricular tachycardia in need of cardioversion have now on several occasions spontaneously returned to sinus rhythm within 20-40 minutes after intranasal administration of dexmedetomidine (4 μg/kg) with a mucosal atomization device. Both children were observed on all occasions at the pediatric outpatient clinic and could return home within 2 hours of cardioversion. For children with supraventricular tachycardia, a selective α2-agonist might be a valuable alternative to cardioversion with adenosine.