Atrial Flutter in Infants

Tachycardia-Induced Cardiomyopathy in an Infant with Atrial Flutter and Prolonged Recovery of Cardiac Function

Background: Tachycardia-induced cardiomyopathy (TIC) is caused by prolonged tachycardia, leading to left ventricular dilatation and systolic dysfunction with heart failure. Although TIC is more common in adults, it is rare in early infancy. Methods: Clinical testing was performed as part of medical evaluation and management. Next-generation sequencing (NGS) was conducted for a patient with TIC. A literature review on TIC was also conducted. Results: The case involved a 5-month-old infant referred to the hospital due to symptoms of heart failure lasting at least two months. The infant's heart rate was 200 beats per minute, the left ventricular ejection fraction fell below 14%, and electrocardiograms showed atrial flutter, suggesting TIC. After cardioversion, there was no recurrence of atrial flutter, and cardiac function improved 98 days after tachycardia arrest. The NGS did not identify any pathogenic variants. The literature review identified eight early infantile cases of TIC. However, no previous reports described a case with such a prolonged duration of TIC as ours. Conclusions: This is the first report of a case of prolonged TIC in a child with the documented time to recover normal cardiac function. The improvement of cardiac function depends on the duration of TIC. Early recognition and intervention in TIC are essential to improve outcomes for infantile patients, as timely treatment offers the potential for recovery.

Catheter ablation of typical right atrial flutter in a 20-day-old neonate with tachycardiomyopathy

Background

Fetal echocardiography can diagnose neonatal atrial flutter, which can cause heart failure in newborns. Little is known about catheter ablation in this population.

Methods

Case report that aimed to review a successful ablation in a 20-day-old patient with refractory atrial flutter.

Results

This is the first report of a successful neonatal atrial flutter ablation without any early recurrence after the procedure.

Conclusions

Atrial flutter ablation performed on newborns is a reliable and long-lasting treatment option.

The diagnostic and therapeutic challenge of atrial flutter in children: a case report

BACKGROUND

Palpitations represent a common cause for consultation in the pediatric Emergency Department (ED). Unlike adults, palpitations in children are less frequently dependent from the heart, recognizing other causes.

CASE PRESENTATION

A 11-year-old male came to our pediatric ED for epigastric pain, vomiting and palpitations. During the previous 6 month the patient was affected by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus). Electrocardiogram (ECG) revealed supraventricular tachycardia. Therefore, adenosine was administered unsuccessfully. The administration of adenosine, however, allowed us to make diagnosis of atypical atrial flutter. Multiple attempts at both electrical cardioversion, transesophageal atrial overdrive, and drug monotherapy were unsuccessful in our patient. Consequently, a triple therapy with amiodarone, flecainide, and beta-blocker was gradually designed to control the arrhythmic pattern with the restoration of a left upper atrial rhythm. There was not any evidence of sinus rhythm in the patient clinical history.

CONCLUSIONS

The present study underlines the rarity of this type of dysrhythmia in childhood and the difficulties in diagnosis and management, above all in a patient who has never showed sinus rhythm. Raising awareness of all available treatment options is essential for a better management of dysrhythmia in children.

2023 HRS expert consensus statement on the management of arrhythmias during pregnancy

This international multidisciplinary expert consensus statement is intended to provide comprehensive guidance that can be referenced at the point of care to cardiac electrophysiologists, cardiologists, and other health care professionals, on the management of cardiac arrhythmias in pregnant patients and in fetuses. This document covers general concepts related to arrhythmias, including both brady- and tachyarrhythmias, in both the patient and the fetus during pregnancy. Recommendations are provided for optimal approaches to diagnosis and evaluation of arrhythmias; selection of invasive and noninvasive options for treatment of arrhythmias; and disease- and patient-specific considerations when risk stratifying, diagnosing, and treating arrhythmias in pregnant patients and fetuses. Gaps in knowledge and new directions for future research are also identified.

A Survey of Academic Neonatologists on Neonatal Electrical Cardioversion and Defibrillation

OBJECTIVE

This study aimed to assess neonatologists' experience and comfort with neonatal electrical cardioversion or defibrillation (EC-D).

STUDY DESIGN

Electronic surveys were distributed to academic neonatologists affiliated with 12 Midwest academic hospitals. Neonatologists were asked about their residency training; years since completing residency; current certification/competency training in the Basic Life Support (BLS), Pediatric Advanced Life Support (PALS), Advanced Cardiovascular Life Support (ACLS), and Neonatal Resuscitation Program (NRP); experiences with EC-D; availability of a pediatric cardiologist; and their comfort levels with such procedures. Standard statistical tests evaluated comfort with EC-D.

RESULTS

Seventy-two out of 180 neonatologists responded to the survey (response rate = 40%). Of them, 98.6% (71), 54.2% (39), and 37.5% (27) maintained current NRP, BLS, and PALS trainings, respectively. Also, 73.6% (n = 53) reported having performed neonatal EC-D. Of those, 50.9% (n = 27) indicated feeling slightly to very uncomfortable performing EC-D. We report a lack of BLS certification being associated with a lack of comfort (odds ratio [OR]: 0.269, 95% confidence interval [CI]: [0.071, 0.936]), and a positive association between a pediatric cardiologist being present and being uncomfortable (OR: 3.722, 95% CI: [1.069, 14.059]). Those reporting greater volume and more recent experience with EC-D report more comfort.

CONCLUSION

Of neonatologists who performed EC-D, half of them reported being uncomfortable. BLS certification and experience are positively associated with comfort in performing EC-D. Simulations to increase training in EC-D should be offered regularly to academic neonatologists.

KEY POINTS

· Most neonatologists have performed EC-D, but many feel uncomfortable with performing EC-D.. · Many do not maintain current certification in BLS, PALS, or ACLS.. · Simulation training in EC-D will increase comfort with EC-D..

Cardiac Arrhythmias Requiring Electric Countershock during the Neonatal Period-A Systematic Review

BACKGROUND

In neonates, cardiac arrhythmias are rare. Electric countershock therapy is an effective alternative to drug therapy for neonatal arrhythmias. There are no randomized controlled studies investigating electric countershock therapy in neonates.

OBJECTIVE

To identify all studies and publications describing electric countershock therapy (including defibrillation, cardioversion, and pacing) in newborn infants within 28 days after birth, and to provide a comprehensive review of this treatment modality and associated outcomes.

METHODS

For this systematic review we searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL). All articles reporting electric countershock therapy in newborn infants within 28 days after birth were included.

RESULTS

In terms of figures, 113 neonates who received electric countershock due to arrhythmias were reported. Atrial flutter (76.1%) was the most common arrhythmia, followed by supraventricular tachycardia (13.3%). Others were ventricular tachycardia (9.7%) and torsade de pointes (0.9%). The main type of electric countershock therapy was synchronized cardioversion (79.6%). Transesophageal pacing was used in twenty neonates (17.7%), and defibrillation was used in five neonates (4.4%).

CONCLUSION

Electric countershock therapy is an effective treatment option in the neonatal period. In atrial flutter especially, excellent outcomes are reported with direct synchronized electric cardioversion.

Clinical characteristics and outcomes of atrial flutter in neonates

BACKGROUND

Atrial flutter is an uncommon arrhythmia that can cause severe morbidity, including heart failure and even death in refractory cases. This study investigated the clinical characteristics, treatment, and long-term outcomes of patients with neonatal atrial flutter and its association with heart failure.

METHODS

We retrospectively reviewed atrial flutter cases observed in our center between 1999 and 2021 and analyzed the clinical characteristics, treatment, and recurrence according to the presence of heart failure.

RESULTS

The study comprised 15 patients with atrial flutter, with median bodyweight and gestational age of 2.7 kg, 37+4 weeks, respectively. Twelve patients were diagnosed with atrial flutter on the first day of life. The median atrial and ventricular rates were 440/min, 220/min, respectively. Four patients exhibited congestive heart failure. Episodic recurrence was noted in five patients and occurred at a higher rate in patients with congestive heart failure (p = 0.004). Antiarrhythmic drugs for maintenance treatment were administered more often in patients with heart failure (p = 0.011). Initial treatment included direct current cardioversion (n = 9), digoxin (n = 4), and observation (n = 2). Four patients treated with cardioversion experienced recurrence during the neonatal period, and none of those treated with digoxin experienced recurrence. The median follow-up duration was 7 years, during which no atrial flutter recurrence was evident.

CONCLUSION

Neonates with congestive heart failure had a higher recurrence of atrial flutter. Direct current cardioversion is the most reliable treatment for neonatal atrial flutter, whereas digoxin may be a viable treatment option in refractory and recurrent cases.

Infantile-onset Pompe disease with neutropenia: Treatment decisions in the face of a unique phenotype

Infantile-onset Pompe disease manifests with early signs of cardiomyopathy during the first few days to weeks of life. We present the case of a newborn born via emergency cesarean section with atrial flutter and moderate biventricular hypertrophy who was diagnosed with Pompe disease on New York State newborn screen. Diagnosis was confirmed with repeat leukocyte acid alpha-glucosidase (GAA) enzyme activity, GAA gene sequencing, urine Hex4, and evaluation of Cross-Reactive Immunological Material (CRIM) status. The patient was also found to be persistently neutropenic which to our knowledge has not been previously reported in the literature in association with Pompe disease. This report highlights the impact that newborn screening had on time to diagnosis and initiation of treatment with enzyme replacement therapy. We also discuss how our patient's concurrent neutropenia impacted decision making related to immune tolerance induction prior to starting enzyme replacement therapy.

Atrial Flutter in Pediatric Patients

Atrial flutter (AFL) in pediatric patients is a rare condition as the physical dimensions of the immature heart are inadequate to support the arrhythmia. This low incidence makes it difficult for patients in this particular setting to be studied. AFL accounts for 30% of fetal tachyarrhythmias, 11% to 18% of neonatal tachyarrhythmias, and 8% of supraventricular tachyarrhythmias in children older than 1 year of age. Transesophageal overdrive pacing can be used, instead, with lower success rate (60%-70%). The recommended drugs are digoxin which can decrease the ventricular rate until the spontaneous interruption of the AFL. Digoxin can be combined with flecainide or amiodarone in case of failure.

Neonatal Atrial Flutter: Clinical Characteristics of 14 Cases in a Single Center

Purpose: Atrial flutter is an uncommon arrhythmia in the neonatal period. This study aimed to describe the cause and clinical course of atrial flutter in neonates.Methods: The medical records of 14 patients diagnosed with atrial flutter at Ulsan University Hospital Neonatal Intensive Care Unit (NICU) between March 2008 and August 2020 were reviewed retrospectively.Results: All 14 cases occurred on the first day of birth. Of these, two were term infants, and 12 were preterm infants. Causes of atrial flutter included three cases of the umbilical venous catheter misplacement, one with a diabetic mother, and one ivolving atrial flutter after an intravenous aminophylline injection. Thirteen patients had structurally normal hearts with no congenital heart diseases. The patient, born to a diabetic mother, had an atrial septal defect and ventricular hypertrophy. Adenosine was administered first to differentiate it from paroxysmal supraventricular tachycardia. Synchronized cardioversion was attempted in 11 patients, while one received it after an esmolol injection that failed to convert to sinus rhythm. One patient had a recurrence after the intrusion of a peripherally inserted central catheter; however, atrial flutter disappeared after repositioning it. No patient had a recurrence after discharge.Conclusion: Neonatal atrial flutter is a rare tachyarrhythmia with the risk factors often unknown; however, it could occur in structural heart disease, mispositioning of the umbilical venous catheter, and if the mother has diabetes. During umbilical venous catheterization, clinicians should be cautious and ensure appropriate monitoring of infants in the NICU as it may cause complications.

Treatment of Fetal Arrhythmias

Fetal arrhythmias are mostly benign and transient. However, some of them are associated with structural defects or can cause heart failure, fetal hydrops, and can lead to intrauterine death. The analysis of fetal heart rhythm is based on ultrasound (M-mode and Doppler echocardiography). Irregular rhythm due to atrial ectopic beats is the most common type of fetal arrhythmia and is generally benign. Tachyarrhythmias are diagnosed when the fetal heart rate is persistently above 180 beats per minute (bpm). The most common fetal tachyarrhythmias are paroxysmal supraventricular tachycardia and atrial flutter. Most fetal tachycardias can be terminated or controlled by transplacental or direct administration of anti-arrhythmic drugs. Fetal bradycardia is diagnosed when the fetal heart rate is slower than 110 bpm. Persistent bradycardia outside labor or in the absence of placental pathology is mostly due to atrioventricular (AV) block. Approximately half of fetal heart blocks are in cases with structural heart defects, and AV block in cases with structurally normal heart is often caused by maternal anti-Ro/SSA antibodies. The efficacy of prenatal treatment for fetal AV block is limited. Our review aims to provide a practical guide for the diagnosis and management of common fetal arrythmias, from the joint perspective of the fetal medicine specialist and the cardiologist.

Recurrent Atrial Flutter Requiring Multiple Cardioversions in a Preterm Infant

We describe the first case of atrial flutter requiring multiple cardioversions in a preterm infant. Direct current cardioversion is one of the best-understood treatment options, with a first-time success rate higher than 96%. The electrocardiograms provided reveal a second run of atrial flutter occurring after successful cardioversion. (Level of Difficulty: Intermediate.).

Neonatal arrhythmias in Turner syndrome: a case report and review of the literature

Background

While left-sided congenital heart defects have been well described in females with Turner syndrome (45, X), the literature is scarce regarding arrhythmias in this patient population.

Case summary

A full-term neonate referred to cardiology was found to have a non-apex forming left ventricle and partial anomalous pulmonary venous return. During the echocardiogram, she developed atrial flutter, followed by orthodromic reentrant supraventricular tachycardia (SVT). She was started on propranolol and eventually switched to sotalol due to breakthrough SVT. A genetics evaluation revealed Turner syndrome with complete monosomy X (45, X). The patient is now 18 months old and has not had any further arrhythmias.

Discussion

We present a rare case of atrial flutter followed by supraventricular tachycardia in a neonate with Turner syndrome and left-sided heart defects. This case highlights the importance of early and precise investigation of cardiac abnormalities in neonatal patients, especially among females with Turner syndrome given their relatively higher risk of cardiovascular disease compared to the general population.

Lone Atrial Flutter in Children and Adolescents: Is It Really "Lone"?

Atrial flutter (AFL) in children and adolescents beyond the neonatal period in the absence of any underlying myocardial disease ("lone AFL") is rare and data is limited. Our study aims to present clinical and electrophysiological data of presumed "lone AFL" in pediatric patients and discuss the role of endomyocardial biopsy (EMB) and further follow-up. Since July 2005, eight consecutive patients at a median age of 12.7 (range 10.4-16.7) years presenting with presumed "lone AFL" after negative non-invasive diagnostic work-up had electrophysiological study (EPS) and induction of cavotricuspid isthmus (CTI) conduction block by radiofrequency (RF) current application. In 6/8 patients EMB could be taken. Induction of CTI conduction block was achieved in all patients. Histopathological examination of EMB from the right ventricular septum exhibited myocarditis or cardiomyopathy in 4/6 patients, respectively. During follow-up, 4/8 patients had recurrent arrhythmia (AFL n = 2, wide QRS complex tachycardia n = 1, monomorphic premature ventricular contractions n = 1) after the ablation procedure. 3/4 patients with recurrent arrhythmia had pathological EMB results. The remaining patient with recurrent arrhythmia had a negative EMB but was diagnosed with Brugada syndrome during further follow-up. Taking together results of EMB and further clinical course, only 3/8 patients finally turned out to have true "lone AFL". Our study demonstrates that true "lone AFL" in children and adolescents is rare. EMB and clinical course revealed an underlying cardiac pathology in the majority of the individuals studied. EMB was very helpful in order to timely establish the diagnosis of myocarditis or cardiomyopathy.

Atrial Flutter-Unique Arrhythmia in Neonatal Population, Presentation of 3 Cases

BACKGROUND

Atrial flutter (AFL) is an uncommon arrhythmia in the pediatric population. It is defined as fast ordered atrial depolarization (about 250-500 beats/min). It occurs mainly in children with congenital heart defects; however, it may also manifest in fetuses and infants with an anatomically healthy heart. In neonates, AFL is most often revealed within the first 2 days after birth.

CLINICAL FINDINGS

In this case report, we present 3 neonates without complex congenital heart defects with AFL, along with the description of the course, diagnostic and therapeutic processes depending on the clinical condition of a child, and response to treatment.

PRIMARY DIAGNOSIS

Symptoms in this group of patients are nonspecific, that is, tachypnea, unwillingness to eat, and fatigue while feeding. The diagnostic process included thorough electro- and echocardiographic assessments. Each child was treated individually due to a different cause of arrhythmia and comorbidities.

INTERVENTIONS

Invasive (electrical cardioversion) and pharmacological methods were used in treatment to achieve conversion to sinus rhythm.

OUTCOMES

One patient required electrical cardioversion, one was treated with amiodarone and digoxin, and one infant received amiodarone. All children achieved conversion to sinus rhythm.

PRACTICE RECOMMENDATIONS

During the follow-up, each child maintained sinus rhythm, which shows that in the neonatal group, it is a unique, but well-controlled, arrhythmia once conversion to sinus rhythm is achieved.

Evaluation and Management of Common Neonatal Arrhythmias

Neonates can have different types of arrhythmias that range from benign to life-threatening. The evaluation, approach to acute presentation, and long-term management depend on correct identification of the arrhythmia. A systematic approach to analyzing the electrocardiogram and the telemetry monitor, if available, is often sufficient to diagnose the type of arrhythmia.

Successful treatment of neonatal atrial flutter by synchronized cardioversion: case report and literature review

BACKGROUND

Atrial flutter (AFL) is a supraventricular tachyarrhythmia. In the ECG tracing, it is marked by a fast, irregular atrial activity of 280-500 beats per minute. AFL is known to be a rare and also life-threatening rhythm disorder both at the fetus and neonatal period. AFL may result in circulatory failure, and in a more severe form, it may lead to a non-immune fetal hydrops. However, with early prenatal diagnosis and proper treatment, the majority of AFL cases show a good prognosis.

CASE PRESENTATION

We report a case of a neonate who was born at 34 weeks of gestational age by C-section because of risk for birth asphyxia, based on abnormal CTG tracing, which had no characteristic rhythms for fetal decelerations. A third day his heart rate was 220/bpm. ECG has shown supraventricular tachycardia with narrow QRS. The administration of adenosine resulted in the obvious appearance of "sawtooth wave" typical for AFL. Arrhythmia was resistant to the therapy of amiodaron. Then cardioversion was performed and the rhythm converted to normal.

CONCLUSIONS

As neonatal AFL might be resistant to conventional pharmacotherapy, one needs to remember about the possibility of electrical cardioversion in the pediatric cardiology referral center. Moreover, CTG monitoring is of limited use because it does not record fetal heart rhythms > 200/min and echocardiography at the reference center is practically the only method to monitor the condition of the fetus with abnormal rapid heart rhythm.

Abordagem de Flutter Atrial Neonatal: Uma Série de Casos

Objetivo: Este estudo teve como objetivo analisar as opções terapêuticas dos pacientes com flutter atrial (FLA) neonatal, considerando os métodos diagnósticos disponíveis e o prognóstico desses pacientes. Metodologia: Foi realizado um estudo retrospectivo através da revisão dos prontuários de uma série de sete pacientes com fibrilação atrial (FA) diagnosticada durante o período fetal ou neonatal. O tempo de seguimento desses pacientes variou de 7 meses a 3 anos e 8 meses (média: 1 ano). Os dados clínicos para o diagnóstico incluíram frequência cardíaca sustentada superior a 180 bpm, que foi confirmada em todos os pacientes por um eletrocardiograma de 12 derivações. Resultados: Quatro (57,1%) dos sete pacientes estudados eram do sexo masculino. A maioria dos pacientes revelou arritmia cardíaca durante o período intrauterino, quando examinados por ultrassom fetal no terceiro trimestre de gestação (5 pacientes, ou seja 71,2%). Apenas à mãe do Paciente 2 foi administrada digoxina antes do parto. A taxa atrial da taquiarritmia revelou uma média de 375 bpm, com um aumento de até 500 bpm. A condução atrioventricular apresentou uma relação de 2:1 em todos os pacientes, com variações de 3:1 e 4:1 observadas nos Pacientes 1, 3 e 6. A frequência ventricular variou de 188 a 250 bpm. Todos os pacientes revelaram características típicas e anti-horárias do eletrocardiograma. A cardioversão elétrica sincronizada foi o tratamento de escolha em 6 pacientes (85,7%), com uma dose de 1 J/kg. Conclusão: Diagnóstico precoce, tratamento prévio e cardioversão elétrica sincronizada indicam um excelente prognóstico, e o tratamento de manutenção prolongada pode ser desnecessário.

Abordagem de Flutter Atrial Neonatal: Uma Série de Casos

Objetivo: Este estudo teve como objetivo analisar as opções terapêuticas dos pacientes com flutter atrial (FLA) neonatal, considerando os métodos diagnósticos disponíveis e o prognóstico desses pacientes. Metodologia: Foi realizado um estudo retrospectivo através da revisão dos prontuários de uma série de sete pacientes com fibrilação atrial (FA) diagnosticada durante o período fetal ou neonatal. O tempo de seguimento desses pacientes variou de 7 meses a 3 anos e 8 meses (média: 1 ano). Os dados clínicos para o diagnóstico incluíram frequência cardíaca sustentada superior a 180 bpm, que foi confirmada em todos os pacientes por um eletrocardiograma de 12 derivações. Resultados: Quatro (57,1%) dos sete pacientes estudados eram do sexo masculino. A maioria dos pacientes revelou arritmia cardíaca durante o período intrauterino, quando examinados por ultrassom fetal no terceiro trimestre de gestação (5 pacientes, ou seja 71,2%). Apenas à mãe do Paciente 2 foi administrada digoxina antes do parto. A taxa atrial da taquiarritmia revelou uma média de 375 bpm, com um aumento de até 500 bpm. A condução atrioventricular apresentou uma relação de 2:1 em todos os pacientes, com variações de 3:1 e 4:1 observadas nos Pacientes 1, 3 e 6. A frequência ventricular variou de 188 a 250 bpm. Todos os pacientes revelaram características típicas e anti-horárias do eletrocardiograma. A cardioversão elétrica sincronizada foi o tratamento de escolha em 6 pacientes (85,7%), com uma dose de 1 J/kg. Conclusão: Diagnóstico precoce, tratamento prévio e cardioversão elétrica sincronizada indicam um excelente prognóstico, e o tratamento de manutenção prolongada pode ser desnecessário.

Neonatal Atrial Flutter Approach: A Case Series

Objective: This study set out to analyze the therapeutic options of patients with neonatal atrial flutter (AFL), considering the diagnostic methods available and the prognosis of these patients. Methodology: A retrospective study was performed by reviewing the medical records of a series of seven patients with atrial fibrillation (AF) diagnosed during fetal or neonatal period. The follow-up time of these patients ranged from 7 months to 3 years and 8 months (mean: 1 year). The clinical data for the diagnosis included sustained heart rate greater than 180 bpm, which was confirmed in all patients by a 12-lead electrocardiogram. Results: Four (57.1%) of the 7 patients studied were male. Most of the patients revealed cardiac arrhythmia during the intrauterine period when screened by fetal ultrasound in the third trimester of gestation (5 patients, i.e. 71.2%). Only the mother of Patient 2 was administered digoxin before childbirth. The atrial rate of the tachyarrhythmia revealed a mean of 375 bpm, with an increase of up to 500 bpm. Atrioventricular conduction presented a 2:1 ratio in all patients, with variations of 3:1 and 4:1 observed in Patients 1, 3 and 6. The ventricular rate ranged from 188 to 250 bpm. All patients revealed typical and counter-clockwise electrocardiogram characteristics. Synchronized electrical cardioversion was the treatment of choice in 6 patients (85.7%), with a dose of 1 J/kg. Conclusion: Early diagnosis, prior treatment, and synchronized electrical cardioversion indicate an excellent prognosis, and prolonged maintenance treatment may be unnecessary.

Low mortality in fetal supraventricular tachycardia: Outcomes in a 30-year single-institution experience

OBJECTIVES

To describe a single institutional experience managing fetuses with supraventricular tachycardia (SVT) and to identify associations between patient characteristics and fetal and postnatal outcomes.

BACKGROUND

Sustained fetal SVT is associated with significant morbidity and mortality if untreated, yet the optimal management strategy remains unclear.

METHODS

Retrospective cohort study including fetuses diagnosed with sustained SVT (>50% of the diagnostic echocardiogram) between 1985 and 2018. Fetuses with congenital heart disease were excluded.

RESULTS

Sustained SVT was diagnosed in 65 fetuses at a median gestational age of 30 weeks (range, 14-37). Atrioventricular re-entrant tachycardia and atrial flutter were the most common diagnoses, seen in 41 and 16 cases, respectively. Moderate/severe ventricular dysfunction was present in 20 fetuses, and hydrops fetalis was present in 13. Of the 57 fetuses initiated on transplacental drug therapy, 47 received digoxin first-line, yet 39 of 57 (68%) required advanced therapy with sotalol, flecainide, or amiodarone. Rate or rhythm control was achieved in 47 of 57 treated fetuses. There were no cases of intrauterine fetal demise. Later gestational age at fetal diagnosis (odds ratio [OR], 1.1, 95% confidence interval [CI], 1.01-1.2, P = .02) and moderate/severe fetal ventricular dysfunction (OR, 6.1, 95% CI, 1.7-21.6, P = .005) were associated with postnatal SVT. Two postnatal deaths occurred.

CONCLUSIONS

Fetuses with structurally normal hearts and sustained SVT can be effectively managed with transplacental drug therapy with minimal risk of intrauterine fetal demise. Treatment requires multiple antiarrhythmic agents in over half of cases. Later gestational age at fetal diagnosis and the presence of depressed fetal ventricular function, but not hydrops, predict postnatal arrhythmia burden.

Successful in utero transesophageal pacing for severe drug-resistant tachyarrhythmia

Sustained fetal tachyarrhythmia can evolve into a life-threatening condition in 40% of cases when hydrops develops, with a 27% risk of perinatal death. Several antiarrhythmic drugs can be given solely or in combination to the mother to achieve therapeutic transplacental concentrations. Therapeutic failure could lead to progressive cardiac insufficiency and restrict therapeutic options to either elective delivery or direct fetal administration of antiarrhythmic drugs, which may increase the risk of death. We report for the first time successful fetal transesophageal pacing to treat a hydropic fetus with drug-resistant tachyarrhythmia.

Neonatal and Pediatric Arrhythmias: Clinical and Electrocardiographic Aspects

Arrhythmias have acquired a specific identity in pediatric cardiology, but for pediatric cardiologists it has always been difficult to recognize and treat them. Changes in anatomy and physiology result in electrocardiogram features that differ from the normal adult pattern and vary according to the age of the child. Sinus arrhythmia, ectopic atrial rhythm, "wandering pacemaker," and junctional rhythm can be normal characteristics in children (15%-25% of healthy children can have these rhythms on the electrocardiogram). Tachyarrhythmias and bradyarrhythmias must be treated according to the severity of symptoms, and the patient's age and weight.

Cost-effectiveness of digoxin, pacing, and direct current cardioversion for conversion of atrial flutter in neonates

IntroductionNewborn atrial flutter can be treated by medications, pacing, or direct current cardioversion. The purpose is to compare the cost-effectiveness of digoxin, pacing, and direct current cardioversion for the treatment of atrial flutter in neonates.Materials and methodsA decision tree model was developed comparing the efficacy and cost of digoxin, pacing, and direct current cardioversion based on a meta-analysis of published studies of success rates of cardioversion of neonatal atrial flutter (age<2 months). Patients who failed initial attempt at cardioversion progressed to the next methodology until successful. Data were analysed to assess the cost-effectiveness of these methods with cost estimates obtained from 2015 Medicare reimbursement rates.

RESULTS

The cost analysis for cardioversion of atrial flutter found the most efficient method to be direct current cardioversion at a cost of $10 304, pacing was next at $11 086, and the least cost-effective was digoxin at $14 374. The majority of additional cost, regardless of method, was from additional neonatal ICU day either owing to digoxin loading or failure to covert. Direct current cardioversion remains the most cost-effective strategy by sensitivity analyses performed on pacing conversion rate and the cost of the neonatal ICU/day. Direct current cardioversion remains cost-effective until the assumed conversion rate is below 64.6%.

CONCLUSION

The most cost-efficient method of cardioverting a neonate with atrial flutter is direct current cardioversion. It has the highest success rates based on the meta-analysis, shorter length of stay in the neonatal ICU owing to its success, and results in cost-savings ranging from $800 to $4000 when compared with alternative approaches.

Management of Supraventricular Tachycardia in Infants

Supraventricular tachycardia is the most common tachyarrhythmia encountered in infants. In older children and adults, definitive treatment of the supraventricular tachycardia substrate with catheter ablation is a common approach to management. However, in infants, the risks of catheter ablation are significantly higher, and the patients often outgrow the potential to experience episodes. Therefore, antiarrhythmic medications are often utilized to minimize the likelihood of experiencing episodes. This article reviews the common arrhythmia mechanisms encountered in infants and the medications used to treat these patients.

Atrial Flutter in the Neonate: A Case Study

Atrial flutter (AF) is an uncommon neonatal tachyarrhythmia that can present during the first few days after birth. The infant with AF may demonstrate an abrupt increase in heart rate greater than 220 bpm that is sustained despite vagal maneuvers. The diagnosis is made by electrocardiogram (ECG), and the treatments may include medication management and cardioversion. We present a case review of an infant diagnosed with AF and describe the incidence, pathophysiology, diagnosis, and management.

Neonatal atrial flutter after insertion of an intracardiac umbilical venous catheter

Objective:

To describe a case of neonatal atrial flutter after the insertion of an intracardiac umbilical venous catheter, reporting the clinical presentation and reviewing the literature on this subject.

Case description:

A late-preterm newborn, born at 35 weeks of gestational age to a diabetic mother and large for gestational age, with respiratory distress and rule-out sepsis, required an umbilical venous access. After the insertion of the umbilical venous catheter, the patient presented with tachycardia. Chest radiography showed that the catheter was placed in the position that corresponds to the left atrium, and traction was applied. The patient persisted with tachycardia, and an electrocardiogram showed atrial flutter. As the patient was hemodynamically unstable, electric cardioversion was successfully applied.

Comments:

The association between atrial arrhythmias and misplaced umbilical catheters has been described in the literature, but in this case, it is noteworthy that the patient was an infant born to a diabetic mother, which consists in another risk factor for heart arrhythmias. Isolated atrial flutter is a rare tachyarrhythmia in the neonatal period and its identification is essential to establish early treatment and prevent systemic complications and even death.

Tachycardia in the Neonate

Atrial flutter (AFL) is the second most common type of tachyarrhythmia in the fetus and neonate. An atrial rate of 240 to 360 beats per minute, 2:1 atrioventricular conduction, and a "saw tooth" appearance on electrocardiogram (ECG) are characteristic. On echocardiogram, bilateral atrial dilatation is the most common finding. Treatment is dependent on the severity of symptoms; delivery is usually indicated in the case of fetal heart failure or hydrops fetalis, whereas postnatal AFL is most commonly treated with direct current cardioversion (DCC). This article presents an illustrative case in which the patient presented antenatally via abnormal nonstress testing and subsequent fetal echocardiogram that was concerning for AFL. Postnatal ECG confirmed this diagnosis and the patient received DCC on the day of birth, followed by digoxin and propranolol as maintenance therapy.

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.

Cavotricuspid isthmus ablation and subcutaneous monitoring device implantation in a 2-year-old baby with 2 SCN5A mutations, sinus node dysfunction, atrial flutter recurrences, and drug induced long-QT syndrome: a tricky case of pediatric overlap syndrome?

We describe the case of 2-year-old baby with compound heterozygosity for paternal and maternal alleles mutation of α-subunit of the cardiac sodium channel (SCN5A), sinus node dysfunction, atrial flutter recurrences, and drug induced long-QT syndrome. In this setting, we chose at first to perform linear ablation of cavotricuspid isthmus resulting in a bidirectional isthmus block. As a second step, we decided to implant a miniaturized loop recorder that, with a minimally invasive procedure, permits us to follow the development of the disease in order to define the future strategy. After 8 months follow-up, automatic daily loop-recorder transmissions disclose the complete absence of any arrhythmia along with asymptomatic ventricular pauses due to sinus node dysfunction. Echocardiography shows normal findings, in particular no left ventricular dysfunction.

Prolonged electrical quiescence after direct current cardioversion for atrial flutter in congenital heart disease

Elective direct current cardioversion is considered first-line treatment in many cases of atrial flutter and fibrillation. This also is true in the pediatric population. This report describes a case of successful cardioversion that resulted in a very prolonged electrical quiescence.