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We describe the case of a newborn with congenital long QT syndrome, with 2:1 AV block and frequent episodes of Torsades de Pointes (TdP) requiring placement of a dual chamber ICD at 33 days and 3.63 kg, the youngest and smallest patient, thus far reported. Long QT syndrome was diagnosed due to bradycardia in the newborn nursery, with frequent episodes of TdP. The patient was initially treated with magnesium and esmolol then given lidocaine which resulted in dramatic transient normalization of the QTc with 1:1 AV nodal conduction. An attempt to transition to oral sodium channel and beta blockade was unsuccessful. An ICD was placed and dual chamber pacing was initiated which facilitated the transition to an oral medical regimen and ultimate discharge from the hospital. Soon after placement of the ICD, genetic testing revealed a novel F1473C mutation in the SCN5A gene. Episodes of TdP continued and left stellate gangliectomy was performed at 3 months of age. At 30 months follow-up, the patient has occasional, self-limited episodes of TdP and has received rare, successful, and appropriate ICD shocks. [ABSTRACT FROM AUTHOR]

Background: DSP cardiomyopathy is a distinct subset of arrhythmogenic cardiomyopathy, reported primarily in adults, that has predominantly left ventricular involvement and features of myocarditis. Clinical characteristics, risk stratification, and management of pediatric patients with DSP variants are not well known. We sought to identify phenotypic features and prognosis of pediatric patients with DSP pathogenic or likely pathogenic variants., Methods: Multicenter, retrospective study of patients <21 years of age with DSP variants from 6 tertiary pediatric hospitals., Results: Thirty-four patients, including 10 probands with clinical disease and 24 genotype-positive phenotype-negative patients, were included in the study. The majority of probands were initially diagnosed with myocarditis (50%) and had biventricular (60%) or left ventricular predominant (40%) disease. Chest pain was the most common symptom at presentation (30%), and all had troponin elevation. Probands with homozygous or compound heterozygous DSP variants were likely to present at an early age (<13 years) with symptoms of heart failure, severe biventricular involvement, and dermatologic abnormalities. Low-voltage QRS was the most prominent ECG abnormality. Of those who underwent implantable cardioverter defibrillator implantation, 50% received appropriate implantable cardioverter defibrillator therapy and were found to have significant biventricular involvement in addition to severe left ventricular dysfunction with an ejection fraction <35%., Conclusions: DSP cardiomyopathy in children and adolescents has varied phenotypic manifestations based on age and genotype and often can be diagnosed as myocarditis. Severe left ventricular dysfunction and biventricular involvement may be associated with a higher likelihood of malignant ventricular tachyarrhythmia., Competing Interests: None.

Importance: The feasibility of implementing genome sequencing as an adjunct to traditional newborn screening (NBS) in newborns of different racial and ethnic groups is not well understood., Objective: To report interim results of acceptability, feasibility, and outcomes of an ongoing genomic NBS study in a diverse population in New York City within the context of the New York State Department of Health Newborn Screening Program., Design, Setting, and Participants: The Genomic Uniform-screening Against Rare Disease in All Newborns (GUARDIAN) study was a multisite, single-group, prospective, observational investigation of supplemental newborn genome screening with a planned enrollment of 100 000 participants. Parent-reported race and ethnicity were recorded at the time of recruitment. Results of the first 4000 newborns enrolled in 6 New York City hospitals between September 2022 and July 2023 are reported here as part of a prespecified interim analysis., Exposure: Sequencing of 156 early-onset genetic conditions with established interventions selected by the investigators were screened in all participants and 99 neurodevelopmental disorders associated with seizures were optional., Main Outcomes and Measures: The primary outcome was screen-positive rate. Additional outcomes included enrollment rate and successful completion of sequencing., Results: Over 11 months, 5555 families were approached and 4000 (72.0%) consented to participate. Enrolled participants reflected a diverse group by parent-reported race (American Indian or Alaska Native, 0.5%; Asian, 16.5%; Black, 25.1%; Native Hawaiian or Other Pacific Islander, 0.1%; White, 44.7%; 2 or more races, 13.0%) and ethnicity (Hispanic, 44.0%; not Hispanic, 56.0%). The majority of families consented to screening of both groups of conditions (both groups, 90.6%; disorders with established interventions only, 9.4%). Testing was successfully completed for 99.6% of cases. The screen-positive rate was 3.7%, including treatable conditions that are not currently included in NBS., Conclusions and Relevance: These interim findings demonstrate the feasibility of targeted interpretation of a predefined set of genes from genome sequencing in a population of different racial and ethnic groups. DNA sequencing offers an additional method to improve screening for conditions already included in NBS and to add those that cannot be readily screened because there is no biomarker currently detectable in dried blood spots. Additional studies are required to understand if these findings are generalizable to populations of different racial and ethnic groups and whether introduction of sequencing leads to changes in management and improved health outcomes., Trial Registration: ClinicalTrials.gov Identifier: NCT05990179.

Clinically significant bradycardia is an uncommon problem in children, but one that can cause significant morbidity and sometimes necessitates implantation of a pacemaker. The most common causes of bradycardia are complete heart block (CHB), which can be congenital or acquired, and sinus node dysfunction, which is rare in children with structurally normal hearts. Pacemaker is indicated as therapy for the majority of children with CHB, and while early mortality is lower in postnatally diagnosed CHB than in fetal CHB, it is still up to 16%. In young children, less invasive transvenous pacemaker systems can be technically challenging to place and carry a high risk of complications, often necessitating surgical epicardial pacemaker placement, which usually entails a median sternotomy. We report three cases of pediatric patients referred for pacemaker implantation for different types of bradycardia, treated at our institution with oral albuterol with therapeutic results that avoided the need for surgical pacemaker implantation at that time., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Little is known about the outcomes of children with second-degree heart block. We aimed to determine whether children with structurally normal hearts and Mobitz 1, 2:1 block or Mobitz 2 are at increased risk for progressing to complete heart block (CHB) or requiring a pacemaker (PM) at long-term follow-up. We searched our institutional electrophysiology database for children with potentially concerning second-degree block on ambulatory rhythm monitoring between 2009 and 2021, defined as frequent episodes of Mobitz 1 or 2:1 block, episodes of Mobitz 1 or 2:1 block with additional evidence of conduction disease (i.e. first-degree heart block, bundle branch block), or episodes of Mobitz 2. Ambulatory rhythm monitor, ECG, and demographic data were reviewed. The primary composite outcome was CHB on follow-up rhythm monitor or PM placement. 20 patients were in the final analysis. Six (30%) patients either developed CHB but do not have a PM (4 = 20%) or have a PM (2 = 10%). Median follow-up was 5.8 years (IQR 4.4-7.0). Patients with CHB or PM were more likely to have second-degree block at maximum sinus rate (67% vs. 0%, p = 0.003), a below normal average heart rate (67% vs. 14%, p = 0.04), and 2:1 block on initial ECG (50% vs. 0%, p = 0.02). In this study of children with potentially concerning second-degree block, 30% of patients progressed to CHB or required a PM. Second-degree block at maximum sinus rate, a low average heart, and 2:1 block on initial ECG were associated with increased risk of disease progression., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Wolff-Parkinson-White syndrome is associated with sudden cardiac death from rapid conduction through the accessory pathway in atrial fibrillation. Adult patients are at higher risk for sudden cardiac death if the shortest-pre-excited-RR-interval in atrial fibrillation (SPERRI) is ≤250 milliseconds (msec) during electrophysiologic study. Exclusive conduction through the atrioventricular node in atrial fibrillation is presumed to convey lower risk. The shortest-pre-excited-paced-cycle-length with atrial pacing has also served as a marker for risk stratification., Objective: To determine accessory pathway characteristic of patients undergoing induction of atrial fibrillation during electrophysiologic study., Methods: We reviewed 321 pediatric patients that underwent electrophysiologic study between 2010 and 2019. Induction of atrial fibrillation was attempted on patients while on isoproterenol and SPERRI was measured if atrial fibrillation was induced. Shortest-pre-excited-paced-cycle-length (SPPCL) was determined while on isoproterenol., Results: Atrial fibrillation was induced in 233 (73%) patients. Of those, 104 (45%) patients conducted exclusively through the atrioventricular node during atrial fibrillation (Group A). The remaining 129 (55%) patients had some conduction through the accessory pathway (Group B). In Group A, SPPCL was 260 msec with 48 (46%) conducting through the accessory pathway at ≤250 msec. In Group B, SPPCL was 240 msec with 92 patients (71%) conducting at ≤250 msec (p < 0.05). In Group B, SPERRI was 250 msec and had a positive correlation with SPPCL (p < 0.001, R 2 = 0.28). Almost half (46%) of those with exclusive conduction through the atrioventricular node in atrial fibrillation had rapid accessory pathway conduction with atrial pacing., Conclusion: Conduction in atrial fibrillation during electrophysiologic study on isoproterenol via the atrioventricular node may not exclude high-risk accessory pathways in pediatric patients.

The AliveCor KardiaMobile (ACKM) is a remote electrocardiogram (ECG) monitoring device. Little research has been conducted on its accuracy with pediatric patients. This prospective study aims to compare the ACKM six-lead device with a standard fifteen-lead ECG in measuring the QTc, QRS, and axis in pediatric patients. Pediatric patients ages 5 to 21 years were enrolled prospectively to have their ECG recorded using an ACKM six-lead device following a recording with the standard 15-lead ECG. A pediatric electrophysiologist measured the QTc, QRS interval, and QRS axis for both ECGs. Bland-Altman analysis was performed to assess agreement among measurements. The study included 141 patients. The mean age was 12.3 ± 4.4 years. Average heart rate was 79 ± 16 bpm. The mean difference in the QTc measurements for a paired standard ECG and ACKM was - 0.6 ms [95% confidence interval - 48 to 47 ms]. Of the ACKM QTc measurements, 117 (83%) were within 30 ms of the standard ECG. The mean difference in paired QRS measurements was - 1.3 ms [95% confidence interval - 23 to 21 ms]. Of the ACKM QRS measurements, 134 (95%) were within 20 ms of the standard ECG. The measured axis was the same for 84% of ACKM and standard ECGs. Over 80% of the ACKM six-lead ECGs produced QTc, QRS, and axis deviation measurements within a clinically useful range of the standard ECG. However, it is not accurate enough to be used consistently in place of a standard ECG for QTc and QRS measurement for pediatric patients., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The Norwood procedure with a right ventricular to pulmonary artery shunt (RVPAS) decreases early mortality, but requires a ventriculotomy, possibly increasing risk of ventricular arrhythmias (VAs) compared with the modified Blalock-Taussig shunt (MBTS). The effect of shunt and Fontan type on arrhythmias by 6 years of age in the SVRII (Single Ventricle Reconstruction Extension Study) was assessed. SVRII data collected on 324 patients pre-/post-Fontan and annually at 2 to 6 years included antiarrhythmic medications, electrocardiography (ECG) at Fontan, and Holter/ECG at 6 years. ECGs and Holters were reviewed for morphology, intervals, atrioventricular conduction, and arrhythmias. Isolated VA were seen on 6-year Holter in >50% of both cohorts (MBTS 54% vs RVPAS 60%), whereas nonsustained ventricular tachycardia was rare and observed in RVPAS only (2.7%). First-degree atrioventricular block was more common in RVPAS than MBTS (21% vs 8%, p = 0.01), whereas right bundle branch block, QRS duration, and QTc were similar. Antiarrhythmic medication usage was common in both groups, but most agents also supported ventricular function (e.g., digoxin, carvedilol). Of the 7 patients with death or transplant between 2 and 6 years, none had documented VAs, but compared with transplant-free survivors, they had somewhat longer QRS (106 vs 93 ms, p = 0.05). Atrial tachyarrhythmias varied little between MBTS and RVPAS but did vary by Fontan type (lateral tunnel 41% vs extracardiac conduit 29%). VAs did not vary by Fontan type. In conclusion, at 6-year follow-up, benign VAs were common in the SVRII population. However, despite the potential for increased VAs and sudden death in the RVPAS cohort, these data do not support significant differences or increased risk at 6 years. The findings highlight the need for ongoing surveillance for arrhythmias in the SVR population., Competing Interests: Disclosures The authors have no conflicts of interest to declare., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: This study sought to describe the electrophysiologic properties and catheter ablation outcomes for atrioventricular reciprocating tacchycardia via twin atrioventricular nodes (T-AVRT)., Background: Although catheter ablation for T-AVRT is an established entity, there are few data on the electrophysiological properties and outcomes of this procedure., Methods: An international, multicenter study was conducted to collect retrospective procedural and outcomes data for catheter ablation of T-AVRT., Results: Fifty-nine patients with T-AVRT were identified (median age at procedure, 8 years [interquartile range: 4.4-17.0 years]; 49% male). Of these, 55 (93%) were diagnosed with heterotaxy syndrome (right atrial isomerism in 39, left atrial isomerism in 8, and indeterminate in 8). Twenty-three (39%) had undergone Fontan operation (12 extracardiac, 11 lateral tunnel). After the Fontan operation, atrial access was conduit or baffle puncture in 15 (65%), fenestration in 5 (22%), and retrograde in 3 (13%). Acute success was achieved in 43 (91%) of 47 attempts (targeting an anterior node in 23 and posterior node in 24). There was no high-grade AV block or change in QRS duration. Over a median of 3.8 years, there were 3 recurrences. Of 7 patients with failed index procedure or recurrent T-AVRT, 6 (86%) were associated with anatomical hurdles such as prior Fontan or catheter course through an interrupted inferior vena cava-to-azygous vein continuation (P = 0.11)., Conclusions: T-AVRT can be targeted successfully with low risk for recurrence. Complications were rare in this population. Anatomical challenges were common among patients with reduced short and long-term efficacy, representing opportunities for improvement in procedural timing and planning., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Background: Cancer-associated pulmonary embolism (PE) places a significant burden on patients and health care systems., Methods: A retrospective cross-sectional analysis of the National Inpatient Sample (NIS) database was performed in patients with acute PE from 2002 to 2014. Among patients hospitalized with PE, we investigated the differences in clinical outcomes and healthcare utilization in patients with and without cancer. A multivariate logistic regression model was applied to calculate adjusted odds ratios (OR) to estimate the impact of cancer on clinical outcomes. Wilcoxon rank sum tests were used to determine the differences in healthcare utilization between the two cohorts., Results: Among 3,313,044 patients who were discharged with a diagnosis of acute PE, 84.2% did not have cancer, while 15.8% had cancer as a comorbidity (56% metastatic cancer, 35% solid tumor without metastasis, and 9% lymphoma). Patients with cancer had a higher mean age but lower rates of common comorbidities except for coagulation deficiency than patients without a cancer diagnosis. In patients with cancer, the rate of IVC filter placement was higher (21.7% vs. 13.11%, OR 1.76 (95% CI 1.73-1.79); p < 0.0001) and thrombolytic use lower (1.34% vs. 2.15%, OR 0.68 (95% CI 0.64-0.72); p < 0.0001). Patients with cancer hospitalized for PE had a higher all-cause in-hospital mortality (11.8% vs. 6.6%, OR 1.79 (95% CI 1.75-1.83); p < 0.0001), longer length of stay (6 vs. 5 days; p < 0.0001), higher total charge per hospitalization ($30,885 vs. $27,273; p < 0.0001), and higher rates of home health services upon discharge (35.8% vs. 23.2%; p < 0.0001) compared with those without cancer., Conclusion: Concurrent cancer diagnosis in patients hospitalized for acute PE was associated with a 90% increase in all-cause mortality, longer length of stay, higher total charge per hospitalization, and higher rates of home health services upon discharge. The majority (56%) of patients with cancer had metastatic disease. Furthermore, there were identifiable differences in the intervention for acute PE between the two groups., (© 2021. The Author(s).)

Sudden cardiac arrest in pediatric patients is a rare occurrence. Supraventricular tachycardia without the presence of ventricular preexcitation in pediatric patients with a structurally normal heart is generally considered benign. Previous literature in adults reported a subset of patients in whom SVT was suspected to be the primary trigger of sudden cardiac arrest. We performed a single-center, retrospective cohort study of pediatric patients without known heart disease, 1-21 years of age, presenting with aborted SCA between 2009 and 2019. We collected diagnostic studies in all patients to identify the etiology of the aborted SCA. Thirty patients met the inclusion criteria. The median age at the time of SCA was 15.2 years. The etiology of SCA was identified in 23 (77%) patients. Of the seven patients with unknown diagnosis after initial diagnostic studies, three patients subsequently developed fast SVT that was presumed to be the etiology of the initial SCA. These three patients had varying diagnoses of atrioventricular nodal reentry tachycardia, ectopic atrial tachycardia, and a concealed accessory pathway with atrioventricular reentrant tachycardia. After ablation or medical treatment of the SVT substrate, no further tachyarrhythmias were observed. Pediatric patients presenting with an aborted SCA of unknown etiology ought to be considered for electrophysiology testing to elicit occult SVT substrates that may lead to a malignant ventricular tachyarrhythmia., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: We aimed to measure the frequency and factors associated with anodal stimulation in a pediatric population with epicardial pacing leads., Background: In bipolar pacemakers, capture of the myocardium typically occurs at the cathode. However, AS with capture at the anode has been described. This has not been described in epicardial pacemakers., Methods: Retrospective data were collected from patients ≤ 21 years of age with permanent bipolar epicardial ventricular pacemakers from 1/2017 to 1/2018. AS was defined as a clear change on surface ECG in at least one of the 12 leads assessed by two blinded pediatric electrophysiologists., Results: Twenty-four bipolar leads in 23 patients were included in the study. One patient had both biventricular leads tested. Median age was 7.1 years (IQR 5.0-10.9), weight was 20.9 kg (IQR 16.5-33.5), and 65% were male. Testing was performed at a median of 2.8 years (IQR 1.6-6.1) after implant. Congenital heart disease was present in 57%. Complete heart block was the pacemaker indication in 78%. AS was identified in 16/24 (67%) of leads tested. Identification of AS was associated with presence of congenital heart disease (p = 0.004) and 3DD between electrodes (p = 0.04)., Conclusions: AS is common in pediatric patients and was associated with a history of congenital heart disease and greater estimated 3DD between electrodes. The prevalent nature of AS may allow clinicians to utilize existing pacemakers as multisite pacing systems., (© 2021 Wiley Periodicals LLC.)

Block in accessory pathway (AP) conduction with adenosine has been previously described. However, conduction characteristics of these APs has not been well defined to date. All patients with APs 2 and Fisher's exact were used for analysis. Fourteen (7%) out of 207 patients had an adenosine sensitive AP. The median age of patients with adenosine sensitive APs was 11.8 (IQR 8.5-13.5) years vs. 14 (IQR 10.6-16.7) for the rest of the cohort (p = 0.04). Three of the 134 patients with preexcitation had adenosine sensitive APs (2%) vs. 11 of the 73 patients with concealed APs (15%) (p = 0.001). The median local AV/VA time at the site of successful ablation was longer in group 1 vs group 2 [78 ms, IQR 62-116 vs. 31 ms, IQR 30-38; p < 0.001]. Antegrade AP effective refractory period and total procedure time were longer in patients with adenosine sensitive APs (p = 0.03 & p = 0.04, respectively). Adenosine sensitive APs which occur in children are more often concealed. These APs have a longer conduction time at the site of successful ablation., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Polymerization-induced microphase separation has been used to prepare solid cross-linked monoliths containing bicontinuous and nanostructured polymer domains. We use this process to fabricate a monolith containing either a negatively or positively charged polyelectrolyte domain inside of the neutral styrene/divinylbenzene-derived matrix. First, the materials are made with a neutral pre-ionic polymer containing masked charged groups. The monoliths are then functionalized to a charged state by treatment with trimethylamine; small-angle X-ray scattering shows no significant morphological change in the microphase-separated structure upon postpolymerization modification. By exchanging dyes with the counterions in the material, we corroborated the continuity of the charged domains. Using ion-exchange capacity measurements, we estimate the number of accessible charges within the material based on macro-chain transfer agent molar mass and loading.

Definitive treatment of supraventricular tachycardia (SVT) substrate involves catheter ablation. While objective success rates have been well established, long-term subjective patient experiences have not been well described. We quantify a subjective cure rate and characterize long-term patient experience after acutely successful ablation. A cross-sectional survey of pediatric patients with accessory pathways or atrioventricular nodal reentrant tachycardia who underwent acutely successful ablation from 2008 to 2012 was performed. Data were obtained from medical records and patient surveys. Patients with congenital heart disease other than patent ductus arteriosus, patent foramen ovale, or coronary artery abnormalities were excluded. Statistical analyses included Student's t-test and χ 2 analysis for continuous and categorical variables, respectively. Surveys were sent to 153 patients of which 147 responded with median follow-up of 7.2 (IQR 6.1-8.5) years. Of the 147 responders, 124 (84%) patients reported cure with a male predominance. Symptoms were present in 130/147 (88%) patients pre-ablation and in 53/147 (36%) post-ablation. Among those with post-ablation symptoms, 50/53 (94%) reported symptomatic improvement. Recurrence occurred in 23/147 (16%) patients and was more prevalent following cryoablation. Ablation of SVT substrate can be curative with excellent long-term results and patient satisfaction. Long-term subjective cure rate is high and there is a substantial decrease in symptoms post-ablation. Many patients continue to have symptoms following ablation; however, the majority of these patients consider themselves cured and symptoms can be attributed to other etiologies. Recurrence is uncommon and occurs more frequently following cryoablation.

Objectives: Multisystem inflammatory syndrome in children (MIS-C) has spread through the pediatric population during the coronavirus disease 2019 pandemic. Our objective for the study was to report the prevalence of conduction anomalies in MIS-C and identify predictive factors for the conduction abnormalities., Methods: We performed a single-center retrospective cohort study of pediatric patients <21 years of age presenting with MIS-C over a 1-month period. We collected clinical outcomes, laboratory findings, and diagnostic studies, including serial electrocardiograms, in all patients with MIS-C to identify those with first-degree atrioventricular block (AVB) during the acute phase and assess for predictive factors., Results: Thirty-two patients met inclusion criteria. Median age at admission was 9 years. Six of 32 patients (19%) were found to have first-degree AVB, with a median longest PR interval of 225 milliseconds (interquartile range 200-302), compared with 140 milliseconds (interquartile range 80-178) in patients without first-degree AVB. The onset of AVB occurred at a median of 8 days after the initial symptoms and returned to normal 3 days thereafter. No patients developed advanced AVB, although 1 patient developed a PR interval >300 milliseconds. Another patient developed new-onset right bundle branch block, which resolved during hospitalization. Cardiac enzymes, inflammatory markers, and cardiac function were not associated with AVB development., Conclusions: In our population, there is a 19% prevalence of first-degree AVB in patients with MIS-C. All patients with a prolonged PR interval recovered without progression to high-degree AVB. Patients admitted with MIS-C require close electrocardiogram monitoring during the acute phase., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2020 by the American Academy of Pediatrics.)

A diagnosis of Brugada pattern in paediatric or adolescent patients is rare. COVID-19 is characterised by fevers and a pro-inflammatory state, which may serve as inciting factors for Brugada pattern. Recently described in two adult patients, we report the first case of Brugada pattern in an adolescent with COVID-19.

Water molecules within a thin hydration layer, spontaneously generated on hydrophobic protein surfaces, are reported to form a poorly dynamic network structure. However, how such a water network affects the conformational change dynamics of polar groups has never been explored, although such polar groups play a critical role in protein-protein and protein-ligand interactions. In the present work, we utilized as model protein surfaces a series of self-assembled monolayers (SAMs) appended with polar (Fmoc) or ionic (FITC) fluorescent head groups that were tethered via a 1.5-nm-long flexible oligoether chain to a hydrophobic silicon wafer surface, which was densely covered with paraffinic chains. We found that, not only in deionized water but also in aqueous buffer, these oligoether-appended head groups at ambient temperatures both displayed an anomalously slow conformational change, which required ∼10 h to reach a thermodynamically equilibrated state. We suppose that these behaviors reflect the poorly dynamic and low-permittivity natures of the thin hydration layer., (© 2020 Wiley-VCH GmbH.)

Approximately, 1.7 million individuals in the United States have been infected with SARS-CoV-2, the virus responsible for the novel coronavirus disease-2019 (COVID-19). This has disproportionately impacted adults, but many children have been infected and hospitalised as well. To date, there is not much information published addressing the cardiac workup and monitoring of children with COVID-19. Here, we share the approach to the cardiac workup and monitoring utilised at a large congenital heart centre in New York City, the epicentre of the COVID-19 pandemic in the United States.

Background: Relative contraindications to adenosine use have included heart transplant and dipyridamole. We previously demonstrated the safety and efficacy of adenosine-induced atrioventricular (AV) block in healthy young heart transplant recipients while suspending dipyridamole therapy (dual antiplatelet agent). This prospective follow-up study evaluated the safety and efficacy of adenosine use in the same cohort of heart transplant recipients while on dipyridamole., Methods: Adenosine was incrementally dosed until AV block occurred (maximum 200 mcg/kg up to 12 mg). The primary outcome was clinically significant asystole (≥12 seconds). Secondary outcomes included maximal adenosine dose, AV block duration, dysrhythmias, and clinical symptoms. Outcomes were compared to the parent study., Results: Thirty of 39 eligible patients (5-24 years) were tested. No patient (0%, CI 0%-8%) experienced clinically significant asystole. AV block occurred in 29/30 patients (97%, CI 86%-100%). The median dose causing AV block was 50mcg/kg (vs 100 mcg/kg off dipyridamole; P = .011). Seventeen patients (57%, CI 39%-72%) required less adenosine to achieve AV block on dipyridamole; six (20%) required more. AV block occurred at doses ≥25 mcg/kg in all patients. In pairwise comparison to prior testing off dipyridamole, no significant change occurred in AV block duration, frequency of cardiac ectopy, or incidence of reported symptoms. No atrial fibrillation/flutter occurred., Conclusions: AV block often occurs at twofold lower adenosine doses in healthy young heart transplant recipients taking oral dipyridamole, compared with previous testing of this cohort off dipyridamole. Results suggest that initial dosing of 25 mcg/kg (maximum 0.8 mg) with stepwise escalation poses low risk of prolonged asystole on dipyridamole., (© 2020 Wiley Periodicals, Inc.)

The standard for ambulatory arrhythmia detection in children is the Holter monitor. The Zio XT (Zio) patch has been FDA-approved for use in adults. However, its utility in children has not been directly compared with the Holter. We studied the ability to detect arrhythmias and patient comfort of the Zio versus the Holter in children. Patients <22 years old were prospectively enrolled to wear the Holter and Zio simultaneously for 48 hours at our institution. Detection of clinically significant arrhythmias was compared using McNemar's test. Wear-time and artifact time was compared using Wilcoxon sign test. Patient satisfaction ratings were analyzed with paired t tests. Two hundred patients (57% male) were included for analysis. The median age was 13.5 years (range 23 days to 21.7 years), and 40% had heart disease. The Zio and Holter had comparable median wear-times, 48.2 hours (interquartile range [IQR] 45.8 to 50.2]) versus 48.0 (48.0 to 48.0), respectively, p = 0.14, but the Zio had less artifact than the Holter, 2.8% (IQR 1.1 to 8.6) versus 5.6% (2.4 to 15.7), respectively, p <0.001. There was no difference in detection of clinically significant arrhythmias for the Zio versus the Holter (p = 0.23), however 75% of patients preferred the Zio over the Holter (p <0.001) due to lack of wires and the ability to shower. In conclusion, the Zio patch is as good as the Holter monitor in detection of clinically significant arrhythmias in children with less artifact. Patients/parents more often preferred the Zio over the Holter., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Arrhythmia localization prior to catheter ablation is critical for clinical decision making and treatment planning. The current standard lies in 12-lead electrocardiogram (ECG) interpretation, but this method is non-specific and anatomically limited. Accurate localization requires intracardiac catheter mapping prior to ablation. Electromechanical Wave Imaging (EWI) is a high frame-rate ultrasound modality capable of non-invasively mapping the electromechanical activation in all cardiac chambers in vivo. In this study, we evaluate 3D-rendered EWI as a technique for consistently localizing the accessory pathway (AP) in Wolff-Parkinson-White (WPW) pediatric patients. A 2000 Hz EWI diverging sequence was used to transthoracically image 13 patients with evidence of ECG pre-excitation, immediately prior to catheter ablation and after successful ablation whenever possible. 3D-rendered activation maps were generated by co-registering and interpolating the 4 resulting multi-2D isochrones. A blinded electrophysiologist predicted the AP location on 12-lead ECG prior to ablation. Double-blinded EWI isochrones and clinician assessments were compared to the successful ablation site as confirmed by intracardiac mapping using a segmented template of the heart with 19 ventricular regions. 3D-rendered EWI was shown capable of consistently localizing AP in all the WPW cases. Clinical ECG interpretation correctly predicted the origin with an accuracy of 53.8%, respectively 84.6% when considering predictions in immediately adjacent segments correct. Our method was also capable of assessing the difference in activation pattern from before to after successful ablation on the same patient. These findings indicate that EWI could inform current diagnosis and expedite treatment planning of WPW ablation procedures.

Objectives: This study sought to demonstrate the feasibility of electromechanical wave imaging (EWI) for localization of accessory pathways (AP) prior to catheter ablation in a pediatric population., Background: Prediction of AP locations in patients with Wolff-Parkinson-White syndrome is currently based on analysis of 12-lead electrocardiography (ECG). In the pediatric population, specific algorithms have been developed to aid in localization, but these can be unreliable. EWI is a noninvasive imaging modality relying on a high frame rate ultrasound sequence capable of visualizing cardiac electromechanical activation., Methods: Pediatric patients with ventricular pre-excitation presenting for catheter ablation were imaged with EWI immediately prior to the start of the procedure. Two clinical pediatric electrophysiologists predicted the location of the AP based on ECG. Both EWI and ECG predictions were blinded to the results of catheter ablation. EWI and ECG localizations were subsequently compared with the site of successful ablation., Results: Fifteen patients were imaged with EWI. One patient was excluded for poor echocardiographic windows and the inability to image the entire ventricular myocardium. EWI correctly predicted the location of the AP in all 14 patients. ECG analysis correctly predicted 11 of 14 (78.6%) of the AP locations., Conclusions: EWI was shown to be capable of consistently localizing accessory pathways. EWI predicted the site of successful ablation more frequently than analysis of 12-lead ECG. EWI isochrones also provide anatomical visualization of ventricular pre-excitation. These findings suggest that EWI can predict AP locations, and EWI may have the potential to better inform clinical electrophysiologists prior to catheter ablation procedures., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The clinical course of children with advanced heart block secondary to Lyme disease has not been well characterized., Objective: To review the presentation, management, and time to resolution of heart block due to Lyme disease in previously healthy children., Methods: An IRB approved single-center retrospective study was conducted of all patients < 21 years old with confirmed Lyme disease and advanced second or third degree heart block between 2007 and 2017., Results: Twelve patients (100% male) with a mean age of 15.9 years (range 13.2-18.1) were identified. Six patients (50%) had mild to moderate atrioventricular valve regurgitation and all had normal biventricular function. Five patients had advanced second degree heart block and 7 had complete heart block with an escape rate of 20-57 bpm. Isoproterenol was used in 4 patients for 3-4 days and one patient required transvenous pacing for 2 days. Patients were treated with 21 days (n = 6, 50%) or 28 days (n = 6, 50%) of antibiotics. Three patients received steroids for 3-4 days. Advanced heart block resolved in all patients within 2-5 days, and all had a normal PR interval within 3 days to 16 months from hospital discharge., Conclusion: Symptomatic children who present with new high-grade heart block from an endemic area should be tested for Lyme disease. Antibiotic therapy provides quick and complete resolution of advanced heart block within 5 days, while steroids did not appear to shorten the time course in this case series. Importantly, no patients required a permanent pacemaker.

Background: Interpretation of pediatric ECGs is limited by lack of accurate sex- and race-specific normal reference values obtained with modern technology for all ages. We sought to obtain contemporary digital ECG measurements in healthy children from North America, to evaluate the effects of sex and race, and to compare our results to commonly used published datasets., Methods: Digital ECGs (12-lead) were retrospectively collected for children ≤18 years old with normal echocardiograms at 19 centers in the Pediatric Heart Network. Patients were classified into 36 groups: 6 age, 2 sex, and 3 race (white, black, and other/mixed) categories. Standard intervals and amplitudes were measured; mean±SD and 2nd/98th percentiles were determined by age group, sex, and race. For each parameter, multivariable analysis, stratified by age, was conducted using sex and race as predictors. Parameters were compared with 2 large pediatric ECG data sets., Results: Among ECGs from 2400 children, significant differences were found by sex and race categories. The corrected QT interval in lead II was greater for girls compared with boys for age groups ≥3 years ( P ≤0.03) and for whites compared with blacks for age groups ≥12 years ( P <0.05). The R wave amplitude in V6 was greater for boys compared with girls for age groups ≥12 years ( P <0.001), for blacks compared with white or other race categories for age groups ≥3 years ( P ≤0.006), and greater compared with a commonly used public data set for age groups ≥12 years ( P <0.0001)., Conclusions: In this large, diverse cohort of healthy children, most ECG intervals and amplitudes varied by sex and race. These differences have important implications for interpreting pediatric ECGs in the modern era when used for diagnosis or screening, including thresholds for left ventricular hypertrophy., (© 2018 American Heart Association, Inc.)

A high dose of oral flecainide has been used for acute termination of atrial fibrillation (AF) and atrial flutter or intra-atrial re-entry tachycardia (AFL-IART) in adults. The use of flecainide for these conditions in children has not been well described. We describe our institutional experience on acute termination of AF or AFL-IART in children with a single high dose of oral flecainide in a hospital setting. All patients who received a single high dose of oral flecainide from 2009 to 2016 who were <21 years of age were included. Patients were treated only if AF or AFL-IART was less than 24 hours of duration. The dose was 300 mg for patients >70 kg, 200 mg for patients 40 to 70 kg, and 5 mg/kg for patients <40 kg. Charts were reviewed to determine demographic information, flecainide dose, termination of arrhythmia, and time to termination. There were 22 patients identified. The median age was 16 years (range 4.6 to 20.3) with a median weight of 75 kg (range 19 to 112). There were 13 patients with AF (11 with a normal heart, 85%) and 9 patients with AFL-IART (1 with a normal heart, 11%) (p <0.05). The median dose of flecainide given was 3.6 mg/kg (range 2.7 to 6.1) or 136 mg/m 2 (range 90 to 171). AF in all patients (13/13, 100%) and AFL-IART in 5 of 9 patients (55%) terminated acutely (p <0.05). All patients with normal heart (12/12, 100%) and 6 of the 10 patients (60%) with heart disease have their arrhythmia terminated acutely (p <0.05). The only patients whose tachycardia did not terminate were 4 patients with IART and heart disease. The arrhythmia terminated in a median time of 60 minutes (range 30 to 120). There were no adverse events or proarrhythmia encountered. In conclusion, a single high dose of oral flecainide successfully terminated AF of less than 24 hours' duration in all pediatric patients without side effects. This approach is less effective for AFL-IART in patients with heart disease., (Copyright © 2018. Published by Elsevier Inc.)

Background: Concealed left-sided accessory pathways (CLAP) are a cause of supraventricular tachycardia (SVT) in the young. Most are mapped with right ventricular (RV) apical/outflow pacing. Rarely, alternative means of mapping are required. We review our experience from three pediatric electrophysiology (EP) centers with a rare form of "hidden" CLAP., Methods: All patients <21 years undergoing EP study from 2008 to 2014 with a "hidden" CLAP (defined as an accessory pathway [AP] for which RV pacing at cycle lengths [CL] stable for mapping did not demonstrate eccentric retrograde conduction) were included., Exclusion Criteria: preexcitation. Demographic, procedural, and follow-up data were collected., Results: A total of 23 patients met the criteria (median age, 14.3 years [range 7-21], weight, 51 kg [31-99]). 21 (96%) had SVT and one AFIB (4%). APs were adenosine sensitive in 7/20 patients (35%) and VA conduction was decremental in six (26%). CLAP conduction was demonstrable with orthodromic reentrant tachycardia in all patients, with RV extrastimulus testing in seven (30%) and with rapid RV pacing (

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.

Background: Supraventricular tachycardia is common after heart transplantation. Adenosine, the standard therapy for treating supraventricular tachycardia in children and adults without transplantation, is relatively contraindicated after transplantation because of a presumed risk of prolonged atrioventricular block in denervated hearts. This study tested whether adenosine caused prolonged asystole after transplantation and if it was effective in blocking atrioventricular nodal conduction in these patients., Methods: This was a single-center prospective clinical study including healthy heart transplant recipients 6 months to 25 years of age presenting for routine cardiac catheterization during 2015 to 2016. After catheterization, a transvenous pacing catheter was placed and adenosine was given following a dose-escalation protocol until atrioventricular block was achieved. The incidence of clinically significant asystole (≥12 seconds after adenosine) was quantified. The effects of patient characteristics on adenosine dose required to produce atrioventricular block and duration of effect were also measured., Results: Eighty patients completed adenosine testing. No patient (0%; 95% confidence interval, 0-3) required rescue ventricular pacing. Atrioventricular block was observed in 77 patients (96%; 95% confidence interval, 89-99). The median longest atrioventricular block was 1.9 seconds (interquartile range, 1.4-3.2 seconds), with a mean duration of adenosine effect of 4.3±2.0 seconds. No patient characteristic significantly predicted the adenosine dose to produce atrioventricular block or duration of effect. Results were similar across patient weight categories., Conclusions: Adenosine induces atrioventricular block in healthy pediatric and young adult heart transplant recipients with minimal risk when low initial doses are used (25 μg/kg; 1.5 mg if ≥60 kg) and therapy is gradually escalated., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02462941., (© 2017 American Heart Association, Inc.)

Risk stratification of patients with Wolff-Parkinson-White syndrome for sudden death is a complex process, particularly in understanding the utility of the repeat exercise stress test. We report a case of an 18-year-old patient who was found to have a high-risk pathway by both invasive and exercise stress testing after an initial exercise stress test showing beat-to-beat loss of pre-excitation.

Objectives: The study objective was to determine the predictors of new-onset arrhythmia among infants with single-ventricle anomalies during the post-Norwood hospitalization and the association of those arrhythmias with postoperative outcomes (ventilator time and length of stay) and interstage mortality., Methods: After excluding patients with preoperative arrhythmias, we used data from the Pediatric Heart Network Single Ventricle Reconstruction Trial to identify risk factors for tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia) and atrioventricular block (second or third degree) among 544 eligible patients. We then determined the association of arrhythmia with outcomes during the post-Norwood hospitalization and interstage period, adjusting for identified risk factors and previously published factors., Results: Tachyarrhythmias were noted in 20% of subjects, and atrioventricular block was noted in 4% of subjects. Potentially significant risk factors for tachyarrhythmia included the presence of modified Blalock-Taussig shunt (P = .08) and age at Norwood (P = .07, with risk decreasing each day at age 8-20 days); the only significant risk factor for atrioventricular block was undergoing a concomitant procedure at the time of the Norwood (P = .001), with the greatest risk being in those undergoing a tricuspid valve procedure. Both tachyarrhythmias and atrioventricular block were associated with longer ventilation time and length of stay (P < .001 for all analyses). Tachyarrhythmias were not associated with interstage mortality; atrioventricular block was associated with mortality among those without a pacemaker in the unadjusted analysis (hazard ratio, 2.3; P = .02), but not after adding covariates., Conclusions: Tachyarrhythmias are common after the Norwood procedure, but atrioventricular block may portend a greater risk for interstage mortality., (Copyright © 2016 The American Association for Thoracic Surgery. All rights reserved.)

Background: Advanced second- or third-degree heart block has been reported with variable incidence after surgery for congenital heart disease in children. We report the incidence of heart block requiring a pacemaker and describe the risk factors for this complication in a large multicenter study., Methods: We performed a retrospective cohort study, using the Pediatric Health Information System database from 45 hospitals in the United States, for all children aged 18 years, discharged between January 1, 2004, and December 31, 2013, who underwent open surgery for congenital heart disease. Patients who had heart block and placement of a pacemaker during the same hospitalization were identified. Demographic characteristics, procedure and diagnostic codes, length of stay, and mortality were analyzed. Univariable and multivariable analyses were performed., Results: There were 101,006 surgeries performed. The median age of patients was 0.5 years (interquartile range, 26 days to 3.2 years), and 1% of patients (n = 990) had heart block and placement of a pacemaker. Surgeries associated with the highest incidences of heart block and placement of a pacemaker included the double switch operation (15.6%), tricuspid valve (7.8%) and mitral valve (7.4%) replacement, atrial switch with ventricular septal defect repair (6.4%), and Rastelli operation (4.8%). On multivariable analysis, after controlling for surgical complexity, other comorbidities, age at surgery, admission year, and clustering by institution, patients with heart block and placement of a pacemaker had higher odds of mortality (odds ratio, 1.67; 95% confidence interval, 1.24-2.26; P < .001)., Conclusions: The incidence of postoperative heart block requiring permanent pacemaker placement immediately after congenital heart surgery is low (1%). However, these patients have higher mortality even after adjusting for heart surgery complexity., (Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Prolongation of the QT interval and development of torsades de pointes are known in patients with complete heart block and profound bradycardia. We report the case of a patient with complete heart block and torsades, with long QT seen during a period of junctional tachycardia at a rate faster than the minimum pacemaker rate.

Privately owned woodlands are an important source of timber and ecosystem services in North America and worldwide. Impacts of management on these ecosystems and timber supply from these woodlands are difficult to estimate because complex behavioral theory informs the owner's management decisions. The decision-making environment consists of exogenous market factors, internal cognitive processes, and social interactions with fellow landowners, foresters, and other rural community members. This study seeks to understand how social interactions, information flow, and peer-to-peer networks influence timber harvesting behavior using an agent-based model. This theoretical model includes forested polygons in various states of 'harvest readiness' and three types of agents: forest landowners, foresters, and peer leaders (individuals trained in conservation who use peer-to-peer networking). Agent rules, interactions, and characteristics were parameterized with values from existing literature and an empirical survey of forest landowner attitudes, intentions, and demographics. The model demonstrates that as trust in foresters and peer leaders increases, the percentage of the forest that is harvested sustainably increases. Furthermore, peer leaders can serve to increase landowner trust in foresters. Model output and equations will inform forest policy and extension/outreach efforts. The model also serves as an important testing ground for new theories of landowner decision making and behavior.

Smartphone applications that record a single-lead ECG are increasingly available. We sought to determine the utility of a smartphone application (AliveCor) to record supraventricular tachycardia (SVT) and to distinguish atrioventricular reentrant tachycardia (AVRT) from atrioventricular nodal reentrant tachycardia (AVNRT) in pediatric patients. A prior study demonstrated that interpretation of standard event and Holter monitors accurately identifies the tachycardia mechanism in only 45 % of recordings. We performed an IRB-approved prospective study in pediatric patients undergoing an ablation for SVT. Tracings were obtained by placing the smartphone in three different positions on the chest (PI-horizontal, PII-rotated 60° clockwise, and PIII-rotated 120° clockwise). Two blinded pediatric electrophysiologists jointly analyzed a pair of sinus and tachycardia tracings in each position. Tracings with visible retrograde P waves were classified as AVRT. The three positions were compared by Chi-square test. Thirty-seven patients (age 13.7 ± 2.8 years) were enrolled in the study. Twenty-four had AVRT, and 13 had AVNRT. One hundred and eight pairs of tracings were obtained. The correct diagnosis was made in 27/37 (73 %) with position PI, 28/37 (76 %) with PII, and 20/34 (59 %) with PIII (p = 0.04 for PII vs. PIII and p = NS for other comparisons). A single-lead ECG obtained with a smartphone monitor can successfully record SVT in pediatric patients and can predict the SVT mechanism at least as well as previously published reports of Holter monitors, along with the added convenience of not requiring patients to carry a dedicated monitor.

Hypoplastic left heart syndrome (HLHS) is a severe form of congenital heart disease characterized by underdevelopment of the left heart. There has been no previously defined "classic" ECG pattern in a large homogenous population of patients with HLHS. We performed a retrospective review of ECGs from neonates with HLHS from 2001 to 2011 with electrocardiograms available prior to surgical intervention. Eighty-nine neonates met the inclusion criteria and were compared to a control population. HLHS patients had a longer PR interval 108 ± 18 versus 98 ± 11 ms (p < 0.05), a wider QRS complex 84 ± 17 versus 54 ± 5 ms (p < 0.05), lower voltage S waves in V1 2.0 ± 3.3 versus 5.8 ± 4.6 mm (p < 0.001) or absent S waves in V1 52 versus 4 % (p < 0.001) and lower voltage R waves in V6 7.8 ± 4.8 versus 9.3 ± 4.2 mm (p < 0.05). Patients with HLHS were more likely to have absent Q waves in the lateral precordial leads 78 versus 0 % (p < 0.001) and inferior leads 20 versus 1 % (p < 0.001) and an abnormal frontal plane QRS axis 26 versus 11 % (p < 0.05). HLHS patients were more likely to have a preexcited appearance 11 versus 0 % (p = 0.001). Despite these findings, 20 % of patients with HLHS had a normal ECG. Compared to age-matched controls, patients with HLHS were more likely to exhibit a longer PR interval, a wider QRS complex, decreased left-sided forces, an absence of septal Q waves in the inferior and lateral leads, an abnormal frontal plane QRS axis and a preexcited appearance.

Background: Three-dimensional electroanatomic mapping systems (3D mapping) allow the creation of an anatomic representation of the cardiac anatomy and real-time monitoring of transvenous pacing catheters. Their use to facilitate pacemaker (PM) and implantable cardioverter defibrillator (ICD) lead placement in the pediatric population has not been well defined. We sought to review our experience using 3D mapping as an adjunct to fluoroscopy for positioning of permanent PM and ICD leads in pediatric patients., Methods: We performed a retrospective review of all patients ≤21 years of age who underwent PM or ICD implantation with the aid of the Ensite Velocity system (Ensite) from May 2012 to September 2014. Fluoroscopy was utilized in addition to 3D mapping to aid obtaining vascular access, to visualize fixation of the lead to the myocardium, and to evaluate lead length within the vasculature., Results: Nineteen patients (mean age 14.6 ± 4.4 years) underwent placement of active fixation PM leads (N = 17) and/or ICD leads (N = 10) with the aid of Ensite. All leads were successfully placed (eight atrial, 19 ventricular). Fluoroscopic exposure was a mean of 3.2 minutes (± 2.8, 0.1-10.5). There was one lead dislodgement., Conclusions: Ensite was used successfully as an adjunct to fluoroscopy in all patients in whom it was attempted to aid the placement of permanent transvenous PM and ICD leads. Future evaluation could focus on the use of 3D mapping systems to further minimize or eliminate fluoroscopy from PM and ICD implantations., (©2015 Wiley Periodicals, Inc.)

Background: Radiofrequency catheter ablations of anteroseptal (AS) accessory pathways (AP) in pediatric patients have higher incidence of atrioventricular (AV) block than other AP locations. We report our experience using cryoablation in pediatric patients where a His bundle electrogram was noted on the ablation catheter at the site of the successful ablation., Methods and Results: We retrospectively reviewed all patients ≤21 years that underwent cryoablation for an AS AP from 2005 to 2012 at our institution (n=70). Patients with a His bundle electrogram noted on the cryoablation catheter at the location of the successful lesion were identified (n=6, 8.5%). All six patients had ventricular preexcitation. Median age of 15.9 years (7.2 - 18.2). AV nodal function was monitored during the cryoablation with intermittent rapid atrial pacing conducted through the AV node (n=2), with atrial extra-stimulus testing (n=2), or during orthodromic reentrant tachycardia (n=2). Acute success occurred in all patients. Two patients had early recurrence of AP conduction. Both patients underwent a second successful cryoablation, again with a His bundle electrogram on the cryoablation catheter. At a median follow-up of 13 months (3 to 37 months) there was no recurrence of accessory pathway conduction and AVN function was normal., Conclusion: In a small number of pediatric patients with AS AP with a His bundle electrogram seen on the ablation catheter, the use of cryotherapy was safe and effective for elimination of AP conduction without impairment of AV nodal conduction.

Background: Limited research exits on utilization and cost-effectiveness of acupuncture among underserved communities, and virtually no evidence has been published with respect to refugee populations. In this study, we examined the relationship between acupuncture and the total utilization of primary care services in a cohort of refugee patients with chronic pain., Methods: We retrospectively reviewed the medical records of 16 refugee patients with chronic pain at Boston Medical Center (BMC). The research was IRB-approved. Demographics and total charges associated with primary care over 18 months were collected., Results: Total charges associated with primary care services decreased by 50.2% in our refugee cohort in the 12 months following acupuncture treatment, equivalent to a savings of $691 per patient per month., Conclusions: This preliminary review demonstrated a statistically significant decrease in total charges associated with primary care following acupuncture treatment (p=0.0308). This study suggests the need for further investigation of the relation between acupuncture and refugees with chronic pain, as well as the financial implications of this relationship. It is unclear why refugees may seek fewer primary care services after acupuncture treatment. Additional study is needed to further explore whether this relationship is generalizable to other hospital services and to other patient populations.

Myocarditis in children can result in significant morbidity and mortality, yet limited prognostic data exist. The aim of this study was to test the hypothesis that pediatric patients with arrhythmias during hospitalization for acute myocarditis have worse outcomes and increased resource utilization. A retrospective study using the Pediatric Health Information System database was performed to examine the effects of clinically significant arrhythmias on in-hospital mortality, length of stay, and costs per day. Data were obtained for children ≤18 years of age, discharged from January 1, 2004 to March 31, 2013, with a diagnosis of myocarditis. Clinically significant tachyarrhythmia was defined as supraventricular tachycardia, atrial fibrillation or flutter, or ventricular tachycardia or fibrillation in patients receiving antiarrhythmic medications or cardioversion. Clinically significant bradyarrhythmia was defined as second-degree, complete, or other heart block for which a pacemaker was placed. Multivariable analyses were performed. A total of 2,041 subjects with myocarditis were identified. Tachyarrhythmias were reported in 234 (11.5%) and bradyarrhythmias in 22 (1.1%). Overall mortality was 8.7%. In multivariable analyses, after considering the effects of gender, age at admission, geographic region, year and month of admission, presence of congenital heart disease or an identified virus, and use of steroids, nonsteroidal anti-inflammatories, or inotropes, and after controlling for clustering by institution, tachyarrhythmias were associated with a 2.3 times increase in the odds of mortality (95% confidence interval 1.6 to 3.3, p < 0.001), a 58% increase in length of stay (95% confidence interval 38% to 82%, p < 0.001), and a 28% increase in costs per day (95% confidence interval 15% to 43%, p < 0.001). Bradyarrhythmia was not associated with mortality, length of stay, or costs per day. In conclusion, tachyarrhythmias are associated with significant increases in mortality and resource utilization in children with myocarditis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Reversible addition/fragmentation chain-transfer polymerization is used to generate a calix[4]pyrrole methacrylate-derived copolymer. The material is found to undergo supramolecular cross-linking upon exposure to select dianionic species (e.g., pyrophosphate and terephthalate salts), altering the viscoelastic properties of the copolymer in solution and in the solid state. The copolymeric material is also used for selective differentiation of mono- and bis-anions under conditions of liquid/liquid extraction.

Background: Transtelephonic monitoring (TTM) of pediatric patients with cardiac pacemakers (PMs) has been shown to have high sensitivity and specificity in identifying PM malfunction. The objective of this study is to determine if there is a difference in the rate of abnormal TTM findings in transvenous versus epicardial PM systems., Methods: Our TTM database was reviewed. Patients younger than 21 years of age enrolled for TTM between 1990 and 2010 were included. The abnormal TTM recordings (not including elective replacement indicator) were identified. Logistic regression was used for statistical analysis. Note that P < 0.05 was considered significant., Results: We identified 186 patients. There were 75 (40%) epicardial systems. The mean age at TTM enrollment was 6.8 ± 5.9 years (2 months-20.2 years). There were 41 (22%) patients with abnormal TTM findings. The abnormalities were found in 23/75 (31%) epicardial and 18/111 (16%) transvenous systems (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.13-4.62, P = 0.02). When controlling for age and presence of heart disease the OR for abnormal transmission in epicardial systems compared with transvenous was 2.1 (95% CI: 1.03-4.43, P = 0.04). Patients with epicardial systems were more likely to have capture abnormalities on TTM than transvenous systems (OR: 6.1, 95% CI: 1.9-19.5, P = 0.002)., Conclusion: Pediatric patients with epicardial PM systems are more likely to have abnormal TTM test (particularly capture problems) than patients with transvenous systems regardless of age or presence of heart disease. Consequently, patients with epicardial PM systems should be followed closely with TTM., (©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.)

Objective: To determine if pediatric patients with a history of lone atrial fibrillation (AF) have other forms of supraventricular tachycardia (SVT) that may potentially trigger AF., Study Design: A multicenter review of patients with lone AF who underwent electrophysiology (EP) study from 2006-2011 was performed., Inclusion Criteria: age ≤21 years, normal ventricular function, structurally normal heart, history of AF, and EP study and/or ablation performed., Exclusion Criteria: congenital heart disease or cardiomyopathy. Patient demographics, findings at EP study and follow-up data were recorded., Results: Eighteen patients met inclusion criteria. The mean age was 17.9 ± 2.2 years, weight was 82 ± 21 kg, body mass index was 27 ± 6, and 15 (83%) were males. Eleven (61%) were overweight or obese. Seven (39%) had inducible SVT during EP study: 5 atrioventricular nodal re-entry tachycardia (71%) and 2 concealed accessory pathways with inducible atrioventricular re-entry tachycardia (29%). All 7 patients with inducible SVT underwent radiofrequency ablation. There were no complications during EP study and/or ablation for all 18 patients. The mean follow-up was 1.7 ± 1.5 years and there were no recurrences in the 7 patients who underwent ablation. There were 2 recurrences of AF in patients with no other form of SVT during EP study., Conclusions: Inducible SVT was found in 39% of pediatric patients undergoing EP study for lone AF. EP study should be considered for pediatric patients presenting with lone AF., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Objective: Although many Fontan patients undergo pacemaker placement, there are few studies characterizing this population. Our purpose was to compare clinical characteristics, functional status and measures of ventricular performance in Fontan patients with and without a pacemaker., Patients and Design: The National Heart, Lung, and Blood Institute funded Pediatric Heart Network Fontan Cross-Sectional Study characterized 546 Fontan survivors. Clinical characteristics, medical history and study outcomes (Child Health Questionnaire [CHQ]), echocardiographic evaluation of ventricular function, and exercise testing) were compared between subjects with and without pacemakers., Results: Of 71 subjects with pacemakers (13%), 43/71 (61%) were in a paced rhythm at the time of study enrollment (age 11.9 ± 3.4 years). Pacemaker subjects were older at study enrollment, more likely to have single left ventricles, and taking more medications. There were no differences in age at Fontan or Fontan type between the pacemaker and no pacemaker groups. There were no differences in exercise performance between groups. CHQ physical summary scores were lower in the pacemaker subjects (39.7 ± 14.3 vs. 46.1 ± 11.2, P =.001). Ventricular ejection fraction z-score was also lower (-1.4 ± 1.9 vs. -0.8 ± 2.0, P =.05) in pacemaker subjects., Conclusions: In our cohort of Fontan survivors, those with a pacemaker have poorer functional status and evidence of decreased ventricular systolic function compared to Fontan survivors without a pacemaker., (© 2012 Wiley Periodicals, Inc.)

Refugees with trauma histories are a difficult medical population to treat. Acupuncture care has gained acceptance in many mainstream hospitals in the United States, but research on acupuncture and refugee populations is limited. Herein, we report our experiences with 50 refugees (total acupuncture treatments = 425) at a major tertiary teaching hospital. Patients often reported extreme trauma including physical torture, rape and witnessing the same in family members. Patients represented 13 different countries, with about half the patients being Somali. The primary complaint of all patients was pain (100%). Using the Wong-Baker Faces Pain scale, 56% patients reported pain decreases. Patient acceptance of acupuncture was high. We provide three case histories as illustrative examples. Further research is warranted.

Background: Acupuncture use remains common in the United States, yet little is known of its utilization by minority and underserved populations. Herein we report first visit data capturing patient profiles, types of conditions presented, and self-reports of their experience and satisfaction with acupuncture accessed at a free care clinic with in a large urban safety net hospital., Methods: Sixty-one adult, English-speaking acupuncture patients were given a 20 min survey after their first visit to a free care acupuncture clinic., Results: Patients were from 12 different countries. Fifty-six percent of the participants were minorities. Sixty-five percent of respondents were female. Average age was 42.1. Eighty percent were acupuncture naïve. Patients' health complaints were similar to those of other surveyed mainstream patients with 57% reporting musculoskeletal conditions. Ninety-three percent would recommend a friend or family for acupuncture, 97% rating their overall experience with the acupuncture clinic as either very good or good., Conclusions: When made available to a diverse population of patients, acupuncture is utilized and perceived to be helpful. In this survey, patients sought treatment for musculoskeletal conditions and were satisfied with their first visit. Future research is warranted., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: First-line therapy for children with attention-deficit-hyperactivity disorder (ADHD) is stimulant medication, which may have potential cardiovascular side-effects. In patients with supraventricular tachycardia or Wolf-Parkinson-White syndrome (WPW), therapy for ADHD could become challenging. The purpose of the present study was to review the authors' experience of performing electrophysiologic study (EPS) with or without ablation to determine how it affected ADHD therapy., Methods: Retrospective chart review of patients who underwent EPS between 2002 and 2009 was carried out. All patients under 21 years of age who had prior diagnosis of ADHD were included., Results: Twenty patients met the inclusion criteria. The mean age was 12.1 ± 2.7 years (range: 5.6-16.8 years). The patients were diagnosed with ADHD on average 3.9 ± 2.7 years (range: 6 months-9 years) prior to the EPS. All patients had a structurally normal heart. Sixteen patients had cardiac symptoms. Seventeen patients underwent ablation of the arrhythmia substrate (16/17, 94% successful). Three patients with asymptomatic WPW were at low risk for life-threatening arrhythmias and did not have ablation. After the EPS, two patients had increased doses of their ADHD medications, and two patients whose health-care providers stopped the stimulant medication prior to EPS because of recurrent tachycardia were restarted on medications. All other patients on ADHD medications continued therapy., Conclusions: EPS for risk stratification and ablation of arrhythmia substrate is safe and effective, allowing more liberal therapy in patients with ADHD and supraventricular tachycardia or WPW., (© 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.)