Health Disparities in the Treatment of Supraventricular Tachycardia in Pediatric Patients.

Supraventricular tachycardia (SVT) is a common pediatric arrhythmia. The objective of this investigation was to investigate the existence and degree of the health disparities in the treatment of pediatric patients with supraventricular tachycardia based on sociodemographic factors. This was retrospective cohort study at a large academic medical center including children ages 5-18 years old diagnosed with SVT. Patients with congenital heart disease and myocarditis were excluded. Initial treatment and ultimate treatment with either medical management or ablation were determined. The odds of having an ablation procedure were determined based on patient age, sex, race, ethnicity, and insurance status. There was a larger portion of non-White patients (p = 0.033) within the cohort that did not receive an ablation during the study period. Patients that were younger, female, American Indian/Alaskan Native, unknown race, and had missing insurance information were less likely to receive ablation therapy during the study period. In this single center, regional evaluation, we demonstrated that disparities in the treatment of pediatric SVT are present based on multiple patient sociodemographic factors. This study adds evidence to the presence of inequities in health care delivery across pediatric populations.

mRNA Coronavirus Disease 2019 Vaccine-Associated Myopericarditis in Adolescents: A Survey Study.

In this survey study of institutions across the US, marked variability in evaluation, treatment, and follow-up of adolescents 12 through 18 years of age with mRNA coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis was noted. Only one adolescent with life-threatening complications was reported, with no deaths at any of the participating institutions.

ATP1A3-Encoded Sodium-Potassium ATPase Subunit Alpha 3 D801N Variant Is Associated With Shortened QT Interval and Predisposition to Ventricular Fibrillation Preceded by Bradycardia.

Background Pathogenic variation in the ATP1A3-encoded sodium-potassium ATPase, ATP1A3, is responsible for alternating hemiplegia of childhood (AHC). Although these patients experience a high rate of sudden unexpected death in epilepsy, the pathophysiologic basis for this risk remains unknown. The objective was to determine the role of ATP1A3 genetic variants on cardiac outcomes as determined by QT and corrected QT (QTc) measurements. Methods and Results We analyzed 12-lead ECG recordings from 62 patients (male subjects=31, female subjects=31) referred for AHC evaluation. Patients were grouped according to AHC presentation (typical versus atypical), ATP1A3 variant status (positive versus negative), and ATP1A3 variant (D801N versus other variants). Manual remeasurements of QT intervals and QTc calculations were performed by 2 pediatric electrophysiologists. QTc measurements were significantly shorter in patients with positive ATP1A3 variant status (P<0.001) than in patients with genotype-negative status, and significantly shorter in patients with the ATP1A3-D801N variant than patients with other variants (P<0.001). The mean QTc for ATP1A3-D801N was 344.9 milliseconds, which varied little with age, and remained <370 milliseconds throughout adulthood. ATP1A3 genotype status was significantly associated with shortened QTc by multivariant regression analysis. Two patients with the ATP1A3-D801N variant experienced ventricular fibrillation, resulting in death in 1 patient. Rare variants in ATP1A3 were identified in a large cohort of genotype-negative patients referred for arrhythmia and sudden unexplained death. Conclusions Patients with AHC who carry the ATP1A3-D801N variant have significantly shorter QTc intervals and an increased likelihood of experiencing bradycardia associated with life-threatening arrhythmias. ATP1A3 variants may represent an independent cause of sudden unexplained death. Patients with AHC should be evaluated to identify risk of sudden death.

Improving Youth Sports Safety: Implementing an Emergency Action Plan for Sudden Cardiac Arrest.

BACKGROUND: Children who participate in youth sports are at risk for sudden cardiac arrest (SCA) related to undetected cardiac anomalies or abrupt impact to the chest. Nurse-led interventions may prevent sudden cardiac death by helping leagues implement an emergency action plan to respond to SCA and improve safety. A youth soccer league in the Southeast with participants between the ages of 5-19 years, led by volunteer board members and coaches, did not have reliable access to automated external defibrillators or receive standardized education on SCA and cardiopulmonary resuscitation with a site-specific action plan. METHODS: A nurse-led quality improvement pilot project used partnerships to provide league access to automated external defibrillators, institute preseason SCA and cardiopulmonary resuscitation training, and establish an emergency action plan for the league's volunteers. Anonymous pre- and post-training testing was conducted to measure participant knowledge, confidence, and willingness to respond to SCA. A cross-sectional survey, using a convenience sample of board members and coaches, evaluated sustainability of the intervention at midseason. INTERVENTION: Training targeted board members (Blue Shirts) to serve as leaders on the field during an SCA event and educated coaches on activating the emergency action plan. RESULTS: Blue Shirts and coaches showed significant (p < .05) improvement of knowledge, confidence, and willingness to respond to SCA after receiving the standardized preseason intervention; Blue Shirts' changes were sustained at midseason. CONCLUSION: Nurses are ideal for helping youth sports leagues implement a sustainable SCA action plan based on best-practice recommendations for emergency health and safety.

Pacing in Patients with Congenital Heart Disease: When Is It Helpful and When Is It Harmful?

PURPOSE OF REVIEW: Pacing in pediatric and adult patients with congenital heart disease requires careful evaluation and thoughtful planning. Review of current guidelines with assessment of risk/benefit must be performed along with planning on a case-by-case basis in order to achieve maximal success and reduce risk in this specialized population of patients that is rapidly increasing in size. RECENT FINDINGS: Guidelines for pacing in pediatric and congenital heart disease patients span many years. Most recent consensus and summary guidelines address pacing in adult patients with or without congenital heart disease. Pediatric recommendations from prior documents must be included in current decision-making. Pacing in pediatric and congenital heart disease patients is important therapy. Creation of an individualized plan of care with attention to risk/benefit decision-making regarding when and how to pace is critical in this population to maximize beneficial outcome.

Recovery of the fetal electrocardiogram for morphological analysis from two trans-abdominal channels via optimal shrinkage.

OBJECTIVE: We propose a novel algorithm to recover fetal electrocardiogram (ECG) for both the fetal heart rate analysis and morphological analysis of its waveform from two or three trans-abdominal maternal ECG channels. APPROACH: We design an algorithm based on the optimal-shrinkage under the wave-shape manifold model. For the fetal heart rate analysis, the algorithm is evaluated on publicly available database, 2013 PhyioNet/Computing in Cardiology Challenge, set A (CinC2013). For the morphological analysis, we analyze CinC2013 and another publicly available database, non-invasive fetal ECG arrhythmia database (nifeadb), and propose to simulate semi-real databases by mixing the MIT-BIH normal sinus rhythm database and MITDB arrhythmia database. MAIN RESULTS: For the fetal R peak detection, the proposed algorithm outperforms all algorithms under comparison. For the morphological analysis, the algorithm provides an encouraging result in recovery of the fetal ECG waveform, including PR, QT and ST intervals, even when the fetus has arrhythmia, both in real and simulated databases. SIGNIFICANCE: To the best of our knowledge, this is the first work focusing on recovering the fetal ECG for morphological analysis from two or three channels with an algorithm potentially applicable for continuous fetal electrocardiographic monitoring, which creates the potential for long term monitoring purpose.

Variability in radiation dose and image quality: A comparison across fluoroscopy-system vendors, generations of equipment and institutions.

OBJECTIVES: To evaluate differences in radiation dose and image quality across institutions, fluoroscope vendors and generations of fluoroscopes for pediatric cardiac catheterization. BACKGROUND: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances in fluoroscopes, as well as increased focus on optimizing fluoroscope performance. There is currently little understanding of variability in the dose-image quality relationship across institutions, fluoroscope vendor and/or generation of equipment. METHODS: We evaluated latest generation fluoroscopes from Phillips, Siemens, GE, and Toshiba, and an older generation Phillips fluoroscope (release date 2003) at three different institutions. Radiation dose was measured using an anthropomorphic dose-assessment phantom with effective dose in mSv estimated from Monte Carlo simulations. Image quality phantom images were scored on a 12-point scale by three blinded reviewers. RESULTS: Fluoroscope effective doses ranged from 0.04 to 0.14 mSv/1,000 pulses for fluoroscopy with associated composite image quality scores ranging from 8.0 ± 0.6 to 10.4 ± 1.3. For cineangiography, effective doses ranged from 0.17 to 0.57 mSv/1,000 frames with image quality scores ranging from 10.1 ± 0.3 to 11.1 ± 0.3. There was modest correlation between effective dose and image quality (r = 0.67, P = 0.006). The older generation fluoroscope delivered consistently higher doses than the newer generation systems (2.3- to 3.5-fold higher for fluoroscopy; 1.1- to 3.4-fold higher for cineangiography) without appreciable differences in image quality. CONCLUSION: Technological advances have markedly improved fluoroscope performance. Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship and speculate that this reflects both equipment and institutional optimization practices.

The Second Annual Think Tank on Prevention of Sudden Cardiac Death in the Young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium.

Sudden cardiac death in the young (SCDY) spans gender, race, ethnicity, and socioeconomic class. The loss of any pediatric patient is a matter of national and international public health concern, and focused efforts should be aimed at preventing these burdensome tragedies. Prepared by members of the Cardiac Safety Research Consortium, this White Paper summarizes and reports the dialogue at the second Think Tank related to the issues and the proposed solutions for the development of a national resource for screening and prevention of SCDY. This Think Tank, sponsored by the Cardiac Safety Research Consortium and the United States Food and Drug Administration, convened on February 18, 2016, in Miami, FL, to identify and resolve the barriers that prevent early identification of patients at risk for SCDY. All potential stakeholders including national and international experts from industry, medicine, academics, engineering, and community advocacy leaders had an opportunity to share ideas and collaborate.

Prevention of sudden cardiac death in the young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium.

This White Paper, prepared by members of the Cardiac Safety Research Consortium, discusses important issues regarding sudden cardiac death in the young (SCDY), a problem that does not discriminate by gender, race, ethnicity, education, socioeconomic level, or athletic status. The occurrence of SCDY has devastating impact on families and communities. Sudden cardiac death in the young is a matter of national and international public health, and its prevention has generated deep interest from multiple stakeholders, including families who have lost children, advocacy groups, academicians, regulators, and the medical industry. To promote scientific and clinical discussion of SCDY prevention and to germinate future initiatives to move this field forward, a Cardiac Safety Research Consortium-sponsored Think Tank was held on February 21, 2015 at the US Food and Drug Administration's White Oak facilities, Silver Spring, MD. The ultimate goal of the Think Tank was to spark initiatives that lead to the development of a rational, reliable, and sustainable national health care resource focused on SCDY prevention. This article provides a detailed summary of discussions at the Think Tank and descriptions of related multistakeholder initiatives now underway: it does not represent regulatory guidance.

Development and impact of arrhythmias after the Norwood procedure: A report from the Pediatric Heart Network.

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.

The comparative relationships between locations of the papillary muscles and electrophysiologic QRS axis in patients with atrioventricular septal defect and common as opposed to separate orifices in the valve guarding the common atrioventricular junction.

BACKGROUND: Knowledge regarding factors that influence deviation of the QRS axis is important when seeking to differentiate between physiological and pathological changes. We hypothesised that, in contrast to those patients with an atrioventricular septal defect and common atrioventricular junction permitting only atrial shunting, those associated with ventricular shunting would show no relationship between the positions of the papillary muscles and the degree of the leftward deviation of the QRS axis. METHODS: We compared the positions of endocardial origin of the papillary muscles, and the frontal plane QRS axis, in patients with atrioventricular septal defects and common atrioventricular junction permitting exclusively atrial as opposed to atrial and ventricular shunting. RESULTS: We analysed 18 patients with atrial and ventricular shunting and 23 patients with exclusively atrial shunting. The correlation coefficient between the ratio of distances of the papillary muscles from the mid-septum and the amount of leftward deviation in the frontal plane QRS axis was 0.1 (p=0.4) in those with ventricular shunting and 0.26 (p=0.01) in those with exclusively atrial shunting. CONCLUSIONS: In contrast to patients with the so-called primum form of atrioventricular septal defect, in whom the locations of the papillary muscles correlate with the degree of QRS axis, such relationships are lacking in patients with defects permitting both atrial and ventricular shunting. It may be, therefore, that the presence of ventricular shunting and/or their younger age causes pressure overload, which negates the leftward QRS forces caused by the abnormally positioned papillary muscles.

Radiofrequency Ablation in the Sinus of Valsalva for Ventricular Arrhythmia in Pediatric Patients.

The need to perform catheter ablation of ventricular arrhythmia from within the sinuses of Valsalva in a pediatric patient is uncommon. This has been reported in adults, but there are little data about the feasibility, safety or efficacy of catheter ablation in the sinuses of Valsalva in the pediatric patients. This is a retrospective review of all patients aged 18 years or less, at two separate institutions with no structural heart disease that underwent an ablation procedure for ventricular arrhythmia mapped to the sinus of Valsalva from 2010 to 2015. We identified 8 total patients meeting inclusion criteria. Median age was 16 years and the median weight was 61 kg. All patients were symptomatic or had developed arrhythmia-induced ventricular dysfunction. Ablation was performed in the left sinus in 4 patients and the right sinus in 4 patients. No ablations were required in the non-coronary sinus. All 8 patients had an acutely successful ablation using radiofrequency energy. There were no complications. At a mean follow-up of 7 months (4-15 months), all patients were known to be living. Follow-up data regarding arrhythmia were available in 6 of the 8 patients, and none had recurrence of their ventricular arrhythmia off of all antiarrhythmic medications. Radiofrequency catheter ablation of ventricular arrhythmia in the sinus of Valsalva can be done safely and effectively in pediatric patients.

Abstract 12670: Variability in Radiation Dose and Image Quality: A Comparison Across Fluoroscopy-system Vendors and Generations of Equipment.

INTRODUCTION: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances to reduce exposure during fluoroscopy. However there is currently little understanding of the dose-image quality (IQ) relationship between fluoroscopy vendors and across generations of equipment used for imaging during pediatric catheterization. METHODS: We evaluated latest generation fluoroscopy systems from Phillips, Siemens, GE and Toshiba, and an older generation Phillips system (2004 release). Fluoroscopy and cineangiography were performed on a tissue simulation anthropomorphic phantom using a standardized imaging approach. Phantom surface exposures were used for Monte Carlo simulations to calculate radiation effective dose, accounting for differences in beam parameters. We also imaged a fluoroscopy IQ phantom to assess contrast-detail and line-per-inch visualization. IQ images were scored by 3 blinded reviewers with scores averaged to produce a composite rating (scale 0-18). To assess the impact of imaging approach we then simulated a neonatal cardiac catheterization incorporating "typical" imaging protocols provided by institutions using the various systems. RESULTS: Effective doses and IQ scores are summarized in the table. Effective doses varied by >400% with the older generation system consistently delivering markedly higher doses. The associated figure summarizes dose and IQ for a simulated neonatal cardiac catheterization which accounts for measured doses as well as the reported institutional imaging parameters summarized in the figure legend. CONCLUSION: These data demonstrate substantial technological improvements in fluoroscopy equipment and may be useful to justify institutional "upgrades". Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship that reflects both equipment and imaging approach.

Multicenter study comparing shunt type in the norwood procedure for single-ventricle lesions: three-dimensional echocardiographic analysis.

BACKGROUND: The Pediatric Heart Network's Single Ventricle Reconstruction (SVR) trial randomized infants with single right ventricles (RVs) undergoing a Norwood procedure to a modified Blalock-Taussig or RV-to-pulmonary artery shunt. This report compares RV parameters in the 2 groups using 3-dimensional echocardiography. METHODS AND RESULTS: Three-dimensional echocardiography studies were obtained at 10 of 15 SVR centers. Of the 549 subjects, 314 underwent 3-dimensional echocardiography studies at 1 to 4 time points (pre-Norwood, post-Norwood, pre-stage II, and 14 months) for a total of 757 3-dimensional echocardiography studies. Of these, 565 (75%) were acceptable for analysis. RV volume, mass, mass:volume ratio, ejection fraction, and severity of tricuspid regurgitation did not differ by shunt type. RV volumes and mass did not change after the Norwood, but increased from pre-Norwood to pre-stage II (end-diastolic volume [milliliters]/body surface area [BSA](1.3), end-systolic volume [milliliters]/BSA(1.3), and mass [grams]/BSA(1.3) mean difference [95% confidence interval]=25.0 [8.7-41.3], 19.3 [8.3-30.4], and 17.9 [7.3-28.5], then decreased by 14 months (end-diastolic volume/BSA(1.3), end-systolic volume/BSA(1.3), and mass/BSA(1.3) mean difference [95% confidence interval]=-24.4 [-35.0 to -13.7], -9.8 [-17.9 to -1.7], and -15.3 [-22.0 to -8.6]. Ejection fraction decreased from pre-Norwood to pre-stage II (mean difference [95% confidence interval]=-3.7 [-6.9 to -0.5]), but did not decrease further by 14 months. CONCLUSIONS: We found no statistically significant differences between study groups in 3-dimensional echocardiography measures of RV size and function, or magnitude of tricuspid regurgitation. Volume unloading was seen after stage II, as expected, but ejection fraction did not improve. This study provides insights into the remodeling of the operated univentricular RV in infancy.

Comparison of Fontan survivors with and without pacemakers: a report from the Pediatric Heart Network Fontan Cross-Sectional Study.

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.