Subcutaneous cardioverter-defibrillator implantation in an adult with congenital heart disease and left infra-mammary pacemaker.

The approach/type of an implantable cardioverter defibrillator (ICD) is determined by the underlying cardiac anatomy, venous access, and pre-existing cardiac implantable electronic devices. We describe a case of subcutaneous ICD implantation in an adult with congenital heart disease (CHD) with a pre-existing inframammary transvenous pacemaker. This was preferred over adding a defibrillator coil to existing pacing leads, extraction/replacement of pacing system, or a sternotomy/epicardial ICD placement. The procedure was accomplished uneventfully with successful defibrillation threshold testing. Innovative approaches are required to manage arrhythmias in adults with CHD, with shared decision making playing a critical role.

Lead Management in Patients with Congenital Heart Disease.

Pediatric patients with congenital heart disease present unique challenges when it comes to cardiac implantable electronic devices. Pacing strategy is often determined by patient size/weight and operator experience. Anatomic considerations, including residual shunts, anatomic obstructions and barriers, and abnormalities in the native conduction system, will affect the type of CIED implanted. Given the young age of patients, it is important to have an "eye on the future" when making pacemaker/defibrillator decisions, as one can expect several generator changes, lead revisions, and potential lead extractions during their lifetime.

Myocardial bridge in a child with cardiac arrest and ventricular fibrillation: a bridge over troubled water?

Resuscitated cardiac arrest in a child triggers a comprehensive workup to identify an aetiology and direct management. The presence of a myocardial bridge does not automatically imply causation. Careful determination of the haemodynamic significance of the myocardial bridge is critical to avoid an unnecessary sternotomy and to provide appropriate treatment.

Significance of electrocardiogram abnormalities in children presenting to the emergency department with acute COVID-19 infection.

OBJECTIVES: Acute COVID-19 infection may be associated with electrocardiogram (EKG) abnormalities in pediatric patients. We have anecdotally observed EKG abnormalities in patients without MIS-C or significant cardiac disease requiring intervention or further follow-up. Our aim was to determine the incidence of abnormal EKG findings and correlate with evidence of significant cardiac pathology in pediatric patients who present to the emergency department during an acute COVID-19 infection. METHODS: We conducted a retrospective chart review of 209 pediatric patients diagnosed in the emergency department with acute COVID-19 infection and had an EKG during the same encounter; patients with MIS-C were excluded. Primary objectives included determination of the incidence of EKG abnormalities in patients presenting to the emergency department (ED) with acute COVID-19 infection who did not require hospitalization. Secondary objectives included correlation of these findings with other concomitant testing of possible cardiac pathology (echocardiograms, biomarkers), and clinical outcomes. RESULTS: EKG abnormalities were identified in 84 (40%) patients. Echo was performed in 28 (13.4%) patients; only 1 was abnormal, and considered an incidental finding. The most common EKG abnormality involved nonspecific ST-T wave patterns, suggestive of but not diagnostic for underlying pericardial or myocardial disease. Serum troponin and BNP values were normal in all patients tested, either with a normal or abnormal EKG. A normal EKG had a 100% sensitivity and negative predictive value in predicting a normal echocardiogram. No patients were hospitalized and there was normalization of EKG abnormalities during short-term follow up. CONCLUSIONS: Despite a high incidence of abnormal EKG repolarization patterns in pediatric patients presenting with acute (non-MIS-C) COVID-19 infections, these patients generally do not have abnormal cardiac biomarkers or echocardiograms, and the risk for adverse cardiac events is low.

Combination Therapy of Ivabradine with Procainamide for the Management of Pediatric Postoperative Junctional Ectopic Tachycardia.

Pediatric postoperative junctional ectopic tachycardia (JET), although usually self-limited, may lead to significant morbidity and mortality. Anti-arrhythmic medications are often necessary to restore atrioventricular synchrony when non-pharmacological measures fail. Multiple drugs have been described for the management of postoperative JET, with enteral ivabradine being the latest addition. While safe administration of ivabradine has been described in combination with other anti-arrhythmics (amiodarone, flecainide), no study has described the use of ivabradine in conjunction with intravenous procainamide for the management of postoperative JET. Our case report describes the safe use of ivabradine and procainamide combination therapy in a young patient.

Left Main Coronary Artery Ostial Stenosis in a Pediatric Patient With Sudden Cardiac Arrest.

Pediatric resuscitated sudden cardiac arrest may result from diverse conditions and, therefore, warrants a comprehensive work-up. Although rare, coronary artery abnormalities must be ruled out in these patients. We describe a case with congenital left main coronary artery ostial stenosis diagnosed using advanced imaging techniques. (Level of Difficulty: Advanced.).

Clinical risk prediction score for postoperative accelerated junctional rhythm and junctional ectopic tachycardia in children with congenital heart disease.

BACKGROUND: Accelerated junctional rhythm (AJR) and junctional ectopic tachycardia (JET) are common postoperative arrhythmias associated with morbidity/mortality. Studies suggest that pre- or intraoperative treatment may improve outcomes, but patient selection remains a challenge. OBJECTIVES: The purpose of this study was to describe contemporary outcomes of postoperative AJR/JET and develop a risk prediction score to identify patients at highest risk. METHODS: This was a retrospective cohort study of children aged 0-18 years undergoing cardiac surgery (2011-2018). AJR was defined as usual complex tachycardia with ≥1:1 ventricular-atrial association and junctional rate >25th percentile of sinus rate for age but <170 bpm, whereas JET was defined as a rate >170 bpm. A risk prediction score was developed using random forest analysis and logistic regression. RESULTS: Among 6364 surgeries, AJR occurred in 215 (3.4%) and JET in 59 (0.9%). Age, heterotaxy syndrome, aortic cross-clamp time, ventricular septal defect closure, and atrioventricular canal repair were independent predictors of AJR/JET on multivariate analysis and included in the risk prediction score. The model accurately predicted the risk of AJR/JET with a C-index of 0.72 (95% confidence interval 0.70-0.75). Postoperative AJR and JET were associated with prolonged intensive care unit and hospital length of stay, but not with early mortality. CONCLUSION: We describe a novel risk prediction score to estimate the risk of postoperative AJR/JET permitting early identification of at-risk patients who may benefit from prophylactic treatment.

Ventricular arrhythmias after fibroma resection: Are patients still at risk?

BACKGROUND: Ventricular fibromas frequently present with life-threatening ventricular tachycardia (VT) or ventricular fibrillation (VF) in children. The long-term risk of sustained ventricular arrhythmias after surgical resection is unknown. OBJECTIVES: The aims of this study were to quantify the VT/VF risk after surgical resection and to examine the results of early (during index surgical hospitalization) and late (≥3 months after surgery) postoperative ventricular stimulation (V-stim) studies. METHODS: We performed a retrospective cohort study of all patients with ventricular fibromas who underwent surgical resection at our institution (2000-2020). The primary outcome was defined as recurrent VT/VF ≥3 months after index surgical resection. RESULTS: Forty-six patients with a median age at surgery of 2 years (range 0.3-18.9 years) formed our study cohort. Indications for surgery included cardiac arrest in 11 (24%), sustained VT in 16 (35%), premature ventricular contractions/nonsustained VT in 10 (22%), and hemodynamic abnormalities in 9 (20%). Of the 11 patients who presented with cardiac arrest, 4 underwent pre-resection implantable cardioverter-defibrillator (ICD) implantation, all of which were explanted at the time of surgery. An early postoperative V-stim study was performed in 26 (57%) patients, and all were negative for inducible VT/VF. Of the 13 late postoperative V-stim studies, 3 were positive: 2 underwent ICD implantation and 1 was initiated on amiodarone and underwent loop recorder implantation. At the time of last follow-up (median 1.5 years; range 0.3-16.5 years), 45 (98%) were free of clinical VT/VF and no patient with an ICD has received an appropriate shock. CONCLUSION: Surgical resection of ventricular fibromas significantly reduces the risk of life-threatening arrhythmias in children; however, a small number of patients remain vulnerable.

Non-fluoroscopic Techniques for Catheter Ablation of Typical Atrioventricular Nodal Re-entry Tachycardia in a Pediatric Patient with Atypical Venous Anatomy.

Catheter ablation of the slow pathway to the atrioventricular node is generally a safe and effective treatment for atrioventricular nodal re-entry tachycardia (AVNRT). However, congenital anomalies of the inferior vena cava and superior draining veins can limit traditional catheter approaches to the right heart from femoral venous access and distort local anatomy within the triangle of Koch, necessitating alternative electrophysiology (EP) mapping and ablation strategies. Despite the widespread availability of non-fluoroscopic 3-dimensional imaging systems, many providers still rely on venography to describe unusual cardiovascular anatomy and fluoroscopy to position EP catheters when mapping and ablating the slow pathway. Herein, we report our experience with a pediatric patient with inducible AVNRT and atypical venous anatomy in whom slow pathway ablation was performed successfully without the use of fluoroscopy. In addition, we describe the modification of a novel mapping technique for targeting the slow pathway for ablation.

Role of functional echocardiographic parameters in the diagnosis of bronchopulmonary dysplasia-associated pulmonary hypertension.

Echocardiogram (echo) is a commonly used noninvasive modality for the diagnosis of bronchopulmonary dysplasia associated pulmonary hypertension (BPD-PH). Though not considered the gold standard for the diagnosis of BPD-PH, it is an extremely valuable tool in the neonatal and pediatric population, especially when cardiac catheterization is not feasible. In addition to the traditional echo parameters that are used to assess the presence of BPD-PH, much attention has been recently placed on newer bedside echo measures, the so-called functional echo parameters, to aid and assist in the diagnosis. This review article provides a brief introduction to BPD-PH, describes the pitfalls of traditional echo parameters and details the newer echo modalities currently available for the diagnosis of neonatal PH.

Adverse Drug Event Prediction Using Noisy Literature-Derived Knowledge Graphs: Algorithm Development and Validation.

BACKGROUND: Adverse drug events (ADEs) are unintended side effects of drugs that cause substantial clinical and economic burdens globally. Not all ADEs are discovered during clinical trials; therefore, postmarketing surveillance, called pharmacovigilance, is routinely conducted to find unknown ADEs. A wealth of information, which facilitates ADE discovery, lies in the growing body of biomedical literature. Knowledge graphs (KGs) encode information from the literature, where the vertices and the edges represent clinical concepts and their relations, respectively. The scale and unstructured form of the literature necessitates the use of natural language processing (NLP) to automatically create such KGs. Previous studies have demonstrated the utility of such literature-derived KGs in ADE prediction. Through unsupervised learning of the representations (features) of clinical concepts from the KG, which are used in machine learning models, state-of-the-art results for ADE prediction were obtained on benchmark data sets. OBJECTIVE: Due to the use of NLP to infer literature-derived KGs, there is noise in the form of false positive (erroneous) and false negative (absent) nodes and edges. Previous representation learning methods do not account for such inaccuracies in the graph. NLP algorithms can quantify the confidence in their inference of extracted concepts and relations from the literature. Our hypothesis, which motivates this work, is that by using such confidence scores during representation learning, the learned embeddings would yield better features for ADE prediction models. METHODS: We developed methods to use these confidence scores on two well-known representation learning methods-DeepWalk and Translating Embeddings for Modeling Multi-relational Data (TransE)-to develop their weighted versions: Weighted DeepWalk and Weighted TransE. These methods were used to learn representations from a large literature-derived KG, the Semantic MEDLINE Database, which contains more than 93 million clinical relations. They were compared with Embedding of Semantic Predications, which, to our knowledge, is the best reported representation learning method using the Semantic MEDLINE Database with state-of-the-art results for ADE prediction. Representations learned from different methods were used (separately) as features of drugs and diseases to build classification models for ADE prediction using benchmark data sets. The methods were compared rigorously over multiple cross-validation settings. RESULTS: The weighted versions we designed were able to learn representations that yielded more accurate predictive models than the corresponding unweighted versions of both DeepWalk and TransE, as well as Embedding of Semantic Predications, in our experiments. There were performance improvements of up to 5.75% in the F1-score and 8.4% in the area under the receiver operating characteristic curve value, thus advancing the state of the art in ADE prediction from literature-derived KGs. CONCLUSIONS: Our classification models can be used to aid pharmacovigilance teams in detecting potentially new ADEs. Our experiments demonstrate the importance of modeling inaccuracies in the inferred KGs for representation learning.

Rheumatic Heart Disease in the United States: Forgotten But Not Gone: Results of a 10 Year Multicenter Review.

Background Recent evaluation of rheumatic heart disease (RHD) mortality demonstrates disproportionate disease burden within the United States. However, there are few contemporary data on US children living with acute rheumatic fever (ARF) and RHD. Methods and Results Twenty-two US pediatric institutions participated in a 10-year review (2008-2018) of electronic medical records and echocardiographic databases of children 4 to 17 years diagnosed with ARF/RHD to determine demographics, diagnosis, and management. Geocoding was used to determine a census tract-based socioeconomic deprivation index. Descriptive statistics of patient characteristics and regression analysis of RHD classification, disease severity, and initial antibiotic prescription according to community deprivation were obtained. Data for 947 cases showed median age at diagnosis of 9 years; 51% and 56% identified as male and non-White, respectively. Most (89%) had health insurance and were first diagnosed in the United States (82%). Only 13% reported travel to an endemic region before diagnosis. Although 96% of patients were prescribed secondary prophylaxis, only 58% were prescribed intramuscular benzathine penicillin G. Higher deprivation was associated with increasing disease severity (odds ratio, 1.25; 95% CI, 1.08-1.46). Conclusions The majority of recent US cases of ARF and RHD are endemic rather than the result of foreign exposure. Children who live in more deprived communities are at risk for more severe disease. This study demonstrates a need to improve guideline-based treatment for ARF/RHD with respect to secondary prophylaxis and to increase research efforts to better understand ARF and RHD in the United States.

N-terminal pro-B-type-natriuretic peptide as a screening tool for pulmonary hypertension in the paediatric population.

BACKGROUND: Although cardiac catheterisation (cath) is the diagnostic test for pulmonary hypertension, it is an invasive procedure. Echocardiography (echo) is commonly used for the non-invasive diagnosis of pulmonary hypertension but maybe limited by lack of adequate signals. Therefore, emphasis has been placed on biomarkers as a potential diagnostic tool. No prior paediatric studies have simultaneously compared N-terminal pro-B-type-natriuretic peptide (NTproBNP) with cath/echo as a potential diagnostic tool. The aim of this study was to determine if NTproBNP was a reliable diagnostic tool for pulmonary hypertension in this population. METHODS: Patients were divided into Study (echo evidence/established diagnosis of pulmonary hypertension undergoing cath) and Control (cath for small atrial septal defect/patent ductus arteriosus and endomyocardial biopsy post cardiac transplant) groups. NTproBNP, cath/echo data were obtained. RESULTS: Thirty-one patients met inclusion criteria (10 Study, 21 Control). Median NTproBNP was significantly higher in the Study group. Echo parameters including transannular plane systolic excursion z scores, pulmonary artery acceleration time and right ventricular fractional area change were lower in the Study group and correlated negatively with NTproBNP. Receiver operation characteristic curve analysis demonstrated NTproBNP > 389 pg/ml was 87% specific for the diagnosis of pulmonary hypertension with the addition of pulmonary artery acceleration time improving the specificity. CONCLUSIONS: NTproBNP may be a valuable adjunctive diagnostic tool for pulmonary hypertension in the paediatric population. Echo measures of transannular plane systolic excursion z score, pulmonary artery acceleration time and right ventricular fractional area change had negative correlations with NTproBNP. The utility of NTproBNP as a screening tool for pulmonary hypertension requires validation in a population with unknown pulmonary hypertension status.