Clinical Predictors of Recurrent Supraventricular Tachycardia in Infancy.

Background: Data regarding recurrence risk among infants with supraventricular tachycardia (SVT) are limited.

Objectives: The purpose of this study was to determine incidence and factors associated with SVT recurrence.

Methods: This was a retrospective single-center study (1984-2020) with prospective phone follow-up of infants with structurally normal hearts diagnosed at age ≤1 year with re-entrant SVT.

Flecainide Toxicity Secondary to Accidental Overdose: A Pediatric Case Report of Two Brothers.

Flecainide is a class 1C antiarrhythmic with a narrow therapeutic window and thereby a high-risk medication for causing acute toxicity. Dysrhythmias secondary to flecainide ingestion are often refractory to antiarrhythmics and cardioversion, and patients commonly require extracorporeal support. We review the successful resuscitation of two brothers aged 2 and 4 who presented two years apart with unstable wide-complex tachyarrhythmia suspicious for severe flecainide toxicity.

Salvage of an epicardial lead in a pacemaker-dependent patient with Fontan palliation using an IS-1 extender.

We present a case report of severed epicardial atrial lead salvage using an IS-1 lead extender. A 37-year-old male with single ventricle physiology, Fontan palliation, sinus node dysfunction, recurrent atrial tachycardias, and atrial fibrillation resulting in failing Fontan physiology presented with failure of the atrial pacing lead. The patient was initially paced with an epicardial system that had to be removed due to pocket infection, and the epicardial leads were cut and abandoned.

The incidence of arrhythmias during exercise stress tests among children with Kawasaki disease: A single-center case series.

Objective: Based on 2017 guidelines, participation in competitive sports with prior history of Kawasaki Disease (KD) requires those with coronary artery aneurysms (CAA) z score ≥ 5 to undergo evaluation for evidence of inducible ischemia or arrhythmias. The use of exercise stress testing (EST) to evaluate arrhythmias among KD patients has never been reported. This retrospective single-center case series study sought to describe the presence of inducible arrhythmias during EST in KD patients with or without CAA.

Allowing Adolescents to Weigh Benefits and Burdens of High-stakes Therapies.

We present the case of a girl aged 17 years and 10 months who has a strong family history of long QT syndrome and genetic testing confirming the diagnosis of long QT syndrome in the patient also. She was initially medically treated with β-blocker therapy; however, after suffering 1 episode of syncope during exertion, she underwent placement of an implantable cardioverter defibrillator. Since then, she has never had syncope.

Early experience with intravenous sotalol in children with and without congenital heart disease.

Background: Arrhythmias are common in the pediatric population. In patients unable to take oral medications or in need of acute therapy, options of intravenous (IV) antiarrhythmic medications are limited. Recently IV sotalol has become readily available, but experience in children is limited.

How active are young cardiac device patients? Objective assessment of activity in children with cardiac devices.

Background: The daily activity of pediatric patients with implantable cardiac devices provides behavioral evidence of functional outcomes. Modern devices provide continuous accelerometer data that are sensitive to movement, but normative values have not been published for pediatric activity rates. This study provides the first normative accelerometer data on activity rates in a large sample of pediatric cardiac device patients.

Utility and Safety of Combined Interventional Catheterization and Electrophysiology Procedures in a Children's Hospital.

Background: Interventional cardiac catheterization (cath) and electrophysiology (EP) procedures are not routinely performed together. There are several perceived barriers affecting this practice, though there are also advantages for both the patient and practitioner to a combined approach.

Methods: This was a single-center retrospective study reviewing combined cath and EP procedures with a preprocedural intention to intervene at Texas Children's Hospital from 2001 to 2014.

Cardiac Arrest in Pediatric Patients Receiving Azithromycin.

Objective: To compare outcomes of pediatric patients treated with azithromycin compared with penicillin or cephalosporin. We hypothesized that azithromycin use would not be associated with increased cardiac mortality in the pediatric population.

Study Design: Retrospective cohort study from the Pediatric Health Information System database between 2008 and 2012.

Percutaneous Pulmonary Valve Implantation-Associated Ventricular Tachycardia in Congenital Heart Disease.

Background: Percutaneous pulmonary valve implantation (PPVI) is utilized for dysfunctional right ventricular outflow tracts (RVOT) to relieve obstruction, regurgitation, and RV dysfunction. PPVI has not been reported to induce arrhythmias. This study is the first to report the incidence of ventricular tachycardia (VT) after PPVI.

Late outcomes in children with Shone's complex: a single-centre, 20-year experience.

Objective: Shone's syndrome is a complex consisting of mitral valve stenosis in addition to left ventricle outflow obstruction. There are a few studies evaluating the long-term outcomes in this population. We sought to determine the long-term outcomes in our paediatric population with Shone's syndrome and the factors associated with left heart growth.

Novel long QT syndrome-associated missense mutation, L762F, in CACNA1C-encoded L-type calcium channel imparts a slower inactivation tau and increased sustained and window current.

Background: Mutations in the CACNA1C-encoded L-type calcium channel have been associated with Timothy syndrome (TS) with severe QT prolongation, syndactyly, facial dysmorphisms, developmental delay, and sudden death. Recently, patients hosting CACNA1C mutations with only long QT syndrome (LQTS) have been described. We sought to identify novel variants in CACNA1C associated with either TS or LQTS, and to determine the impact of the mutation on channel function.

Reassessing Risk Factors in Pediatric Patients With Pacemakers Implanted for Atrioventricular Block: The Impact of Nonsustained Ventricular Tachycardia.

Introduction: In pediatric patients with pacemakers implanted for atrioventricular block (AVB), nonsustained ventricular tachycardia (NSVT) detected during routine surveillance is a finding of unknown significance. We sought to describe the incidence of NSVT and determine if there was an association between NSVT and adverse outcomes in these patients.

Methods And Results: This is a single-center retrospective study of 136 patients (1971-2013) with pacemakers implanted for advanced and complete AVB.