Efficacy of Flecainide in the Treatment of Catecholaminergic Polymorphic Ventricular Tachycardia: A Randomized Clinical Trial.

Importance: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal genetic arrhythmia syndrome characterized by polymorphic ventricular tachycardia with physical or emotional stress, for which current therapy with β-blockers is incompletely effective. Flecainide acetate directly suppresses sarcoplasmic reticulum calcium release-the cellular mechanism responsible for triggering ventricular arrhythmias in CPVT-but has never been assessed prospectively.

Objective: To determine whether flecainide dosed to therapeutic levels and added to β-blocker therapy is superior to β-blocker therapy alone for the prevention of exercise-induced arrhythmias in CPVT.

QRS Duration Changes in Patients with Single Ventricle Physiology: Birth to 10 Years.

Background: QRS prolongation may be a predictor of mortality in certain forms of congenital heart disease. Minimal data exist describing changes in QRS duration in patients with single ventricles (SVs). The goal was to describe changes in QRS duration in patients with SV and to determine if differences existed between single right ventricle (sRV) versus single left ventricle (sLV) patients.

Fascicular and nonfascicular left ventricular tachycardias in the young: an international multicenter study.

Introduction: The aim of this study was to evaluate the clinical presentation and outcomes of pediatric patients with ventricular tachycardia (VT) originating from left heart structures.

Methods And Results: This international multicenter retrospective study including 152 patients (age 10.0 ± 5.

QRS duration changes in patients with hypoplastic left heart syndrome undergoing hybrid palliation: prehybrid to post-Fontan.

Background: QRS prolongation has been shown to be a predictor of mortality in patients with certain forms of congenital heart disease. QRS changes have not been well described in patients with single ventricle physiology, particularly in those undergoing the hybrid procedure.

Objective: To describe QRS changes in a cohort of patients with hypoplastic left heart syndrome (HLHS) who underwent hybrid palliation and to evaluate if QRS duration is associated with mortality.

The study of antiarrhythmic medications in infancy (SAMIS): a multicenter, randomized controlled trial comparing the efficacy and safety of digoxin versus propranolol for prophylaxis of supraventricular tachycardia in infants.

Background: Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergent cardiac care in children, yet its management has never been subjected to a randomized controlled clinical trial. The purpose of this study was to compare the efficacy and safety of the 2 most commonly used medications for antiarrhythmic prophylaxis of SVT in infants: digoxin and propranolol.

Methods And Results: This was a randomized, double-blind, multicenter study of infants <4 months with SVT (atrioventricular reciprocating tachycardia or atrioventricular nodal reentrant tachycardia), excluding Wolff-Parkinson-White, comparing digoxin with propranolol.

Measuring true Young's modulus of a cantilevered nanowire: effect of clamping on resonance frequency.

The effect of clamping on resonance frequency and thus measured Young's modulus of nanowires (NWs) is systematically investigated via a combined experimental and simulation approach. ZnO NWs are used in this work as an example. The resonance tests are performed in situ inside a scanning electron microscope and the NWs are cantilevered on a tungsten probe by electron-beam-induced deposition (EBID) of hydrocarbon.

Changes in hemodynamic parameters and cerebral saturation during supraventricular tachycardia.

Induced supraventricular tachycardia (SVT) during electrophysiology studies (EPS) can be associated with hemodynamic changes. Traditionally, invasive arterial blood pressure has been used for continuous monitoring of these changes. This prospective study evaluated the efficacy of near-infrared spectroscopy (NIRS) monitoring during SVT.

Optimization of biventricular pacing via strain dyssynchrony measurements in a paediatric patient.

Cardiac resynchronization therapy is increasingly being used in the paediatric population as a tool for managing patients with heart failure. Various non-invasive parameters have been used to optimize the settings on the biventricular pacemaker. We describe implantation of a biventricular pacemaker in a nineteen-month-old child because of intractable heart failure.

Changes in near-infrared spectroscopy and the bispectral index during tilt-table examination.

The head-upright tilt-table test is an important tool for the diagnosis of vasodepressor or neurocardiogenic syncope. The use of noninvasive near-infrared spectroscopy (NIRS) monitoring and bispectral index (BIS) monitoring during these cases can add another tool to the real-time monitoring and aid in their diagnosis. The authors report their experience using NIRS and BIS monitoring during tilt-table testing to investigate syncope in a 14-year-old adolescent.

Rate of inducible ventricular arrhythmia in adults with congenital heart disease.

Patients with adult congenital heart disease are at increased risk of ventricular arrhythmia (VA) and sudden cardiac death, although no clear predictors have been found. Ventricular programmed stimulation has been shown to predict clinical ventricular tachycardia and sudden death events, but the role of screening electrophysiology studies (S-EPSs) in this population remains poorly defined. Therefore, we sought to determine the prevalence of inducible VA and to evaluate the clinical predictors in a heterogeneous group of patients with adult congenital heart disease (> or =18 years old) undergoing S-EPSs at preoperative or interventional cardiac catheterization.

Tissue doppler changes in pediatric complete heart block patients who are chronically paced.

Introduction: Pediatric patients with complete heart block (CHB) often require pacemaker therapy. Adult studies have shown chronic right ventricular pacemaker therapy may be associated with decreased echocardiographic parameters and increased brain natriuretic peptide (BNP) values. The goal of this study was to determine if there are echocardiographic or BNP changes in a pediatric population that is chronically paced.

Managed ventricular pacing in pediatric patients and patients with congenital heart disease.

Ventricular dyssynchrony induced by ventricular pacing (VP) may predispose patients to congestive heart failure. The detrimental effects of VP are directly related to the cumulative percentage of VP (Cum%VP). Managed VP (MVP) is a novel pacing algorithm developed to minimize unnecessary VP by uncoupling atrial pacing from VP.

An object transport system using flexural ultrasonic progressive waves generated by two-mode excitation.

An object transport system using low amplitude and high frequency progressive waves generated by two-mode excitation is presented. A theoretical model for the system was developed using normal mode expansion and the modal participation factor. To identify the factors that affect the transport speed, the changes with the mass of objects on the beam, the input power, the phase difference, and the excitation frequency were experimentally investigated.

Randomized, double-blind, placebo-controlled trial of cephalexin for treatment of uncomplicated skin abscesses in a population at risk for community-acquired methicillin-resistant Staphylococcus aureus infection.

Empirical use of beta-lactam antibiotics, the preferred agents for treating uncomplicated skin and soft tissue infections, may no longer be appropriate for these infections because of the increasing prevalence of community strains of methicillin-resistant Staphylococcus aureus (MRSA). Retrospective studies, however, suggest that outcomes are good even when beta-lactams are used. We conducted a randomized, double-blind trial of 166 outpatient subjects comparing placebo to cephalexin at 500 mg orally four times for 7 days after incision and drainage of skin and soft tissue abscesses.

A multicenter experience with novel implantable cardioverter defibrillator configurations in the pediatric and congenital heart disease population.

Introduction: In pediatric and congenital heart disease patients, transvenous ICD implantation may be limited secondary to patient size, venous, or cardiac anatomy. Epicardial patches require a thoracotomy, and may lead to a restrictive pericardial process. Because of these issues, we have explored novel ICD configurations.

Hunting increases adaptive auditory map plasticity in adult barn owls.

The optic tectum (OT) of barn owls contains topographic maps of auditory and visual space. Barn owls reared with horizontally displacing prismatic spectacles (prisms) acquire a novel auditory space map in the OT that restores alignment with the prismatically displaced visual map. Although juvenile owls readily acquire alternative maps of auditory space as a result of experience, this plasticity is reduced greatly in adults.

Congenital superior vena cava obstruction causing anasarca and respiratory failure in a newborn: successful transcatheter therapy.

Superior vena cava (SVC) obstruction is a rare entity in the pediatric population. It usually presents in association with either previous cardiac surgery or external compression from a neoplasm. We present the case of an infant born with congenital SVC obstruction and significant bilateral chylothorax and anasarca necessitating mechanical ventilation.

Diagnostic assessment before Fontan operation in patients with bidirectional cavopulmonary anastomosis: are noninvasive methods sufficient?

Objectives: This study was designed to determine if a subset of patients who have undergone bidirectional cavopulmonary anastomosis could be identified in which catheterization was of little benefit before completion of the Fontan procedure.

Background: Diagnostic evaluation before Fontan procedure has typically included cardiac catheterization. However, the overall management strategy for patients with functional single ventricle has evolved to include staging bidirectional cavopulmonary anastomosis in most, and it has become uncommon to exclude patients from Fontan based on catheterization data.

Effects of beta-adrenergic antagonists on the QT measurements from exercise stress tests in pediatric patients with long QT syndrome.

It has been proposed that beta-adrenergic antagonist protection against cardiac events in patients with long QT syndrome (LQTS) may be related to a decrease in baseline QTc dispersion. To determine the effects of beta-blocker therapy on QT measurements, we evaluated the exercise tests of 25 pediatric patients with LQTS. Measurements were made of the maximum QTc interval and QTc dispersion during the various segments of the exercise test.

Acoustic streaming induced by ultrasonic flexural vibrations and associated enhancement of convective heat transfer.

Acoustic streaming induced by ultrasonic flexural vibrations and the associated convection enhancement are investigated. Acoustic streaming pattern, streaming velocity, and associated heat transfer characteristics are experimentally observed. Moreover, analytical analysis based on Nyborg's formulation is performed along with computational fluid dynamics (CFD) simulation using a numerical solver CFX 4.

Thrombus formation after the Fontan operation.

Background: Thrombus formation is common after a Fontan operation. We investigated the frequency and location of thrombus in our population of children based on the type of Fontan operation performed.

Methods And Results: Between January 1987 and January 1999, 592 patients underwent echocardiography after Fontan operation and 52 (8.

Atrioventricular node reentry tachycardia in pediatric patients.

Atrioventricular node reentry tachycardia (AVNRT) is a significant cause of paroxysmal supraventricular tachycardia (SVT) in the pediatric population. Symptoms can include palpitations, chest pain, fatigue, light-headedness and syncope. AVNRT is a reentry tachycardia that is comprised of dual conduction pathways through the AV node.

Airway growth after pediatric lung transplantation.

Background: Lung transplantation (LT) has been successfully offered to pediatric patients. Very little is known about the growth of the transplanted lung, especially in the infant population. Computerized tomography (CT) scanning is a simple method for studying pediatric patients who have undergone LT.

Outcome of infants listed for lung or heart/lung transplantation.

Background: Little is known about outcome, characteristics, or organ availability for infants listed for lung or heart/lung transplantation.

Methods: Within a 45-month period at one institution, all pediatric patients who were listed for primary lung or heart/lung transplantation and who reached the end point of either transplant or death prior to transplant were identified. Outcomes for those patients listed as younger than and older than 1 year of age were compared.