Patterns of Electrocardiographic Abnormalities in Children with Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM), a common cardiomyopathy in children, is an important cause of morbidity and mortality. Early recognition and appropriate management are important. An electrocardiogram (ECG) is often used as a screening tool in children to detect heart disease.

Impact of Obesity on Left Ventricular Thickness in Children with Hypertrophic Cardiomyopathy.

Obesity is associated with additional left ventricular hypertrophy (LVH) in adults with hypertrophic cardiomyopathy (HCM). It is not known whether obesity can lead to further LVH in children with HCM. Echocardiographic LV dimensions were determined in 504 children with HCM.

Risk factors for lethal arrhythmic events in children and adolescents with hypertrophic cardiomyopathy and an implantable defibrillator: An international multicenter study.

Background: Predictors of risk of lethal arrhythmic events (LAE) is poorly understood and may differ from adults in children with hypertrophic cardiomyopathy (HCM).

Objective: The purpose of this study was to determine predictors of LAE in children with HCM.

Methods: A retrospective data collection was performed on 446 children and teenagers 20 years and younger (290 [65%] male; mean age 10.

Insights on Atrial Fibrillation in Congenital Heart Disease.

Patients with congenital heart disease (CHD) have been surviving late into adulthood, with atrial arrhythmias being the most common long-term complication. In recent reports, atrial fibrillation (AF) tended to be the most common form of arrhythmias among groups of patients with adult CHD (ACHD) older than 50 years of age. When compared with their adult counterparts without CHD, AF in patients with ACHD has been characterized by a higher incidence and prevalence, younger age of onset, and a greater risk of progression to persistent AF.

Strain Rate in Children and Young Piglets Mirrors Changes in Contractility and Demonstrates a Force-Frequency Relationship.

Background: In adult humans and pig models, strain rate (SR) correlates strongly with invasive measures of contractility but does not demonstrate a force-frequency relationship, which is a fundamental behavior of myocardial contraction. Given the considerable maturational changes of the myocardium from fetal stages to adulthood, extrapolation of adult findings to the young heart may not be appropriate. We sought to evaluate the SR response of the immature heart to increased heart rate (HR) and inotropic stimulation.

The clinical and genetic spectrum of catecholaminergic polymorphic ventricular tachycardia: findings from an international multicentre registry.

Aims: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an ion channelopathy characterized by ventricular arrhythmia during exertion or stress. Mutations in RYR2-coded Ryanodine Receptor-2 (RyR2) and CASQ2-coded Calsequestrin-2 (CASQ2) genes underlie CPVT1 and CPVT2, respectively. However, prognostic markers are scarce.

Catecholaminergic polymorphic ventricular tachycardia in children: analysis of therapeutic strategies and outcomes from an international multicenter registry.

Background: Catecholaminergic polymorphic ventricular tachycardia is an uncommon, potentially lethal, ion channelopathy. Standard therapies have high failure rates and little is known about treatment in children. Newer options such as flecainide and left cardiac sympathetic denervation are not well validated.

Current management of focal atrial tachycardia in children: a multicenter experience.

Background: Focal atrial tachycardia (FAT) is an uncommon cause of supraventricular tachycardia in children. Incessant FAT can lead to tachycardia-induced cardiomyopathy. There is limited information regarding the clinical course and management of FAT.

Management of pediatric tachyarrhythmias on mechanical support.

Background: Pediatric patients with persistent arrhythmias may require mechanical cardiopulmonary support. We sought to classify the population, spectrum, and success of current treatment strategies.

Methods And Results: A multicenter retrospective chart review was undertaken at 11 sites.

Permanent junctional reciprocating tachycardia in children: a multicenter experience.

Background: Permanent junctional reciprocating tachycardia (PJRT) is an uncommon form of supraventricular tachycardia in children. Treatment of this arrhythmia has been considered difficult because of a high medication failure rate and risk of cardiomyopathy. Outcomes in the current era of interventional treatment with catheter ablation have not been published.

Lone atrial fibrillation in the pediatric population.

Background: There are few reports of pediatric studies of atrial fibrillation (AF). We sought to describe the clinical characteristics, management strategies, and recurrence rates and to identify predictors of AF recurrence in a contemporary pediatric population.

Methods: A retrospective review was performed of patients ≤ 18 years with lone AF who were seen at 4 pediatric institutions from 1996-2011.

Efficacy of implantable cardioverter defibrillators in young patients with catecholaminergic polymorphic ventricular tachycardia: success depends on substrate.

Background: The effectiveness of implantable cardioverter-defibrillator (ICD) therapy for the management of catecholaminergic polymorphic ventricular tachycardia (VT) in young patients is not known. ICD discharges are not always effective and inappropriate discharges are common, both resulting in morbidity and mortality.

Methods And Results: This is a multicenter, retrospective review of young patients with catecholaminergic polymorphic VT and ICDs from 5 centers.

Management of adults with congenital heart disease using videoconferencing across Western Canada: a 3-year experience.

Background: Management of adults with congenital heart disease (ACHD) requires quaternary centres with cardiologists and cardiac surgeons who have expertise in the diagnosis and management of this patient population. We report on the feasibility of the management of ACHD patients using videoconferencing and streaming through 1 regional referral centre covering 4 western Canadian provinces, roughly 30% of Canada's land and population.

Methods: Videoconferencing sessions from January 2008 to December 2010 were systematically reviewed.

Dynamic changes of myocardial oxygen consumption at pacing increased heart rate - the first observation by the continuous measurement of systemic oxygen consumption.

Objectives: To assess dynamic changes in myocardial oxygen consumption (myoVO(2)) during atrial pacing increased heart rate by continuous measurement of systemic oxygen consumption (sysVO(2)).

Methods: Six mechanically ventilated pigs were atrially paced to increase heart rate from baseline 98 ± 9 to 120-140-160-180 bpm for 10 minutes at each stage, with 10 minute intervals without pacing between stages. sysVO(2) was continuously measured with a respiratory mass spectrometer.

Short- and long-term outcomes in children undergoing radiofrequency catheter ablation before their second birthday.

Background: Tachyarrhythmias can cause substantial morbidity and mortality in infants and very young children. Our objective was to assess early and late outcomes in children undergoing radiofrequency catheter ablation before their second birthday.

Methods: This is a retrospective review of medical records from 1995 till 2009 at a single institution with a large referral base.

Recommendations for the use of genetic testing in the clinical evaluation of inherited cardiac arrhythmias associated with sudden cardiac death: Canadian Cardiovascular Society/Canadian Heart Rhythm Society joint position paper.

The era of gene discovery and molecular medicine has had a significant impact on clinical practice. Knowledge of specific genetic findings causative for or associated with human disease may enhance diagnostic accuracy and influence treatment decisions. In cardiovascular disease, gene discovery for inherited arrhythmia syndromes has advanced most rapidly.

Atrio-ventricular conduction following radiofrequency ablation for atrio-ventricular node reentry tachycardia in children.

Aims: The study was designed to assess atrio-ventricular (AV) conduction with non-invasive methods at least 1 year after radiofrequency ablation (RFA) of the slow pathway for AV node reentry tachycardia.

Methods And Results: Medical records of all patients who underwent RFA before their 18th birthday were reviewed. Patients were brought back for clinical evaluation, an electrocardiogram, an exercise stress test, and ambulatory Holter monitoring.

Torsades de Pointes ventricular tachycardia in a pediatric patient treated with fluconazole.

Fluconazole is an antifungal medication that has been reported to cause prolongation of the QT interval and Torsades de Pointes (TdP) ventricular tachycardia in adults. We describe the case of an 11-year-old child treated with fluconazole who developed ventricular arrhythmia culminating in TdP. We discuss the possible roles played by genetic and environmental factors in this child's rhythm disturbances.

Management of infants with idiopathic dilatation of the right atrium and atrial tachycardia.

Idiopathic dilatation of the right atrium (IDRA) is a rare anomaly defined as isolated enlargement of the right atrium in the absence of other cardiac lesions known to cause right atrial dilatation. IDRA is a congenital anomaly with unknown pathogenesis and highly variable clinical presentation. Optimal management of severe IDRA is controversial and individualized.

Direct intracardiac placement of an automatic implantable cardioverter defibrillator coil lead in a small child.

A 3.5-year-old child with hypertrophic obstructive cardiomyopathy and recurrent syncope underwent surgical left-ventricular outflow tract myectomy and implantation of a single-chamber automatic cardioverter defibrillator. A single-coil active fixation lead was introduced via a purse-string suture in the right atrial appendage and the lead tip positioned and fixed in the right-ventricular apex under direct visualization via a small right atriotomy incision.

Right ventricular outflow tract tachycardia in children.

Objective: To assess the clinical spectrum of right ventricular outflow tract tachycardia and its management in children.

Study Design: Five centers identified patients for retrospective review. Patients (age <18 years) demonstrating ventricular tachycardia with an inferior axis and left bundle branch block were included.

The significance of cardiac surgery scars in adult patients with congenital heart disease.

Background: Scars resulting from heart surgery mark patients for life, yet their effect on patients' well-being is unknown.

Aim: To determine what spheres of life may be affected by surgical chest scarring.

Methods: A preliminary questionnaire asked 10 random patients at our adult congenital heart disease clinic to describe personal consequences (if any) of having a cardiac surgery scar.

Supraventricular tachycardia in children.

Several different mechanisms are responsible for paroxysmal supraventricular tachycardia in children. Different forms of tachycardia occur at different age. Atrio-ventricular reentry tachycardia results from the presence of congenital atrio-ventricular bypass tracts and is frequently encountered at all ages.

A case report of Noonan's syndrome with pulmonary valvar stenosis and coronary aneurysms.

Background: Noonan syndrome is a rare disease, mainly presenting with malformations such as dysplasia and stenosis of the pulmonary valve, atrial septal defect and a typical pattern of hypertrophic cardiomyopathy. We report a case of Noonan syndrome with giant coronary aneurysms.

Case Report: A young woman with the phenotypic characteristics of Noonan's syndrome presented with severe pulmonary stenosis and giant coronary aneurysms.