Longitudinal Observational Study of Cardiac Outcome Risk Factor Prediction in Children, Adolescents, and Adults with Barth Syndrome.

Barth Syndrome (BTHS) is an X-linked mitochondrial cardioskeletal myopathy caused by defects in TAFAZZIN, a gene responsible for cardiolipin remodeling. Altered mitochondrial levels of cardiolipin lead to cardiomyopathy (CM), muscle weakness, exercise intolerance, and mortality. Cardiac risk factors predicting outcome are unknown.

Cardiac transplantation in children and adolescents with long QT syndrome.

Background: Long QT syndrome (LQTS) is a potentially lethal, yet highly treatable, cardiac channelopathy. Cardiac transplantation has been reported anecdotally for patients with severe LQTS refractory to standard therapies.

Objective: The purpose of this study was to evaluate the incidence of and risk factors for cardiac transplantation in children evaluated and treated in an LQTS specialty center.

How implantable cardioverter-defibrillators work and simple programming.

Following the sudden death of a friend in 1966, Dr Michel Mirowski began pioneering work on the first implantable cardioverter-defibrillator. By 1969 he had developed an experimental model and performed the first transvenous defibrillation. In 1970 he reported on the use of a "standby automatic defibrillator" that was tested successfully in dogs.

Artefactual atrial flutter due to interference from a portable media device.

Portable media devices are widely used by today's youth. When used in hospitals, these devices can produce artefactual arrhythmias on telemetry.

Impaired cardiac reserve and severely diminished skeletal muscle O₂ utilization mediate exercise intolerance in Barth syndrome.

Barth syndrome (BTHS) is a mitochondrial myopathy characterized by reports of exercise intolerance. We sought to determine if 1) BTHS leads to abnormalities of skeletal muscle O(2) extraction/utilization and 2) exercise intolerance in BTHS is related to impaired O(2) extraction/utilization, impaired cardiac function, or both. Participants with BTHS (age: 17 ± 5 yr, n = 15) and control participants (age: 13 ± 4 yr, n = 9) underwent graded exercise testing on a cycle ergometer with continuous ECG and metabolic measurements.

Quality of life in pediatric patients with implantable cardioverter defibrillators.

Psychosocial and quality-of-life (QOL) outcomes in adult patients with implantable cardioverter-defibrillators (ICDs) are well studied. Minimal research exists regarding pediatric adjustment, despite a potentially more challenging adjustment process. The purpose of the present study was to examine psychosocial and QOL functioning of pediatric ICD patients from patient and parent self-reports.

Protective effect of KCNH2 single nucleotide polymorphism K897T in LQTS families and identification of novel KCNQ1 and KCNH2 mutations.

Background: KCNQ1 and KCNH2 are the two most common potassium channel genes causing long QT syndrome (LQTS), an inherited cardiac arrhythmia featured by QT prolongation and increased risks of developing torsade de pointes and sudden death. To investigate the disease expressivity, this study aimed to identify mutations and common variants that can modify LQTS phenotype.

Methods: In this study, a cohort of 112 LQTS families were investigated.

Cardiac and clinical phenotype in Barth syndrome.

Objective: Barth syndrome, an X-linked disorder that is characterized by cardiomyopathy, neutropenia, skeletal myopathy, and growth delay, is caused by mutations in the taffazin gene at Xq28 that result in cardiolipin deficiency and abnormal mitochondria. The clinical phenotype in Barth syndrome has not been characterized systematically, and the condition may be underrecognized. We sought to evaluate extent of cardioskeletal myopathy, potential for arrhythmia, delays in growth, and biochemical correlates of disease severity in patients with this disorder.

Catecholaminergic polymorphic ventricular tachycardia in a 3-year-old with occult myocarditis.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare clinical entity in children. Occult myocarditis has not been previously implicated as an etiologic agent. A 3-year-old female presents with a presumed breath-holding spell and is found to have ventricular fibrillation requiring DC cardioversion.