Objectives: This study was designed to investigate the clinical course of women with long QT syndrome (LQTS) throughout their potential childbearing years.
Background: Only limited data exist regarding the risks associated with pregnancy in women with LQTS.
Methods: The risk of experiencing an adverse cardiac event, including syncope, aborted cardiac arrest, and sudden death, during and after pregnancy was analyzed for women who had their first birth from 1980 to 2003 (n = 391).
Background: The potential pathophysiological role of common SCN5A polymorphisms in cardiac arrhythmias has been increasingly recognized. However, little is known about the impact of those polymorphisms on the pharmocological response of hNav1.5 to various antiarrhythmic agents.
View Article and Find Full Text PDFObjective: In 1984, the first successful infant heart transplant was performed at Texas Children's Hospital. This study analyzes the 21-year experience with pediatric heart transplantation at Texas Children's Hospital to assess whether and how survival has changed over time.
Methods: Between November 1, 1984, and October 3, 2005, 164 consecutive orthotopic heart transplants were performed on 154 patients.
Background: Current information on the epidemiology and outcomes of hypertrophic cardiomyopathy (HCM) in children is limited by disease diversity and small case series.
Methods And Results: The Pediatric Cardiomyopathy Registry has collected prospective and retrospective data on children diagnosed with HCM since 1990. We identified the various causes of HCM in childhood and determined the relationship between outcomes, cause, and age at presentation.
Dilated cardiomyopathy (DCM), characterized by ventricular dilation and decreased systolic function, is estimated to be of genetic origin in up to 50% of cases. In the present study, we investigated the role of two genes, encoding the Z line proteins PDZ and LIM domain protein 3 (PDLIM3) and myozenin-1 (MYOZ1), in the etiology of DCM. The coding regions of PDLIM3 and MYOZ1 were first amplified from the genomic DNA of 185 unrelated DCM patients by polymerase chain reaction (PCR), followed by denaturing high-performance liquid chromatography (DHPLC) analysis.
View Article and Find Full Text PDFObjectives: The aims of this study were: 1) to evaluate risk factors influencing the clinical course of mutation-confirmed adult patients with long QT syndrome (LQTS), 2) to study life-threatening cardiac events as a specific end point in adults, and 3) to examine the protective effect of beta-blocker therapy on cardiac events in adult LQTS patients with known cardiac channel mutations.
Background: The clinical course and risk factors for cardiac events in genotype-confirmed adult patients with LQTS have not been previously investigated.
Methods: The clinical characteristics of 812 mutation-confirmed LQTS patients age 18 years or older were studied with both univariate and multivariate analyses to determine the genotype-phenotype factors that influence the clinical course of adult patients with this disorder.
The use of mechanical circulatory support as a bridge to cardiac transplantation is now an accepted therapeutic option. Also, as the criteria for organ transplantation have broadened, multi-organ transplantation has become more feasible. We report the cases of 2 children with end-stage heart failure and renal failure who were successfully bridged to combined, single-donor heart and kidney transplantation with mechanical circulatory support.
View Article and Find Full Text PDFBackground: Left ventricular non-compaction (LVNC) may manifest an undulating phenotype ranging from dilated to hypertrophic appearance. It is unknown whether tissue Doppler (TD) velocities can predict adverse clinical outcomes including death and need for transplantation in children with LVNC.
Methods And Results: 56 children (median age 4.
Biochem Biophys Res Commun
December 2006
Hypertrophic cardiomyopathy (HCM) can be classified into at least four major anatomic subsets based upon the septal contour, and the location and extent of hypertrophy: reverse curvature-, sigmoidal-, apical-, and neutral contour-HCM. Here, we sought to identify genetic determinants for sigmoidal-HCM and hypothesized that Z-disc-HCM may be associated preferentially with a sigmoidal phenotype. Utilizing PCR, DHPLC, and direct DNA sequencing, we performed mutational analysis of five genes encoding cardiomyopathy-associated Z-disc proteins.
View Article and Find Full Text PDFBackground: Congenital long-QT syndrome (LQTS) is a primary arrhythmogenic syndrome stemming from perturbed cardiac repolarization. LQTS, which affects approximately 1 in 3000 persons, is 1 of the most common causes of autopsy-negative sudden death in the young. Since the sentinel discovery of cardiac channel gene mutations in LQTS in 1995, hundreds of mutations in 8 LQTS susceptibility genes have been identified.
View Article and Find Full Text PDFContext: Dilated cardiomyopathy (DCM) is the most common form of cardiomyopathy and cause of cardiac transplantation in children. However, the epidemiology and clinical course of DCM in children are not well established.
Objective: To provide a detailed description of the incidence, causes, outcomes, and related risk factors for DCM in children.
Objective: The goal was to identify the clinical variables associated with establishing a cause of cardiomyopathy in children.
Methods: The Pediatric Cardiomyopathy Registry contains clinical and causal testing information for 916 children who were diagnosed as having cardiomyopathy in North America between 1990 and 1995. Children with a causal diagnosis were compared with those without with respect to several demographic, clinical, and causal testing variables.
Context: Analysis of predictors of cardiac events in hereditary long-QT syndrome (LQTS) has primarily considered syncope as the predominant end point. Risk factors specific for aborted cardiac arrest and sudden cardiac death have not been investigated.
Objective: To identify risk factors associated with aborted cardiac arrest and sudden cardiac death during adolescence in patients with clinically suspected LQTS.
Background: Plasma B-type natriuretic peptide (BNP) levels are elevated in adults with heart failure and correlate with functional classification and prognosis. The range and predictive power of BNP concentrations in children with chronic heart failure, however, are not known.
Methods And Results: Whole blood BNP concentrations were measured in 53 consecutive patients with chronic left ventricular (LV) systolic dysfunction (biventricular hearts, ejection fraction < 50%, > 3 months since diagnosis).
In this chapter, the up-to-date understanding of the molecular basis of disorders causing arrhythmias are outlined. Several arrhythmic disorders have been well described at the molecular level, including the long QT syndromes (LQTS), Brugada syndrome, and polymorphic ventricular tachycardia. The genes identified have been determined using genetic linkage analysis, cloning, and mutation analyses.
View Article and Find Full Text PDFArrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by progressive degeneration of the right ventricular myocardium, ventricular arrhythmias, fibrous-fatty replacement, and increased risk of sudden death. Mutations in 6 genes, including 4 encoding desmosomal proteins (Junctional plakoglobin (JUP), Desmoplakin (DSP), Plakophilin 2, and Desmoglein 2), have been identified in patients with ARVD/C. Mutation analysis of 66 probands identified 4 variants in DSP; V30M, Q90R, W233X, and R2834H.
View Article and Find Full Text PDFIntroduction: Data regarding risk factors and clinical course of patients affected with Jervell and Lange-Nielsen syndrome (JLNS), an autosomal recessive form of the congenital long-QT syndrome (LQTS), are limited to several reported cases and a retrospective analysis.
Methods And Results: We prospectively followed-up 44 JLNS patients from the U.S.
This study sought to determine the potential of recombinant B-type natriuretic peptide (nesiritide) for the treatment of pediatric decompensated heart failure. Nesiritide is a widely used and effective treatment for decompensated heart failure (HF) in adults, but its safety and efficacy in pediatric patients is unclear. Outcomes of 55 separate nesiritide infusions of varying durations in 32 patients (13 males and 19 females; mean age, 8.
View Article and Find Full Text PDFJ Cardiovasc Electrophysiol
August 2006
Background: Noncompaction of the ventricular myocardium (NVM) is a relatively uncommon form of cardiomyopathy characterized by a highly trabeculated myocardium. This report describes the clinical and genetic evaluation of a 3-generation kindred.
Methods: Family members were initially evaluated by 2-dimensional echocardiography.
Background: Sympathetic activation influences the risk of ventricular arrhythmias and sudden cardiac death (SCD), mediated in part by the beta2-adrenergic receptor (B2AR). We investigated whether variation in the B2AR gene is associated with SCD risk.
Methods And Results: In this study, 4441 white and 808 black Cardiovascular Health Study (CHS) participants were followed up prospectively for SCD and genotyped for B2AR Gly16Arg and Gln27Glu polymorphisms.
Background: Andersen-Tawil syndrome (ATS) is a rare inherited disorder, characterised by periodic paralysis, cardiac dysarrhythmias, and dysmorphic features, and is caused by mutations in the gene KCNJ2, which encodes the inward rectifier potassium channel, Kir2.1. This study sought to analyse KCNJ2 in patients with familial ATS and to determine the functional characteristics of the mutated gene.
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