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Conduction Disease (conduction + disease)

Distribution by Scientific Domains
Life Sciences60%
Medical Sciences40%

Selected Abstracts

Intrahisian Conduction Disease and Junctional Ectopic Tachycardia

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2008
VALENTINO DUCCESCHI M.D.
Junctional ectopic tachycardia (JET) is an uncommon arrhythmia that mainly affects pediatric patients. However, its clinical presentation may rarely occur in adulthood. Owing to its incessant nature, limited responsiveness to antiarrhythmic agents and poor prognosis, catheter ablation of the junctional focus is often required, even though this may be accompanied by the occurrence of complete atrioventricular block. We report the case of a 68-year-old man with episodes of sustained ventricular tachycardia and repetitive JET whose initiation was often anticipated by a sudden intrahisian conduction delay in the immediately preceding sinus beats. [source]

Myotonia and muscle contractile properties in mice with SIX5 deficiency

MUSCLE AND NERVE, Issue 4 2005
Kirkwood E. Personius PhD
Abstract Myotonic dystrophy (DM1) is an autosomal-dominant multisystem disease characterized by progressive skeletal muscle weakness, myotonia, cataracts, cardiac arrhythmias, mild mental retardation, and endocrinopathies. Heterozygous loss of SIX5 in mice causes cataracts and cardiac conduction disease, and homozygous loss also leads to sterility and decreased testicular mass, reminiscent of DM1 in humans. The effect of SIX5 deficiency in muscle is unknown. In this study, we found that muscle contractile properties, electromyographic insertional activity, and muscle histology were normal in SIX5 deficient mice. The implications of these findings for the pathogenesis of DM1 are discussed. Muscle Nerve, 2004 [source]

Genetics of atrioventricular conduction disease in humans

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 2 2004
D. Woodrow Benson
Abstract Atrioventricular (AV) conduction disease (block) describes impairment of the electrical continuity between the atria and ventricles. Classification of AV block has utilized biophysical characteristics, usually the extent (first, second, or third degree) and site of block (above or below His bundle recording site). The genetic significance of this classification is unknown. In young patients, AV block may result from injury or be the major cardiac manifestation of neuromuscular disease. However, in some cases, AV block has unknown or idiopathic cause. In such cases, familial clustering has been noted and published pedigrees show autosomal dominant inheritance; associated heart disease is common (e.g., congenital heart malformation, cardiomyopathy). The latter finding is not surprising given the common origin of working myocytes and specialized conduction system elements. Using genetic models incorporating reduced penetrance (disease absence in some individuals with disease gene), variable expressivity (individuals with disease gene have different phenotypes), and genetic heterogeneity (similar phenotypes, different genetic cause), molecular genetic causes of AV block are being identified. Mutations identified in genes with diverse functions (transcription, excitability, and energy homeostasis) for the first time provide the means to assess risk and offer insight into the molecular basis of this important clinical condition previously defined only by biophysical characteristics. © 2004 Wiley-Liss, Inc. [source]

Familial progressive sinoatrial and atrioventricular conduction disease of adult onset with sudden death, dilated cardiomyopathy, and brachydactyly.

CLINICAL GENETICS, Issue 2 2005
A new type of heart-hand syndrome?
We identified a family with 10 affected members in four generations suffering from adult-onset progressive sinoatrial and atrioventricular conduction disease, sudden death due to ventricular tachyarrhythmia, dilated cardiomyopathy, and a unique type of brachydactyly with mild hand involvement (short distal, middle, proximal phalanges and clinodactyly) and more severe foot involvement (short distal, proximal phalanges and metatarsal bones, short or absent middle phalanges, terminal symphalangism, duplication of the bases of the second metatarsals, extra ossicles, and syndactyly). The phenotype differences from other reported genetic abnormalities and linkage exclusion of Holt,Oram syndrome, ulnar,mammary syndrome, brachydactyly type B or Robinow syndrome, and cardiac conduction disease or Brugada syndrome loci suggest that we report on a new hereditary heart-hand syndrome. [source]