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2002 Fiscal Year Final Research Report Summary

Effects of atrial muscle structure on the initiation mechanism of atrial fibrillation and its drug therapy

Research Project

Project/Area Number 13670083
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field General pharmacology
Research InstitutionShinshu University

Principal Investigator

HIROSE Masamichi  Shinshu University School of Medicine, Assistant Professor, 医学部, 講師 (40273081)

Project Period (FY) 2001 – 2002
KeywordsPACAP / Atrial muscle structure / Atriai fibrillation / Action potential / E-4031 / Zatebradine / Autonomic nervous system
Research Abstract

In isolated arterially perfused canine atria, transmural repolarization gradients were observed using high resolution optical mapping techniques to measure action potentials from the epicardial and endocardial surface on the right at rial free wall. These are performed during control conditions, during electrical stimulation of the fat pad at the right pulmonary vein-atrial junction (i.e. intracardiac parasympathetic stimulations) and during acetylcholine (ACh) infusion. Transmural repolarization gradients did not increase during intracardiac parasympathetic stimulation and during ACh infusion compared to during control. During ACh infusion, at rial tachyarrhythmia (AT) was initiated with a single premature stimulus and was associated with a focal pattern of activation (84 %). Importantly, AT initiation during intracardiac parasympathetic stimulations was also associated with the focal pattern of activity (36 %) without conduction block when repolarization gradients were small. During … More intracardiac parasympathetic stimulations, however, when repolarization gradients were large, patterns of conduction block and incomplete macroreentry were often observed (64 %). During pituitary adenylate activating polypeptide injection, repolarization gradients were small across the atrial surface and transmirally and a single premature stimulus initiated AT which was associated with a focal pattern of activation (100 %) without conduction block. These results suggest that the complicated tissue structure of atrial tissue has an important role for initiating focal pattern of AT. We examined the spatial variation in ionic current density us ing E-4031, the rapidly activating component of delayed rectifier potassium current blocker, and Zatebradine, hyperpolarization activated-current blocker. E-4031 increased action potential duration (APD) greater in the right atrial free wall than in the pulmonary vein area of left atrium. In contrast, Zatebradine equally increased APD between them. These results suggest the regional variation in atrial ionic currents. Less

  • Research Products

    (4 results)

All Other

All Publications (4 results)

  • [Publications] 弘瀬 雅教: "Cellular mechanisms of vagally-mediated atrial tachyarrhythmia in isolated arterially perfused canine right atria"Journal of Cardiovascular Electrophysiology. 13巻9号. 918-926 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 弘瀬 雅教: "Partial Vagal Denervation Increases Vulnerability to Vagally Induced Atrial Fibrillation"Journal of Cardiovascular Electrophysiology. 13巻12号. 1272-1279 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Masamichi Hirose: "Cellular mechanisms of vagally-mediated atrial tachyarrhythmia in isolated arterially perfused canine right atria"J Cardiovas Electrophysiol. Vol.13 No.9. 918-926 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Masamichi Hirose: "Partial Vagal Denervation Increases Vulnerability to Vagally Induced Atrial Fibrillation"J Cardiovas Electrophysiol. Vol.13 No.12. 1272-1279 (2002)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2004-04-14  

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