| Evaluation of post-repolarization refractoriness for conduction block in cardiac muscle: studies in an artificial isthmus in the canine right atrium. | |
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MedLine Citation:
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PMID: 11153820 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Post-repolarization refractoriness (PRR) is an important factor in determining conduction block and is the difference between the effective refractory period (ERP) and the duration of the monophasic action potential (MAPD). In the present study, conduction block in an artificial isthmus in the canine atrium was evaluated and the coupling interval of a premature beat, which caused the block, was defined as the block coupling interval (BCI). The usefulness of this value was also evaluated. Radiofrequency linear ablation was performed on the right atrial surface parallel to the atrioventricular groove in 5 mongrel dogs, and an artificial isthmus (8-10mm wide and 25-30mm long) was created. Fourteen simultaneous unipolar recordings were performed in the isthmus with a resolution of 1.2 mm. Single extra-stimuli with basic drive train were delivered to induce conduction block in the isthmus and when it occurred, the coupling interval at the recording site just proximal to the site of the block was defined as the BCI. At the site of the block, the ERP and MAPD at each drive cycle length were measured. The PRR was calculated using 2 different formulae: (1) [ERP-MAPD], and (2) [BCI-MAPD]. It was found that each value was shortened in accordance with the shortening of the basic drive cycle length. In all basic drive trains, BCI>ERP>MAPD, and [ERP-MAPD] was always shorter than [BCI-MAPD]. In the shorter cycle length of basic drives, the difference between [ERP-MAPD] and [BCI-MAPD] was more prominent. In the artificial isthmus model in the canine atrium, BCI was always longer than the ERP measured at the same site as the block. Because the ERP may not directly reflect the block phenomenon, the electrophysiologic evaluation should use the BCI instead, as in the PRR evaluation. |
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Authors:
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S Niwano; N Yoshizawa; K Inuo; J Saito; M Moriguchi; Y Kitano; T Izumi |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Japanese circulation journal Volume: 65 ISSN: 0047-1828 ISO Abbreviation: Jpn. Circ. J. Publication Date: 2001 Jan |
Date Detail:
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Created Date: 2001-01-10 Completed Date: 2001-05-17 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7806868 Medline TA: Jpn Circ J Country: Australia |
Other Details:
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Languages: eng Pagination: 40-5 Citation Subset: IM |
Affiliation:
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Department of Internal Medicine, Kitasato Universit, School of Medicine, Sagamihara, Japan. niwano@med.kitasato-u.ac.jp |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials
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physiology Animals Atrial Premature Complexes / physiopathology Disease Models, Animal Dogs Electrocardiography Electrophysiologic Techniques, Cardiac Heart Atria / physiopathology Heart Block / diagnosis, etiology, physiopathology* Heart Conduction System / injuries |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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