Document Detail


Double component action potentials in the posterior approach to the atrioventricular node: do they reflect activation delay in the slow pathway?
MedLine Citation:
PMID:  10440175     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: The aim of the study was to elucidate the mechanism of double component action potentials in the posterior approach to the atrioventricular (AV) junctional area. BACKGROUND: Double component action potentials are often associated with activation delay and therefore might be a marker of the location of the so-called slow pathway. METHODS: The AV junction was scanned for double component action potentials in Langendorff perfused pig and dog hearts, using conventional microelectrode recordings. Characteristics of these action potentials were investigated during basic and premature stimulation and cooling of the anterior approach to the node. RESULTS: During basic stimulation, double component action potentials were recorded in 19 out of 20 hearts. In 74% of these cases, the second component occurred before the His deflection. During premature stimulation this percentage was 50%, while delay between the two components always increased. In 80% of the cases, the amplitude of the two components became <20 mV during progressive shortening of the coupling interval. The first component was generated by activation in superficial layers, the second one by activation in deeper layers. Cooling of the anterior region revealed that the second component was caused by activation arriving from the anterior region. CONCLUSIONS: Double component action potentials in the posterior approach to the AV node are generated by the asynchronous arrival of wave fronts in different, weakly coupled layers or by the summation of asynchronously arriving wave fronts. They are not always associated with activation delay in the slow pathway.
Authors:
J M de Bakker; P Loh; M Hocini; B Thibault; M J Janse
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of the American College of Cardiology     Volume:  34     ISSN:  0735-1097     ISO Abbreviation:  J. Am. Coll. Cardiol.     Publication Date:  1999 Aug 
Date Detail:
Created Date:  1999-08-17     Completed Date:  1999-08-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8301365     Medline TA:  J Am Coll Cardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  570-7     Citation Subset:  AIM; IM    
Affiliation:
Interuniversity Cardiology Institute of The Netherlands, Utrecht. j.m.debakker@amc.uva.nl
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MeSH Terms
Descriptor/Qualifier:
Action Potentials
Animals
Atrioventricular Node / physiology*
Bundle of His / physiology
Cardiac Pacing, Artificial
Dogs
Microelectrodes
Swine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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