Document Detail


Isoarea distributions during ectopic stimulation of isolated rabbit hearts.
MedLine Citation:
PMID:  7276785     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
These studies were designed to explore the effects of ectopic left ventricular stimulation on the area distributions recorded during the QRS, ST-T and QRST intervals. Twenty rabbit hearts were suspended in a spherical volume conductor, perfused with an electrolyte solution and stimulated from an anterior and/or a posterior subepicardial left ventricular site. ECG signals were sensed from 32 surface electrodes and were processed to compute areas under the three intervals, to construct area maps and to fit the computed areas to a single moving dipole equivalent cardiac generator model. Results demonstrated that control distributions were overtly nondipolar in 62.5% of cases. Second, ectopic pacing increased the dipolarity of the QRS and ST-T intervals significantly by both dipole ranging and isoarea methods. All area distributions became dipolar. Last, the QRST distribution response to ectopic stimulation varied widely, with major as well as minor changes in patterns occurring with alteration in excitation sequence. Thus, (1) ectopic stimulation changed electrical field properties of mean cardiac forces, and (2) QRST area distributions were dependent upon activation sequence. Each of these observations has direct bearing upon the ventricular gradient concept.
Authors:
D M Mirvis
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of electrocardiology     Volume:  14     ISSN:  0022-0736     ISO Abbreviation:  J Electrocardiol     Publication Date:  1981  
Date Detail:
Created Date:  1981-11-22     Completed Date:  1981-11-22     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0153605     Medline TA:  J Electrocardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  159-68     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Electric Stimulation
Electrocardiography*
Heart / physiology*
Heart Ventricles
Rabbits
Grant Support
ID/Acronym/Agency:
HL-00560/HL/NHLBI NIH HHS; HL-20597/HL/NHLBI NIH HHS

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


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