| The effect of cardiac electric anisotropy on epicardial potential fields during ventricular repolarization. | |
| | |
MedLine Citation:
|
PMID: 3820587 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
We tried to establish whether some of the manifestations of electrical anisotropy previously observed on the canine ventricular epicardium during the spread of excitation were also present during repolarization, with the appropriate polarity. To this end we determined the potential distribution on the ventricular surface of exposed dog hearts during ventricular excitation and repolarization. The ventricles were paced by means of epicardial or intramural electrodes. During the early stages of ventricular excitation following epicardial pacing we observed typical, previously described potential patterns, with negative, elliptical equipotential lines surrounding the pacing site, and two maxima aligned along the direction of subepicardial fibers. Intramural pacing gave rise to similar patterns. The axis joining the maxima, however, was oriented along the direction of intramural fibers. The repolarization potential pattern relating to epicardial excitation exhibited some features similar to those observed during the spread of excitation, namely the presence of families of elliptical equipotential lines around the pacing site, with pairs of potential extrema along the major or minor axes of the ellipses or both. The location of the extrema and the distribution of the epicardial potential gradients during repolarization suggested the presence of anisotropic current generators mainly oriented along the direction of deep myocardial fibers, with some contribution from more superficial sources which were oriented along the direction of subepicardial fibers. Deep stimulation elicited more complicated epicardial patterns whose interpretation is still obscure. We conclude that the electrical anisotropy of the heart affects the distribution of repolarization potentials and probably the strength of electrical generators during ventricular repolarization. |
| | |
Authors:
|
S Spaggiari; S Baruffi; E Macchi; M Traversa; G Arisi; B Taccardi |
Related Documents
:
|
16394597 - Blood b-type natriuretic peptide changes in different periods and different cardiac pac... 7471377 - Strength-interval relations in a chronic canine model of myocardial infarction. implica... 11449587 - Effect of different pacing protocols on the induction of atrial fibrillation in a trans... 1374887 - Is ddd pacing superior to vvi,r? a study on cardiac sympathetic nerve activity and myoc... 15687537 - Reversible severe ischemic mitral regurgitation and cardiogenic shock as a complication... 2613377 - Assessment of hemodynamic changes in the early phase of uncomplicated acute myocardial ... |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Japanese heart journal Volume: 27 Suppl 1 ISSN: 0021-4868 ISO Abbreviation: Jpn Heart J Publication Date: 1986 Nov |
Date Detail:
|
Created Date: 1987-04-21 Completed Date: 1987-04-21 Revised Date: 2008-11-21 |
Medline Journal Info:
|
Nlm Unique ID: 0401175 Medline TA: Jpn Heart J Country: JAPAN |
Other Details:
|
Languages: eng Pagination: 217-23 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Action Potentials Animals Dogs Heart Conduction System / physiology* Membrane Potentials Pericardium / physiology Ventricular Function |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Determination of activation and recovery sequences and local repolarization durations from distant e...
Next Document: 3-dimensional computer simulation of depolarization and repolarization processes in the myocardium.