Document Detail


Effects of propafenone on anisotropic conduction properties within the three-dimensional structure of the canine ventricular wall.
MedLine Citation:
PMID:  11327336     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Structural complexities of the intact ventricular wall cause a very complex spread of activation. The effects of regional tissue damage and of antiarrhythmic drugs on directional differences in activation should help to further elucidate intramural conduction patterns. METHODS AND RESULTS: In 10 healthy dogs and in 5 dogs with subacute anterior wall infarction, 6 parallel rows of 6 needle electrodes with 4 bipolar electrode pairs per needle were inserted into the left anterior ventricular wall. Using a computerized multiplexer-mapping system, the spread of activation in epi-, endo- and midmyocardial muscle layers and in the surviving epicardium, respectively, was reconstructed. Marked differences in conduction velocities relative to fiber orientation were evident in the surviving epicardium of infarcted hearts. Directional differences in conduction velocities, although less pronounced, were still preserved throughout the intact ventricular wall. Epicardial transverse conduction in intact hearts was significantly faster than transverse conduction in infarcted hearts (0.87 +/- 0.11 m/s vs 0.68 +/- 0.1 m/s). In normal hearts, propafenone (2 mg/kg) decreased conduction velocities primarily in longitudinal directions (-27 +/- 10%), but also moderately in transverse directions (-13 +/- 7 %) of all muscle layers, with no significant effect on straight (-4 +/- 8 %), but on oblique transmural conduction (-33 +/- 18 %). In infarcted hearts propafenone decreased conduction particularly in longitudinal direction (-23 +/- 14 %) without affecting conduction transverse to the fiber orientation (+3 +/- 6%). CONCLUSIONS: Longitudinal intramural shortcircuits reduce directional differences in activation. Transmural infarction results in a loss of alternative intramural pathways, unmasking marked anisotropy in the surviving epicardium. Conduction delay in intramural pathways explains the effects of propafenone on transverse and oblique transmural conduction. Primarily longitudinal conduction delay results in reduced tissue anisotropy.
Authors:
A Bauer; P A Schnabel; K D Schreiner; R Becker; F Voss; P Kraft; J Senges; M Licka; W Kübler; W Schoels
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Basic research in cardiology     Volume:  96     ISSN:  0300-8428     ISO Abbreviation:  Basic Res. Cardiol.     Publication Date:  2001 Apr 
Date Detail:
Created Date:  2001-04-30     Completed Date:  2001-08-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0360342     Medline TA:  Basic Res Cardiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  175-83     Citation Subset:  IM    
Affiliation:
Abteilung Innere Medizin III, Medizinische Universitätsklinik, Heidelberg, Germany. alexander_bauer@med.uni-heidelberg.de
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MeSH Terms
Descriptor/Qualifier:
Animals
Anisotropy
Anti-Arrhythmia Agents / pharmacology*
Dogs
Heart / physiopathology*
Heart Ventricles / physiopathology
Membrane Potentials / drug effects,  physiology
Myocardial Infarction / drug therapy,  physiopathology*
Propafenone / pharmacology*
Tachycardia, Ventricular / drug therapy,  physiopathology*
Chemical
Reg. No./Substance:
0/Anti-Arrhythmia Agents; 54063-53-5/Propafenone

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


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