Document Detail

Mapping of epicardial activation in a rabbit model of chronic myocardial infarction:.
MedLine Citation:
PMID:  17537208     Owner:  NLM     Status:  MEDLINE    
INTRODUCTION: This study examines the consequences of a large transmural apical infarct on the epicardial electrical activity in isolated rabbit hearts. METHODS AND RESULTS: Hearts were isolated 8 weeks after coronary artery ligation. Membrane voltage from the epicardial surface of the left ventricle (LV) including the infarct was monitored using the voltage sensitive dye RH237. Optical action potentials were detected from the epicardial surface of the infarct; the signal amplitude was approximately 20% of those in the noninfarcted zone (NZ). Epicardial activation mapping of the LV free wall showed that during right atrial (RA) pacing, the activation sequence was not significantly different between infarcted and sham-operated groups. However, direct stimulation of the epicardium in the NZ revealed an area of slow conduction velocity (CV approximately 5 cm/s(-1), approximately 10% of normal values) at the margin of the infarct zone (IZ). Within the IZ, CV was approximately 50% of normal. A prominent endocardial rim of myocardium in the infarct was not the source of epicardial optical signals because chemical ablation of the endocardium did not affect the epicardial activation pattern. CONCLUSION: Therefore, remnant groups of myocytes in the mid-wall and epicardium of the infarct scar support normal electrical activation during RA pacing. Areas of delayed conduction emerge only on epicardial stimulation.
Nicola L Walker; Francis L Burton; Sarah Kettlewell; Godfrey L Smith; Stuart M Cobbe
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-05-30
Journal Detail:
Title:  Journal of cardiovascular electrophysiology     Volume:  18     ISSN:  1540-8167     ISO Abbreviation:  J. Cardiovasc. Electrophysiol.     Publication Date:  2007 Aug 
Date Detail:
Created Date:  2007-07-26     Completed Date:  2007-09-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9010756     Medline TA:  J Cardiovasc Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  862-8     Citation Subset:  IM    
Division of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK.
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MeSH Terms
Action Potentials*
Body Surface Potential Mapping*
Chronic Disease
Disease Models, Animal*
Heart Conduction System / physiopathology*
Myocardial Infarction / physiopathology*
Pericardium / physiopathology*

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