Document Detail

Vulnerability in simulated ischemic ventricular transmural tissues.
MedLine Citation:
PMID:  22229511     Owner:  NLM     Status:  MEDLINE    
Vulnerability is an effective index to evaluate increased risk for unidirectional conduction block and reentry in hearts. Recent reports in animal experiments have indicated an opposite characteristics of the vulnerability in normal and ischemic transmural tissues. In order to clarify the differences and to investigate the mechanisms, a computer simulation method was used in this study to investigate the vulnerability relative to the premature pacing sites in normal and ischemic transmural tissues. Endo-, mid- and epi-cardial myocytes incorporating different severities of ischemia were developed across a tissue strand. The sodium channel inactivation gating variable h was calculated to provide the degree of sodium current recovery preceding the premature pacing. In the normal tissue, the measured vulnerable window was demonstrated to be wider by delivering an endocardial premature beat than that by applying an epicardial premature pacing. On the contrary, during ischemia the epicardium showed a wider vulnerable window than the endocardium. The results illustrated that during ischemia h decreased with accumulation of [K⁺]o, and action potential duration dispersion was obviously altered due to anoxia. In contrast, the elevated [K⁺]o was suggested to play an important role in the difference of the location-dependent vulnerability in normal and ischemic tissues.
Hong Zhang; Juan Wang; Lin Yang; Rui-Juan Wu; Xi Mei; Wei Zhao
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Chinese journal of physiology     Volume:  54     ISSN:  0304-4920     ISO Abbreviation:  Chin J Physiol     Publication Date:  2011 Dec 
Date Detail:
Created Date:  2012-01-10     Completed Date:  2012-02-21     Revised Date:  2012-03-22    
Medline Journal Info:
Nlm Unique ID:  7804502     Medline TA:  Chin J Physiol     Country:  China (Republic : 1949- )    
Other Details:
Languages:  eng     Pagination:  427-34     Citation Subset:  IM    
Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.
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MeSH Terms
Acidosis / physiopathology
Action Potentials / physiology
Computer Simulation*
Guinea Pigs
Heart Block / physiopathology*
Heart Ventricles / physiopathology
Models, Cardiovascular*
Myocardial Ischemia / physiopathology*
Myocytes, Cardiac / physiology*
Potassium / metabolism
Refractory Period, Electrophysiological / physiology
Sodium / metabolism
Reg. No./Substance:
7440-09-7/Potassium; 7440-23-5/Sodium
Erratum In:
Chin J Physiol. 2012 Feb;55(1):72

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