Document Detail


Optical mapping of electrical activation in the developing heart.
MedLine Citation:
PMID:  16060973     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Specialized conduction tissues mediate coordinated propagation of electrical activity through the adult vertebrate heart. Following activation of the atria, the activation wave is slowed down in the atrioventricular canal or node, after which it spreads rapidly into the left and right ventricles via the His-Purkinje system (HPS). This results in the ventricles being activated from the apex toward the base, which is a hallmark of HPS function. The development of mature HPS function follows significant phases of cardiac morphogenesis. Initially, the cardiac impulse propagates in a slow, linear, and isotropic fashion from the sinus venosus at the most caudal portion of the tubular heart. Although the speed of impulse propagation gradually increases as it travels toward the anterior regions of the heart tube, the actual sequence of ventricular activation in the looped heart proceeds in the same direction as blood flow. Eventually, the immature base-to-apex sequence of ventricular activation undergoes an apparent reversal, changing to the mature apex-to-base pattern. Using an optical mapping approach, we demonstrate that the timing of this last transition shows striking dependence on hemodynamic loading of the ventricle, being accelerated by pressure overload and delayed in left ventricular hypoplasia. Comparison of chick and mammalian hearts revealed some striking similarities as well as key differences in the timing of such events during cardiac organogenesis.
Authors:
David Sedmera; Maria Reckova; Carlin Rosengarten; Maria I Torres; Robert G Gourdie; Robert P Thompson
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada     Volume:  11     ISSN:  1431-9276     ISO Abbreviation:  Microsc. Microanal.     Publication Date:  2005 Jun 
Date Detail:
Created Date:  2005-08-02     Completed Date:  2005-08-18     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9712707     Medline TA:  Microsc Microanal     Country:  United States    
Other Details:
Languages:  eng     Pagination:  209-15     Citation Subset:  IM    
Affiliation:
Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, SC 29425, USA. sedmerad@musc.edu
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MeSH Terms
Descriptor/Qualifier:
Action Potentials
Animals
Bundle of His / embryology
Female
Heart / embryology*,  physiology
Heart Ventricles / embryology
Models, Animal
Pregnancy
Rats
Grant Support
ID/Acronym/Agency:
HD 39446/HD/NICHD NIH HHS; HL 50582/HL/NHLBI NIH HHS; RR 16434/RR/NCRR NIH HHS

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


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