Document Detail


Developmental transitions in electrical activation patterns in chick embryonic heart.
MedLine Citation:
PMID:  15368341     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The specialized conduction tissue network mediates 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, then spreads rapidly into the left and right ventricles via the His-Purkinje system (HPS). This results in the ventricle being activated from the apex toward the base and is thought to represent HPS function. The development of mature HPS function in embryogenesis follows significant phases of cardiac morphogenesis. Initially, 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, ventricular activation in the looped heart still follows the direction of blood flow. Eventually, the immature base-to-apex sequence of ventricular activation undergoes an apparent reversal, maturing to apex-to-base pattern. The embryonic chick heart has been studied intensively by both electrophysiological and morphological techniques, and the morphology of its conduction system (which is similar to mammals) is well characterized. One interesting but seldom studied feature is the anterior septal branch (ASB), which came sharply to focus (together with the rest of the ventricular conduction system) in our birthdating studies. Using an optical mapping approach, we show that ASB serves to activate ventricular surface between stages 16 and 25, predating the functionality of the His bundle/bundle branches. Heart morphogenesis and conduction system formation are thus linked, and studying the abnormal activation patterns could further our understanding of pathogenesis of congenital heart disease.
Authors:
David Sedmera; Maria Reckova; Michael R Bigelow; Angela Dealmeida; Chiffvon P Stanley; Takashi Mikawa; Robert G Gourdie; Robert P Thompson
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology     Volume:  280     ISSN:  1552-4884     ISO Abbreviation:  -     Publication Date:  2004 Oct 
Date Detail:
Created Date:  2004-10-06     Completed Date:  2005-02-03     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  101234285     Medline TA:  Anat Rec A Discov Mol Cell Evol Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1001-9     Citation Subset:  IM    
Copyright Information:
copyright 2004 Wiley-Liss, Inc.
Affiliation:
Department of Cell Biology and Anatomy, Medical University of South Carolina, 173 Ashley Avenue, BSB 603, Charleston, SC 29425, USA. sedmerad@musc.edu
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MeSH Terms
Descriptor/Qualifier:
Action Potentials*
Animals
Bundle of His / embryology*
Chick Embryo / physiology*
Electric Stimulation
Electrophysiology
Heart Conduction System* / embryology,  physiology
Heart Ventricles* / embryology
Ventricular Function
Grant Support
ID/Acronym/Agency:
HD39946/HD/NICHD NIH HHS; HL50582/HL/NHLBI NIH HHS; HL67150/HL/NHLBI NIH HHS; RR16434/RR/NCRR NIH HHS

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


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