Document Detail

Self-terminating AF depends on electrical remodeling while persistent AF depends on additional structural changes in a rapid atrially paced sheep model.
MedLine Citation:
PMID:  17597147     Owner:  NLM     Status:  MEDLINE    
The development of atrial fibrillation (AF) is associated with electrical and structural remodeling. The aim of this study was to assess the contribution of electrical and structural remodeling to the development of AF in a rapid atrially paced ovine model with and without His bundle ablation and to determine the role of the angiotensin pathway and matrix metalloproteinases in this process. Thirty-five sheep were rapidly paced in the atrium and were randomized to undergo His bundle ablation (HBA) (21 sheep; HBA sheep) or not (14 sheep; non-HBA sheep). After HBA the ventricles were paced at 80 bpm. Both groups were subdivided to receive active treatment (quinapril+losartan) or placebo. Sheep were followed for 15 weeks. Inducible AF was defined as a rapid irregular atrial rhythm lasting >1 min. Inducible AF was considered to be persistent if during further follow-up no sinus rhythm (SR) was documented anymore. The inducibility of AF with atrial tachypacing was not different between the 4 groups. On the other hand, non-HBA sheep developed persistent AF significantly earlier than HBA sheep (p=0.028). They had elevated ventricular rates, diminished atrial MMP-2, increased TIMP-2 expression, and more extensive atrial fibrosis. Active treatment in these sheep significantly lowered AT-II (p=0.018), prevented atrial fibrogenesis (p<0.001) and slowed the development of persistent AF (p=0.049). Electrical remodeling is sufficient to induce AF, while structural changes are needed for persistent AF. Fibrosis development in our model is the result of an increased expression of AT-II in combination with changes in MMP expression. Inhibition of the angiotensin pathway suppresses atrial fibrosis and the development of persistent AF.
Wim Anné; Rik Willems; Patricia Holemans; Frank Beckers; Tania Roskams; Ilse Lenaerts; Hugo Ector; Hein Heidbüchel
Related Documents :
25154677 - Comparison of starting ovarian stimulation on day 2 versus day 15 of the menstrual cyc...
1511097 - Effect of 48-hour infusion of the synthetic oxytocin antagonist, [1-beta-mercapto(beta-...
25324327 - Evaluation of health in pregnancy grants in scotland: a protocol for a natural experiment.
736137 - Bidirectional sodium fluxes across the placenta of conscious sheep.
16669917 - Oligozoospermia: recent prognosis and the outcome of 73 pregnancies in oligozoospermic ...
9886547 - External validation of prognostic models for ongoing pregnancy after in-vitro fertiliza...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-05-21
Journal Detail:
Title:  Journal of molecular and cellular cardiology     Volume:  43     ISSN:  0022-2828     ISO Abbreviation:  J. Mol. Cell. Cardiol.     Publication Date:  2007 Aug 
Date Detail:
Created Date:  2007-07-23     Completed Date:  2007-09-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0262322     Medline TA:  J Mol Cell Cardiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  148-58     Citation Subset:  IM    
Department of Cardiology, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Angiotensin II / metabolism
Atrial Fibrillation / physiopathology*
Bundle of His / pathology
Cardiac Output
Cardiac Pacing, Artificial*
Disease Models, Animal*
Kaplan-Meiers Estimate
Matrix Metalloproteinases / metabolism
Myocytes, Cardiac / enzymology,  pathology
Refractory Period, Electrophysiological
Renin-Angiotensin System
Time Factors
Tissue Inhibitor of Metalloproteinases / metabolism
Reg. No./Substance:
0/Tissue Inhibitor of Metalloproteinases; 11128-99-7/Angiotensin II; EC 3.4.24.-/Matrix Metalloproteinases

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

Previous Document:  Cardiac repolarization is prolonged in CD4C/HIV transgenic mice.
Next Document:  Hypoxia/reoxygenation of isolated rat heart mitochondria causes cytochrome c release and oxidative s...