Skip Navigation


Europace Advance Access originally published online on May 15, 2007
Europace 2007 9(6):411-416; doi:10.1093/europace/eum065
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
9/6/411    most recent
eum065v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Gizurarson, S.
Right arrow Articles by Omerovic, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gizurarson, S.
Right arrow Articles by Omerovic, E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The European Society of Cardiology 2007. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

COMPLETE HEART BLOCK

Effects of complete heart block on myocardial function, morphology, and energy metabolism in the rat

S. Gizurarson, M. Lorentzon, T. Råmunddal, F. Waagstein, L. Bergfeldt and E. Omerovic*

Department of Cardiology and Wallenberg Laboratory at Sahlgrenska Academy, Bruna stråket 16, 413 45 Gothenburg, Sweden

Aims Severe sustained bradycardia may cause acute and possibly chronic congestive heart failure (CHF). The aim of this study was to investigate acute and chronic effects of complete heart block (CHB) on cardiac function, morphology, and creatine (Cr) metabolism.

Methods and results CHB was induced in male Sprague–Dawley rats (~250 g, n = 11) by means of electrocautery applied to the region of AV node and were compared with controls (n = 15). The rats were investigated at 1, 3, and 12 weeks after CHB induction with transthoracic echocardiography. Invasive haemodynamic assessment of left and right ventricular pressures was performed at 12 weeks. After the sacrifice, the hearts were freeze-clamped for analysis of myocardial Cr, and high energy phosphometabolites. The efficacy of operative procedure was 54%. The peri-operative mortality rate was 20%. Heart rate (HR) decreased by ~50% (P < 0.01) while stroke volume (SV) increased 2.5 times (P < 0.01) in the CHB rats. Cardiac index remained unchanged. The rats with CHB grew normally and were in no apparent distress. Filling pressures in left and right ventricles were normal. The CHB rats developed marked cardiomegaly with biventricular dilatation and eccentric left ventricular hypertrophy (P < 0.01). There was no change in the myocardial content of Cr and high energy phosphometabolites.

Conclusion Rats with CHB are compensating for reduction in HR with increased SV without haemodynamic and biochemical characteristics of CHF. This model may be useful to study the effects of CHB and bradycardia on myocardial structure, function, electrophysiology, and metabolism as well as for studies of cell therapy for reparation of AV conductance.

Key Words: Complete heart block, Cardiac remodelling, Small-animal model, Echocardiography, Energy metabolism

* Corresponding author. Tel: +46 31 342 7560.E-mail address: elmir{at}wlab.gu.se

M. Lorentzon and T. Råmunddal have made equal contribution.

Manuscript submitted 11 May 2006. Accepted after revision 16 March 2007.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.