Journal article
Postmyocardial infarction remodeling and coronary reserve: effects of ivabradine and beta blockade therapy
American journal of physiology. Heart and circulatory physiology, Vol.297(1), pp.H322-330
07/01/2009
DOI: 10.1152/ajpheart.01337.2008
PMID: 19411283
Abstract
We compared the effects of heart rate reduction (HRR) by the hyperpolarization-activated pacemaker current (I...) channel inhibitor ivabradine (MI+Iva) and the β...-blocker atenolol (MI+Aten) on ventricular remodeling and perfusion after myocardial infarction (MI) in middle-aged (12 mo) Sprague-Dawley rats. Mean HRR was virtually identical in the two treated groups (19%). Four weeks after coronary artery ligation, maximal myocardial perfusion fell in the MI group but was preserved in infarcted rats treated with either Iva or Aten. However, coronary reserve in the remodeled hearts was preserved only with Iva, since Aten treatment elevated baseline perfusion in response to a higher wall stress. The higher maximal perfusion noted in the two treated groups was not due to arteriogenesis or angiogenesis. Plasma levels of angiotensin (ANG) II and myocardial ANG type 1 (AT...) receptor and transforming growth factor (TGF)-β1 were reduced during the first week of treatment by both Iva and Aten. Moreover, treatment also reduced arteriolar perivascular collagen density. Despite these similar effects of Iva and Aten on vascularity and ANG II, Iva, but not Aten, attenuated the decline in ejection fraction and lowered left ventricular (LV) end-diastolic volume (LVEDV)-to-LV mass ratio, determined by echocardiography. In conclusion, 1) Iva has advantages over Aten in postinfarction therapy that are not due to differential effects of the drugs on heart rate, and 2) age limits growth factor upregulation, angiogenesis, and arteriogenesis in the postinfarcted heart. (ProQuest: ... denotes formulae/symbols omitted.)
Details
- Title: Subtitle
- Postmyocardial infarction remodeling and coronary reserve: effects of ivabradine and beta blockade therapy
- Creators
- Lance Christensen - University of IowaRon-ling Zhang - University of IowaWei Zheng - University of IowaJoseph Campanelli - University of IowaEduard Dedkov - University of IowaRobert Weiss - University of IowaRobert Tomanek - University of Iowa
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.297(1), pp.H322-330
- DOI
- 10.1152/ajpheart.01337.2008
- PMID
- 19411283
- NLM abbreviation
- Am J Physiol Heart Circ Physiol
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Publisher
- American Physiological Society
- Language
- English
- Date published
- 07/01/2009
- Academic Unit
- Anatomy and Cell Biology; Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984359575802771
Metrics
10 Record Views