Ischaemia induced development of functional coronary collateral circulation in ponies.
Abstract: The response of coronary collaterals in nine ponies subjected to repeated reversible occlusions (2 min duration, 30 min interval) of the left anterior descending coronary artery was studied at rest. Each pony was instrumented with a Doppler flowmeter and hydraulic cuff occluder around the left anterior descending coronary artery, left ventricular subendocardial sonomicrometers, and a left ventricular micromanometer. Initial occlusions increased end diastolic myocardial segment length by 3% and decreased segment systolic shortening, stroke work, and velocity of shortening by 103%, 95%, and 79% respectively in the left ventricular apex. Left ventricular systolic and end diastolic pressure, peak positive dP/dt, and heart rate were not significantly changed by occlusion. After 421(70) (mean(SEM)) occlusions no sustained alterations in myocardial segment function occurred in response to occlusion. Thus the presence of a subendocardial plexus did not protect against a severe loss of myocardial segment function when the ponies were initially subjected to occlusions of the left anterior descending coronary artery. However, repeated reversible occlusions enhanced coronary collateral blood flow such that it was adequate to maintain left ventricular function in the absence of left anterior descending coronary artery flow. It is concluded that the pony is highly suitable for use in studies of coronary collateral circulation because of its coronary anatomical similarity to man and its capacity to develop functional collateralisation.
Publication Date: 1987-10-01 PubMed ID: 3440265DOI: 10.1093/cvr/21.10.730Google Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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The research article discusses the effects of induced ischemia on the development of functional coronary collateral circulation in ponies. Experimenting with repeated reversible occlusions (blocking/unblocking) of a significant coronary artery, the study found that over time, collateral blood flow improved, compensating for blocked arterial flow.
Methodology
- The study was performed on nine ponies at rest, which underwent repeated reversible occlusions of the left anterior descending coronary artery (lasted for 2 minutes with a 30-minute interval).
- Each pony was equipped with a Doppler flowmeter, a hydraulic cuff occluder (to occlude the artery), left ventricular subendocardial sonomicrometers (for measuring microscopic distances in the heart), and a left ventricular micromanometer (for measuring pressure).
Initial Observations and Effects
- Initial occlusions caused an increase in end diastolic myocardial segment length by 3% and a decrease in segment systolic shortening, stroke work, and velocity of shortening by 103%, 95%, and 79% respectively in the left ventricular apex (tip of the heart).
- Left ventricular systolic and end diastolic pressure, peak positive dP/dt (rate of pressure increase in the heart), and heart rate were not significantly affected by the occlusion.
Findings After Repeated Occlusions
- After performing a mean of 421 occlusions, no sustained alterations in myocardial segment function were observed in response to occlusion.
- Although the presence of a subendocardial plexus (network of tiny blood vessels) did not protect against severe loss of myocardial segment function when first exposed to occlusions, through repeated reversible occlusions, coronary collateral blood flow improved.
- Collateral blood flow compensated enough to maintain left ventricular function despite the absence of blood flow from the left anterior descending coronary artery.
Conclusion
- The study demonstrate that the pony, due to its coronary anatomical similarity to humans and its ability to develop functional collateralisation, is highly suitable for use in studies pertaining to coronary collateral circulation.
Cite This Article
APA
Rugh KS, Garner HE, Hatfield DG, Miramonti JR.
(1987).
Ischaemia induced development of functional coronary collateral circulation in ponies.
Cardiovasc Res, 21(10), 730-736.
https://doi.org/10.1093/cvr/21.10.730 Publication
Researcher Affiliations
- John M Dalton Research Center, University of Missouri, Columbia 65211.
MeSH Terms
- Animals
- Arterial Occlusive Diseases / physiopathology
- Collateral Circulation
- Coronary Circulation
- Coronary Disease / physiopathology
- Disease Models, Animal
- Heart Ventricles / physiopathology
- Hemodynamics
- Horses
Grant Funding
- F32-HL06999 / NHLBI NIH HHS
- R01-HL29007 / NHLBI NIH HHS
- T32-HL07187 / NHLBI NIH HHS
Citations
This article has been cited 2 times.- Ou L, Li W, Liu Y, Zhang Y, Jie S, Kong D, Steinhoff G, Ma N. Animal models of cardiac disease and stem cell therapy. Open Cardiovasc Med J 2010 Nov 26;4:231-9.
- Jiang B, Rugh KS, Hatfield DG, Jiang D, Hahn AW. Nonlinear algorithm for identification of a fiducial marker for various cardiac events. Proc Annu Symp Comput Appl Med Care 1991;:455-9.
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