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Coronary vascular morphology in pressure-overload left ventricular hypertrophy
S P Bishop1, P C Powell, N Hasebe
1Department of Pathology, University of Alabama at Birmingham 35294, USA.
Journal of Molecular and Cellular Cardiology
|January 1, 1996
Summary
Chronic pressure-overload cardiac hypertrophy in dogs leads to reduced subendocardial coronary reserve. Morphological changes in coronary vessels do not fully explain this loss, suggesting regional functional differences may be involved.
Area of Science:
- Cardiovascular Physiology
- Cardiac Hypertrophy
- Coronary Circulation
Background:
- Chronic pressure-overload leads to left ventricular hypertrophy (LVH).
- Subendocardial coronary reserve is often diminished in LVH.
- The morphologic basis for this loss is not fully understood.
Purpose of the Study:
- To investigate the morphologic basis for the loss of subendocardial coronary reserve in chronic pressure-overload cardiac hypertrophy.
- To measure capillary capacity and coronary artery/arteriole medial wall area in dogs with LVH.
Main Methods:
- Induction of LVH in puppies via aortic banding.
- Hemodynamic assessment and perfusion fixation of hearts 8-16 months post-banding.
- Image analysis of capillary density, arteriolar density, and medial wall area in different LV regions.
Main Results:
- LVH dogs showed a 72% greater LV mass/body weight ratio compared to controls.
- Subendocardial coronary reserve decreased significantly in LVH dogs (endo/epi flow ratio: 0.34 vs 0.68).
- Capillary and arteriolar density changes were minimal, with no significant transmural differences, suggesting angiogenesis and increased resistance vessel length.
Conclusions:
- Morphologic alterations in coronary vessels do not appear to be the primary cause for the loss of subendocardial coronary reserve in chronic LVH.
- Regional functional differences, potentially arising from morphologic changes, cannot be excluded as a contributing factor.