- Title
- Factors regulating coronary blood flow in the normal and diseased heart
- Creator
- White, Saxon William; Reid, John V. O.
- Relation
- Medical Journal of Australia Vol. 2, Issue 23, p. 1054-1060
- Publisher
- Australasian Medical Publishing Company
- Resource Type
- journal article
- Date
- 1973
- Description
- Phasic changes in intramyocardial tension during the cardiac cycle interrupt coronary blood flow (CBF) so that most of the nutrient flow to the ventricular myocardium occurs in ventricular diastole. Rapid changes in mean arterial pressure cause transient changes in CBF before autoregulatory factors return flow toward previous levels. Myocardial oxygen consumption (MVo2) appears to be the major determinant of CBF and the factors determining MVo2 (mainly developed tension and contractile state) are, therefore, major determinants of CBF. The direct effects of autonomic excitation on CBF appear relatively minor, however; the vagus, sympathetic nerves and adrenal medullary hormones profoundly alter CBF indirectly through changes in MVo2. In the eschaemic heart with atheromatous occlusion of large vessels there is a reduced capacity for autoregulation, and nutrient flow is more dependent on pressure gradient. Hypertension and valvular disorders are often associated with raised MVo2 but associated abnormalities in pressure gradient and resistance to flow often hinder the supply of CBF needed to meet high demands.
- Subject
- coronary blood flow; CBF; coronary heart disease; CHD
- Identifier
- http://hdl.handle.net/1959.13/938943
- Identifier
- uon:12705
- Identifier
- ISSN:0025-729X
- Language
- eng
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