Myocardial Oxygen Demand
Myocardial Oxygen Demand - Related Videos
12:43
Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption
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Cited by 7 •
2016
Isolated working heart models can be used to measure the effect of loading conditions, heart rate, and medications on myocardial performance and oxygen consumption. We describe methods for preparation of a rodent left heart working model that permits study of systolic and diastolic performance and oxygen consumption under various conditions.
01:26
Demand
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2024
Economists define demand as a consumer's willingness and financial capacity to purchase a product at a specific price point. These factors jointly influence the demand for a product or service. Imagine a college student who needs textbooks for their courses. Their demand for textbooks depends on different factors, such as: Price Changes: Alterations in price directly impact demand. If textbook prices decrease, students may consider purchasing additional textbooks or supplementary materials.
01:28
Degrees of Elasticity of Demand and the Demand Graph
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2024
Demand curves visually represent how consumers respond to changes in prices. The elasticity of demand determines the steepness of the curve, with higher elasticity resulting in a flatter curve and lower elasticity leading to a steeper curve. Perfectly Elastic Demand: Represented by a horizontal line, indicating that any change in price results in an infinite change in quantity demanded. Although this is a theoretical extreme, it signifies a scenario where consumers are extremely sensitive to...
11:45
Piaget's Conservation Task and the Influence of Task Demands
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2023
Source: Laboratories of Judith Danovitch and Nicholaus Noles—University of Louisville Jean Piaget was a pioneer in the field of developmental psychology, and his theory of cognitive development is one of the most well-known psychological theories. At the heart of Piaget’s theory is the idea that children’s ways of thinking change over the course of childhood. Piaget provided evidence for these changes by comparing how children of different ages responded to questions and problems that he...
07:45
Acute Myocardial Infarction in Rats
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Cited by 103 •
2011
The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.
FAQs
Each rise in heart rate, contractility, ventricular pressure, or wall stress increases the energy required for pumping. Faster beating leaves cardiac muscle performing work more often, while stronger contraction and greater pressure generation intensify force production. These changes increase reliance on aerobic metabolism, so oxygen consumption rises as overall cardiac workload increases.
Ventricular volume and arterial pressure affect wall tension, and greater wall tension increases the force the cardiac muscle must generate. Because force production requires energy, these loading conditions can raise oxygen use even without an explicit change in heart rate. Their contribution helps explain why ventricular workload, not heart rate alone, matters pharmacologically.
Ischemic heart disease reflects a mismatch between oxygen available to the myocardium and oxygen required by the working cardiac muscle. When heart rate, contractility, pressure, or wall stress increases, demand can rise and worsen that imbalance. Myocardial oxygen demand therefore provides a framework for explaining why reducing cardiac workload can support a more favorable oxygen balance.
A pharmacologic approach is to identify which demand-related variable is elevated, then select a drug effect that reduces that workload. If heart rate or contractility is prominent, beta-adrenergic blockade is relevant; if ventricular workload is increased by pressure or wall stress, vasodilation may help. This links drug selection to oxygen consumption rather than to drug class alone.
Beta-adrenergic blockers reduce myocardial oxygen demand by lowering heart rate and contractility. Those effects decrease how frequently the myocardium performs work and lessen the force generated during contraction. In pharmacology, this makes the class particularly relevant when treatment is intended to reduce oxygen consumption through direct control of cardiac activity rather than through a general reduction in workload.
Vasodilators address demand through ventricular workload rather than by directly reducing heart rate or contractility. Lowering that workload can reduce the force-related energy requirement of the heart and help rebalance oxygen consumption with oxygen supply. They therefore provide a complementary pharmacologic strategy to beta-adrenergic blockers when the goal is to limit the heart’s overall work.