The Lewis A. Connor Memorial Lecture

Hamilton, W. F.

doi:10.1161/01.cir.8.4.527

Cited by 72 publications

(3 citation statements)

References 50 publications

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“…The idea that the increase in cardiac output with muscular exercise is closely related to vasodilatation in the muscles with a fall in peripheral resistance has been emphasized previously (21,22). It has been suggested that the mechanisms which control arterial blood pressure, such as the carotid sinus reflex, are responsible for the increased cardiac output in the presence of the locally determined decrease in resistance to flow through the muscles.…”

Section: Discussionmentioning

confidence: 99%

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Caldini

Permutt

Waddell

et al. 1974

Circulation Research

186

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The effect of epinephrine on peripheral circulation was studied in ten anesthetized open-chest dogs. Blood flow and right atrial pressure were independently controlled by a right heart bypass; changes in blood volume could be precisely determined from the changes occurring in the bypass reservoir. At constant blood flow and right atrial pressure, a constant infusion of epinephrine (5.8 Mg/kg min" 1 ) decreased blood volume by an average of 208 ml. During epinephrine infusion, the ratio of changes in blood volume to changes in blood flow measured at constant right atrial pressure, (A V/A0)p ra , decreased from 0.226 minutes to 0.153 minutes and the ratio of changes in blood volume to changes in right atrial pressure at constant blood flow, the vascular compliance, decreased from 27.1 ml/cm H 2 O to 20.7 ml/cm H 2 O. Transient changes in blood volume following a step decrease in right atrial pressure at constant blood flow showed that blood was draining from two vascular compartments with different time constants: 0.059 minutes and 0.388 minutes before epinephrine infusion and 0.058 minutes and 0.486 minutes during epinephrine infusion. We analyzed the data using a mathematical model of the peripheral circulation consisting of two compartments with different time constants. The analysis showed that the primary effect of epinephrine on the systemic circulation was to redistribute blood flow away from the compartment with the longest time constant. The reduction in (&VI&Q) Pra and the decrease in blood volume at constant flow and right atrial pressure were essentially determined by the change in flow distribution brought about by a change in arteriolar tone and not by a change in venous tone. KEY WORDS peripheral circulation vascular compliance cardiac output circulatory model venous resistance mean circulatory pressure venous return• For well over a hundred years, it has been recognized that the level of cardiac output is determined not only by the state of the heart but also by the state of the blood vessels (1,2). Grodins (3) has succinctly stated the reason behind this phenomenon: "... mechanical coupling between heart and circuit dictates that cardiac output is a function of both heart and circuit parameters." Guyton (4) has explained this relationship in more detail. The pressure of blood within the right atrium plays a unique role in the coupling between heart and blood vessels. On the one hand, the level of right atrial pressure relative to intrapleural pressure determines the filling pressure of the right ventricle. Therefore, right

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Section: Discussionmentioning

confidence: 99%

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Caldini

Permutt

Waddell

et al. 1974

Circulation Research

186

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“…The base of the curve now becomes the time taken for dye on the first circulation to pass the sampling site. A simple numerical example (Hamilton, 1953) makes the method clear. Suppose that the dose of dye injected is 12 mg., and that the average concentration of dye (average height of dye curve) is 4 mg./litre.…”

Section: Dr Lawson Mcdonald (London)mentioning

confidence: 99%

Discussion on Indicator Dilution Curves in Heart Disease

1959

Proceedings of the Royal Society of Medicine

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“…BACKGROUND The dilution technique of discharge measurement was developed for flow measurement applications not accessible by mechanical meter methods. The indicator dilution technique for discharge measurement existed as early as the turn of the twentieth century (Hamilton, 1953). The dilution technique did not require knowledge of the flow depth, width, or velocity and could be performed rapidly (Hull, 1958).…”

Section: Introductionmentioning

confidence: 99%

CHANNEL DISCHARGE MEASUREMENT BY THERMODILUTION¹

Wittier¹,

Abt²,

Sanders

1987

J American Water Resour Assoc

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An investigation was conducted to determine the feasibility of applying thermodilution technology to discharge measurements in small open channels. A series of tests were performed in which the time‐temperature dilution curves were recorded and analyzed. The independent variables included the channel discharge, the injectate drop height, the volume of tracer, and the mixing distance. Flows ranged from 0.67 cfs to 2.45 cfs with Froude numbers less than 0.30. The results indicated that the thermodilution technique is a feasible method for discharge measurement. It was determined that a heat content, 1°, of 40°C provides a design criteria in which the mixing distance was related to the flow depth and discharge in a rectangular channel. An empirical expression was derived to determine the approximate mixing distance as a function of the flow depth.

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The Lewis A. Connor Memorial Lecture

Cited by 72 publications

References 50 publications

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Discussion on Indicator Dilution Curves in Heart Disease

CHANNEL DISCHARGE MEASUREMENT BY THERMODILUTION¹

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The Lewis A. Connor Memorial Lecture

Cited by 72 publications

References 50 publications

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Effect of Epinephrine on Pressure, Flow, and Volume Relationships in the Systemic Circulation of Dogs

Discussion on Indicator Dilution Curves in Heart Disease

CHANNEL DISCHARGE MEASUREMENT BY THERMODILUTION1

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Product

Resources

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CHANNEL DISCHARGE MEASUREMENT BY THERMODILUTION¹