Myocardial Blood Flow and Oxygen Consumption during Moderate Cardiac Tamponade: Role of Reflex Vasoconstriction

1979 ◽  
Vol 160 (1) ◽  
pp. 65-68 ◽  
Author(s):  
G. J. Crystal ◽  
F. A. Bashour ◽  
H. F. Downey ◽  
P. E. Parker
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow ◽  
Cardiac Tamponade

EFFECTS OF HYPEROXEMIA ON MYOCARDIAL BLOOD FLOW AND OXYGEN CONSUMPTION IN AN ISOLATED RABBIT HEART

1988 ◽  
Vol 69 (3A) ◽  
pp. A216-A216 ◽  
Author(s):  
J. F. Baron ◽  
E. Vicaut ◽  
X. HOU ◽  
P. Vlars ◽  
M. Duvelleroy
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow ◽  
Rabbit Heart ◽  
Isolated Rabbit Heart

Alteration in myocardial oxygen balance during exercise after beta-adrenergic blockade in dogs

1980 ◽  
Vol 49 (1) ◽  
pp. 28-33 ◽  
Author(s):  
G. R. Heyndrickx ◽  
J. L. Pannier ◽  
P. Muylaert ◽  
C. Mabilde ◽  
I. Leusen
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Sinus ◽  
Myocardial Oxygen Consumption ◽  
Left Ventricular ◽  
Adrenergic Blockade ◽  
Oxygen Balance

The effects of beta-adrenergic blockade upon myocardial blood flow and oxygen balance during exercise were evaluated in eight conscious dogs, instrumented for chronic measurements of coronary blood flow, left ventricular pressure, aortic blood pressure, heart rate, and sampling of arterial and coronary sinus venous blood. The administration of propranolol (1.5 mg/kg iv) produced a decrease in heart rate, peak left ventricular (LV) dP/dt, LV (dP/dt/P, and an increase in LV end-diastolic pressure during exercise. Mean coronary blood flow and myocardial oxygen consumption were lower after propranolol than at the same exercise intensity in control conditions. The oxygen delivery-to-oxygen consumption ratio and the coronary sinus oxygen content were also significantly lower. It is concluded that the relationship between myocardial oxygen supply and demand is modified during exercise after propranolol, so that a given level of myocardial oxygen consumption is achieved with a proportionally lower myocardial blood flow and a higher oxygen extraction.

Myocardial Blood Flow and Oxygen Consumption After Aortic Cross-Clamping

1990 ◽  
Vol 34 (4) ◽  
pp. 201
Author(s):  
F. VAN DER VEEN ◽  
G. VAN DER VUSSE ◽  
R. RENEMAN
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow

Role of adenosine in postprandial and reactive hyperemia in canine jejunum

1992 ◽  
Vol 263 (4) ◽  
pp. G487-G493 ◽  
Author(s):  
D. R. Sawmiller ◽  
C. C. Chou
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Adenosine Deaminase ◽  
Reactive Hyperemia ◽  
Concentration Difference ◽  
Adenosine Concentration ◽  
Anesthetized Dogs ◽  
Series Of Experiments ◽  
Increased Blood Flow

The role of adenosine in postprandial jejunal hyperemia was investigated by determining the effect of placement of predigested food into the jejunal lumen on blood flow and oxygen consumption before and during intra-arterial infusion of dipyridamole (1.5 microM arterial concn) or adenosine deaminase (9 U/ml arterial concn) in anesthetized dogs. Neither drug significantly altered resting jejunal blood flow and oxygen consumption. Before dipyridamole or deaminase, food placement increased blood flow by 30-36%, 26-42%, and 21-46%, and oxygen consumption by 13-22%, 21-22%, and 26-29%, during 0- to 3-, 4- to 7-, and 8- to 11-min placement periods, respectively. Adenosine deaminase abolished the entire 11-min hyperemia, whereas dipyridamole significantly enhanced the initial 7-min hyperemia (45-49%). Both drugs abolished the initial 7-min food-induced increase in oxygen consumption. Dipyridamole attenuated (14%), whereas deaminase did not alter (28%), the increased oxygen consumption that occurred at 8-11 min. Adenosine deaminase also prevented the food-induced increase in venoarterial adenosine concentration difference. In separate series of experiments, luminal placement of food significantly increased jejunal lymphatic adenosine concentration and release. Also, reactive hyperemia was accompanied by an increase in venous adenosine concentration and release. This study provides further evidence to support the thesis that adenosine plays a role in postprandial and reactive hyperemia in the canine jejunum.

LV pressure-volume area and oxygen consumption: evaluation in intact dog by fast CT

1990 ◽  
Vol 258 (4) ◽  
pp. H1208-H1215
Author(s):  
N. Chung ◽  
X. Wu ◽  
K. R. Bailey ◽  
E. L. Ritman
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow ◽  
Myocardial Oxygen Consumption ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Adrenergic Blockade ◽  
Ct Scanner ◽  
Beta Adrenergic ◽  
The Relationship

The relationship between left ventricular (LV) myocardial oxygen consumption (MVO2) and LV systolic pressure-volume area (PVA) was investigated in anesthetized closed-chest dogs with intact reflexes and subsequently with beta-adrenergic blockade, with or without simultaneous muscarinic blockade. LV chamber volumes were measured using a fast computerized tomography (CT) scanner (dynamic spatial reconstructor, DSR) at 33-ms intervals. Myocardial blood flow was measured from the DSR scans of aortic root angiograms. With intact reflexes, LV MVO2 (Y) related to PVA (X) values as Y = (4.28 +/- 1.81)X + (1.94 +/- 6.0) (n = 24) (mJ.g-1.cycle-1). With beta-adrenergic blockade, LV MVO2 (Y) related to PVA (X) value as Y = (4.24 +/- 1.03)X - (6.43 +/- 6.5), (n = 9) (mJ.g-1.cycle-1). With beta-adrenergic and muscarinic blockade, LV MVO2 (Y) related to PVA (X) value as Y = (2.84 +/- 1.72)X + (3.51 +/- 5.15), (n = 13) (mJ.g-1.cycle-1). The slopes of these regressions are higher than the slopes demonstrated by others in isolated ventricles but very similar to those demonstrated in open-chest dogs.

scholarly journals The role of acquisition and quantification methods in myocardial blood flow estimability for myocardial perfusion imaging CT

2018 ◽  
Vol 63 (18) ◽  
pp. 185011 ◽  
Author(s):  
Brendan L Eck ◽  
Raymond F Muzic ◽  
Jacob Levi ◽  
Hao Wu ◽  
Rachid Fahmi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Perfusion Imaging ◽  
Myocardial Perfusion ◽  
Myocardial Blood Flow ◽  
Perfusion Imaging

Effects of cardiac tamponade on colonic hemodynamics and oxygen uptake

1983 ◽  
Vol 244 (6) ◽  
pp. G604-G612 ◽  
Author(s):  
G. B. Bulkley ◽  
P. R. Kvietys ◽  
M. A. Perry ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Cardiac Tamponade ◽  
Arterial Occlusion ◽  
Systemic Resistance ◽  
Fundamental Relation ◽  
Nonocclusive Mesenteric Ischemia ◽  
Blood Flows ◽  
Colonic Blood Flow ◽  
Pericardial Pressure

The local hemodynamic response of the innervated but vascularly isolated colon to decreased systemic perfusion induced by cardiac tamponade was studied in anesthesized dogs as a model of nonocclusive mesenteric ischemia. Increasing levels of pericardial pressure caused progressive decreases in colonic blood flow associated with substantial increases in colonic vascular resistance. These increases in local colonic resistance were proportionately larger than concurrent increases in systemic resistance. The disproportionate response of the colonic resistance vessels was not diminished by colonic (sympathetic) denervation. Reductions of blood flow to 30 ml . min-1 . 100 g-1 resulted in compensatory increases in colonic oxygen extraction such that colonic oxygen consumption remained constant (flow independent) at about 1.5 ml . min-1 . 100 g-1. At blood flows below 30 ml . min-1 . 100 g-1 colonic oxygen consumption was markedly dependent on blood flow. This fundamental relation of colonic oxygen consumption to blood flow was the same whether ischemia was induced by cardiac tamponade, partial mechanical arterial occlusion, or vasoconstrictor (norepinephrine or digoxin) infusion. Furthermore, this relationship was not altered by vasodilation with isoproterenol after the induction of ischemia by any of the above means.

Heat loss from feet of herring gulls at rest and during flight

1976 ◽  
Vol 230 (4) ◽  
pp. 920-924 ◽  
Author(s):  
RV Baudinette ◽  
JP Loveridge ◽  
KJ Wilson ◽  
CD Mills ◽  
K Schmidt-Nielsen
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Wind Tunnel ◽  
Heat Loss ◽  
Heat Production ◽  
Heat Dissipation ◽  
Larus Argentatus ◽  
Herring Gull ◽  
Herring Gulls

The role of the feet of herring gulls (Larus argentatus) in heat dissipation was estimated during rest and wind-tunnel flight. We determined the blood flow to the feet and the arteriovenous temperature difference and thus estimated heat loss from the feet. Determinations of oxygen consumption and respiratory water loss at rest gave a heat production of about 8 W; 37-56% of this heat was lost from the feet (air temp = 10-35 degrees C). During flight heat production was estimated to be about 57 W and heat loss from the feet was 46 W, about 80% of the heat production in flight. Thus the webbed feet are an important avenue of heat loss in the herring gull.

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