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

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.

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Effects of Inositol Hexaphosphate Induced High P50 on an Isolated Rabbit Heart with Free and Limited Coranary Blood Flow

Biomaterials Artificial Cells and Artificial Organs ◽

10.3109/10731198809132586 ◽

1988 ◽

Vol 16 (1-3) ◽

pp. 359-361 ◽

Cited By ~ 1

Author(s):

J. F. Baron ◽

E. Vicaut ◽

O. Stucker ◽

M. C. Villereal ◽

C. Ropers ◽

...

Keyword(s):

Blood Flow ◽

Rabbit Heart ◽

Inositol Hexaphosphate ◽

Isolated Rabbit Heart

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Myocardial Blood Flow and Oxygen Consumption After Aortic Cross-Clamping

Survey of Anesthesiology ◽

10.1097/00132586-199008000-00001 ◽

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

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

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1990.258.4.h1208 ◽

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.

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