Effect of Increasing Heart Rate by Atrial Pacing on Myocardial Tissue Oxygen Tension

1973 ◽  
pp. 553-559 ◽  
Author(s):  
Harvey R. Weiss
Keyword(s):  
Heart Rate ◽  
Oxygen Tension ◽  
Tissue Oxygen Tension ◽  
Myocardial Tissue ◽  
Atrial Pacing ◽  
Tissue Oxygen

scholarly journals Metoprolol Reduces Cerebral Tissue Oxygen Tension after Acute Hemodilution in Rats

2009 ◽  
Vol 111 (5) ◽  
pp. 988-1000 ◽  
Author(s):  
Tenille E. Ragoonanan ◽  
W Scott Beattie ◽  
C David Mazer ◽  
Albert K.Y. Tsui ◽  
Howard Leong-Poi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Oxygen Tension ◽  
Tissue Oxygen Tension ◽  
Beta Blockade ◽  
Tissue Oxygen ◽  
Cerebral Tissue ◽  
Protein Levels

Background Perioperative beta-blockade and anemia are independent predictors of increased stroke and mortality by undefined mechanisms. This study investigated the effect of beta-blockade on cerebral tissue oxygen delivery in an experimental model of blood loss and fluid resuscitation (hemodilution). Methods Anesthetized rats were treated with metoprolol (3 mg x kg) or saline before undergoing hemodilution with pentastarch (1:1 blood volume exchange, 30 ml x kg). Outcomes included cardiac output, cerebral blood flow, and brain (PBrO2) and kidney (PKO2) tissue oxygen tension. Hypoxia inducible factor-1alpha (HIF-1alpha) protein levels were assessed by Western blot. Systemic catecholamines, erythropoietin, and angiotensin II levels were measured. Results Hemodilution increased heart rate, stroke volume, cardiac output (60%), and cerebral blood flow (50%), thereby maintaining PBrO2 despite an approximately 50% reduction in blood oxygen content (P < 0.05 for all). By contrast, PKO2 decreased (50%) under the same conditions (P < 0.05). Beta-blockade reduced baseline heart rate (20%) and abolished the compensatory increase in cardiac output after hemodilution (P < 0.05). This attenuated the cerebral blood flow response and reduced PBrO2 (50%), without further decreasing PKO2. Cerebral HIF-1alpha protein levels were increased in beta-blocked hemodiluted rats relative to hemodiluted controls (P < 0.05). Systemic catecholamine and erythropoietin levels increased comparably after hemodilution in both groups, whereas angiotensin II levels increased only after beta-blockade and hemodilution. Conclusions Cerebral tissue oxygen tension is preferentially maintained during hemodilution, relative to the kidney, despite elevated systemic catecholamines. Acute beta-blockade impaired the compensatory cardiac output response to hemodilution, resulting in a reduction in cerebral tissue oxygen tension and increased expression of HIF-1alpha.

FETAL SCALP TISSUE OXYGEN TENSION MEASUREMENTS IN RELATION TO MATERNAL DERMAL OXYGEN TENSION AND FETAL HEART RATE

1971 ◽  
Vol 78 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Adrian Walker ◽  
Lynne Maddern ◽  
Evan Day ◽  
Peter Renou ◽  
James Talbot ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Tension ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Tissue Oxygen Tension ◽  
Tissue Oxygen ◽  
Fetal Scalp

A549 EFFECT OF CARBON DIOXIDE (HYPOCAPNIA AND HYPEPXAPNIA) ON REGIONAL MYOCARDIAL TISSUE OXYGEN TENSION IN DOGES WITH CORONARY STENOSIS

1990 ◽  
Vol 73 (3A) ◽  
pp. NA-NA
Author(s):  
K. Okazaki ◽  
K. Hashimoto ◽  
Y. Okutsu ◽  
F. Okumura ◽  
A. F. Fukunaga
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Tension ◽  
Coronary Stenosis ◽  
Tissue Oxygen Tension ◽  
Myocardial Tissue ◽  
Tissue Oxygen

EFFECT OF CARBON DIOXIDE (HYPOCAPNIA AND HYPERCAPNIA) ON REGIONAL MYOCARDIAL TISSUE OXYGEN TENSION IN THE DOG

1989 ◽  
Vol 71 (Supplement) ◽  
pp. A486
Author(s):  
K. Okazaki ◽  
K. Hashimoto ◽  
Y. Okutsu ◽  
A. F. Fukunaga
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Tension ◽  
Tissue Oxygen Tension ◽  
Myocardial Tissue ◽  
Tissue Oxygen
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