Role of autonomics in the initiation of electromechanical dissociation

1981 ◽  
Vol 241 (3) ◽  
pp. R213-R216
Author(s):  
D. R. Kostreva ◽  
A. Castaner ◽  
J. P. Kampine
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiac Tamponade ◽  
Early Onset ◽  
Increase Heart Rate ◽  
Apparent Effect ◽  
Cardiac Work ◽  
Double Product ◽  
Bilateral Vagotomy

The onset of electromechanical dissociation during acute cardiac tamponade in mongrel dogs is significantly prolonged by either surgical or pharmacologic sympathectomy. Bilateral vagotomy does not have any apparent effect on the initiation of electromechanical dissociation. Pretreatment with isoproterenol just prior to tamponade does not significantly increase heart rate or the double product. Cardiopulmonary sympathetic efferent stimulation significantly decreases the time to the onset of electromechanical dissociation by increasing the heart rate and double product. The early onset of electromechanical dissociation appears to be related to cardiac work and oxygen consumption.

Effect of heart rate on the relation between global and regional cardiac work and oxygen consumption

1988 ◽  
Vol 20 (2) ◽  
pp. III-III
Author(s):  
M SCHEINOWITZ ◽  
J SONN ◽  
J KEDEM ◽  
H WEISS
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiac Work

Physiological variability in neonatal armadillo quadruplets: within- and between-litter differences

2000 ◽  
Vol 203 (11) ◽  
pp. 1733-1740 ◽  
Author(s):  
B. Bagatto ◽  
D.A. Crossley ◽  
W.W. Burggren
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Ventilation Rate ◽  
Dasypus Novemcinctus ◽  
Genetic Components ◽  
Physiological Variability ◽  
In Captivity ◽  
Flow Through ◽  
Physiological Characters

The role of genetics on neonatal physiological variability was examined in the nine-banded armadillo (Dasypus novemcinctus). Since armadillos give birth to only monozygous quadruplets, the genetic variation within litters is essentially zero. Quadruplets born in captivity were isolated and weighed within 8 h of birth. Oxygen consumption (V.(O2)) was measured in resting neonates by flow-through respirometry, heart rate obtained from an electrocardiogram and ventilation was measured by impedance techniques. Following the measurements, neonates were returned to the mother. Measurements were repeated at 4 and 8 days after birth. Mean heart rate significantly increased from 132 beats min(−1) on the day of birth to 169 beats min(−1) on day 8. Mean ventilation rate significantly decreased from 81 breaths min(−1) on the day of birth to 54 breaths min(−1) on day 8. During this same developmental period, mean mass significantly increased from 100 g to 129 g, and mean mass-specific oxygen consumption significantly decreased from 32.2 ml O(2)kg(−1)min(−1) to 28.6 ml O(2)kg(−1) min(−1). For all variables measured, within-litter variability was always significantly less than between-litter variability, confirming a ‘sibling effect’ that we attribute to the genetic components determining physiological characters.

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

scholarly journals 582 THE ROLE OF HYPERVOLEMIA AND STROKE VOLUME IN THE HEART RATE AND OXYGEN CONSUMPTION RELATIONSHIP FOLLOWING INTENSE TRAINING

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S104
Author(s):  
R. S. Richardson ◽  
D. Verestraete ◽  
A. Hochstein ◽  
W. Schultz ◽  
S. C. Johnson ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Intense Training

Neuropeptide Y and coronary vasoconstriction: role of thromboxane A2

1992 ◽  
Vol 263 (4) ◽  
pp. H1045-H1053
Author(s):  
S. E. Martin ◽  
J. T. Kuvin ◽  
S. Offenbacher ◽  
B. M. Odle ◽  
R. E. Patterson
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Neuropeptide Y ◽  
Coronary Blood Flow ◽  
Myocardial Oxygen Consumption ◽  
Thromboxane A2 ◽  
Coronary Resistance ◽  
Txa2 Receptor

We previously reported that coronary constriction following neuropeptide Y (NPY) was alleviated by cyclooxygenase blockade. To determine the role of thromboxane A2 (TxA2), anesthetized dogs received two paired doses of NPY given 2 h apart. Nine control dogs received NPY alone. Nine test dogs received one of three TxA2 receptor antagonists given between the doses of NPY. Also, five dogs received NPY during which prostaglandins were measured. In controls, NPY decreased coronary blood flow and increased aortic pressure; coronary resistance was increased significantly. Heart rate fell, and myocardial oxygen consumption was unchanged. Thromboxane receptor blockers significantly relieved the coronary constrictor effect of NPY. The reduction in coronary blood flow was blunted, while heart rate, first derivative of left ventricular pressure, and myocardial oxygen consumption were unchanged. Alleviation by TxA2 receptor blockade paralleled that reported for cyclooxygenase inhibitors. Also, significant increases in coronary venous TxA2 were seen at the time of maximal increases in coronary resistance, while prostacyclin was unchanged. In summary, TxA2 appears to mediate part of the coronary constrictor effect of NPY.

Effect of Heart Rate on Cardiac Work, Myocardial Oxygen Consumption and Coronary Blood Flow in the Dog

1958 ◽  
Vol 42 (2) ◽  
pp. 185-198 ◽  
Author(s):  
ERIK BERGLUND ◽  
HANS G. BORST ◽  
FRANK DUFF ◽  
GÜNTHER L. SCHREINER
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Coronary Blood Flow ◽  
Myocardial Oxygen Consumption ◽  
Cardiac Work

Bainbridge reflex in conscious, unrestrained, and tranquilized baboons

1981 ◽  
Vol 240 (2) ◽  
pp. H164-H167 ◽  
Author(s):  
S. F. Vatner ◽  
M. Zimpfer
Keyword(s):  
Heart Rate ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Increase Heart Rate ◽  
Cardiac Rate ◽  
Volume Loading ◽  
Heart Rates ◽  
Cholinergic Blockade ◽  
Bilateral Vagotomy

The effects of volume loading were examined in conscious, unrestrained, and tranquilized baboons (20-25 kg) 1-3 mo after instrumentation with miniature left ventricular pressure and diameter gauges. The response to volume loading was accompanied by significant increases (P less than 0.01) in cardiac rate (32 +/- 4 beats/min) in tranquilized baboons. When rapid saline infusion was accomplished in conscious unrestrained baboons by means of activating a remote-controlled interrogator, heart rate also rose significantly (41 +/- 8 beats/min, P less than 0.01). After cholinergic blockade with atropine, ganglionic blockade with hexamethonium, bilateral vagotomy, or combined cholinergic and beta-adrenergic blockades, volume loading failed to increase heart rate. In two smaller (12-14 kg) intact conscious baboons with relatively high spontaneous heart rates, volume loading did not alter heart rate. These experiments suggest that the Bainbridge reflex exists in larger primates with relatively low spontaneous heart rates.

Role of the Thyroid in Metabolic Response to Low Temperature

1956 ◽  
Vol 188 (1) ◽  
pp. 40-44 ◽  
Author(s):  
A. C. L. Hsieh ◽  
L. D. Carlson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Low Temperature ◽  
Metabolic Response ◽  
Muscular Activity ◽  
Half Time ◽  
High Metabolic Rate ◽  
Cold Adapted ◽  
Exposure To Cold

Cold-adapted rats, kept at 5°C, and warm-adapted rats, kept at 28°C, were curarized and oxygen consumption; heart rate; muscular activity; rectal, foot and room temperatures recorded during a period at 30°C and during exposure to cold. The experiments were performed before and at varying intervals after thyroidectomy. Oxygen consumption measured at 30°C reached a minimum 8 days after thyroidectomy in the rats kept at 5°C and 12 days after thyroidectomy in the rats kept at 28°C. The half-time for the decline was twice as long for the rats kept at 28°C, indicating that thyroxin stores were being utilized twice as fast by the rats kept at 5°C. Upon exposure to cold the rats responded by an increase in oxygen consumption. Since the response persisted after thyroxin stores had been depleted it is concluded that the metabolic response to cold is not directly dependent upon the amount of circulating thyroxin. Rats kept at 5°C reduced their food intake and lost weight following thyroidectomy, but maintained a high metabolic rate. The significance of these findings are discussed.

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