Cardiac output and oxygen consumption in exercising Thoroughbred horses

1987 ◽  
Vol 253 (6) ◽  
pp. R890-R895 ◽  
Author(s):  
J. M. Weber ◽  
G. P. Dobson ◽  
W. S. Parkhouse ◽  
D. Wheeldon ◽  
J. C. Harman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Maximal Exercise ◽  
Treadmill Exercise ◽  
Aerobic Scope ◽  
O2 Uptake ◽  
Thoroughbred Racehorses ◽  
Thoroughbred Horses ◽  
Mean Heart Rate

This study characterizes the effects of exercise on the cardiac output (Q) and the metabolic rate (VO2) of trained Thoroughbred racehorses. Heart rate, Q, and arteriovenous (a-v)O2 difference were measured at rest and at three levels of submaximal treadmill exercise (1.6 m/s walk and 3-4 m/s trot at 6% incline, and 6.5 m/s horizontal canter). Heart rate and (a-v)O2 difference were also measured during maximal exercise (12.5 m/s gallop, 5% incline) to obtain an estimate of maximum O2 uptake (VO2max). The walk, trot, and canter represented 25, 45, and 55% VO2max. Mean heart rate went from 48.9 (rest) to 197 beats/min (gallop). Q ranged from 106 (rest) to 571 ml.min-1.kg-1 (canter), and stroke volume went from 1.34 (rest) to a maximum of 1.58 liters (walk). Thoroughbreds were able to bring hematocrit from 38 (rest) to 63% (gallop), and this adjustment allowed them to reach an impressive (a-v)O2 difference of 23 vol%, which represents a fivefold increase over resting values. These outstanding athletes probably support an aerobic scope of 40-fold.

Effect of long-term anemia and retransfusion on central circulation during exercise

1986 ◽  
Vol 61 (4) ◽  
pp. 1358-1362 ◽  
Author(s):  
F. Celsing ◽  
J. Nystrom ◽  
P. Pihlstedt ◽  
B. Werner ◽  
B. Ekblom
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Maximal Exercise ◽  
Hemoglobin Concentration ◽  
Close Correlation ◽  
O2 Uptake ◽  
Exercise Tests ◽  
O2 Extraction ◽  
Male Subjects

The purpose of this study was to evaluate the effect of long-term anemia and subsequent retransfusion of erythrocytes on various circulatory parameters. Anemia was induced in nine healthy male subjects by repeated venesections. The stored blood was retransfused after 9 wk (range 8–11 wk). Exercise tests were performed before venesection in the control state (C), in the anemic state (A), and 48 h after retransfusion (R). Hemoglobin concentration levels were 146 +/- 10 g/l in C, 110 +/- 7 g/l in A, and 145 +/- 9 g/l in R. Maximal O2 uptake was 4.55 +/- 0.6, 3.74 +/- 0.7, and 4.45 +/- 0.6 l/min in C, A, and R, respectively. A decrease in heart rate of 7 beats/min (P less than 0.01) and in cardiac output of 2 l/min (P less than 0.05) at maximal exercise occurred in the anemic state compared with control values. These decreases were not reversed but, rather, were further accentuated after retransfusion. The adaptive response to submaximal exercise (cycling at 150–175 W) in anemia was mediated to the amount of 50% by an increase in cardiac output (mainly an increase in heart rate) and 50% was due to increased O2 extraction in the peripheral tissue. In conclusion, long-term anemia was found to decrease the heart rate and cardiac output at maximal exercise. Furthermore the close correlation between hemoglobin concentration and maximal O2 uptake in humans is confirmed.

Cardiovascular response to cycle exercise during and after pregnancy

1989 ◽  
Vol 66 (1) ◽  
pp. 336-341 ◽  
Author(s):  
S. P. Sady ◽  
M. W. Carpenter ◽  
P. D. Thompson ◽  
M. A. Sady ◽  
B. Haydon ◽  
...  
Keyword(s):  
Heart Rate ◽  
Maximal Exercise ◽  
Cardiovascular Response ◽  
Work Load ◽  
Cycle Ergometry ◽  
Maximal Heart Rate ◽  
O2 Uptake ◽  
Cycle Exercise ◽  
Vascular Beds ◽  
Response To Exercise

Our purpose was to determine if pregnancy alters the cardiovascular response to exercise. Thirty-nine women [29 +/- 4 (SD) yr], performed submaximal and maximal exercise cycle ergometry during pregnancy (antepartum, AP, 26 +/- 3 wk of gestation) and postpartum (PP, 8 +/- 2 wk). Neither maximal O2 uptake (VO2max) nor maximal heart rate (HR) was different AP and PP (VO2 = 1.91 +/- 0.32 and 1.83 +/- 0.31 l/min; HR = 182 +/- 8 and 184 +/- 7 beats/min, P greater than 0.05 for both). Cardiac output (Q, acetylene rebreathing technique) averaged 2.2 to 2.8 l/min higher AP (P less than 0.01) at rest and at each exercise work load. Increases in both HR and stroke volume (SV) contributed to the elevated Q at the lower exercise work loads, whereas an increased SV was primarily responsible for the higher Q at higher levels. The slope of the Q vs. VO2 relationship was not different AP and PP (6.15 +/- 1.32 and 6.18 +/- 1.34 l/min Q/l/min VO2, P greater than 0.05). In contrast, the arteriovenous O2 difference (a-vO2 difference) was lower at each exercise work load AP, suggesting that the higher Q AP was distributed to nonexercising vascular beds. We conclude that Q is greater and a-vO2 difference is less at all levels of exercise in pregnant subjects than in the same women postpartum but that the coupling of the increase in Q to the increase in systemic O2 demand (VO2) is not different.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Demam pada Penggunaan Analgesia Persalinan Epidural

2020 ◽  
Vol 1 (1) ◽  
pp. 72-9
Author(s):  
Alfan Mahdi Nugroho ◽  
Yusmein Uyun ◽  
Annemarie Chrysantia Melati
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Epidural Analgesia ◽  
Neonatal Seizure ◽  
Increased Temperature ◽  
Fetal Infection ◽  
Labour Epidural Analgesia ◽  
Clinical Consequences ◽  
The Relationship

Analgesia epidural telah diperkenalkan secara rutin sebagai salah satu modalitas analgesia pada proses persalinan sejak lama. Hubungan antara analgesia epidural persalinan dengan demam intrapartum pada maternal sudah disebutkan pada beberapa literatur. Demam didefinisikan sebagai peningkatan suhu tubuh lebih dari 38 oC yang didapat dari dua kali pemeriksaan. Beberapa teori yang disebutkan antara lain perubahan termoregulasi, infeksi pada ibu-janin dan inflamasi non-infeksi yang dimediasi oleh sitokin proinflamasi. Namun demikian berbagai mekanisme analgesia epidural dapat menyebabkan demam masih terus diteliti. Identifikasi demam pada ibu saat persalinan merupakan hal yang penting untuk dilakukan karena memiliki konsekuensi klinis pada ibu dan neonatus. Pada ibu ditemukan suhu yang meningkat dikaitkan dengan peningkatan denyut jantung ibu, curah jantung, konsumsi oksigen, dan produksi katekolamin. Sedangkan pada janin demam intrapartum dapat menyebabkan sepsis, perubahan skor APGAR, peningkatan kebutuhan bantuan napas dan kejadian kejang. Efek demam pada ibu dan janin masih terus dipelajari, sehingga suatu saat didapatkan cara pencegahan yang paling baik yang pada akhirnya menghindarkan keraguan untuk melakukan analgesia persalinan.   Fever during labour epidural analgesia Abstract Epidural analgesia has been routinely introduced as one of the analgesia modalities during labour. Literature has mentioned the relationship between epidural analgesia and intrapartum fever among mothers. Fever is defined as increased temperature above 38 oC in more than two measurements. Several theories have been proposed, inculing thermoregulation changes, mother-fetal infection, and non-infectious inflammation mediated by proinflammatory cytokines. However, these mechanisms have been continued to evolve. Fever identification in pregnant women is essential to recognize clinical consequences to both mothers and neonates. Increased temperature in mothers is associated with increased heart rate, cardiac output, oxygen consumption, and catecholamines production. Meanwhile, in neonates intrapartum fever is related to sepsis, APGAR score changes, the need of respiratory support and incidence of neonatal seizure. Therefore, these consequences are extensively studied in order to determine the appropriate prevention.

scholarly journals Cost analysis of manual bund shaping in paddy fields: Economical and physiological

2021 ◽  
Vol 67 (No. 4) ◽  
pp. 181-189
Author(s):  
Ritesh Ranjan ◽  
Prabhanjan Kumar Pranav
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Maximal Exercise ◽  
Average Rate ◽  
Economic Cost ◽  
Maximum Volume ◽  
Physiological Cost ◽  
Expenditure Rate ◽  
Maximum Aerobic Capacity ◽  
The Cost

Bund shaping is one of the essential operations in preparing a paddy transplanting field. This operation is undertaken manually by spades in a traditional way as this has not been mechanised thus far. Therefore, this study was conducted to expose this operation by evaluating the economic, as well as physiological, cost involved in the bund shaping. For the economic cost, the study was conducted in nine different districts of Assam (India). The bund length for the estimated area was measured and estimated for one ha of land. The average rate of manual bund shaping was also measured to calculate the cost involved in this operation. Moreover, for the physiological cost, ten experienced subjects were calibrated and measured for their maximum aerobic capacity by sub-maximal exercise in laboratory condition. Furthermore, the heart rate was measured during the manual bund shaping and was then correlated with the calibrated data. It was found that the average required bund shaping length per ha was 3 669 m which was associated with a cost of 2 062.8 rupees. It was found that the bund shaping consumed 76.96% of the maximum volume of the oxygen consumption capacity of the subjects; however, the energy expenditure rate with respect to time and bund length were 7.37 kcal·min<sup>–1</sup> and 4.33 kcal·m<sup>–1</sup>, respectively. Hence, bund shaping in a paddy field comes under a severe workload category which emphasises the need of mechanisation for the bund shaping operation.

Cardiovascular changes in the exercising emu

1983 ◽  
Vol 104 (1) ◽  
pp. 193-201 ◽  
Author(s):  
B. Grubb ◽  
D. D. Jorgensen ◽  
M. Conner
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Body Mass ◽  
Fold Increase ◽  
Exercise Heart Rate ◽  
Rate Of Oxygen Consumption ◽  
Cardiovascular Variables

Cardiovascular variables were studied as a function of oxygen consumption in the emu, a large, flightless ratite bird well suited to treadmill exercise. At the highest level of exercise, the birds' rate of oxygen consumption (VO2) was approximately 11.4 times the resting level (4.2 ml kg-1 min-1). Cardiac output was linearly related to VO2, increasing 9.5 ml for each 1 ml increase in oxygen consumption. The increase in cardiac output is similar to that in other birds, but appears to be larger than in mammals. The venous oxygen content dropped during exercise, thus increasing the arteriovenous oxygen content difference. At the highest levels of exercise, heart rate showed a 3.9-fold increase over the resting rate (45.8 beats min-1). The mean resting specific stroke volume was 1.5 ml per kg body mass, which is larger than shown by most mammals. However, birds have larger hearts relative to body mass than do mammals, and stroke volume expressed per gram of heart (0.18 ml g-1) is similar to that for mammals. Stroke volume showed a 1.8-fold increase as a result of exercise in the emus, but a change in heart rate plays a greater role in increasing cardiac output during exercise.

Cardiopulmonary effects of continuous pressure breathing in hypothermic dogs

1965 ◽  
Vol 20 (4) ◽  
pp. 669-674 ◽  
Author(s):  
J. Salzano ◽  
F. G. Hall
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Negative Pressure ◽  
Alveolar Ventilation ◽  
Positive Pressure ◽  
Negative Pressure Breathing ◽  
Continuous Positive Pressure ◽  
Respiratory Dead Space

Continuous pressure breathing was studied in hypothermic anesthetized dogs. Alveolar ventilation decreased during continuous positive-pressure breathing and increased during continuous negative-pressure breathing. The changes in alveolar ventilation were due to changes in respiratory rate as well as in respiratory dead space. Cardiac output fell significantly during continuous positive-pressure breathing due to a reduction in heart rate and stroke volume. During continuous negative-pressure breathing cardiac output was only slightly greater than during control as a result of a fall in heart rate and an increase in stroke volume. Oxygen consumption was reduced to 60% of control during continuous positive-pressure breathing of 16 cm H2O but was 25% greater than control during continuous negative-pressure breathing. Qualitatively, CO2 production changed as did O2 consumption but was different quantitatively during continuous negative-pressure breathing indicating hyperventilation due to increased respiratory rate. Mean pulmonary artery pressures and pulmonary resistance varied directly with the applied intratracheal pressure. The results indicate that the hypothermic animal can tolerate an imposed stress such as continuous pressure breathing and can increase its oxygen consumption during continuous negative-pressure breathing as does the normothermic animal. hypothermia; respiratory dead space; metabolic rate; cardiac output Submitted on December 8, 1964

Hemodynamic response of normal men to graded treadmill exercise

1964 ◽  
Vol 19 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Burton S. Tabakin ◽  
John S. Hanson ◽  
Thornton W. Merriam ◽  
Edgar J. Caldwell
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Treadmill Exercise ◽  
Minute Volume ◽  
Peripheral Vascular ◽  
Carbon Dioxide Elimination ◽  
Oxygen Utilization

The physiologic variables defining the circulatory and respiratory state in normal man have been measured in recumbency, standing at rest and during progressively severe grades of exercise approaching near-maximal levels. Indicator-dilution technique was used for determination of cardiac output with simultaneous radio-electrocardiographic recordings of heart rate. Direct intra-arterial pressure measurements were utilized for calculation of peripheral vascular resistance. Minute volume of ventilation, oxygen utilization, and carbon dioxide elimination were obtained from analysis of expired air collected at the time of each cardiac output determination. A peak mean workload of 1,501 kg-m/min was realized during the treadmill exercise. Increases in cardiac output over the range of exercise employed correlated well with indices of workload such as heart rate, oxygen utilization, and minute volume of ventilation. There was no correlation of stroke volume with these indices. It is concluded from examination of individual stroke-volume responses that a progressive increase in stroke volume is not a necessary or constant phenomenon in adapting to increasing workload. cardiac output in treadmill exercise; dye-dilution cardiac output determinations; arterial pressure during upright exercise; stroke-volume response to graded treadmill exercise; exercise response of cardiac output and stroke volume; peripheral vascular resistance response to position and exercise; treadmill exercise—effects on cardiac output, stroke volume, and oxygen uptake; minute ventilation, cardiac output, and stroke volume during exercise; carbon dioxide elimination during treadmill exercise; heart rate and cardiac output during treadmill exercise; exercise; physiology Submitted on July 12, 1963

Oxygen consumption and hemodynamic responses during graded treadmill exercise in the dog

1984 ◽  
Vol 57 (2) ◽  
pp. 601-607 ◽  
Author(s):  
G. A. Ordway ◽  
D. L. Floyd ◽  
J. C. Longhurst ◽  
J. H. Mitchell
Keyword(s):  
Maximal Exercise ◽  
Treadmill Exercise ◽  
Work Load ◽  
Dynamic Exercise ◽  
O2 Consumption ◽  
Treadmill Test ◽  
O2 Uptake ◽  
Hemodynamic Variables ◽  
Linear Relationships ◽  
H 20

A description is given of a technique that provides a relatively simple means by which O2 consumption and hemodynamic variables can be measured in exercising dogs. We used a multistage submaximal treadmill test to study the responses of 10 foxhounds to dynamic exercise. They were also studied during maximal treadmill exercise. O2 consumption increased from 16.3 +/- 1.7 ml O2 X min-1 X kg-1 at rest to 92.9 +/- 9.7 ml O2 X min-1 X kg-1 at a work load of 6.4 km/h, 20% grade and to 111.9 +/- 9.6 ml O2 X min-1 X kg-1 during maximal exercise. Cardiac output (CO) increased from 6.11 +/- 0.45 l/min at rest to 16.91 +/- 1.46 and 17.66 +/- 0.60 l/min at 6.4 km/h, 20% grade and maximal exercise, respectively. Arteriovenous O2 difference increased from 5.8 +/- 0.3 vol% at rest to 12.0 +/- 0.4 and 13.2 +/- 0.7 vol% at 6.4 km/h, 20% grade and maximal exercise, respectively. Heart rate (HR) increased from 116 +/- 7 beats/min at rest to 250 +/- 8 beats/min at 6.4 km/h, 20% grade and to 278 +/- 6 beats/min during maximal exercise. O2 uptake, CO, and arteriovenous O2 difference increased with the onset of exercise, appeared to level at lower work intensities (6.4 km/h, 4 and 8% grade), and increased significantly at each of the higher work intensities (6.4 km/h, 12, 16, and 20% grade). Additionally, we observed linear relationships between O2 consumption and HR (HR = 1.35 X VO2 + 120.5; r = 0.87; P less than 0.001) and between O2 consumption and CO (CO = 5.91 X VO2 + 216.6; r = 0.96; P less than 0.001). Further, the linear relationship between O2 consumption and CO demonstrated in the present study is similar to that observed in humans.

Plateau in Oxygen Uptake at Maximal Exercise in Male Children

1996 ◽  
Vol 8 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Glen E. Duncan ◽  
Anthony D. Mahon ◽  
Cheryl A. Howe ◽  
Pedro Del Corral
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Maximal Exercise ◽  
Treadmill Exercise ◽  
Pulmonary Ventilation ◽  
Anaerobic Capacity ◽  
Test Duration ◽  
Run Time ◽  
Aerobic And Anaerobic

This study examined the influence of test duration and anaerobic capacity on VO2max and the occurrence of a VO2 plateau during treadmill exercise in 25 boys (10.4 ± 0.8 years). Protocols with 1-min (P1) and 2-min (P2) stages, but identical speed and grade changes, were used to manipulate test duration. On separate days, VO2max was measured on P1 and P2, and 200-m run time was assessed. At maximal exercise, VO2, heart rate (HR), and pulmonary ventilation (VE) were similar between protocols, however, respiratory exchange ratio (RER) and treadmill elevation were higher (p < .05) on P1 than on P2. Plateau achievement was not significantly different. On P1, there were no differences between plateau achievers and nonachievers. On P2, test duration and 200-m run time were superior (p < .05), and relative VO2max tended to be higher (p < .10) in plateau achievers. Indices of aerobic and anaerobic capacity may influence plateau achievement on long, but not short duration tests.

Sign in / Sign up

Export Citation Format

Share Document