Comparison of the cardiac pumping capability and cardiac pumping reserve in double-muscled and conventional calves

1993 ◽  
Vol 71 (12) ◽  
pp. 946-951 ◽  
Author(s):  
H. Amory ◽  
K. McEntee ◽  
A. S. Linden ◽  
D. J. M. Desmecht ◽  
J. M. L. Beduin ◽  
...  
Keyword(s):  
Heart Rate ◽  
Aerobic Capacity ◽  
Power Output ◽  
Cardiac Performance ◽  
Muscular Hypertrophy ◽  
Transport Pathway ◽  
Cardiac Reserve ◽  
Cardiac Power ◽  
Cardiac Pumping ◽  
Pulmonary Arterial

Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional commercial value but ones with a lower aerobic capacity than that of conventional cattle. The purpose of this work was to study the role of cardiac function as a potential limiting factor of aerobic capacity in double-muscled calves. Two groups of healthy calves were studied, one consisting of nine calves of conventional conformation and the other of nine double-muscled calves. Pulmonary arterial and capillary wedge, central venous, and systemic arterial pressures were measured by fluid-filled catheters and recorded together with the electrocardiogram. Cardiac output was measured by the thermodilution technique. From these measurements, the heart rate, the cardiac and the stroke indices, the pulmonary and the systemic vascular resistances, and the cardiac power output were calculated. The parameters were recorded under basal resting conditions and during incremental dobutamine challenge, which allowed determination of the resting cardiac power output, the cardiac pumping capability, and the cardiac reserve. Dobutamine challenge induced a significant rise in cardiac and stroke indices, heart rate, and cardiac power output, a significant decrease in pulmonary and systemic vascular resistances, and no change in systemic and pulmonary arterial pressures. The cardiac reserve obtained in the present study was low in comparison with those previously reported in humans, dogs, and horses. This may be related to the poor running capability of bovine species relative to that of the former species. The double-muscled calves had significantly lower cardiac and stroke indices, resting cardiac power output, cardiac pumping capability, and cardiac reserve than did conventional calves. Therefore, the cardiac performance, capability, and reserve were reduced in double-muscled calves. It was concluded that cardiac performance is a critical step in the oxygen-transport pathway in double-muscled cattle.Key words: cattle, hereditary muscular hypertrophy, oxygen consumption, cardiovascular system, cardiac power output.

Randomized controlled trial of home-based exercise training to evaluate cardiac functional gains

2001 ◽  
Vol 101 (5) ◽  
pp. 477-483 ◽  
Author(s):  
Paul MARSHALL ◽  
Jawad AL-TIMMAN ◽  
Rhona RILEY ◽  
Jay WRIGHT ◽  
Simon WILLIAMS ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Training ◽  
Aerobic Capacity ◽  
Power Output ◽  
Moderate Intensity ◽  
Exercise Tests ◽  
Cardiac Reserve ◽  
Cardiac Power ◽  
Home Based ◽  
Functional Gains

There is evidence that multiple benefits can be obtained through exercise training that leads to increases in peak oxygen consumption (O2). It is unclear whether significant improvements can also be achieved through unsupervised low-budget home-based training regimes, especially in terms of cardiac functional gains. A randomized cross-over trial was conducted to investigate the effects of a home-based unsupervised exercise training programme of moderate intensity on aerobic capacity, cardiac reserve and peak cardiac power output in healthy middle-aged volunteers. Nine subjects with no known cardiovascular diseases performed symptom-limited treadmill cardiopulmonary exercise tests after an 8-week period of exercise training, and results were compared with those obtained after a similar ‘non-exercising’ control period. Cardiac output was measured non-invasively during exercise tests using the CO2-rebreathing method. With exercise training, resting heart rate decreased significantly from 88.3±3.4 to 78.7±3.2beatsċmin-1 (P < 0.05), heart rate at a submaximal workload (O2 = 1.5litresċmin-1) decreased from 125.5±2.4 to 115.5±1.6beatsċmin-1, and peak O2 increased by 9% from 2.62±0.19 to 2.85±0.18litresċmin-1 (P < 0.01). Baseline cardiac power output was 1.11±0.05W, and this remained unchanged with training. Peak cardiac power output increased by 16% from 4.1±0.3 to 4.7±0.3W (P < 0.001), and cardiac reserve increased by 21% (P < 0.01). A major contribution to these increases was from the 11% increase in stroke volume, from 100.1±5.3 to 111.2±6.2ml (P < 0.001). All subjects reported more positive perceptions of their health (P < 0.05), fitness (P < 0.01) and levels of activity (P < 0.01) after the training period. These results show that motivated subjects undergoing low-budget unsupervised home-based exercise training of moderate intensity can derive benefit in terms of symptoms, aerobic capacity and cardiac functional reserve.

Effects of swimming and environmental hypoxia on coronary blood flow in rainbow trout

1995 ◽  
Vol 269 (5) ◽  
pp. R1258-R1266 ◽  
Author(s):  
A. K. Gamperl ◽  
M. Axelsson ◽  
A. P. Farrell
Keyword(s):  
Blood Flow ◽  
Rainbow Trout ◽  
Coronary Blood Flow ◽  
Swimming Speed ◽  
Power Output ◽  
Cardiac Performance ◽  
Coronary Perfusion ◽  
Cardiac Power ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aortic Blood Pressure

Previous studies have suggested that trout cardiac performance is highly dependent on coronary blood flow during periods of increased activity or hypoxia. To examine the relationship between coronary perfusion and cardiac performance in swimming trout, cardiac output (Q), coronary blood flow (qcor), and dorsal aortic blood pressure were measured in rainbow trout (Oncorhynchus mykiss) during normoxia and hypoxia (PO2 approximately 9 kPa). In normoxic trout, stepwise changes in cardiovascular variables were observed as the swimming speed was incrementally increased from 0.15 body lengths (bl)/s to 1.0 bl/s. At 1.0 bl/s, qcor and cardiac power output had both increased by approximately 110%, and coronary artery resistance (Rcor) had decreased by 40%. During hypoxia, resting qcor was 35% higher, and Rcor was 20% lower, compared with normoxic values. In hypoxic swimming trout, the maximum changes in qcor (155% increase) and Rcor (50% decrease) were recorded at 0.75 bl/s. In contrast, cardiac power output and Q increased by an additional 40 and 20%, respectively, as swimming speed was increased from 0.75 to 1.0 bl/s. The results indicate that 1) increases in qcor parallel changes in cardiac power output; 2) during hypoxia there are compensatory increases in cardiac performance and coronary perfusion; and 3) the scope for increasing qcor in swimming trout is approximately 150%. In addition, results from preliminary experiments suggest that beta-adrenergic, but not cholinergic, mechanisms are involved in the regulation of coronary blood flow during exercise.

scholarly journals Sexual Maturity Can Double Heart Mass and Cardiac Power Output in Male Rainbow Trout

1992 ◽  
Vol 171 (1) ◽  
pp. 139-148 ◽  
Author(s):  
CRAIG E. FRANKLIN ◽  
PETER S. DAVIE
Keyword(s):  
Rainbow Trout ◽  
Body Mass ◽  
Power Output ◽  
Cardiac Performance ◽  
Mature Male ◽  
Perfused Heart ◽  
Cardiac Power ◽  
Heart Preparation ◽  
Ovary Growth

Mature male rainbow trout have significantly higher relative ventricle masses (RVM, ventricle mass as a percentage of body mass) than do immature males or females. Hatchery-reared maturing male trout had a mean RVM of 0.139%, whereas females had an RVM of only 0.074 %. Moreover, as males matured and their testes grew from 0.07 to 3.92 % of body mass, RVM more than doubled. In female trout no such heart growth occurred; RVM remained unchanged during the period of ovary growth. Cardiac performance was assessed using an in situ perfused heart preparation. Mature male trout have larger ventricles and could generate significantly greater maximum cardiac power output per kilogram body mass than could immature males or females. This enhanced cardiac performance by the mature males was attributable to delivery of greater cardiac outputs (through larger stroke volumes) and an increased ability of the heart to work against higher output pressures. Power output per gram ventricle mass was similar in both sexes. Note: Present address: Department of Zoology, University of Queensland, Brisbane 4072, Australia.

scholarly journals Cardiopulmonary coupling indices to assess weaning readiness from mechanical ventilation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Armañac-Julián ◽  
David Hernando ◽  
Jesús Lázaro ◽  
Candelaria de Haro ◽  
Rudys Magrans ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mechanical Ventilation ◽  
Spontaneous Breathing Trial ◽  
Sinus Arrhythmia ◽  
Time Frequency ◽  
Cardiopulmonary Coupling ◽  
Cardiac Pumping ◽  
Successful Weaning ◽  
Frequency Coherence ◽  
Subspace Projections

AbstractThe ideal moment to withdraw respiratory supply of patients under Mechanical Ventilation at Intensive Care Units (ICU), is not easy to be determined for clinicians. Although the Spontaneous Breathing Trial (SBT) provides a measure of the patients’ readiness, there is still around 15–20% of predictive failure rate. This work is a proof of concept focused on adding new value to the prediction of the weaning outcome. Heart Rate Variability (HRV) and Cardiopulmonary Coupling (CPC) methods are evaluated as new complementary estimates to assess weaning readiness. The CPC is related to how the mechanisms regulating respiration and cardiac pumping are working simultaneously, and it is defined from HRV in combination with respiratory information. Three different techniques are used to estimate the CPC, including Time-Frequency Coherence, Dynamic Mutual Information and Orthogonal Subspace Projections. The cohort study includes 22 patients in pressure support ventilation, ready to undergo the SBT, analysed in the 24 h previous to the SBT. Of these, 13 had a successful weaning and 9 failed the SBT or needed reintubation –being both considered as failed weaning. Results illustrate that traditional variables such as heart rate, respiratory frequency, and the parameters derived from HRV do not differ in patients with successful or failed weaning. Results revealed that HRV parameters can vary considerably depending on the time at which they are measured. This fact could be attributed to circadian rhythms, having a strong influence on HRV values. On the contrary, significant statistical differences are found in the proposed CPC parameters when comparing the values of the two groups, and throughout the whole recordings. In addition, differences are greater at night, probably because patients with failed weaning might be experiencing more respiratory episodes, e.g. apneas during the night, which is directly related to a reduced respiratory sinus arrhythmia. Therefore, results suggest that the traditional measures could be used in combination with the proposed CPC biomarkers to improve weaning readiness.

A Systematic Review of Submaximal Cycle Tests to Predict, Monitor, and Optimize Cycling Performance

2016 ◽  
Vol 11 (6) ◽  
pp. 707-714 ◽  
Author(s):  
Benoit Capostagno ◽  
Michael I. Lambert ◽  
Robert P. Lamberts
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Perceived Exertion ◽  
Heart Rate Recovery ◽  
Mechanical Efficiency ◽  
Cycling Performance ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Gross Mechanical Efficiency ◽  
Multiple Variables

Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status. Twelve studies met the inclusion criteria, and 3 separate submaximal cycling tests were identified from within those 12. Submaximal variables including gross mechanical efficiency, oxygen uptake (VO2), heart rate, lactate, predicted time to exhaustion (pTE), rating of perceived exertion (RPE), power output, and heart-rate recovery (HRR) were the components of the 3 tests. pTE, submaximal power output, RPE, and HRR appear to have the most value for monitoring improvements in performance and indicate a state of fatigue. This literature review shows that several submaximal cycle tests have been developed over the last decade with the aim to predict, monitor, and optimize cycling performance. To be able to conduct a submaximal test on a regular basis, the test needs to be short in duration and as noninvasive as possible. In addition, a test should capture multiple variables and use multivariate analyses to interpret the submaximal outcomes correctly and alter training prescription if needed.

Abstract 15293: Noninvasive Echocardiographic Cardiac Power Output Predicts Mortality in Cardiac Intensive Care Unit Patients

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Barry Burstein ◽  
Vidhu Anand ◽  
Bradley Ternus ◽  
Meir Tabi ◽  
Nandan S Anavekar ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Hospital Mortality ◽  
Critically Ill ◽  
Power Output ◽  
Critically Ill Patients ◽  
Cardiac Intensive Care Unit ◽  
Cardiac Power ◽  
The Mean ◽  
Cardiac Intensive Care

Introduction: A low cardiac power output (CPO), measured invasively, identifies critically ill patients at increased risk of mortality. CPO can also be measured non-invasively with transthoracic echocardiography (TTE), although prognostic data in critically ill patients is not available. Hypothesis: Reduced CPO measured by TTE is associated with increased hospital mortality in cardiac intensive care unit (CICU) patients. Methods: Using a database of CICU patients admitted between 2007 and 2018, we identified patients with TTE within one day (before or after) of CICU admission who had data necessary for calculation of CPO. Multivariable logistic regression determined the relationship between CPO and adjusted hospital mortality. Results: We included 5,585 patients with a mean age of 68.3±14.8 years, including 36.7% females. Admission diagnoses included acute coronary syndrome (ACS) in 57%, heart failure (HF) in 50%, cardiac arrest (CA) in 12%, and cardiogenic shock (CS) in 13%. The mean left ventricular ejection fraction (LVEF) was 47±16%, and the mean CPO was 1.0±0.4 W. CPO was inversely associated with the risk of hospital mortality (Figure A), including among patients with ACS, HF, and CS (Figure B). On multivariable analysis, lower CPO was associated with higher hospital mortality (OR 0.96 per 0.1 W, 95% CI 0.0.93-0.99, p=0.03). Hospital mortality was highest in patients with low CPO coupled with reduced LVEF, increased vasopressor requirements, or higher admission lactate. Hospital mortality was higher among patients with a CPO <0.6 W (adjusted OR 1.57, 95% CI 1.13-2.19, p = 0.007), particularly in the presence of admission lactate level >4 mmol/L (50.9%). Conclusions: Echocardiographic CPO was inversely associated with hospital mortality in CICU patients, particularly among patients with increased lactate and vasopressor requirements. Routine measurement of CPO provides important information beyond LVEF and should be considered in CICU patients.

Interaction of interval-force relationship with aortic pressure and stroke volume

1976 ◽  
Vol 230 (4) ◽  
pp. 893-900 ◽  
Author(s):  
ER Powers ◽  
Foster ◽  
Powell WJ
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Cardiac Performance ◽  
Right Heart ◽  
Anesthetized Dogs ◽  
Right Heart Bypass ◽  
Force Relationship

The modification by aortic pressure and stroke volume of the response in cardiac performance to increases in heart rate (interval-force relationship) has not been previously studied. To investigate this interaction, 30 adrenergically blocked anesthetized dogs on right heart bypass were studied. At constant low aortic pressure and stroke volume, increasing heart rate (over the entire range 60-180) is associated with a continuously increasing stroke power, decreasing systolic ejection period, and an unchanging left ventricular end-diastolic pressure and circumference. At increased aortic pressure or stroke volume at low rates (60-120), increases in heart rate were associated with an increased performance. However, at increased aortic pressure or stroke volume at high rates (120-180), increases in heart rate were associated with a leveling or decrease in performance. Thus, an increase in aortic pressure or stroke volume results in an accentuation of the improvement in cardiac performance observed with increases in heart rate, but this response is limited to a low heart rate range. Therefore, the hemodynamic response to given increases in heart rate is critically dependent on aortic pressure and stroke volume.

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