scholarly journals Methylprednisolone Protects Cardiac Pumping Mechanics from Deteriorating in Lipopolysaccharide-Treated Rats

2015 ◽  
Vol 6 ◽  
Author(s):  
Ya-Hui Ko ◽  
Ming-Shian Tsai ◽  
Ru-Wen Chang ◽  
Chun-Yi Chang ◽  
Chih-Hsien Wang ◽  
...  
Keyword(s):  
Cardiac Pumping

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.

scholarly journals Acetyl-l-Carnitine and Oxfenicine on Cardiac Pumping Mechanics in Streptozotocin-Induced Diabetes in Male Wistar Rats

PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e69977 ◽  
Author(s):  
Chih-Hsien Wang ◽  
Shoei-Shen Wang ◽  
Wen-Je Ko ◽  
Yih-Sharng Chen ◽  
Chun-Yi Chang ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Cardiac Pumping ◽  
Male Wistar Rats ◽  
Streptozotocin Induced Diabetes

The Transitional Cardiac Pumping Mechanics in the Embryonic Heart

2013 ◽  
Vol 4 (3) ◽  
pp. 246-255 ◽  
Author(s):  
Brennan M. Johnson ◽  
Deborah M. Garrity ◽  
Lakshmi Prasad Dasi
Keyword(s):  
Embryonic Heart ◽  
Cardiac Pumping

scholarly journals Effect of muscle length on cross-bridge kinetics in intact cardiac trabeculae at body temperature

2012 ◽  
Vol 141 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Nima Milani-Nejad ◽  
Ying Xu ◽  
Jonathan P. Davis ◽  
Kenneth S. Campbell ◽  
Paul M.L. Janssen
Keyword(s):  
Body Temperature ◽  
Cardiac Muscle ◽  
Muscle Length ◽  
Ventricular Volume ◽  
Dynamic Force ◽  
Rabbit Muscle ◽  
Optimal Length ◽  
Rat Muscle ◽  
Cross Bridge ◽  
Cardiac Pumping

Dynamic force generation in cardiac muscle, which determines cardiac pumping activity, depends on both the number of sarcomeric cross-bridges and on their cycling kinetics. The Frank–Starling mechanism dictates that cardiac force development increases with increasing cardiac muscle length (corresponding to increased ventricular volume). It is, however, unclear to what extent this increase in cardiac muscle length affects the rate of cross-bridge cycling. Previous studies using permeabilized cardiac preparations, sub-physiological temperatures, or both have obtained conflicting results. Here, we developed a protocol that allowed us to reliably and reproducibly measure the rate of tension redevelopment (ktr; which depends on the rate of cross-bridge cycling) in intact trabeculae at body temperature. Using K+ contractures to induce a tonic level of force, we showed the ktr was slower in rabbit muscle (which contains predominantly β myosin) than in rat muscle (which contains predominantly α myosin). Analyses of ktr in rat muscle at optimal length (Lopt) and 90% of optimal length (L90) revealed that ktr was significantly slower at Lopt (27.7 ± 3.3 and 27.8 ± 3.0 s−1 in duplicate analyses) than at L90 (45.1 ± 7.6 and 47.5 ± 9.2 s−1). We therefore show that ktr can be measured in intact rat and rabbit cardiac trabeculae, and that the ktr decreases when muscles are stretched to their optimal length under near-physiological conditions, indicating that the Frank–Starling mechanism not only increases force but also affects cross-bridge cycling kinetics.

Influence of 5-HT2 Receptor Agonist on Cardiac Pumping Function of Trained Offspring of Trained Rats

2012 ◽  
Vol 153 (3) ◽  
pp. 315-318 ◽  
Author(s):  
A. M. Valeev ◽  
N. I. Abzalov ◽  
R. A. Abzalov ◽  
R. R. Nigmatullina ◽  
R. R. Abzalov ◽  
...  
Keyword(s):  
Receptor Agonist ◽  
Cardiac Pumping ◽  
Pumping Function

Improved Lymphocyte Beta-Receptor Function and Cardiac Pumping Capacity after Converting Enzyme Inhibition in Heart Failure

1991 ◽  
Vol 80 (s24) ◽  
pp. 9P-9P
Author(s):  
JN Townend ◽  
SJS Virk ◽  
FX Qiang ◽  
N Lawson ◽  
WA Littler ◽  
...  
Keyword(s):  
Heart Failure ◽  
Enzyme Inhibition ◽  
Converting Enzyme ◽  
Receptor Function ◽  
Beta Receptor ◽  
Cardiac Pumping ◽  
Converting Enzyme Inhibition

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.

Relationship between peak cardiac pumping capability and indices of cardio-respiratory fitness in healthy individuals

2012 ◽  
Vol 32 (5) ◽  
pp. 388-393 ◽  
Author(s):  
Djordje G Jakovljevic ◽  
Jelena Z Popadic-Gacesa ◽  
Otto F Barak ◽  
David Nunan ◽  
Gay Donovan ◽  
...  
Keyword(s):  
Healthy Individuals ◽  
Cardiac Pumping ◽  
Cardio Respiratory Fitness
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