Analyze Diet

Topic:Hemodynamics

Hemodynamics in horses refers to the study of blood flow and the forces involved in circulation within the equine cardiovascular system. It encompasses the examination of heart function, blood pressure, and the distribution of blood to various tissues and organs. Key parameters in equine hemodynamics include cardiac output, vascular resistance, and blood volume. These factors are integral to understanding how horses respond to exercise, stress, and various health conditions. This page aggregates peer-reviewed research studies and scholarly articles that explore the mechanisms, measurement techniques, and clinical implications of hemodynamic processes in equine physiology and veterinary medicine.
Hemodynamic and respiratory effects of xylazine-morphine sulfate in horses.
American journal of veterinary research    October 1, 1979   Volume 40, Issue 10 1417-1420 
Muir WW, Skarda RT, Sheehan WC.The cardiopulmonary effects of two xylazine-morphine sulfate drug combinations (mixtures) given IV were evaluated in horses. In horses given xylazine (0.66 mg/kg of body weight) and morphine sulfate (0.12 mg/kv) IV (experiment 1), there were significant (P less than 0.05) decreases in heart rate, cardiac output, and respiratory rate. Central venous pressure was significantly (P less than 0.05) increased. Arterial and pulmonary arterial blood pressures increased significantly (P less than 0.05) but transiently. Arterial blood gas tensions (PaCO2 and PaO2) and pH remained unchanged. In the horse...
Distribution of cardiac output in anaesthetised horses.
Research in veterinary science    July 1, 1979   Volume 27, Issue 1 38-45 
Staddon GE, Weaver BM, Webb AI.The radioactive microsphere method was used to determine the distribution of cardiac output in six anaesthetised ponies. Simultaneous measurements of cardiac output allowed calculation of the tissue perfusions (ml/min/100 g). Allowing for the fact that measurements were carried out on animals under halothane anaesthesia and which had respiratory acidosis, the results were comparable with published values for other species.
Indirect measurement of mean blood pressure in the normotensive and hypotensive horse.
Equine veterinary journal    July 1, 1979   Volume 11, Issue 3 191-194 doi: 10.1111/j.2042-3306.1979.tb01340.x
Latshaw H, Fessler JF, Whistler SJ, Geddes LA.Indirect mean arterial pressure was obtained from the tails of 78 anaesthetised and unanaesthetised normotensive and hypotensive horses. Data were obtained to determine the optimum cuff width in relation to tail circumference. A cuff that is too wide under-estimates and a cuff that is too narrow over-estimates blood pressure. With the optimum cuff width, which is slightly in excess of about one-fifth of the tail circumference, indirect mean blood pressure was obtained consistently in normotensive and hypotensive animals with mean blood pressures of 40 mmHg and frequently in animals with pressu...
Phonocardiography in the horse: 2. The relationship of the external phonocardiogram to intracardiac pressure and sound.
Equine veterinary journal    July 1, 1979   Volume 11, Issue 3 183-186 doi: 10.1111/j.2042-3306.1979.tb01337.x
Brown CM, Holmes JR.The paper describes observations during individual cardiac cycles on the changing pressures and sounds recorded from the various chambers of the heart and aorta, related to phonocardiograms from an external microphone hand-held over the cardiac area. The majority of the first sound appears to arise from the left side of the heart after the AV valves have closed and the second sound is a consequence of sudden deceleration of blood against already closed semilunar valves. Systolic murmurs at the aortic root may be benign from increased flow and turbulence at the peak of ejection but these may no...
[Effects of exercise and training on the heart and circulation in horses (author’s transl)].
DTW. Deutsche tierarztliche Wochenschrift    January 5, 1979   Volume 86, Issue 1 2-7 
von Engelhardt W.No abstract available
The pony as a model for septic shock.
Advances in shock research    January 1, 1979   Volume 2 137-151 
Sembrat RF, Di Stazio J, Stremple JF.This study was conducted to determine the feasibility of using alert, conscious ponies as a model for septic shock in man. Ten ponies were given 0.7-5 X 10(9) organisms/kg of body weight of live E coli intravenously over one hour. All ponies died and exhibited signs of low cardiac output septic shock. significant decreases were found in cardiac index to 3.15 +/- 0.1 liters/min/m2 (P less than 0.05), white blood cell count to 1,930 +/- 100 cells/m3 (P less than 0.05), preterminal blood glucose to 75 +/- 5 mg/dl (P less than 0.05), PaO2 to 75.7 +/- 5.7 mm Hg (P less than 0.05), and pH to 7.15 +/...
Blood-volume determination with Evans blue dye in foals.
Acta veterinaria Scandinavica    January 1, 1979   Volume 20, Issue 1 10-15 doi: 10.1186/BF03546624
Persson SG, Ullberg LE.The rate of disappearance of Evans blue dye from the blood after an intravenous injection was studied in young foals, between 4 and 105 days of age. This was found to be age dependant, especially during the first month, the initial dye disappearance being much faster than in the adult horse. This would mean an overestimation of plasma volume, using the single sampling technique, of about 5% during the first day of life, i.e. negligible from a practical point of view considering the standard error of estimation. The effect of exercise on the venous haematocrit was studied, too, in foals less th...
Swimming–a method to study the physiologic response of the horse to exercise.
Journal of the South African Veterinary Association    December 1, 1978   Volume 49, Issue 4 313-315 
Nicholl TK, Fregin GF, Gerber NH.The literature on exercise physiology in the horse with special reference to swimming is briefly reviewed. The use of a pool for swimming horses is described and a technique discussed for the collection of haematologic and haemodynamic data using this form of exercise.
Myocardial perfusion and function during acute right ventricular systolic hypertension.
The American journal of physiology    December 1, 1978   Volume 235, Issue 6 H628-H636 doi: 10.1152/ajpheart.1978.235.6.H628
Manohar M, Bisgard GE, Bullard V, Will JA, Anderson D, Rankin JH.Hemodynamics, myocardial function, and regional myocardial blood flow (MBF) were measured in 6 closed-chest ponies anesthetized with ketamine hydrochloride before (control) and after creation of acute right ventricular systolic hypertension (RVSH) during normoxia and isocapnic hypoxia. The right ventricular (RV) systolic pressure during each RVSH approached 90 mmHg. There were significant alterations in the pattern of total ventricular MBG distribution in favor of the RV. Because RV myocardium received proportionate increments to its endocardium as well as epicardium, it is concluded that auto...
Electromagnetic measurements of metacarpal and digital blood flow in the pony.
American journal of veterinary research    November 1, 1978   Volume 39, Issue 11 1853-1855 
Scott EA, Sandler GA.No abstract available
An investigation of the action and haemolytic effect of glyceryl guaiacolate in the horse.
Equine veterinary journal    October 1, 1978   Volume 10, Issue 4 224-228 doi: 10.1111/j.2042-3306.1978.tb02266.x
Schatzmann U, Tschudi P, Held JP, Muhlebach B.Glyceryl guaiacolate (GGE) was found to be a useful and safe casting agent when given by rapid intravenous infusion. It was administered to premedicated horses under controlled conditions at various concentrations from 10 to 20 per cent GGE solution. The onset and degree of relaxation was dependent only on the speed of infusion. For casting adult horses 350 to 450 ml of 15 per cent solution must be given within 30 to 60 seconds. A slight transient hypoxaemia occurred which seemed to be related to the animal being in lateral recumbency rather than the depressive action of GGE on respiratory fun...
Haemodynamics in the horse: 2. Intracardiac, pulmonary arterial and aortic pressures.
Equine veterinary journal    October 1, 1978   Volume 10, Issue 4 207-215 doi: 10.1111/j.2042-3306.1978.tb02263.x
Brown CM, Holmes JR.The paper reports the changing pressure values during the cardiac cycle recorded from various chambers of the heart and great vessels using 2 catheter-mounted transducers, 9 cm apart. Pulse pressures are calculated. Transvalval pressure differences are determined taking account of the effect of hydrostatic pressure between the 2 sensors. The effects of some valvular lesions and arrhythmias and of changes in intrathoracic pressure are also described.
Haemodynamics in the horse: 3. Duration of the phases of the cardiac cycle.
Equine veterinary journal    October 1, 1978   Volume 10, Issue 4 216-223 doi: 10.1111/j.2042-3306.1978.tb02265.x
Brown CM, Holmes JR.The paper reports observations on the duration of various phases of the cardiac cycle using a bipole ECG record as a time base from which to measure the timing of pressure changes in the chambers of the heart and great vessels. From the findings the likely sequence of mechanical events during the cardiac cycle in the atria and ventricles is described.
Effects of furosemide on plasma volume and extracellular fluid volume in horses.
American journal of veterinary research    October 1, 1978   Volume 39, Issue 10 1688-1691 
Muir WW, Kohn CW, Sams R.The effects of IV administered furosemide upon plasma volume (PV) and extracellular fluid volume were determined in horses at rest and after exercise. Serum sodium, potassium, chloride, and osmolality determinations were made. Furosemide caused a significant (P less than 0.05) decrease in PV and serum potassium concentrations in resting horses only. Furosemide's effects upon PV and electrolytes were evident longer than its hemodynamic effects.
Electromagnetic blood flowmeters and flow probes: theoretic and practical considerations.
American journal of veterinary research    September 1, 1978   Volume 39, Issue 9 1567-1571 
Scott EA, Sandler GA.Electromagnetic blood flowmeters and flow probes are used to measure blood flow in blood vessels throughout the circulatory system. The principle of this measuring device is based on laws of electromagnetic induction discovered in the 19th century. The instrument has been predominantly used in research, but is presently used in human cardiovascular units to measure blood flow in blood vessels, and in prosthesis in conjection with cardiovascular surgical procedures. Electromagnetic flow equipment provides the most accurate measurement (in vivo) of blood flow available, both for acute and chroni...
Pulmonary artery pressures in normal horses and in horses affected with chronic obstructive pulmonary disease.
Equine veterinary journal    July 1, 1978   Volume 10, Issue 3 195-198 doi: 10.1111/j.2042-3306.1978.tb02260.x
Dixon PM.Horses clinically affected with chronic obstructive pulmonary disease (COPD) were found to have pulmonary artery hypertension which was associated with systemic arterial hypoxia. The pulmonary hypertension in symptomatic COPD-affected horses was partially reversible upon remission of clinical signs or by oxygen administration. The induction of acute hypoxaemia caused an increase in pulmonary artery pressure in both normal and COPD-affected horses.
Potency of halothane-N20 in the horse.
American journal of veterinary research    July 1, 1978   Volume 39, Issue 7 1141-1146 
Steffey EP, Howland D.The minimal alveolar concentration (MAC) of halothane which just prevented purposeful movement in response to electrical stimulation was determined in 11 young, healthy, unpremedicated horses breathing oxygen (O2) or nitrous oxide (N2O) and O2. Ventilation was controlled during these MAC studies. The arterial PO2 was always greater than 90 mm of Hg and the average PaCO2. range was 36 to 40 mm of Hg. The MAC for halothane in O2 was 0.93 vol %. Alveolar N2O concentrations of 25% and 50% reduced the halothane MAC about 12% and 25%, respectively. In 8 of these horses, the cardiovascular effects of...
Haemodynamics in the horse: 1. Pressure pulse contours.
Equine veterinary journal    July 1, 1978   Volume 10, Issue 3 188-194 doi: 10.1111/j.2042-3306.1978.tb02257.x
Brown CM, Holmes JR.Using a catheter with 2 transducers, one mounted at the tip and one 9 cm proximal to it, enabled transvalval pressure waveforms to be recorded in 8 horses. A simultaneous electrocardiogram acted as a time base. The changing waveforms produced in the chambers of the heart and great vessels are described and related to the events of the cardiac cycle. The effect of second degree AV block, ectopic beats, a pan diastolic murmur and chronic obstructive pulmonary disease are described.
Plasma volume and extracellular fluid volume in horses at rest and following exercise.
American journal of veterinary research    May 1, 1978   Volume 39, Issue 5 871-874 
Kohn CW, Muir WW, Sams R.Plasma volume and extracellular fluid volume were determined in horses at rest and immediately after a standardized exercise test. Exercising during training demonstrated no detectable effect on plasma or extracellular fluid volume determinations when compared with resting values. An explanation of this finding and an argument for the proper analysis of plasma and extravascular fluid volumes are presented.
Influence of promazine on the venous haematocrit and plasma protein concentration in the horse.
Zentralblatt fur Veterinarmedizin. Reihe A    April 1, 1978   Volume 25, Issue 3 189-197 doi: 10.1111/j.1439-0442.1978.tb00919.x
de Moor A, van den Hende C, Moens Y, Desmet P.No abstract available
Tricuspid atresia in a foal.
Journal of the American Veterinary Medical Association    April 1, 1978   Volume 172, Issue 7 825-830 
Button C, Gross DR, Allert JA, Kitzman JV.An Arabian crossbred foal was examined because of a suspected congenital cardiac anomaly. There was a grade V/V crescendo-decresendo holosystolic murmur and thrill in the left 4th intercostal space. The foal was slightly cyanotic and polycythemic. Electrocardiography suggested left ventricular hypertrophy. Angiography and cardiac and vascular pressure recordings led to a diagnosis of pulmonic stenosis. The foal died after cardiac bypass and corrective surgery. Postmortem examination revealed an enlarged right atrium, atresia of the tricuspid orifice, a large, fenestrated patent foramen ovale, ...
Cardiovascular effects of halothane in the horse.
American journal of veterinary research    April 1, 1978   Volume 39, Issue 4 611-615 
Steffey EP, Howland D.Cardiovascular effects of venous alveolar concentrations of halothane in oxygen were studied in 8 young, healthy horses under conditions of constant arterial carbon dioxide tension. The alveolar concentration of halothane was expressed as a multiple of the minimal alveolar concentration (MAC) which was known for each animal. Increasing alveolar halothane concentrations to MAC 2.0 resulted in a progressive and significant (P less than 0.05) decline in systemic arterial pressure and left ventricular work. Cardiac output decreased between MAC 1.0 and MAC 2.0 as a result of a significant (P less t...
Artifact production with micromanometers used to record intracardiac pressure and sound.
Catheterization and cardiovascular diagnosis    January 1, 1978   Volume 4, Issue 3 275-282 doi: 10.1002/ccd.1810040309
Brown CM, Holmes JR.In horses experimental right and left heart catheterization using a catheter with two microtransducers 9 cm apart, usually in a transvalval position produced pressure and sound artifacts that confounded the diagnosis. Most were probably due to malpositioning resulting in movement through a valve during recording or impingement on the valve cusps or the chordae tendineae or lodgement in the apex of the heart. The recognition of these artifacts is particularly important in studies of large animals in which catheter siting cannot be monitored by radiography.
Indirect mean blood pressure in the anesthetized pony.
American journal of veterinary research    December 1, 1977   Volume 38, Issue 12 2055-2057 
Geddes LA, Chaffee V, Whistler SJ, Bourland JD, Tacker WA.No abstract available
Regional blood flow to the stomach and small intestine in ponies.
American journal of veterinary research    December 1, 1977   Volume 38, Issue 12 2047-2048 
Reddy VK, Kammula RG, Randolph A, Graham TC, Srungaram SK.Studies on regional blood flow to the stomach and small intestine were performed in 9 anesthetized ponies. Carbonized microspheres (15 +/- 5 micron in diameter) labeled with 85Sr were injected into the left atrium to determine blood flow distribution. In 4 ponies, the regional flows to mucosal-submucosal layers of the stomach and the small intestine were also measured. The nonglandular region of the stomach received the least blood per 100 g of tissue, and the duodenum received the greatest. The regional blood flow to the duodenum was significantly higher than that to the glandular stomach reg...
The value of arterial blood pressure measurement in assessing the prognosis in equine colic.
Equine veterinary journal    October 1, 1977   Volume 9, Issue 4 202-204 doi: 10.1111/j.2042-3306.1977.tb04030.x
Gay CC, Carter J, McCarthy M, Mason TA, Christie BA, Reynolds WT, Smyth B.Indirect arterial blood pressure was determined on 33 horses prior to surgical intervention for the diagnosis and/or correction of acute abdominal disorders and a relationship between low systolic blood pressure and non-survival was established. It is suggested that blood pressure determination should be used to augment other methods of clinical and laboratory examination in cases of equine colic.
Cardiac output, left ventricular ejection rate, plasma volume, and heart rate changes in equine laminitis-hypertension.
American journal of veterinary research    June 1, 1977   Volume 38, Issue 6 725-729 
Garner HE, Hahn AW, Salem C, Coffman JR, Hutcheson DP, Johnson JH.Acute laminitis-hypertension was produced experimentally by carbohydrate overloading of the gastrointestinal tract in 8 horses, and the resulting hemodynamic changes were measured. Statistically significant (P less than 0.01) increases in cardiac output, left ventricular ejection rate, heart rate, and arterial pressure were related to statistically nonsignificant changes in peripheral resistance and a delayed (Obel grade 3 plus 24 hours) decrease in plasma volume. When compared with control values, the doubling of cardiac output and left ventricular ejection rate simultaneous with little or no...
Influence of general anesthesia on peripheral resistance in the horse.
The British veterinary journal    May 1, 1977   Volume 133, Issue 3 225-230 doi: 10.1016/s0007-1935(17)34083-6
Hillidge CJ, Lees P.No abstract available
Left ventricular systole in conscious and anesthetized horses.
American journal of veterinary research    May 1, 1977   Volume 38, Issue 5 675-680 
Hillidge CJ, Lees P.No abstract available
Echocardiography in the horse.
Journal of the American Veterinary Medical Association    April 15, 1977   Volume 170, Issue 8 815-819 
Pipers FS, Hamlin RL.Echocardiograms were obtained from 25 standing, clinically normal horses, using an ultrasonic recording device. The echobeam penetrated the right thoracic wall in the area of the 4th to 5th intercostal space, with a frequency of 2.5 mHz. Measurements of left ventricular wall thickness generated a mean value of 3.2 +/- 0.18 (SEM)cm, whereas the left ventricular chamber diameter in diastole was 9.3 +/- 0.30 cm and in systole was 5.7 +/- 0.23 cm. The aortic root dimensions had a mean of 7.7 cm, with a SEM of 0.16. Mitral valve closing slope (E-F) was calculated to be 17.7 +/- 0.87 mm/second, and ...
1 25 26 27 28 29 31