Heart rate and stroke volume contribution to cardiac output in swimming yellowfin tuna: response to exercise and temperature.

1997 ◽  
Vol 200 (14) ◽  
pp. 1975-1986 ◽  
Author(s):  
K E Korsmeyer ◽  
N C Lai ◽  
R E Shadwick ◽  
J B Graham
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Fork Length ◽  
Yellowfin Tuna ◽  
Swimming Velocity ◽  
Flow Measurements ◽  
C 30 ◽  
Blood Flow Measurements

Cardiac performance in the yellowfin tuna (Thunnus albacares, 673-2470 g, 33-53 cm fork length, FL) was examined in unanesthetized fish swimming in a large water tunnel. Yellowfin tuna were fitted with either electrocardiogram electrodes or a transcutaneous Doppler blood-flow probe over the ventral aorta and exposed to changes in swimming velocity (range 0.8-2.9 FLs-1) or to an acute change in temperature (18-28 degrees C). Heart rates (fH) at +/-1 degree C (30-130 beats min-1) were lower on average than previous measurements with non-swimming (restrained) tunas and comparable with those for other active teleosts at similar relative swimming velocities. Although highly variable among individuals, fH increased with velocity (U, in FLs-1) in all fish (fH = 17.93U + 49.93, r2 = 0.14, P < 0.0001). Heart rate was rapidly and strongly affected by temperature (Q10 = 2.37). Blood flow measurements revealed a mean increase in relative cardiac output of 13.6 +/- 3.0% with exercise (mean velocities 1.23-2.10 FLs-1) caused by an 18.8 +/- 5.4% increase in fH and a 3.9 +/- 2.3% decrease in stroke volume. These results indicate that, unlike most other fishes, cardiac output in yellowfin tuna is regulated primarily through increases in fH. Acute reductions in ambient temperature at slow swimming velocities resulted in decreases in cardiac output (Q10 = 1.52) and fH (Q10 = 2.16), but increases in stroke volume (Q10 = 0.78). This observation suggests that the lack of an increase in stroke volume during exercise is not due to the tuna heart operating at maximal anatomical limits.

Cardiovascular Changes in Preterm Infants Nursed Under Radiant Warmers

PEDIATRICS ◽  
1987 ◽  
Vol 80 (2) ◽  
pp. 235-239
Author(s):  
Frans J. Walther ◽  
Paul Y.K. Wu ◽  
Bijan Siassi
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Newborn Infants ◽  
Cardiovascular Effects ◽  
Radiant Heat ◽  
Flow Measurements ◽  
Blood Flow Measurements ◽  
Radiant Warmer

Radiant heat is known to increase insensible water loss and, to a certain extent, oxygen consumption. Little is known about its cardiovascular effects. We measured cardiac output, stroke volume, heart rate, and lower limb and skin blood flow in 20 preterm newborn infants nursed in an incubator and under a radiant warmer at an abdominal skin temperature of 36.5°C. Mean (±SEM) birth weight was 1.57 (0.06) kg, gestational age 31.7 (0.4) weeks, and weight at examination 1.69 (0.02) kg; median postnatal age was 15 days. Skin and limb blood flow measurements increased by 44% to 55% with radiant heat (P < .001 and P < .01, respectively). Cardiac output increased by 5.4% (P < .02) under the radiant warmer secondary to a small but significant (P < .05) increase in heart rate. The changes in cardiac output during radiant heat administration are comparable to those reported for oxygen consumption.

Effect of exercise on cardiac output and distribution of uterine blood flow in pregnant ewes

1976 ◽  
Vol 40 (5) ◽  
pp. 725-728 ◽  
Author(s):  
L. B. Curet ◽  
J. A. Orr ◽  
H. G. Rankin ◽  
T. Ungerer
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Stroke Volume ◽  
Physical Training ◽  
Exercise Stress ◽  
Compensatory Mechanism ◽  
Uterine Blood Flow ◽  
Flow Measurements ◽  
Before And After ◽  
Blood Flow Measurements

This study was designed to determine what effect physical training has on heart rate and stroke volume responses to exercise stress and to determine if exercise altered the distribution of uterine blood flow. Measurements were made in ten pregnant ewes at rest and immediately following exercise on a treadmill. Five ewes underwent physical training for 3 wk prior to measurement. An increase in heart rate with no change in stroke volume was observed following exercise in both trained and untrained ewes. Total uterine blood flow was not changed following exercise, but distribution was altered in favor of the placenta. Blood flow was evenly distributed within the placenta before and after exercise. The redistribution of flow to the placenta that occurs after exercise. tphe redistribution of flow to the placenta that occurs after exercise might represent a compensatory mechanism for the fetus.

scholarly journals Development of a Simple ImageJ-Based Method for Dynamic Blood Flow Tracking in Zebrafish Embryos and Its Application in Drug Toxicity Evaluation

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 65 ◽  
Author(s):  
Fiorency Santoso ◽  
Bonifasius Putera Sampurna ◽  
Yu-Heng Lai ◽  
Sung-Tzu Liang ◽  
Erwei Hao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Blood Cell ◽  
Stroke Volume ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Video Recording ◽  
Cardiovascular Function ◽  
Zebrafish Embryos

This study aimed to develop a simple and cost-effective method to measure blood flow in zebrafish by using an image-based approach. Three days post fertilization (dpf) zebrafish embryos were mounted with methylcellulose and subjected to video recording for tracking blood flow under an inverted microscope equipped with a high-speed CCD camera. In addition, Hoffman lens was used to enhance the blood cell contrast. The red blood cell movement was tracked by using the TrackMate plug-in in the ImageJ image processing program. Moreover, Stack Difference and Time Series Analyzer plug-in were used to detect dynamic pixel changes over time to calculate the blood flow rate. In addition to blood flow velocity and heart rate, the effect of drug treatments on other cardiovascular function parameters, such as stroke volume and cardiac output remains to be explored. Therefore, by using this method, the potential side effects on the cardiovascular performance of ethyl 3-aminobenzoate methanesulfonate (MS222) and 3-isobutyl-1-methylxanthine (IBMX) were evaluated. MS222 is a common anesthetic, while IBMX is a naturally occurring methylxanthine. Compared to normal embryos, MS222- and IBMX-treated embryos had a reduced blood flow velocity by approximately 72% and 58%, respectively. This study showed that MS222 significantly decreased the heart rate, whereas IBMX increased the heart rate. Moreover, it also demonstrated that MS222 treatment reduced 50% of the stroke volume and cardiac output. While IBMX decreased the stroke volume only. The results are in line with previous studies that used expensive instruments and complicated software analysis to assess cardiovascular function. In conclusion, a simple and low-cost method can be used to study blood flow in zebrafish embryos for compound screening. Furthermore, it could provide a precise measurement of clinically relevant cardiac functions, specifically heart rate, stroke volume, and cardiac output.

Leg crossing with muscle tensing, a physical counter-manoeuvre to prevent syncope, enhances leg blood flow

2007 ◽  
Vol 112 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Jan T. Groothuis ◽  
Nynke van Dijk ◽  
Walter ter Woerds ◽  
Wouter Wieling ◽  
Maria T. E. Hopman
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Orthostatic Intolerance ◽  
Peripheral Resistance ◽  
Haemodynamic Effects ◽  
Vascular Conductance ◽  
Leg Blood Flow ◽  
Head Up Tilt

In patients with orthostatic intolerance, the mechanisms to maintain BP (blood pressure) fail. A physical counter-manoeuvre to postpone or even prevent orthostatic intolerance in these patients is leg crossing combined with muscle tensing. Although the central haemodynamic effects of physical counter-manoeuvres are well documented, not much is known about the peripheral haemodynamic events. Therefore the purpose of the present study was to examine the peripheral haemodynamic effects of leg crossing combined with muscle tensing during 70° head-up tilt. Healthy subjects (n=13) were monitored for 10 min in the supine position followed by 10 min in 70° head-up tilt and, finally, for 2 min of leg crossing with muscle tensing in 70° head-up tilt. MAP (mean arterial BP), heart rate, stroke volume, cardiac output and total peripheral resistance were measured continuously by Portapres. Leg blood flow was measured using Doppler ultrasound. Leg vascular conductance was calculated as leg blood flow/MAP. A significant increase in MAP (13 mmHg), stroke volume (27%) and cardiac output (18%), a significant decrease in heart rate (−5 beats/min) and no change in total peripheral resistance during the physical counter-manoeuvre were observed when compared with baseline 70° head-up tilt. A significant increase in leg blood flow (325 ml/min) and leg vascular conductance (2.9 arbitrary units) were seen during the physical counter-manoeuvre when compared with baseline 70° head-up tilt. In conclusion, the present study indicates that the physical counter-manoeuvre of leg crossing combined with muscle tensing clearly enhances leg blood flow and, at the same time, elevates MAP.

Systemic and uterine responses to chronic infusion of estradiol-17 beta

1993 ◽  
Vol 265 (5) ◽  
pp. E690-E698 ◽  
Author(s):  
R. R. Magness ◽  
C. R. Parker ◽  
C. R. Rosenfeld
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Angiotensin Ii ◽  
Mean Arterial Pressure ◽  
Stroke Volume ◽  
Ang Ii ◽  
Uterine Blood Flow ◽  
Pressor Responses ◽  
Chronic Infusion

Human and ovine pregnancies are associated with increases in plasma levels of estrogens and angiotensin II (ANG II), cardiac output (CO), blood volume (BV), and uterine blood flow (UBF), as well as attenuated ANG II pressor responses. We hypothesized that, in nonpregnant animals, prolonged estradiol-17 beta (E2 beta) treatment would reproduce these endocrine and hemodynamic alterations. Nonpregnant ovariectomized ewes (n = 5) received 5 microgram E2 beta/kg iv followed by 220 micrograms/day for 14 days. Plasma E2 beta increased from 36 +/- 6 to 269 +/- 79 (SE) pg/ml (P < 0.05) during E2 beta treatment, returning to control values 4 days posttreatment. By 3 days of E2 beta, mean arterial pressure (MAP) and systemic vascular resistance (SVR) fell 9 +/- 1 and 29 +/- 1%, whereas heart rate (HR) and CO increased 20 +/- 5 and 26 +/- 1% (P < 0.05). Stroke volume (SV), BV, and plasma volume were unchanged until 7 days of E2 beta, with values rising 17 +/- 5, 13 +/- 3, and 14 +/- 4, respectively (P < 0.05). Although MAP remained similarly depressed (-11 +/- 1%) during week 2 of E2 beta, SVR decreased further (-37 +/- 3%) and was associated with additional increases (P < 0.05) in CO to 44 +/- 5%, reflecting rises in SV (21 +/- 2%) but not HR. Increases in BV correlated with rises in CO (r = 0.55) and SV (r = 0.64) but not HR (r = -0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Stroke volume decline during prolonged exercise is influenced by the increase in heart rate

1999 ◽  
Vol 86 (3) ◽  
pp. 799-805 ◽  
Author(s):  
Ricardo G. Fritzsche ◽  
Thomas W. Switzer ◽  
Bradley J. Hodgkinson ◽  
Edward F. Coyle
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Prolonged Exercise ◽  
Placebo Control ◽  
Cutaneous Blood Flow ◽  
Con A ◽  
Adrenoceptor Blocker ◽  
Cutaneous Blood

This study determined whether the decline in stroke volume (SV) during prolonged exercise is related to an increase in heart rate (HR) and/or an increase in cutaneous blood flow (CBF). Seven active men cycled for 60 min at ∼57% peak O2 uptake in a neutral environment (i.e., 27°C, <40% relative humidity). They received a placebo control (CON) or a small oral dose (i.e., ∼7 mg) of the β1-adrenoceptor blocker atenolol (BB) at the onset of exercise. At 15 min, HR and SV were similar during CON and BB. From 15 to 55 min during CON, a 13% decline in SV was associated with an 11% increase in HR and not with an increase in CBF. CBF increased mainly from 5 to 15 min and remained stable from 20 to 60 min of exercise in both treatments. However, from 15 to 55 min during BB, when the increase in HR was prevented by atenolol, the decline in SV was also prevented, despite a normal CBF response (i.e., similar to CON). Cardiac output was similar in both treatments and stable throughout the exercise bouts. We conclude that during prolonged exercise in a neutral environment the decline in SV is related to the increase in HR and is not affected by CBF.

scholarly journals Central and peripheral contributors to skeletal muscle hyperemia: response to passive limb movement

2010 ◽  
Vol 108 (1) ◽  
pp. 76-84 ◽  
Author(s):  
John McDaniel ◽  
Anette S. Fjeldstad ◽  
Steve Ives ◽  
Melissa Hayman ◽  
Phil Kithas ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Limb Movement ◽  
Leg Blood Flow ◽  
Passive Exercise

The central and peripheral contributions to exercise-induced hyperemia are not well understood. Thus, utilizing a reductionist approach, we determined the sequential peripheral and central responses to passive exercise in nine healthy men (33 ± 9 yr). Cardiac output, heart rate, stroke volume, mean arterial pressure, and femoral blood flow of the passively moved leg and stationary (control) leg were evaluated second by second during 3 min of passive knee extension with and without a thigh cuff that occluded leg blood flow. Without the thigh cuff, significant transient increases in cardiac output (1.0 ± 0.6 l/min, Δ15%), heart rate (7 ± 4 beats/min, Δ12%), stroke volume (7 ± 5 ml, Δ7%), passive leg blood flow (411 ± 146 ml/min, Δ151%), and control leg blood flow (125 ± 68 ml/min, Δ43%) and a transient decrease in mean arterial pressure (3 ± 3 mmHg, 4%) occurred shortly after the onset of limb movement. Although the rise and fall rates of these variables differed, they all returned to baseline values within 45 s; therefore, continued limb movement beyond 45 s does not maintain an increase in cardiac output or net blood flow. Similar changes in the central variables occurred when blood flow to the passively moving leg was occluded. These data confirm the role of peripheral factors and reveal an essential supportive role of cardiac output in the hyperemia at the onset of passive limb movement. This cardiac output response provides an important potential link between the physiology of active and passive exercise.

Cardiovascular changes associated with thermal polypnea in the chicken

1964 ◽  
Vol 207 (6) ◽  
pp. 1349-1353 ◽  
Author(s):  
G. C. Whittow ◽  
P. D. Sturkie ◽  
G. Stein
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Respiratory Rate ◽  
Peripheral Resistance ◽  
Flow Through ◽  
Skin Temperatures ◽  
Increased Blood Flow

The effect of hyperthermia on the respiratory rate, cardiac output, blood pressure, arterial hematocrit, and the skin temperatures of the extremities of unanesthetized hens has been investigated. During hyperthermia, the respiratory rate increased to a maximal value and then declined. There was also an increase in cardiac output, followed by a decrease, but the peak cardiac output occurred at a rectal temperature which was significantly higher than that at which the peak respiratory rate was recorded. The increase in cardiac output was the result of an increase in both stroke volume and heart rate. The diminution of cardiac output seemed to be related to a decrease in the stroke volume at high levels of heart rate. The decrease in blood pressure and total peripheral resistance was attributed partly to an increased blood flow through the extremities.

scholarly journals Head-up suspension in humans: effects on sympathetic vasomotor activity and cardiovascular responses

1998 ◽  
Vol 84 (5) ◽  
pp. 1513-1519 ◽  
Author(s):  
A. S. M. Shamsuzzaman ◽  
Y. Sugiyama ◽  
A. Kamiya ◽  
Q. Fu ◽  
T. Mano
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Left Atrial ◽  
Muscle Sympathetic Nerve Activity ◽  
Cardiovascular Responses ◽  
Left Atrial Diameter ◽  
Calf Blood Flow ◽  
Significant Difference

We hypothesized that muscle sympathetic nerve activity (MSNA) and cardiovascular responses to the conventional head-up tilt (HUT) are different from those to head-up suspension (HUS) because of antigravity muscle activity. The MSNA from the tibial nerve, heart rate, blood pressure, stroke volume, cardiac output, and calf blood flow were measured in 13 healthy young subjects. Left atrial diameter was measured by two-dimensional echocardiography in another nine subjects. The resting MSNA and cardiovascular responses at a low level (20°) of orthostasis were similar during both modes. At higher levels (40 and 60°), the responses of MSNA, heart rate, stroke volume, and cardiac output were significantly stronger and there was a smaller reduction in calf blood flow during HUT than during HUS ( P < 0.05). Left atrial diameter was decreased significantly from the resting values during HUT and HUS without any significant difference between the modes of orthostasis. The results provide evidence that the engagement of antigravity muscles during HUT may have additive effects on sympathetic vasoconstrictor and cardiovascular responses to orthostatic stress.

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