Effect of heart rate and hypoxia on the performance of a perfused trout heart

1989 ◽  
Vol 67 (2) ◽  
pp. 274-280 ◽  
Author(s):  
A. P. Farrell ◽  
S. Small ◽  
M. S. Graham
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Oxygen Supply ◽  
Filling Pressure ◽  
Cardiac Performance ◽  
Isolated Perfused Heart ◽  
Adrenergic Stimulation ◽  
Perfused Heart ◽  
Filling Time ◽  
Cardiac Stroke Volume

While adrenergic stimulation and increased filling pressure of the heart are recognized to increase cardiac stroke volume in the trout heart, the effects of factors such as heart rate and oxygen supply have not been examined. The present study used isolated, saline-perfused trout hearts to determine the maximum cardiac performance during hypoxic perfusion and during changes in pacing frequency similar to the range of heart rate observed in intact trout. The threshold oxygen tension of the perfusate was between 25 and 46 Torr (3.33–6.13 kPa) for maintaining resting and maximum cardiac ouput, but was between 46 and 67 Torr (6.13 – 8.93 kPa) for maintaining maximum power output. Increasing the pacing frequency from 30 to 58 beats/min did not produce a proportionate increase in the maximum cardiac output because maximum stroke volume was reduced significantly. It is suggested that the reduction in maximum stroke volume occurs because atrial filling time is compromised at higher pacing frequencies in the isolated perfused heart.

scholarly journals Cardiac performance in the in situ perfused fish heart during extracellular acidosis: interactive effects of adrenaline

1983 ◽  
Vol 107 (1) ◽  
pp. 415-429 ◽  
Author(s):  
A. P. Farrell ◽  
K. R. MacLeod ◽  
W. R. Driedzic ◽  
S. Wood
Keyword(s):  
Stroke Volume ◽  
Cardiac Performance ◽  
Interactive Effects ◽  
Perfused Heart ◽  
Fish Heart ◽  
Extracellular Acidosis ◽  
Sea Raven ◽  
Filling Time ◽  
Inotropic Responses

The physiological integrity of the in situ perfused heart of the ocean pout was established by its ability to maintain cardiac output (Q) over a range of work loads, and by the dependence of Q upon the filling pressure of the heart. Similar observations have been reported previously for the in situ perfused heart of the sea raven. Physiological levels of extracellular acidosis (pH 7.6/1% CO2 and pH 7.4/2% CO2) significantly depressed cardiac performance in sea raven and ocean pout hearts in situ. Negative chronotropic and inotropic responses were observed. Adrenaline (AD; 10(−7) M) under control conditions (pH 7.9/0.5% CO2) produced a sustained tachycardia. The tachycardia reduced filling time of the ventricle and stroke volume was compromised because of the constant preload to the heart. Consequently, AD produced only an initial, transient increase in stroke volume and Q. Thereafter, stroke volume was reduced in proportion with the increase in heart rate, and Q remained unchanged. The combined challenge of extracellular acidosis and AD demonstrated interactive effects between AD and acidosis in situ. Q and power output were maintained in both species at both levels of extracellular acidosis during the combined challenge. Thus AD alone can maintain (but not improve upon) basal Q during extracellular acidosis. The effects of extracellular acidosis, circulating catecholamines and venous return pressure to the heart are discussed in relation to the regulation of Q following exhaustive exercise.

scholarly journals Non-invasive quantification of cardiac stroke volume in the edible crab Cancer pagurus

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Bastian Maus ◽  
Sebastian Gutsfeld ◽  
Hans-Otto Pörtner ◽  
Christian Bock
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Cardiac Performance ◽  
Severe Hypoxia ◽  
Cine Mri ◽  
Performance Parameters ◽  
Non Invasive ◽  
Cancer Pagurus ◽  
Cardiac Stroke Volume

Abstract Background Brachyuran crabs can effectively modulate cardiac stroke volume independently of heart rate in response to abiotic drivers. Non-invasive techniques can help to improve the understanding of cardiac performance parameters of these animals. This study demonstrates the in vivo quantification of cardiac performance parameters through magnetic resonance imaging (MRI) on the edible crab Cancer pagurus. Furthermore, the suitability of signal integrals of infra-red photoplethysmographs as a qualitative tool is assessed under severe hypoxia. Results Multi-slice self-gated cardiac cinematic (CINE) MRI revealed the structure and motion of the ventricle to quantify heart rates, end-diastolic volume, end-systolic volume, stroke volume and ejection fraction. CINE MRI showed that stroke volumes increased under hypoxia because of a reduction of end-systolic volumes at constant end-diastolic volumes. Plethysmograph recordings allowed for automated heart rate measurements but determination of a qualitative stroke volume proxy strongly depended on the position of the sensor on the animal. Both techniques revealed a doubling in stroke volumes after 6 h under severe hypoxia (water PO2 = 15% air saturation). Conclusions MRI has allowed for detailed descriptions of cardiac performance in intact animals under hypoxia. The temporal resolution of quantitative non-invasive CINE MRI is limited but should encourage further refining. The stroke volume proxy based on plethysmograph recordings is feasible to complement other cardiac measurements over time. The presented methods allow for non-destructive in vivo determinations of multiple cardiac performance parameters, with the possibility to study neuro-hormonal or environmental effects on decapod cardio physiology.

scholarly journals Effects of temperature, epinephrine and Ca2+ on the hearts of yellowfin tuna (Thunnus albacares)

2002 ◽  
Vol 205 (13) ◽  
pp. 1881-1888 ◽  
Author(s):  
Jason M. Blank ◽  
Jeffery M. Morrissette ◽  
Peter S. Davie ◽  
Barbara A. Block
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Temperature Dependence ◽  
Cardiac Performance ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Strong Temperature Dependence ◽  
Perfused Heart ◽  
Heart Preparation

SUMMARYTuna are endothermic fish with high metabolic rates, cardiac outputs and aerobic capacities. While tuna warm their skeletal muscle, viscera, brain and eyes, their hearts remain near ambient temperature, raising the possibility that cardiac performance may limit their thermal niches. We used an in situ perfused heart preparation to investigate the effects of acute temperature change and the effects of epinephrine and extracellular Ca2+ on cardiac function in yellowfin tuna (Thunnus albacares). Heart rate showed a strong temperature-dependence, ranging from 20 beats min-1 at 10 °C to 109 beats min-1 at 25 °C. Maximal stroke volume showed an inverse temperature-dependence,ranging from 1.4 ml kg-1 at 15 °C to 0.9 ml kg-1 at 25 °C. Maximal cardiac outputs were 27 ml kg-1 min-1at 10 °C and 98 ml kg-1 min-1 at 25 °C. There were no significant effects of perfusate epinephrine concentrations between 1 and 100 nmoll-1 at 20 °C. Increasing extracellular Ca2+ concentration from 1.84 to 7.36 mmoll-1 at 20°C produced significant increases in maximal stroke volume, cardiac output and myocardial power output. These data demonstrate that changes in heart rate and stroke volume are involved in maintaining cardiac output during temperature changes in tuna and support the hypothesis that cardiac performance may limit the thermal niches of yellowfin tuna.

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.

Analysis of heart rate-based control of arterial blood pressure

1996 ◽  
Vol 271 (2) ◽  
pp. H812-H822 ◽  
Author(s):  
W. C. Rose ◽  
J. S. Schwaber
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Vascular System ◽  
Reciprocal Relation ◽  
Arterial Baroreflex ◽  
Arterial Blood ◽  
Limited Effectiveness ◽  
Filling Time

Vagal control of the heart is the most rapidly responding limb of the arterial baroreflex. We created a mathematical model of the left heart and vascular system to evaluate the ability of heart rate to influence blood pressure. The results show that arterial pressure depends nonlinearly on rate and that changes in rate are of limited effectiveness, particularly when rate is increased above the basal level. A 10% change in heart rate from rest causes a change of only 2.4% in arterial pressure due to the reciprocal relation between heart rate and stroke volume; at higher rates, insufficient filling time causes stroke volume to fall. These findings agree well with published experimental data and challenge the idea that changes in heart rate alone can strongly and rapidly affect arterial pressure. Possible implications are that vagally mediated alterations in inotropic and dromotropic state, which are not included in this model, play important roles in the fast reflex control of blood pressure or that the vagal limb of the baroreflex is of rather limited effectiveness.

Cardiac performance in relation to oxygen supply varies with dietary lipid composition in sturgeon

1996 ◽  
Vol 271 (2) ◽  
pp. R417-R425 ◽  
Author(s):  
C. Agnisola ◽  
D. J. McKenzie ◽  
E. W. Taylor ◽  
C. L. Bolis ◽  
B. Tota
Keyword(s):  
Fatty Acids ◽  
Heart Rate ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Oxygen Supply ◽  
Cardiac Performance ◽  
Beneficial Effects ◽  
Dietary Fatty Acid Composition

Dietary polyunsaturated fatty acids (PUFA) of the n-3 series that have beneficial effects on mammalian heart function are typically found at high levels in fish tissues. The effects of dietary fatty acid composition on cardiac function were investigated in the sturgeon. When compared with sturgeon maintained for 1 yr on a diet enriched with saturated fatty acids (SFA) (the coconut oil-supplemented diet, COD), sturgeon maintained on a diet enriched with n-3 PUFA (the fish oil-supplemented diet, FOD) had higher myocardial 20:5(n-3) and lower 20:4(n-6) content with a consequent decrease in the n-6-to-n-3 ratio (from 0.86 to 0.25) and a lower intrinsic in vitro heart rate (22.0 +/- 1.5 vs. 29.9 +/- 1.0 beats/min) and cardiac power output (PO) (0.33 +/- 0.08 vs. 0.48 +/- 0.03 mW/g), but had a greater in vitro scope for cardiac work (almost twice the maximal-to-basal PO ratio). Reducing the oxygen supply to the hearts significantly decreased, by approximately 40%, the maximal in vitro PO in the COD group of animals but had no effect in the FOD group. These differences in performance were not reflected in heart rate or blood pressure in vivo, either in normoxia or hypoxia. Addition of vitamin E as an antioxidant to the diets reduced intrinsic heart rate by approximately 25% but did not influence the effects (dietary fatty acid composition on in vitro cardiac performance. The results indicate that dietary n-3 PUFA can have beneficial effects on the resistance of the fish heart to environmental stressors such as hypoxia.

scholarly journals THE INTRINSIC PROPERTIES OF AN IN SITU PERFUSED CROCODILE HEART

1994 ◽  
Vol 186 (1) ◽  
pp. 269-288 ◽  
Author(s):  
C. Franklin ◽  
M. Axelsson
Keyword(s):  
Pulmonary Artery ◽  
Stroke Volume ◽  
Right Ventricular ◽  
Filling Pressure ◽  
Perfused Heart ◽  
Output Pressure ◽  
Heart Preparation ◽  
Left And Right ◽  
The Right

An in situ perfused crocodile (Crocodylus porosus) heart preparation was developed to investigate the effects of input and output pressure on cardiac dynamics and to determine the conditions that lead to a right-to-left cardiac shunt. The pericardium was kept intact, both the left and right atria were perfused and all three outflow tracts (right aortic, left aortic and pulmonary) were cannulated, enabling pressures and flows to be monitored. The perfused heart preparation had an intrinsic heart rate of 34 beats min-1 and generated a physiological power output. Both the left and right sides of the heart were sensitive to filling pressure. Increasing the filling pressure to both atria resulted in an increase in stroke volume and cardiac output (Frank­Starling effect). Increasing the filling pressure to the right atrium also had a positive chronotropic effect. Large right ventricular stroke volumes initiated a right-to-left shunt, despite the left aorta having a pressure 1.5 kPa higher than the pulmonary output pressure. The left ventricle was able to maintain its output and stroke volume up to an output pressure of approximately 8 kPa. However, the right ventricle was significantly weaker. Right ventricular output and stroke volume showed a marked decrease when the output pressure was increased above 5 kPa. A right-to-left shunt occurred when pulmonary output pressure was increased. Surprisingly, a shunt occurred into the left aorta before the pressure in the pulmonary artery became greater than that in the left aorta. Once the pressure in the pulmonary artery exceeded the left aortic pressure, pulmonary artery flow ceased and right ventricular output was solely via the left aorta. A right-to-left shunt could also be initiated by increasing the filling pressure to the left atrium.

THE ANTIACCELERATOR EFFECT OF VERATRAMINE ON THE ISOLATED PERFUSED HEART OF THE CAT

1957 ◽  
Vol 35 (3) ◽  
pp. 173-179 ◽  
Author(s):  
Maurice F. Murnaghan
Keyword(s):  
Heart Rate ◽  
Coronary Flow ◽  
Elevated Level ◽  
Isolated Perfused Heart ◽  
Perfused Heart ◽  
The Mean

When isopropylarterenol was continuously infused in the isolated perfused heart of the cat, the heart rate remained at a steady elevated level for more than 2 hours. Veratramine selectively antagonized the accelerator effect of isopropylarterenol, and the dose required to cause a 50% reduction in acceleration (I50) was determined. The mean I50 value in 13 experiments (mean of the 13 individual I50 values) is 0.415 micromolar (μM) with fiducial limits of 0.182–0.648. Cardiac irregularities, arising from the sinoauricular node, occurred in seven out of 13 experiments after the administration of veratramine. The results indicate that in this preparation coronary flow is related to amplitude but is independent of heart rate.

THE ANTIACCELERATOR EFFECT OF VERATRAMINE ON THE ISOLATED PERFUSED HEART OF THE CAT

1957 ◽  
Vol 35 (1) ◽  
pp. 173-179
Author(s):  
Maurice F. Murnaghan
Keyword(s):  
Heart Rate ◽  
Coronary Flow ◽  
Elevated Level ◽  
Isolated Perfused Heart ◽  
Perfused Heart ◽  
The Mean

When isopropylarterenol was continuously infused in the isolated perfused heart of the cat, the heart rate remained at a steady elevated level for more than 2 hours. Veratramine selectively antagonized the accelerator effect of isopropylarterenol, and the dose required to cause a 50% reduction in acceleration (I50) was determined. The mean I50 value in 13 experiments (mean of the 13 individual I50 values) is 0.415 micromolar (μM) with fiducial limits of 0.182–0.648. Cardiac irregularities, arising from the sinoauricular node, occurred in seven out of 13 experiments after the administration of veratramine. The results indicate that in this preparation coronary flow is related to amplitude but is independent of heart rate.

Hemodynamic effects of cardiac cycle-specific increases in intrathoracic pressure

1986 ◽  
Vol 60 (2) ◽  
pp. 604-612 ◽  
Author(s):  
M. R. Pinsky ◽  
G. M. Matuschak ◽  
L. Bernardi ◽  
M. Klain
Keyword(s):  
Stroke Volume ◽  
Cardiac Cycle ◽  
Intrathoracic Pressure ◽  
Canine Model ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Cardiac Performance ◽  
Hemodynamic Effects ◽  
Volume Measurements ◽  
Systemic Venous Return

Changes in intrathoracic pressure (ITP) can influence cardiac performance by affecting ventricular loading conditions. Because both systemic venous return and factors determining left ventricular (LV) ejection may vary over the cardiac cycle, phasic increases in ITP may differentially affect preload or afterload if delivered at specific points within the cardiac cycle. We studied the hemodynamic effects of cardiac cycle-specific increases in ITP (pulses) delivered by a high-frequency jet ventilator in an acute closed-chested canine model (n = 11), using electromagnetic flow probes to measure biventricular stroke volume. Measurements were taken during a control condition after the induction of acute ventricular failure (AVF) by propranolol hydrochloride and volume infusion. ITP was independently varied without changing lung volume by the inflation of thoracoabdominal binders. Although synchronous pulses had minimal hemodynamic effects in unbound controls, binding pulses timed to occur in early diastole resulted in decreases in LV filling pressure and left ventricular stroke volume (SVlv) (P less than 0.05). In the AVF condition, pulses increased LV performance, evidenced by increases in SVlv (P less than 0.01), despite decreases in LV filling pressure (P less than 0.05). This effect is maximized by binding and by timing the pulses to occur in systole. We conclude that cardiac cycle-specific increases in ITP can significantly affect cardiac performance. These effects appear to be related to the ability of such timed pulses to selectively affect LV preload and afterload.

Sign in / Sign up

Export Citation Format

Share Document