Use of the cardiopulmonary flow index to evaluate cardiac function in Thoroughbred horses

1991 ◽  
Vol 62 (2) ◽  
pp. 43-47 ◽  
Author(s):  
A. J. Guthrie ◽  
Valerie M. Killeen ◽  
Maria S.G. Mülders ◽  
J. F.W. Grosskopf
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiac Function ◽  
Cardiac Disease ◽  
Clinical Signs ◽  
Simultaneous Recording ◽  
Flow Index ◽  
Heart Rates ◽  
Thoroughbred Horses ◽  
The Mean

The ratio of the cardiopulmonary blood volume to stroke volume is called the cardiopulmonary flow index (CPFI). The CPFI can be determined indirectly from the simultaneous recording of a radio cardiogram and an electrocardiogram. The CPFI and cardiac output were measured simultaneously in horses (n = 10) that were diagnosed as having cardiac disease. The diseased subjects were probably all exposed to feed contaminated with the ionophore, salinomycin, and all showed clinical signs indicative of chronic toxic myocarditis. The results obtained from these subjects were compared with those from control animals and significant differences (P 0,05) were found between the mean CPFI of the control horses and those with macroscopically visible myocardial fibrosis on post mortem examination. No significant differences were found between the means of the cardiac output measured in either of the groups of horses. The effect of pharmacological acceleration of the heart rate on the CPFI was also studied. Significant differences (P 0,05) were found between the mean CPFI and the slopes of the regression lines of CPFI on heart rate of the control and principal groups of horses. These differences were greatest at heart rates near to the resting heart rates of the individuals. The CPFI was found to be a more sensitive measure of cardiac function than cardiac output, in the horses.

scholarly journals Heart rates and swim speeds of emperor penguins diving under sea ice

1992 ◽  
Vol 165 (1) ◽  
pp. 161-180 ◽  
Author(s):  
G. L. Kooyman ◽  
P. J. Ponganis ◽  
M. A. Castellini ◽  
E. P. Ponganis ◽  
K. V. Ponganis ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Sea Ice ◽  
Body Mass ◽  
Anaerobic Glycolysis ◽  
Energy Contribution ◽  
Heart Rates ◽  
Emperor Penguins ◽  
The Mean

Heart rate during overnight rest and while diving were recorded from five emperor penguins with a microprocessor-controlled submersible recorder. Heart rate, cardiac output and stroke volume were also measured in two resting emperor penguins using standard electrocardiography and thermodilution measurements. Swim velocities from eight birds were obtained with the submersible recorder. The resting average of the mean heart rates was 72 beats min-1. Diving heart rates were about 15% lower than resting rates. Cardiac outputs of 1.9-2.9 ml kg-1 s-1 and stroke volumes of 1.6-2.7 ml kg-1 were similar to values recorded from mammals of the same body mass. Swim velocities averaged 3 m s-1. The swim speeds and heart rates suggest that muscle O2 depletion must occur frequently: therefore, many dives require a significant energy contribution from anaerobic glycolysis.

scholarly journals Synergistic Effects between Phosphorylation of Phospholamban and Troponin I Promote Relaxation at Higher Heart Rate

2011 ◽  
Vol 2011 ◽  
pp. 1-10
Author(s):  
Lin Zhang ◽  
Yuan Yu ◽  
Zhen Song ◽  
Yun-Ying Wang ◽  
Zhi-Bin Yu
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiac Function ◽  
Troponin I ◽  
Synergistic Effects ◽  
Stimulation Frequency ◽  
Diastolic Filling ◽  
Relaxant Effect ◽  
Heart Rates ◽  
Working Heart

We hypothesized that the extent of frequency-dependent acceleration of relaxation (FDAR) would be less than that of isoproterenol-(ISO-)dependent acceleration of relaxation (IDAR) at the same increment of heart rates, and ISO may improve FDAR. Cardiac function and phosphorylation of PLB and cTnI were compared in pacing, ISO treatment, and combined pacing and ISO treatment in isolated working heart. The increase in cardiac output and the degree of relaxation was less in pacing than in ISO treatment at the same increment of heart rates. The increasing stimulation frequency induced more significant relaxant effect in ISO perfusion than that in physiological salt perfusion. The pacing only phosphorylated PLB at Thr17, but ISO induced phosphorylation of cTnI and PLB at Ser16 and Thr17. Those results suggest that the synergistic effects of PLB and cTnI induce higher degree of relaxation which makes a sufficient diastolic filling of the ventricle at higher heart rate.

Heart rate as a marker of relapse during withdrawal of heart failure therapy in patients with recovered dilated cardiomyopathy: an analysis from TRED-HF

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B Halliday ◽  
A Vazir ◽  
R Owen ◽  
J Gregson ◽  
R Wassall ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Function ◽  
Dilated Cardiomyopathy ◽  
Funding Source ◽  
End Point ◽  
Therapy Withdrawal ◽  
The Mean ◽  
Withdrawal Of Therapy ◽  
Continue Therapy

Abstract Introduction In TRED-HF, 40% of patients with recovered dilated cardiomyopathy (DCM) relapsed in the short-term during phased withdrawal of drug therapy. Non-invasive markers of relapse may be used to monitor patients who wish a trial of therapy withdrawal and provide insights into the pathophysiological drivers of relapse. Purpose To investigate the relationship between changes in heart rate (HR) and relapse amongst patients with recovered DCM undergoing therapy withdrawal in TRED-HF. Methods Patients with recovered DCM were randomised to phased withdrawal of therapy or to continue therapy for 6 months. After 6 months of continued therapy, those in the control arm underwent withdrawal of therapy in a single arm crossover phase. HR was measured at each study visit. Mean HR and 95% confidence intervals (CI) were calculated at baseline, 45 days after baseline, 45 days prior to the end of the study or relapse and at the end of the study or relapse. Patients were stratified by treatment arm and the occurrence of the primary relapse end-point. Heart rate at follow-up was compared amongst patients who had therapy withdrawn and relapsed versus those who had therapy withdrawn and did not. ANCOVA was used to adjust for differences in HR at baseline between the two groups. Results Of 51 patients randomised, 26 were assigned to continue therapy and 25 to withdraw therapy. In the randomised and cross-over phases, 20 patients met the primary relapse end-point; one patient withdrew from the study and one patient completed follow-up in the control arm but did not enter the cross-over phase. Mean HR (standard deviation) at baseline and follow-up for (i) patients in the control arm was 69.9 (9.8) & 65.9 (9.1) respectively; (ii) for those who had therapy withdrawn and did not relapse was 64.6 (10.7) & 74.7 (10.4) respectively; and (iii) for those who had therapy withdrawn and relapsed was 68.3 (11.3) & 86.1 (11.8) respectively [all beats per minute]. The mean change in HR between the penultimate visit and the final visit for those who had therapy withdrawn and did not relapse was −2.4 (9.7) compared to 3.1 (15.5) for those who relapsed. After adjusting for differences in HR at baseline, the mean difference in HR measured at follow-up between patients who underwent therapy withdrawal and did, and did not relapse was 10.4bpm (95% CI 4.0–16.8; p=0.002) (Figure 1 & Table 1). Conclusion(s) A larger increase in HR may be a simple and effective marker of relapse for patients with recovered DCM who have insisted on a trial of therapy withdrawal. Whether HR control is crucial to the maintenance of remission amongst patients with improved cardiac function, or is simply a marker of deteriorating cardiac function, warrants further investigation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation

Anticipatory, exercise, and recovery heart rates of girls as affected by four running events

1964 ◽  
Vol 19 (5) ◽  
pp. 853-856 ◽  
Author(s):  
Vera Skubic ◽  
Jane Hilgendorf
Keyword(s):  
Heart Rate ◽  
Cardiac Function ◽  
Heart Rate Response ◽  
Heart Rates

The heart rate response to running various distances was studied using five highly trained girls as subjects. A telemetering instrument was employed so that the testing could be done under actual sport conditions. The findings indicated that 1) the anticipatory heart rate just prior to exercise represented 59% of the total adjustment to exercise, 2) the heart rates during exercise were 2.5 times the resting values, and 3) heart rates observed at the end of the 220-, 440-, 880-yard, and mile events were simila cardiac function; exercise Submitted on October 22, 1963

scholarly journals Non-Invasive Scale Measurement of Cardiac Output Compared with the Gold-Standard Direct Fick Method: A Feasibility Study

2021 ◽  
Author(s):  
Daniel Yazdi ◽  
Sarin Patel ◽  
Suriya Sridaran ◽  
Evan Wilson ◽  
Sarah Smith ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Exercise Test ◽  
Gold Standard ◽  
Cardiopulmonary Exercise Test ◽  
Cardiac Monitoring ◽  
Non Invasive ◽  
Cardiopulmonary Exercise ◽  
The Mean

AbstractBackgroundObjective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions.ObjectiveWe assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared to the gold-standard direct Fick method.MethodsThirty-two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test.ResultsStroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r = 0.81 and r = 0.85, respectively (P < 0.001 each). The mean absolute error of the scale estimated stroke volume was -1.58 mL, with a 95% limits of agreement (LOA) of -21.97 mL to 18.81 mL. The mean error for the scale estimated cardiac output was -0.31 L/min, with a 95% LOA of -2.62 L/min to 2.00 L/min. The change in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively between the two measuring methods.ConclusionsThis novel scale with cardiac monitoring abilities may allow for non-invasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.

Pulsatile Flow Characteristics in a Stenotic Aortic Valve Model: An In Vitro Experimental Study

2019 ◽  
Author(s):  
Ruihang Zhang ◽  
Yan Zhang
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Aortic Valve ◽  
Pulsatile Flow ◽  
Heart Diseases ◽  
Flow Characteristics ◽  
Aortic Valve Area ◽  
Heart Rates ◽  
Valvular Heart Diseases

Abstract Aortic stenosis (AS) is one of the most common valvular heart diseases around the globe. The accurate assessment of AS severity is important and strongly associated with accurate interpretation of the hemodynamic parameters across the stenotic valve. In this study, we conducted in vitro fluid dynamic experiments to investigate the pulsatile flow characteristics of a stenotic aortic valve as a function of heart rate. An in vitro cardiovascular flow simulator was used to generate pulsatile flow with a prescribed waveform (40% systolic period and 4L/min cardiac output) under varied heart rates (50 bpm, 75 bpm and 100 bpm). The stenotic valve was constructed by molding silicone into three-leaflet aortic valve geometries wrapping around thin fabrics which increases its stiffness and tensile strength. Two-dimensional phase-locked particle image velocimetry (PIV) was employed to quantify the flow field characteristics of the stenotic valve. Pressure waveforms were recorded to evaluate the severity of the stenosis via the Gorlin and Hakki equations. Results suggest that as the heart rate increases, the peak pressure gradient across the stenotic aortic valve increases significantly under the same cardiac output. Analysis also shows the estimated aortic valve area (AVA) decreases as the heart rate increases under the same cardiac output using Gorlin equation estimation, while the trend is reversed using Hakki equation estimation. Under phase-locked conditions, quantitative flow characteristics, such as phase-averaged flow velocity, turbulence kinetic energy (TKE) for the stenotic aortic valve were analyzed based on the PIV data. Results suggest that the peak systolic jet velocity downstream of the valve increases as the heart rate increases, implying a longer pressure recovery distance as heart rate increases. While the turbulence at peak systole is higher under the slower heart rate, the faster heart rate contributes to a higher turbulence during the late systole and early diastole phases. Based on the comparison with no-valve cases, the differences in TKE was mainly related to the dynamics of leaflets under different heart rates. Overall, the results obtained in this study demonstrate that the hemodynamics of a stenotic aortic valve is complex and the assessment of AS could be significantly affected by the pulsating rate of the flow.

scholarly journals CARDIAC FUNCTION DURING MINI-INVASIVE REPAIR OF PECTUS EXCAVATUM WITH THE NUSS PROCEDURE

2021 ◽  
Vol 74 (8) ◽  
pp. 1809-1815
Author(s):  
Ulbolhan A. Fesenko ◽  
Ivan Myhal
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiac Index ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Epidural Anaesthesia ◽  
Pectus Excavatum ◽  
Stroke Volume Index ◽  
Volume Index ◽  
Nuss Procedure

The aim of the study was to analyze cardiac function during Nuss procedure under the combination of general anesthesia with different variants of the regional block. Materials and methods: The observative prospective study included 60 adolescents (boys/girls=47/13) undergone Nuss procedure for pectus excavatum correction under the combination of general anaesthesia and regional blocks. The patients were randomized into three groups (n=20 in each) according to the perioperative regional analgesia technique: standart epidural anaesthesia (SEA), high epidural anaesthesia (HEA) and bilateral paravertebral anaesthesia (PVA). The following parameters of cardiac function were analyzed: heart rate, estimated cardiac output (esCCO), cardiac index (esCCI), stroke volume (esSV) and stroke volume index (esSVI) using non-invasive monitoring. Results: Induction of anesthesia and regional blocks led to a significant decrease in esCCO (-9.4%) and esCCI (-9.8%), while esSV and esSVI remained almost unchanged in all groups (H=4.9; p=0.09). At this stage, the decrease in cardiac output was mainly due to decreased heart rate. At the stage of sternal elevation we found an increase in esSV, which was more pronounced in the groups of epidural blocks (+23.1% in HEA and +18.5% in SEA). After awakening from anesthesia and tracheal extubation esSV was by 11% higher than before surgery without ingergroup difference. Conclusions: The Nuss procedure for pectus excavatum correction lead to improved cardiac function. increase in stroke volume and its index were more informative than cardiac output and cardiac index which are dependent on heart rate that is under the influence of anaesthesia technique.

scholarly journals Heart rates and abdominal temperatures of free-ranging South Georgian shags, Phalacrocorax georgianus

1997 ◽  
Vol 200 (4) ◽  
pp. 661-675 ◽  
Author(s):  
R M Bevan ◽  
I L Boyd ◽  
P J Butler ◽  
K Reid ◽  
A J Woakes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
The South ◽  
Data Logger ◽  
Heart Rates ◽  
The Mean ◽  
Free Ranging ◽  
Mean Heart Rate

The South Georgian shag (Phalacrocorax georgianus) shows a remarkable diving ability comparable to that of penguins, yet nothing is known of the physiology of these birds. In this study, heart rates and abdominal temperatures were recorded continuously in four free-ranging South Georgian shags using an implanted data-logger. A time&shy;depth recorder was also attached to the back of the implanted birds to record their diving behaviour. The diving behaviour of the birds was essentially similar to that reported in other studies, with maximum dive durations for individual birds ranging between 140 and 287 s, and maximum depths between 35 and 101 m. The birds, while at the nest, had a heart rate of 104.0&plusmn;13.1 beats min-1 (mean &plusmn; s.e.m.) and an abdominal temperature of 39.1&plusmn;0.2 &deg;C. During flights of 221&plusmn;29 s, heart rate and abdominal temperature rose to 309.5&plusmn;18.0 beats min-1 and 40.1&plusmn;0.3 &deg;C, respectively. The mean heart rate during diving, at 103.7&plusmn;13.7 beats min-1, was not significantly different from the resting values, but the minimum heart rate during a dive was significantly lower at 64.8&plusmn;5.8 beats min-1. The minimum heart rate during a dive was negatively correlated with both dive duration and dive depth. Abdominal temperature fell progressively during a diving bout, with a mean temperature at the end of a bout of 35.1&plusmn;1.7 &deg;C. The minimum heart rate during diving is at a sub-resting level, which suggests that the South Georgian shag responds to submersion with the 'classic' dive response of bradycardia and the associated peripheral vasoconstriction and utilisation of anaerobic metabolism. However, the reduction in abdominal temperature may reflect a reduction in the overall metabolic rate of the animal such that the bird can remain aerobic while submerged.

scholarly journals COMPARATIVE CHARACTERISTICS OF THE DYNAMICS OF CARDIOVASCULAR AND RESPIRATORY EFFECTS OF PNEUMOPERITONEUM BASED ON CARBON DIOXIDE AND ARGON IN LAPAROSCOPIC CHOLECYSTECTOMY

2021 ◽  
pp. 90-95
Author(s):  
O. L. Tkachuk ◽  
R. L. Parakhoniak ◽  
S. V. Melnyk ◽  
O. O. Tkachuk-Hryhorchuk
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Cardiac Output ◽  
Laparoscopic Cholecystectomy ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Negative Impact ◽  
Abdominal Pressure ◽  
The Mean ◽  
Respiratory Systems

Pneumoperitoneum is one of the most critical components of laparoscopic surgery, which has a negative effect on gas exchange and stress to circulatory buffering system. One of the top priorities of laparoscopic technologies is to minimize the impact on the respiratory and cardiovascular systems, metabolic dynamics and compensatory abilities of homeostasis. The main goal of this research work is to compare the effects of carboxyperitoneum and argonoperitoneum on the intraoperative dynamics of CO2 concentration as well as cardiovascular and respiratory characteristics in patients undergoing laparoscopic cholecystectomy for various forms of cholelithiasis. Materials and methods. Four experimental groups involved patients based on their nosological form of cholelithiasis and the gas used to induce pneumoperitoneum. All patients underwent laparoscopic cholecystectomy by means of standard procedure. Either medical carbon dioxide or medical argon was used to induce pneumoperitoneum. Intraoperative monitoring of blood carbon dioxide levels PaCO2 was performed by taking venous blood every 15 minutes. Capnometry was performed by means of mainstream analysis using “BIOMED” BM1000C modular patient monitor by recording the discrete values of PetCO2 every 15 minutes, as well as by analyzing photocopies of capnography curves every 15 minutes. Intraoperative echocardiography was performed to identify the mean arterial pressure (MAP), heart rate (HR) and cardiac output (CO) in order to assess the effects of different types of pneumoperitoneum on the cardiovascular system. Results. The obtained data confirm the expected difference in the indices of cardiorespiratory functions between patients with acute cholecystitis and cholelithiasis without signs of inflammation. The investigation revealed that under the influence of pneumoperitoneum, heart rate and mean arterial pressure increase, while the cardiac output decreases. The respiratory pressure marker depends more on the intra-abdominal pressure and presumably the patient’s body type than on the presence of inflammatory syndrome. Argon insufflation has a slight negative impact on the cardiovascular system. Particularly, the mean arterial pressure and heart rate increase, while the cardiac output marker is less decreased as compared to the use of carbon dioxide. Abdominal pressure has a significant effect on the cardiovascular and respiratory systems regardless of the used type of gas. The combination of high intra-abdominal pressure with the elevated head end of the operating table, which is a common practise during cholecystectomy, has especially great influence on cardiovascular and respiratory functions. Operation which is carried out at decreased pressure allows reducing the deviations of practically all indices. Conclusions. Thus, the cardiovascular and respiratory systems adapt under the influence of pneumoperitoneum, providing compensation for the negative effects of mechanical and resorptive-metabolic character. Compensatory-adaptive abilities of the cardiovascular and respiratory systems increase with the decrease of intra-abdominal pressure. The use of argon as a working gas for insufflation into the abdominal cavity during laparoscopy reduces the negative impact of pneumoperitoneum on the cardiovascular and respiratory systems, providing a greater reserve of homeostatic and buffer systems of the body.

scholarly journals Hemodynamic Consequence of Different Pacing Modes after Aortic Valve Replacement

2018 ◽  
Vol 21 (2) ◽  
pp. 090
Author(s):  
Arndt H Kiessling
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Aortic Valve ◽  
Left Ventricular Hypertrophy ◽  
Aortic Valve Replacement ◽  
Diastolic Function ◽  
Valve Replacement ◽  
Ventricular Hypertrophy ◽  
Left Ventricular ◽  
Heart Rates

Objectives: Ventricular pacemaker stimulation may cause deterioration of hemodynamics in patients with left-ventricular hypertrophy following aortic valve replacement. Since the diastolic function is often impaired, it remains unclear which heart rate best optimizes cardiac output. Low heart rates are suggested to treat impaired diastolic function chronically, but it is possible that cardiac output may be augmented by increasing the heart rate in patients with a fixed stroke volume (SV). The aim of this study is the identification of the best pacing mode and heart rate for the surrogate parameter SV and cardiac index(CI) in patients with left ventricular hypertrophy.Methods: Various pacemaker stimulation modes and different heart rates, as well as their influence on hemodynamics, were tested following aortic valve replacement in 48 patients with severe left-ventricular hypertrophy (Intraventricular septum (IVS)>1.5 cm) and aortic stenosis. SV and cardiac output were recorded by pulse curve analysis. Four modes of stimulation (right ventricular pacemaker stimulation (DDDright), left ventricular pacemaker stimulation (DDDleft), biventricular pacemaker stimulation (DDDbi), atrial pacemaker stimulation (AAI)) were documented at five different rates (60, 80, 100, 120, 140 beats/min) and three different postoperative time points (intraoperatively, 3h and 24h postoperatively).Results: The highest CI was found at linear rates between 60 to 140bpm. AAI was the best mode of stimulation in the majority of cases (35%), but in others, either left, right and/or biventricular stimulation was found to be better (15%). SV showed a u-shaped trend with a peak at 100 beats/min.Conclusion: An increase in the heart rate does not lead to a notable drop in SV postoperatively in left-ventricular hypertrophy; hence a rise in cardiac output can be anticipated up to a rate of 100 beats/min. A standardized response in terms of an ideal pacemaker stimulation mode could not be identified.

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