Aspects of lymph-heart function in Rana catesbeiana

2002 ◽  
Vol 80 (12) ◽  
pp. 2125-2130 ◽  
Author(s):  
A J Esbaugh ◽  
M Hazel ◽  
D P Toews
Keyword(s):  
Heart Rate ◽  
Femoral Artery ◽  
Rana Catesbeiana ◽  
Heart Function ◽  
Heart Rates ◽  
Axial Coordination ◽  
Venous Circulation ◽  
Lymph Heart ◽  
First Time ◽  
Sampling Times

The effect of voluntary dives on the posterior lymph heart rate of the bullfrog, Rana catesbeiana, was tested and compared with the blood-heart rate (n = 6). This was performed by cannulating the posterior lymph heart and femoral artery simultaneously. Blood-heart rates during submergence were significantly lower (α = 0.05) then pre-submergence rates at all sampling times. In contrast, the lymph hearts showed significantly lower rates only during the first and last submergence intervals. It is believed that the lymph-heart bradycardia found during these intervals is due in part to the physiological "preparations" for diving by the frog. Further information regarding posterior lymph heart contractions was gained by cannulating two posterior lymph hearts on one side of the frog (n = 5). It was found that these hearts beat within 100 ms of each other between 66 and 97% of the time (α = 0.05). The combined contraction of the three posterior lymph hearts could facilitate the movement of lymph through the outflow valve and into the venous circulation. This study represents the first time the axial coordination of homolateral lymph hearts has been shown to extend to the multiple posterior lymph hearts.

Performing international outreach: PhUn Week in an Australian primary school

2017 ◽  
Vol 41 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Patricia A. Halpin
Keyword(s):  
Heart Rate ◽  
Primary School ◽  
Heart Function ◽  
Outreach Program ◽  
Science Outreach ◽  
Heart Rates ◽  
Set Up ◽  
K 12 ◽  
Family Vacation

Physiology Understanding (PhUn) Week is an annual science outreach program sponsored by the American Physiological Society in which K–12 students learn about physiology through meeting a physiologist and performing an experiment. Performing PhUn Week at an Australian private primary school during a family vacation in 2014 enabled me to receive a fellowship to return the following year for further implementation. To set up the outreach, I contacted the assistant principal of a public primary school, and she connected me with the physical education (PE) teacher. Together, the PE teacher and I planned the event. Over the course of 2 days, I taught eight classes, a total of 176 K–12 students. I started each lesson by explaining the role of a physiologist. The scientific method was described and explained. A hypothesis, “Exercise increases heart rate,” was designed and tested. The students measured their heart rates, exercised, and measured their heart rates again. After data collection, results were reported, and the students all agreed that their hypothesis was supported. We then discussed heart function and why heart rate increases with exercise. The students then performed a pedometer challenge, where they estimated the number of steps during walking, running, and kangaroo hopping. They enjoyed testing their predictions and repeated these experiments several times. The students then made suggestions of ways they could continue this lesson outside of school. This first report of an international PhUn week confirmed that these events form partnerships among educators and inspire K–12 students to think about becoming scientists.

Synchrony in the amphibian lymphatic system: evidence for bilateral posterior lymph heart synchrony and cardiac–lymphatic synchrony in Rana catesbeiana and Bufo marinus

2006 ◽  
Vol 84 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Emily H Coolidge ◽  
Marla J MacAulay ◽  
Daniel P Toews
Keyword(s):  
Lymphatic System ◽  
Rana Catesbeiana ◽  
Heart Function ◽  
Bufo Marinus ◽  
Poincaré Plot ◽  
Plot Analysis ◽  
Lymph Heart ◽  
Systemic Heart ◽  
Homeostatic Mechanisms

Early investigations into amphibian lymph heart function established that lymph heart contractions were synchronous with neither the systemic heart, nor the lungs, nor each other. However, the present study concludes that there is synchronization between the cardiac heart and the lymph hearts and that the posterior lymph hearts in both Rana catesbeiana Shaw, 1802 and Bufo marinus (L., 1758) beat synchronously as well. Pressure peaks were recorded through cannulation of the ischiatic artery and each posterior lymph heart and subsequently analyzed to determine the time differences between arterial diastole and lymph heart systole or between two bilateral lymph heart systoles. Results show that there is clear synchronization between the lymph heart systoles of two bilateral posterior lymph hearts. This lymph heart synchrony is further supported by using Poincaré plot analysis to visually compare the lymph heart inter-beats. Cardiac heart and lymph heart contractions also show a degree of synchronization, even though the lymph hearts beat up to three times as fast as the cardiac heart. These results support the conclusion that synchrony is characteristic of the anuran lymphatic system and that synchronization of the cardiac heart and the lymph hearts could impart an energetic advantage that benefits fluid homeostatic mechanisms.

Effect of amiodarone on heart rate variability in patients with newly diagnosed atrial fibrillation (clinical observation)

2020 ◽  
pp. 81-85
Author(s):  
E. P. Popova ◽  
O. T. Bogova ◽  
S. N. Puzin ◽  
D. A. Sychyov ◽  
V. P. Fisenko
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Drug Therapy ◽  
Heart Function ◽  
Newly Diagnosed ◽  
Class Iii ◽  
Spectral Parameters ◽  
Patient Will ◽  
The Individual

Spectral analysis of heart rate variability gives an idea of the role of the autonomic nervous system in the regulation of chronotropic heart function. This method can be used to evaluate the effectiveness of drug therapy. Drug therapy should be carried out taking into account the individual clinical form of atrial fibrillation. Information about the vegetative status of the patient will undoubtedly increase the effectiveness of treatment. In this study, spectral parameters were studied in patients with newly diagnosed atrial fibrillation. The effect of antiarrhythmic drug class III amiodarone on the spectral parameters of heart rate variability was studied.

scholarly journals Heart Rate–Induced Myocardial Ca 2+ Retention and Left Ventricular Volume Loss in Patients With Heart Failure With Preserved Ejection Fraction

2020 ◽  
Vol 9 (17) ◽  
Author(s):  
Daniel N. Silverman ◽  
Mehdi Rambod ◽  
Daniel L. Lustgarten ◽  
Robert Lobel ◽  
Martin M. LeWinter ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Ejection Fraction ◽  
Sinus Rhythm ◽  
Left Ventricular ◽  
Atrial Pacing ◽  
Preserved Ejection Fraction ◽  
Volume Loss ◽  
Heart Rates ◽  
Patients With Heart Failure

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca 2+ overload caused by increased myocardial Na + levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension. Methods and Results In 22 fully sedated and instrumented patients (12 controls and 10 patients with HFpEF) in sinus rhythm with a preserved ejection fraction (≥50%) we assessed left‐sided filling pressures and volumes in sinus rhythm and with atrial pacing (95 beats per minute and 125 beats per minute) before atrial fibrillation ablation. Coronary sinus blood samples and flow measurements were also obtained. Seven women and 15 men were studied (aged 59±10 years, ejection fraction 61%±4%). Patients with HFpEF had a history of hypertension, dyspnea on exertion, concentric LV remodeling and a dilated left atrium, whereas controls did not. Pacing at 125 beats per minute lowered the mean LV end‐diastolic pressure in both groups (controls −4.3±4.1 mm Hg versus patients with HFpEF −8.5±6.0 mm Hg, P =0.08). Pacing also reduced LV end‐diastolic volumes. The volume loss was about twice as much in the HFpEF group (controls −15%±14% versus patients with HFpEF −32%±11%, P =0.009). Coronary venous [Ca 2+ ] increased after pacing at 125 beats per minute in patients with HFpEF but not in controls. [Na + ] did not change. Conclusions Higher resting heart rates are associated with lower filling pressures in patients with and without HFpEF. Incomplete relaxation and LV filling at high heart rates lead to a reduction in LV volumes that is more pronounced in patients with HFpEF and may be associated with myocardial Ca 2+ retention.

Heart Rate and Performance in Manual Missile Guidance

1971 ◽  
Vol 32 (2) ◽  
pp. 352-354
Author(s):  
Bengt Bergstroem ◽  
Peter Arnberg
Keyword(s):  
Heart Rate ◽  
Performance Data ◽  
Tracking Performance ◽  
Missile Guidance ◽  
Heart Rates ◽  
Laboratory Conditions ◽  
Stress Studies ◽  
And Performance

Earlier stress studies under laboratory conditions show that heart rates from 100 to 110 bpm are associated with significant decrements in missile-tracking performance. Data from real missile tracking by 8 operators with no stress deliberately induced indicate, however, that performance is unaffected up to 135 bpm, and only moderately affected in the 135- to 170-bpm region. The disagreement between the two sets of results highlights the difficulties in generalizing from stress experiments.

Stress level in wild harbour porpoises (Phocoena phocoena) during satellite tagging measured by respiration, heart rate and cortisol

2009 ◽  
Vol 89 (5) ◽  
pp. 885-892 ◽  
Author(s):  
I.G. Eskesen ◽  
J. Teilmann ◽  
B.M. Geertsen ◽  
G. Desportes ◽  
F. Riget ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiration Rate ◽  
Serum Cortisol ◽  
Phocoena Phocoena ◽  
Heart Rates ◽  
Stress Effects ◽  
Respiration Rates ◽  
Stressed Animal ◽  
Cortisol Levels ◽  
Satellite Tagging

During satellite tagging of harbour porpoises (Phocoena phocoena), heart rate, respiration rate and cortisol value were measured to evaluate stress effects during handling and tagging. Respiration rates were obtained using video recordings, heart rates were recorded and serum cortisol levels were analysed from blood samples. Differences in heart rates, respiration rates and cortisol levels before and during the tagging events were investigated. An overall significant decrease of 31.5% in respiration rate was found during the tagging event period, while mature porpoises respired significantly more often than immature individuals. Though significant differences in heart rates were found for some individuals, no general significant change for all animals was detected. We found no correlation between cortisol concentration and either heart rate or respiration rate, nor did we find any relationships between cortisol and month of year, sex and body length. As high individual variations occurred in response to tagging of harbour porpoises, it is not possible to give general advice based on the factors investigated, on how to reduce stress during handling. However, pouring water over the animal and lowering it into the water seem to stabilize a stressed animal. Therefore, general precaution and individual judgement based on experience is essential when handling wild harbour porpoises.

Abstract P132: Increased Cardiovascular Parasympathetic Tone in African Americans With CD36 Partial Deficiency

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Shahram Ejtemaei Mehr
Keyword(s):  
Heart Rate ◽  
Fatty Acid ◽  
African Americans ◽  
Heart Function ◽  
Taste Perception ◽  
Acid Uptake ◽  
High Fat ◽  
Cd36 Deficiency ◽  
Parasympathetic Tone ◽  
Fat Meal

Cardiovascular disease is the leading cause of death among African Americans (AA). Reduced parasympathetic tone as measured by high frequency heart rate variability (HF RRI ) predicts cardiovascular mortality. HF RRI is reduced after a high fat meal through caveolar sequestration of muscarinic M2 receptors. The fatty acid translocase CD36 is a protein abundant in the myocardium and important for heart function and lipid metabolism. CD36 plasma membrane localization and function in fatty acid uptake is modulated by its interaction with caveolin. One in four AAs are G-allele carriers for CD36 SNP rs3211938 resulting in ~50% decreased CD36 expression. CD36 deficiency also reduces fat taste perception, which might lead to higher fat intake to reach taste saturation. We tested the hypothesis that obese AAs with partial CD36 deficiency have altered parasympathetic tone during fasting and after a high-fat meal. We recruited 13 G-allele carriers and 39 non-carriers. Subjects were matched by age (P=0.820), BMI (P=0.751), and blood pressure (P=0.701). There was a trend towards reduction in heart rate in carriers (P=0.07). Baseline HF RRI was elevated in G carriers (557.1 [251 to 942] vs. 224 [95 to 655] ms 2 , P=0.046). Eleven subjects received a high-fat meal (700 Cal/m 2 BSA, 80% fat). HF RRI was measured at baseline and 30, 60, 120, 240 minutes after meal. Non-carriers (n=4) showed a time-dependent decline in the percent change in HF RRI (-23, -32, -70, -84, respectively). In G-allele carriers (N=6), the decline in HF RRI (21, -11, -61, -70 min) was attenuated. Conclusion: AAs with partial CD36 deficiency have enhanced fasting parasympathetic tone and a blunted response to a high fat meal.

Direct measurement of flow from the posterior lymph hearts of hydrated and dehydrated toads (Bufo marinus).

1997 ◽  
Vol 200 (11) ◽  
pp. 1695-1702 ◽  
Author(s):  
J M Jones ◽  
A K Gamperl ◽  
A P Farrell ◽  
D P Toews
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Systolic Pressure ◽  
Lymph Flow ◽  
Bufo Marinus ◽  
Experimental Chamber ◽  
Doppler Flow ◽  
Simultaneous Measurements ◽  
Pressure Development ◽  
Lymph Heart

Flow from the posterior lymph hearts of Bufo marinus was measured using Doppler flow probes. These probes were placed on the posterior vertebral vein and recorded flow as lymph was ejected from the heart. In resting, hydrated toads, mean lymph flow from one of the paired posterior lymph hearts was 25.9 +/- 4.9 ml kg-1 h-1, stroke volume was 8.9 +/- 1.4 microL kg-1 and lymph heart rate was 47.5 +/- 3.7 beats min-1. We estimate that, together, the paired posterior lymph hearts are capable of generating flows that are approximately one-sixtieth of the resting cardiac output. Mean peak systolic pressure developed by the posterior lymph hearts was 1.62 +/- 0.08 kPa. Simultaneous measurements of lymph heart pressure development and flow revealed that the outflow pore of the heart opened at a pressure of 0.71 +/- 0.04 kPa, approximately 113 +/- 5 ms into systole. When toads were moderately disturbed, stroke volume increased by as much as fourfold with little change in lymph heart rate (< 5 beats min-1). When toads were dehydrated, lymph flow decreased by 70% at 12h and by 80% and 24h. Since there was only a modest non-significant decrease in lymph heart rate (30%), this reduction in flow was attributed to decreases in stroke volume (approximately 80%). Lymph heart flow and stroke volume returned to control values 30 min after adding water back into the experimental chamber. Stroke volume was clearly more important in regulating lymph flow than lymph heart rate under these conditions in Bufo marinus.

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 Merits and perils of targeted neonatal echocardiography-based hemodynamic research: a position statement

2019 ◽  
Vol 97 (3) ◽  
pp. 183-186 ◽  
Author(s):  
Ashraf Kharrat ◽  
Patrick J. McNamara ◽  
Dany Weisz ◽  
Amish Jain
Keyword(s):  
Neonatal Intensive Care ◽  
Heart Function ◽  
Point Of Care ◽  
Position Statement ◽  
Neonatal Intensive Care Units ◽  
Point Of Care Ultrasound ◽  
First Time ◽  
Neonatal Echocardiography ◽  
Clinical Problems ◽  
Time Assessment

In the neonatal setting, point-of-care ultrasound is increasingly being used to help clinicians with the evaluation of heart function. Practices in neonatology, particularly with regard to acute and chronic hemodynamic managements, were traditionally more driven on dogma and predefined thresholds and not always supported by demonstrable physiology. For the first time, targeted neonatal echocardiography (TNE) provided neonatal intensivists with a bedside tool that made real-time assessment of neonatal hemodynamics status feasible in even the tiniest of babies. This opened the door towards more targeted physiological driven practices, allowing us to test historical approaches to clinical problems in a more precise way. Despite the standardization of TNE training and the creation of a formalized curriculum, little attention has been paid to the establishment of an empirical framework to adjudicate scientific investigation. In this position statement, we reflect on the evolution of TNE in Canadian neonatal intensive care units, appraise its strengths and limitations, and suggest guiding principles for clinicians and researchers to consider as they take this field forward.

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