Heart action of the freshwater bivalve Anodonta anatina during activity

1976 ◽  
Vol 65 (3) ◽  
pp. 685-698
Author(s):  
A. R. Brand
Keyword(s):  
Heart Rate ◽  
Systolic Pressure ◽  
Respiratory Control ◽  
Regulatory System ◽  
Heart Beat ◽  
Heart Activity ◽  
Freshwater Bivalve ◽  
Normal Behaviour ◽  
Muscle System ◽  
Pericardial Cavity

1. Heart action of Anodonta anatina (L.) was investigated by recording the electrocardiogram (ECG), heart impedance, and ventricular and pericardial cavity pressure during different aspects of the normal behaviour. The contribution of mechanical and nervous mechanisms in controlling changes in heart action is discussed. 2. Pressure recordings were generally more reliable than the other methods and it is suggested that pericardial pressure pulses indicate the stroke volume output of the ventricle. 3. During spontaneous periods of prolonged shell closure there was an initial small increase in heart activity followed by a large reduction in both heart rate and systolic pressure, indicating that total heart output was considerably reduced. When the shell reopened, heart rate increased very rapidly with an initial overshoot of the normal level; systolic pressure increased more slowly with no overshoot. 4. These major changes in heart activity appear to be associated with respiratory changes and are controlled largely by the nervous regulatory system, but some minor rhythmic variations in the amplitude of heart beat are probably caused by mechanical factors. 5. Characteristic patterns of change in heart action were recorded during burrowing. These appear to result from haemodynamic changes associated with the muscular movements of the digging cycle. Control of the heart by the nervous regulatory system is apparently of much greater importance in relation to respiratory control than in relation to the haemodynamic functioning of the fluid-muscle system in locomotion.

scholarly journals Ontogeny of Heart Function in the Little Skate Raja Erinacea

1991 ◽  
Vol 156 (1) ◽  
pp. 387-398 ◽  
Author(s):  
BERND PELSTER ◽  
WILLIAM E. BEMIS
Keyword(s):  
Heart Rate ◽  
Body Mass ◽  
Diastolic Pressure ◽  
Heart Function ◽  
Systolic Pressure ◽  
Heart Beat ◽  
Raja Erinacea ◽  
Arterial Blood ◽  
Ventral Aorta ◽  
Post Spawning

The development of the cardiovascular system has been analysed in embryos of the little skate, Raja erinacea, ranging in age from 27 to 144 days after spawning. Circulation starts at the end of the first month. At that time, the heart is S-shaped, there is no differentiation between ventricle and conus arteriosus and no valve formation is detectable. Complete differentiation of the central circulatory system and its valves was observed at about 40 days after spawning, although there are changes in proportion that occur before hatching. In the smallest embryos used for physiological studies, 27 days post-spawning (0.01-0.03g body mass), circulation of blood was observed and heart rate was 35–40 beats min−1. Heart rate increased with development, reaching a maximum of 65–68 beats min−1 at a body mass of 0.2 g (60 days post-spawning) and then slowly decreased until just prior to hatching. Ventricular diastolic pressure remained below 0.1 kPa throughout development whereas ventricular systolic pressure increased significantly with increasing body mass. In small embryos (<0.05 g) the conus arteriosus collapsed at the end of each heart beat, completely occluding its lumen and separating the ventral aorta from the diastolic heart. In larger animals (>0.1g) serial flap valves in the conus separated the ventral aorta from the diastolic ventricle, and the conus supported ventral arterial blood pressure because of its elastic properties. Note: Present address: Institut für Physiologie, Ruhr-Universität Bochum, Universitätsstrasse 150, D-4630 Bochum, Germany.

Factors affecting the heart activity and blood pressure of the swan mussel Anodonta cygnea

1975 ◽  
Vol 62 (2) ◽  
pp. 341-355
Author(s):  
B. A. Sommerville
Keyword(s):  
Heart Beat ◽  
Cavity Pressure ◽  
Heart Activity ◽  
Shell Valve ◽  
Anodonta Cygnea ◽  
Visceral Ganglion ◽  
Factors Affecting ◽  
Pericardial Cavity ◽  
Valve Movement ◽  
Pressure Changes

1. The rate of heart beat increased with temperature and was three times as high in the active as in the inactive animal. 2. The rate of shell valve movement rose and the rate of heart beat fell when the foot was extended. 3. The rates of heart beat and shell valve movement decreased when the water was saturated with carbon dioxide. This heart response remained when the visceral ganglion was destroyed. 4. Ventricular contraction occurred simultaneously over the shole chamber. The passage of blood into the posterior aorta could be restricted by the protuberances on its wall. 5. Pericardial cavity pressure rose by about 5 cm H2O at shell valve adduction and 0–25--0-6 cm H2O at ventricular diastole. 6. Pulse pressure changes of 0–25--0-6 cm H2O occurred in the auricle and 1--3 cm H2O in the ventricle and anterior aorta.

Heart Rate Variability, Emotions, and Music

2010 ◽  
Vol 24 (2) ◽  
pp. 112-119 ◽  
Author(s):  
F. Riganello ◽  
A. Candelieri ◽  
M. Quintieri ◽  
G. Dolce
Keyword(s):  
Data Mining ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Vegetative State ◽  
Low Frequency ◽  
Emotional Reactions ◽  
Heart Beat ◽  
Healthy Controls ◽  
Frequency Spectra ◽  
Emotional Value

The purpose of the study was to identify significant changes in heart rate variability (an emerging descriptor of emotional conditions; HRV) concomitant to complex auditory stimuli with emotional value (music). In healthy controls, traumatic brain injured (TBI) patients, and subjects in the vegetative state (VS) the heart beat was continuously recorded while the subjects were passively listening to each of four music samples of different authorship. The heart rate (parametric and nonparametric) frequency spectra were computed and the spectra descriptors were processed by data-mining procedures. Data-mining sorted the nu_lf (normalized parameter unit of the spectrum low frequency range) as the significant descriptor by which the healthy controls, TBI patients, and VS subjects’ HRV responses to music could be clustered in classes matching those defined by the controls and TBI patients’ subjective reports. These findings promote the potential for HRV to reflect complex emotional stimuli and suggest that residual emotional reactions continue to occur in VS. HRV descriptors and data-mining appear applicable in brain function research in the absence of consciousness.

Relationship between Invasive and Non-Invasive Hemodynamic Measures in Experimental Pulmonary Hypertension

2020 ◽  
Vol 16 (1) ◽  
pp. 47-53
Author(s):  
Vicente Benavides-Córdoba ◽  
Mauricio Palacios Gómez
Keyword(s):  
Heart Rate ◽  
Pulmonary Hypertension ◽  
Ejection Fraction ◽  
Right Ventricle ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Systolic Pressure ◽  
Control Group ◽  
Pearson Correlation Coefficient ◽  
Non Invasive

Introduction: Animal models have been used to understand the pathophysiology of pulmonary hypertension, to describe the mechanisms of action and to evaluate promising active ingredients. The monocrotaline-induced pulmonary hypertension model is the most used animal model. In this model, invasive and non-invasive hemodynamic variables that resemble human measurements have been used. Aim: To define if non-invasive variables can predict hemodynamic measures in the monocrotaline-induced pulmonary hypertension model. Materials and Methods: Twenty 6-week old male Wistar rats weighing between 250-300g from the bioterium of the Universidad del Valle (Cali - Colombia) were used in order to establish that the relationships between invasive and non-invasive variables are sustained in different conditions (healthy, hypertrophy and treated). The animals were organized into three groups, a control group who was given 0.9% saline solution subcutaneously (sc), a group with pulmonary hypertension induced with a single subcutaneous dose of Monocrotaline 30 mg/kg, and a group with pulmonary hypertension with 30 mg/kg of monocrotaline treated with Sildenafil. Right ventricle ejection fraction, heart rate, right ventricle systolic pressure and the extent of hypertrophy were measured. The functional relation between any two variables was evaluated by the Pearson correlation coefficient. Results: It was found that all correlations were statistically significant (p <0.01). The strongest correlation was the inverse one between the RVEF and the Fulton index (r = -0.82). The Fulton index also had a strong correlation with the RVSP (r = 0.79). The Pearson correlation coefficient between the RVEF and the RVSP was -0.81, meaning that the higher the systolic pressure in the right ventricle, the lower the ejection fraction value. Heart rate was significantly correlated to the other three variables studied, although with relatively low correlation. Conclusion: The correlations obtained in this study indicate that the parameters evaluated in the research related to experimental pulmonary hypertension correlate adequately and that the measurements that are currently made are adequate and consistent with each other, that is, they have good predictive capacity.

scholarly journals Hypertension in Prenatally Undernourished Young-Adult Rats Is Maintained by Tonic Reciprocal Paraventricular–Coerulear Excitatory Interactions

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3568
Author(s):  
Bernardita Cayupe ◽  
Carlos Morgan ◽  
Gustavo Puentes ◽  
Luis Valladares ◽  
Héctor Burgos ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Young Adult ◽  
Binding Sites ◽  
Systolic Pressure ◽  
Adult Rats ◽  
Excitatory Pathways ◽  
Induced Hypertension ◽  
Prenatal Undernutrition ◽  
Number Of Cells

Prenatally malnourished rats develop hypertension in adulthood, in part through increased α1-adrenoceptor-mediated outflow from the paraventricular nucleus (PVN) to the sympathetic system. We studied whether both α1-adrenoceptor-mediated noradrenergic excitatory pathways from the locus coeruleus (LC) to the PVN and their reciprocal excitatory CRFergic connections contribute to prenatal undernutrition-induced hypertension. For that purpose, we microinjected either α1-adrenoceptor or CRH receptor agonists and/or antagonists in the PVN or the LC, respectively. We also determined the α1-adrenoceptor density in whole hypothalamus and the expression levels of α1A-adrenoceptor mRNA in the PVN. The results showed that: (i) agonists microinjection increased systolic blood pressure and heart rate in normotensive eutrophic rats, but not in prenatally malnourished subjects; (ii) antagonists microinjection reduced hypertension and tachycardia in undernourished rats, but not in eutrophic controls; (iii) in undernourished animals, antagonist administration to one nuclei allowed the agonists recover full efficacy in the complementary nucleus, inducing hypertension and tachycardia; (iv) early undernutrition did not modify the number of α1-adrenoceptor binding sites in hypothalamus, but reduced the number of cells expressing α1A-adrenoceptor mRNA in the PVN. These results support the hypothesis that systolic pressure and heart rate are increased by tonic reciprocal paraventricular–coerulear excitatory interactions in prenatally undernourished young-adult rats.

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 (&lt; 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.

Rhythm effects on contractility of the beating isovolumic left ventricle

1960 ◽  
Vol 199 (6) ◽  
pp. 1115-1120 ◽  
Author(s):  
B. Lendrum ◽  
H. Feinberg ◽  
E. Boyd ◽  
L. N. Katz
Keyword(s):  
Heart Rate ◽  
Left Ventricle ◽  
Systolic Pressure ◽  
Ventricular Volume ◽  
Contractile Force ◽  
Postextrasystolic Potentiation ◽  
Pressure Development ◽  
Induced Changes ◽  
Electrical Alternans

Variation in contractile force of the isovolumic contracting left ventricle of the dog was studied in open-chested in situ hearts. The electrocardiogram and intraventricular pressures were recorded at various heart volumes. Spontaneous changes in heart rate and rhythm occurred at all volumes. Isovolumic systolic pressure development (contractile force) varied with rate and rhythm. Contractile force increased with heart rate (treppe) regardless of pacemaker origin. When a premature beat was followed by a compensatory pause, the premature beat showed a decrease and the next beat an increase in contractile force (postextrasystolic potentiation). The magnitude of the changes varied directly with the prematurity of the beat. Mechanical alternans was observed with electrical alternans, despite the absence of significant volume change. Rate-induced changes, postextrasystolic potentiation and mechanical alternans were additive when they occurred simultaneously. For practical purposes, ventricular volume (filling), hence muscle fiber length, remained constant during these rate and rhythm change, therefore could not affect the strength of contraction. Contractile force changes directly attributable to rate and rhythm changes do, therefore, occur in the intact mammalian heart.

scholarly journals Attention Deficit/Hyperactivity Disorder (ADHD) Is Associated With Altered Heart Rate Asymmetry

2014 ◽  
pp. S509-S519 ◽  
Author(s):  
I. TONHAJZEROVÁ ◽  
I. ONDREJKA ◽  
I. FARSKÝ ◽  
Z. VIŠŇOVCOVÁ ◽  
M. MEŠŤANÍK ◽  
...  
Keyword(s):  
Heart Rate ◽  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Physiological Stress ◽  
Regulatory System ◽  
Adverse Outcomes ◽  
Time Asymmetry ◽  
Hyperactivity Disorder ◽  
Rate Asymmetry ◽  
Heart Rate Asymmetry

Attention deficit/hyperactivity disorder (ADHD) is associated with complex neurocardiac integrity. We aimed to study heart rate time asymmetry as a nonlinear qualitative feature of heart rate variability indicating complexity of cardiac autonomic control at rest and in response to physiological stress (orthostasis) in children suffering from ADHD. Twenty boys with ADHD and 20 healthy age-matched boys at the age of 8 to 12 years were examined. The continuous ECG was recorded in a supine position and during postural change from lying to standing (orthostasis). Time irreversibility indices – Porta’s (P%), Guzik’s (G%) and Ehlers’ (E) – were evaluated. Our analysis showed significantly reduced heart rate asymmetry indices at rest (P%: 49.8 % vs. 52.2 %; G%: 50.2 % vs. 53.2 %; p<0.02), and in response to orthostatic load (P%: 52.4 % vs. 54.5 %, G%: 52.3 % vs. 54.5 %; p<0.05) associated with tachycardia in ADHD children compared to controls. Concluding, our study firstly revealed the altered heart rate asymmetry pattern in children suffering from ADHD at rest as well as in response to posture change from lying to standing (orthostasis). These findings might reflect an abnormal complex cardiac regulatory system as a potential mechanism leading to later cardiac adverse outcomes in ADHD.

scholarly journals Non-Contact Pulse Detector using Video Analytics

2020 ◽  
Vol 9 (5) ◽  
pp. 1597-1600
Keyword(s):  
Computer Vision ◽  
Heart Rate ◽  
Computational Cost ◽  
Heart Beat ◽  
Signal Frequency ◽  
Waiting Room ◽  
Non Invasive ◽  
Safe Side ◽  
Patient Will ◽  
Low Computational Cost

Non-contact pulse detector used for heart beat measurement based on computer vision, where a standard color camera captures the plethysmographic signal and the heart rates are processed and estimated dynamically. It is important that the quantities are taken in a non-invasive manner, which is invisible to the patient. Presently, many methods have been proposed for non-contact measurement. The proposed method based on the computer vision technique is enhanced to overcome the above drawbacks and it requires low computational cost. Many of the hospitals are using surveillance cameras, from these cameras we can monitor the video of the patients waiting in the queue. The camera is attached in the patients’ waiting room and the faces of the patients are monitored. Many factors are considered in the phases of image acquisition, as well as in the plethysmographic signal development, pre-processing and filtering. The pre-filter step uses numerical analysis techniques to cut the signal offset. The proposed method decouples the heart rate from the plethysmographic signal frequency. The proposed system helps in detecting the heart rate of a Patient who is waiting in queue for longer time. Based on the heart rate the seriousness of patient is identified and giving the preference to the patient and treatment will be started, with this the patient will be in safe side.

Sign in / Sign up

Export Citation Format

Share Document