scholarly journals Effect of exercise on cardiovascular parameters in search and rescue-trained dogs

2018 ◽  
Vol 70 (4) ◽  
pp. 1036-1044 ◽  
Author(s):  
P.O.P.R. Santos ◽  
E.A. Santos ◽  
A.C. Reis ◽  
A.M.M.R. Santos ◽  
M.C.C. Kuster ◽  
...  
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Oxygen Demand ◽  
Poor Performance ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Left Ventricular ◽  
Search And Rescue ◽  
Exercise Session ◽  
Physical Conditioning

ABSTRACT Physical activity alters the cardiovascular system of dogs, depending on the exercise characteristics and the animal’s physical conditioning. Little is known about the cardiovascular changes in rescue-trained dogs. This study evaluated the cardiovascular responses to a search and rescue exercise session to differentiate these alterations from cases of exhaustion or some possible pathology. Nine healthy rescue-trained dogs that trained for at least one year were used. Seven German Shepherds and two Belgian Shepherd Malinois were evaluated twice, immediately before exercise (M0) and immediately after a 20-minute training (M1). Electrocardiographic, echocardiographic, and systemic blood pressure (SBP) measurements were performed at each evaluation. Heart rate was evaluated in three moments, M0, M1 and five minutes after the end of the physical activity (M2). The results indicated that training increased oxygen demand and significantly increased cardiac output, left ventricular volume in diastole and aortic artery diameter, and the contraction force with the increased mitral annular motion without impairing systolic and diastolic cardiac functions. Heart rate values immediately and five minutes after exercise were similar to baseline values. Training did not alter SBP and the electrocardiographic parameters. The present study indicated good cardiac performance to the physical effort of rescue-trained dogs and reduced the chances of poor performance and the occurrence of sudden death caused by exercise in response to the pattern of activity performed.

Reflex cardiac effects of local cutaneous cold exposure in dogs

1980 ◽  
Vol 239 (1) ◽  
pp. H114-H120
Author(s):  
J. F. Borgia ◽  
S. M. Horvath
Keyword(s):  
Heart Rate ◽  
Cardiac Contractility ◽  
Oxygen Demand ◽  
Cardiovascular Responses ◽  
Left Ventricular ◽  
Myocardial Oxygen Demand ◽  
Adrenergic Blockade ◽  
Stroke Index ◽  
Ventricular Contractility ◽  
Cold Stimulation

Cardiovascular responses initiated by local cutaneous cooling were evaluated in 16 anesthetized dogs of which 8 were pretreated with propranolol. Heart rate, cardiac index (CI), and indices of ventricular contractility were significantly elevated in untreated animals during cold stimulation. Myocardial oxygen uptake (MVo2) and left ventricular work (LVW) were also increased, and cardiac mechanical efficiency was significantly reduced. Total peripheral vascular resistance remained unchanged. In the propranolol group, heart rate decreased by 12 beats/min, but CI was maintained constant during cold by a rise in stroke index. Left ventricular dP/dtmax was reduced and ventricular preload elevated, but LVW, MVo2, and cardiac efficiency were unchanged. These data indicate that local cutaneous cooling increases myocardial oxygen demand by reflexly elevating heart rate and cardiac contractility rather than by increasing cardiac afterload. The response is completely eliminated by beta-adrenergic blockade. The significance of these observations in regard to the cold-intolerant individual with coronary disease is discussed.

HEART COMPLICATIONS IN HYPERTHYROIDISM

2011 ◽  
pp. 7-17
Author(s):  
Hai Thuy Nguyen ◽  
Anh Vu Nguyen
Keyword(s):  
Atrial Fibrillation ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Diseases ◽  
Systolic Dysfunction ◽  
Oxygen Demand ◽  
Left Ventricular ◽  
Cardiac Contraction ◽  
Cardiac Complications ◽  
Cardiac Symptoms

Thyroid hormone increases the force of the contraction and the amount of the heart muscle oxygen demand. It also increases the heart rate. Due to these reasons, the work of the heart is greatly increased in hyperthyroidism. Hyperthyroidism increases the amount of nitric oxide in the intima, lead them to be dilated and become less stiff. Cardiac symptoms can be seen in anybody with hyperthyroidism, but can be particularly dangerous in whom have underlying heart diseases. Common symptoms include: tachycardia and palpitations. Occult hyperthyroidism is a common cause of an increased heart rate at rest and with mild exertion. Hyperthyroidism can also produce a host of other arrhythmias such as PVCs, ventricular tachycardia and especially atrial fibrillation. Left ventricular diastolic dysfunction and systolic dysfunction, Mitral regurgitation and mitral valve prolapsed are heart complications of hyperthyroism could be detected by echocardiography. The forceful cardiac contraction increases the systolic blood pressure despite the increased relaxation in the blood vessels reduces the diastolic blood pressure. Atrial fibrillation, atrial enlargement and congestive heart failure are important cardiac complications of hyperthyroidism. An increased risks of stroke is common in patients with atrial fibrillation. Graves disease is linked to autoimmune complications, such as cardiac valve involvement, pulmonary arterial hypertension and specific cardiomyopathy. Worsening angina: Patients with coronary artery disease often experience a marked worsening in symptoms with hyperthyroidism. These can include an increase in chest pain (angina) or even a heart attack.

Endogenous bradykinin in the thoracic spinal cord contributes to the exercise pressor reflex

1996 ◽  
Vol 81 (3) ◽  
pp. 1288-1294 ◽  
Author(s):  
C. L. Stebbins ◽  
S. Bonigut
Keyword(s):  
Spinal Cord ◽  
Heart Rate ◽  
Intrathecal Injection ◽  
Cardiovascular Responses ◽  
Left Ventricular ◽  
Thoracic Spinal Cord ◽  
Exercise Pressor Reflex ◽  
Thoracic Spinal ◽  
Pressor Reflex ◽  
Hoe 140

This investigation tested the hypothesis that bradykinin causes excitatory effects in the thoracic spinal cord that augment the exercise pressor reflex. Thus we performed 30 s of electrically stimulated static contraction of the hindlimb in the anesthetized cat (alpha-chloralose) to provoke reflex-induced increases in mean arterial pressure, maximal rate of rise of left ventricular pressure (dP/dt), and heart rate (i.e., the exercise pressor reflex). These three responses were compared before and 15 min after intrathecal injection of 2 micrograms (n = 3), 10 micrograms (n = 6), or 50 micrograms (n = 3) of the selective bradykinin B2- receptor antagonist HOE-140 into the thoracic spinal cord or 10 micrograms of this antagonist into the lumbar (n = 3) spinal cord. In three of the six cats in which 10 micrograms of HOE-140 were injected into the thoracic spinal cord, an additional contraction was performed 60-90 min after treatment. The 2-microgram dose of HOE-140 had no effect on the exercise pressor reflex. Injection of 10 micrograms of this antagonist into the thoracic spinal cord reduced the contraction-evoked pressor, maximal dP/dt, and heart rate responses by 49 +/-7, 58 +/- 4, and 64 +/- 13%, respectively (P < 0.05). Fifty micrograms of HOE-140 failed to attenuate these responses further. In the three cats in which an additional contraction was performed 60-90 min after treatment with 10 micrograms of the antagonist, blood pressure and dP/dt responses had returned, in part, toward initial values. Neither intravenous (n = 3) nor intrathecal injection of 10 micrograms of HOE-140 into the lumbar spinal cord had any effect on the contraction-induced cardiovascular responses. Thoracic injection of 50-200 ng of bradykinin provoked a pressor response of 26 +/- 5 mmHg that was abolished by a similar injection of 10 micrograms of HOE-140. These data suggest that endogenous bradykinin contributes to the exercise pressor reflex by an excitatory action in the thoracic spinal cord.

Respiratory and cardiovascular responses to increased and decreased carotid sinus pressure in sleeping dogs

1995 ◽  
Vol 78 (5) ◽  
pp. 1688-1698 ◽  
Author(s):  
K. W. Saupe ◽  
C. A. Smith ◽  
K. S. Henderson ◽  
J. A. Dempsey
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Eye Movement ◽  
Carotid Sinus ◽  
Minute Ventilation ◽  
Control Level ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep

The purpose of this study was to determine the effects of changing blood pressure in the carotid sinus (Pcs) on ventilatory output during wakefulness and non-rapid-eye-movement sleep in unanesthetized dogs. Eight dogs were chronically instrumented so that ventilation, heart rate, and blood pressure could be measured while pressure in the isolated carotid sinus was rapidly changed by means of an extracorporeal perfusion circuit. Raising Pcs 35–75 mmHg consistently reduced ventilation 15–40% in a dose-response fashion, with little or no further diminution in minute ventilation as Pcs was further increased > 75 mmHg above control level. This decrease in minute ventilation was immediate, due primarily to a decrease in tidal volume, and was sustained over the 20-s period of elevated Pcs. Increases in Pcs also caused immediate sustained reductions in systemic blood pressure and heart rate, both of which also fell in a dose-dependent fashion. The ventilatory and systemic cardiovascular responses to increased Pcs were the same during wakefulness and non-rapid-eye-movement sleep. Decreasing Pcs 40–80 mmHg caused a sudden carotid chemoreceptor-mediated hyperpnea that was eliminated by hyperoxia. We conclude that increasing Pcs causes a reflex inhibition of ventilation and that this reflex may play a role in sleep-disordered breathing.

scholarly journals Cardiovascular Responses Associated with Daily Walking in Subacute Stroke

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sanjay K. Prajapati ◽  
Avril Mansfield ◽  
William H. Gage ◽  
Dina Brooks ◽  
William E. McIlroy
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Aerobic Exercise ◽  
Cardiovascular Responses ◽  
Heart Rate Reserve ◽  
Heart Rate Monitors ◽  
Bout Duration ◽  
Subacute Stroke ◽  
Independent Ambulation ◽  
Minimum Intensity

Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1) walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%–60% heart rate reserve) or (2) heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve). Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve) and duration (>10 minutes continuously) necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.

scholarly journals Predictive factors of cardiovascular changes depending on the type and intensity of physical activity in professional athletes

2021 ◽  
Vol 26 (10) ◽  
pp. 4647
Author(s):  
N. P Garganeeva ◽  
I. F. Taminova ◽  
V. V. Kalyuzhin ◽  
E. V Kalyuzhina ◽  
I. N. Smirnova
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Heart Rate ◽  
Logistic Regression ◽  
Prognostic Factors ◽  
Predictive Models ◽  
Left Ventricular ◽  
Professional Athletes ◽  
Young Athletes ◽  
Cardiovascular Changes

Aim. To determine the early predictive factors of cardiovascular changes in professional athletes, depending on the type and intensity of physical activity.Material and methods. A total of 136 male athletes were examined. Of these, 116 were professional athletes (age, 22,07±4,1 years) as follows: freestyle wrestling, judo (n=30), cross-country skiing, biathlon (n=27), powerlifting (n=33), volleyball (n=26). Control group included 20 athletes (age, 17,95±1,5 years) with a history of training less than 3 years. All participants underwent electrocardiography (ECG), echocardiography, cycle ergometry (CE) with assessment of physical performance at a heart rate of 170 bpm (PWC170) and maximum oxygen consumption (MOC). When creating predictive models of early cardiovascular changes, we used logistic regression, stepwise regression and Wald statistics. Differences were considered significant at p<0,05.Results. Predictive models of logistic regression using ROC analysis showed high sensitivity and specificity, a high percentage of correct predictions using data from echocardiography — 86,8%, CE — 80,9%, ECG and other indicators — 83,1%. A stepwise algorithm was used to select prognostic factors determining early cardiovascular changes in young athletes, depending on the stage of sports training, the intensity and type of dynamic and/or static exercise: left ventricular posterior wall thickness (p=0,008), left ventricular mass (p=0,001), stroke volume (p=0,002), end-systolic volume (p=0,001), PWC170 (p=0,025), MOC (p=0,003), recovery time of heart rate (HR) (p=0,029) and blood pressure (p=0,032) after submaximal exercise on a cycle ergometer, body mass index (p=0,029), heart rate (p=0,034), office systolic blood pressure (p=0,009), intraventricular (bundle) block (p=0,046), left ventricular repolarization abnormalities (p=0,010), mild cardiac connective tissue anomalies (p=0,035).Conclusion. The early prognostic factors established by the logistic regression affect the characteristics and risk of cardiovascular changes in each group of young athletes. This demonstrates the need to develop individual medical support programs, further monitoring, evaluation, correction and prevention of identified disorders, taking into account the type of sports, intensity and exercise.

Apnea, tachypnea, and hypotension elicited by cardiac vagal afferents

1979 ◽  
Vol 47 (2) ◽  
pp. 312-318 ◽  
Author(s):  
D. R. Kostreva ◽  
F. A. Hopp ◽  
E. J. Zuperku ◽  
J. P. Kampine
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Initial Rate ◽  
Systemic Blood Pressure ◽  
Left Ventricular ◽  
Vagal Afferents ◽  
Systemic Hypotension ◽  
Stellate Ganglia ◽  
Conduction Velocities ◽  
The Right

The reflex effects of right and left ventricular distension, mediated by vagal afferents, were studied in mongrel dogs anesthetized with halothane or pentobarbital sodium on heart-lung bypass. Diaphragm electromyogram (D-EMG), systemic blood pressure, and left ventricular cardiogram were all measured during ventricular distension. After bilateral section of the stellate ganglia, distension of the left ventricle produced an apnea, or slowing of respiration and systemic hypotension, without a change in heart rate. A reflex decrease in the amplitude of the D-EMG occurred if the initial breathing rate was high; a decrease in frequency of the D-EMG bursts occurred if the initial rate was low. The left ventricular vagal afferents altering respiration had conduction velocities between 22 and 70 m/s, whereas those causing hypotension had conduction velocities less than 22 m/s. Distension of the right ventricle resulted in a significant tachypnea and systemic hypotension without a change in heart rate. The conduction velocities of the right ventricular vagal afferents causing both tachypnea and hypotension were less than 9 m/s. These reflex changes in respiration and blood pressure elicited by both right and left ventricular distension were eliminated with vagotomy.

Similarity of cardiovascular responses to exercise and to diencephalic stimulation

1960 ◽  
Vol 198 (6) ◽  
pp. 1139-1142 ◽  
Author(s):  
Orville A. Smith ◽  
Robert F. Rushmer ◽  
Earl P. Lasher
Keyword(s):  
Heart Rate ◽  
Third Ventricle ◽  
Left Ventricular Pressure ◽  
Cardiovascular Responses ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
The Third ◽  
Stimulating Electrodes ◽  
Stimulation Of

Devices to measure left ventricular pressure, diameter and heart rate in animals with closed chests were placed on the hearts of dogs. After recovery from this operation the dogs were trained to exercise on a treadmill and the cardiovascular responses to this exercise were recorded. Stimulating electrodes were then stereotaxically placed in the diencephalon. In some dogs the electrodes were chronically implanted, and the stimulation was carried out after recovery from this second operation. In other animals stimulation was carried out immediately while they were under chloralose anesthesia. Stimulation of the H1 and H2 fields of Forel and the periventricular gray of the third ventricle resulted in cardiovascular responses similar to those which result from exercise.

scholarly journals Tempo-Fit Heart Rate App: Using Heart Rate Sonification As Exercise Performance Feedback

2016 ◽  
Author(s):  
Steven Landry ◽  
Yuangjing Sun ◽  
Darnishia Slade ◽  
Myounghoon Jeon
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Performance Feedback ◽  
Physical Inactivity ◽  
Exercise Session ◽  
Activity Levels ◽  
Review Of The Literature ◽  
Target Heart Rate ◽  
Exit Interviews ◽  
Natural Inclination

Physical inactivity is a worldwide issue causing a variety of health problems. Exploring novel ways to encourage people to engage in physical activity is a topic at the forefront of research for countless stakeholders. Based upon a review of the literature, a pilot study, and exit interviews, we propose an app prototype that utilizes music tempo manipulation to guide users into a target heart rate zone during an exercise session. A study was conducted with 26 participants in a fifteenminute cycling session using different sonification mappings and combinations of audiovisual feedback based on the user’s current heart rate. Results suggest manipulating the playback speed of music in real time based on heart rate zone departures can be an effective motivational tool for increasing or decreasing activity levels of the listener. Participants vastly preferred prescriptive sonifications mappings over descriptive mappings, due to people’s natural inclination to follow the tempo of music.

Cardiovascular Responses to the Intracarotid Injections of Ionic Contrast Media and Iohexol in the Dog

1986 ◽  
Vol 27 (6) ◽  
pp. 729-733 ◽  
Author(s):  
K. Hayakawa ◽  
T. W. Morris ◽  
R. W. Katzberg ◽  
H. W. Fischer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Contrast Media ◽  
Vascular Resistance ◽  
Isotonic Saline ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Ionic Contrast ◽  
S Period

Hypotension and bradycardia are the most significant cardiovascular responses resulting from intracarotid injections of hypertonic contrast media (CM). We have assessed both local and systemic vascular responses to the selective intracarotid injections of ionic and non-ionic CM in twelve pentobarbital anesthetized dogs. Alterations in blood pressure, heart rate, and femoral, renal and carotid blood flows were monitored following right common carotid artery injections of ionic contrast media (282–288 mg I/ml), isotonic saline, and iohexol (300 mg I/ml). Ionic CM led to early (0 to 10 s) decreases in blood pressure, heart rate and femoral vascular resistance. Isotonic saline induced no significant early changes in these same parameters while iohexol caused a decrease in heart rate. Our observations suggest that the early (0 to 10 s) decreases in femoral vascular resistance, heart rate and pressure that occur with the intracarotid injection of hypertonic CM are mediated via the autonomic nervous system and initiated from a site in the carotid circulation. During the 15 to 40 s period when the CM has reached the systemic circulation, iohexol produced smaller effects on systemic blood pressure and peripheral vascular resistances than did the ionic CM. During this 15 to 40 s period there were decreased vascular resistances in the carotid and renal vascular beds that probably result from local effects of the CM, however, the femoral resistance was actually increased. This later increase in femoral resistance probably represents the results of increased sympathetic nervous system activity working to offset the decrease in renal and carotid resistances and thus maintain pressure at baseline values. The vascular resistance changes observed demonstrate a complexity of responses to CM not previously appreciated.

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