scholarly journals Heart rate and cardiac response to exercise during voluntary dives in captive sea turtles (Cheloniidae)

Biology Open ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. bio049247
Author(s):  
Junichi Okuyama ◽  
Maika Shiozawa ◽  
Daisuke Shiode
Keyword(s):  
Heart Rate ◽  
Sea Turtles ◽  
Cardiac Response ◽  
Response To Exercise

scholarly journals Heart rate and its relationship with activity in free-ranging Cheloniidae sea turtles

2019 ◽  
Author(s):  
Junichi Okuyama ◽  
Maika Shiozawa ◽  
Daisuke Shiode
Keyword(s):  
Heart Rate ◽  
Sea Turtles ◽  
Cardiac Response ◽  
Oxygen Storage ◽  
Resting Heart Rate ◽  
Peripheral Tissues ◽  
Green Turtles ◽  
Oxygen Stores ◽  
Response To Exercise ◽  
Free Ranging

AbstractThe primary oxygen stores in Cheloniidae sea turtles are in the lungs. Therefore, management of blood oxygen transportation to peripheral tissues by cardiovascular adjustments while diving is crucial to maximize benefits from dives. However, heart rate, particularly cardiac response to exercise in free-ranging dives, has rarely been examined for sea turtles. In this study, heart rate and its relationship with the amount of activity were determined in six free-ranging green turtles using bio-logging techniques. Our results demonstrated that resting heart rate took 7–11 h to reduce to steady levels after turtles were released in the tank, indicating that turtles may not present normal physiological rates right after release. After heart rate reduction, resting heart rate of green turtles in free-ranging dives was generally low (10.9 ± 2.5 bpm), but they often presented arrhythmia (4–54 bpm) even in resting states. The amount of activity during a dive linearly increased heart rate, but maximum heart rates (39.0–69.8 bpm) were recorded during ventilation at surface. These results indicate that turtles have the capability of cardiac response to increased metabolic demands in their muscles while submerged, and also of cardiovascular adjustment for a rapid renewal of oxygen stores and removal of CO2 during ventilation. Such well-organized cardiac adjustments may be because of characteristics of Cheloniidae sea turtles such as ectothermy and oxygen storage in lungs while submerged.Summary statementGreen sea turtles in free-ranging dive had generally lower heart rate compared to other air-breathing divers and it varied with the amount of exercise. Turtles often showed extreme arrhythmia.

Constancy of stroke volume in ventricular responses to exertion

1959 ◽  
Vol 196 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Robert F. Rushmer
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Response ◽  
Indirect Measurements ◽  
Increase Stroke Volume ◽  
Normal Man ◽  
The Right ◽  
Response To Exercise ◽  
Indicator Dilution Techniques

Diastolic and systolic dimensions of the left ventricle and the free wall of the right ventricle in intact dogs are affected little by spontaneous exercise. The concept that stroke volume and heart rate in normal man increase by about the same relative amounts was derived from estimations of cardiac output, particularly in athletes, based upon indirect measurements using foreign gases or CO2. Data for man obtained with the modern cardiac catheterization or indicator dilution techniques confirm the impression derived from intact dogs that increased stroke volume is neither an essential nor a characteristic feature of the normal cardiac response to exercise. Stroke volume undoubtedly increases whenever cardiac output is increased with little change in heart rate (e.g. in athletes or in patients with chronic volume loads on the heart). Tachycardia produced experimentally with an artificial pacemaker in a resting dog causes a marked reduction in diastolic and systolic dimensions and in the stroke change of dimensions. The factors generally postulated to increase stroke volume during normal exercise may prevent the reduction in stroke volume accompanying tachycardia.

Aortic blood flow in dogs during treadmill exercise

1959 ◽  
Vol 14 (5) ◽  
pp. 809-812 ◽  
Author(s):  
Dean L. Franklin ◽  
Richard M. Ellis ◽  
R. F. Rushmer
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Treadmill Exercise ◽  
Essential Feature ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Aortic Blood Flow ◽  
Direct Measurements ◽  
Flow Through ◽  
Response To Exercise

Instantaneous blood flow through the thoracic aorta was monitored continuously during spontaneous activity in intact dogs by means of a new, pulsed, ultrasonic flowmeter. Integrated flow per stroke, accumulated flow per unit time and heart rate were simultaneously derived by means of electronic computers. During treadmill exercise at 3 mph on a 5% grade, the heart rate increased by two- or threefold, but the aortic flow per stroke was only slightly increased. This observation was confirmed by direct measurements, of left ventricular diameter. An increase in stroke volume is not an essential feature of the cardiac response to exercise in these experiments. Submitted on December 15, 1958

HEMODYNAMIC RESPONSE TO EXERCISE AFTER BETA-ADRENERGIC AND PARASYMPATHETIC BLOCKADE

1967 ◽  
Vol 45 (5) ◽  
pp. 813-819 ◽  
Author(s):  
Gordon R. Cumming ◽  
W. Carr
Keyword(s):  
Heart Rate ◽  
Cardiac Index ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Exercise Heart Rate ◽  
Stroke Index ◽  
Beta Adrenergic ◽  
The Mean ◽  
Response To Exercise ◽  
Control Exercise

Cardiac responses to supine bicycle exercise were studied in six normal subjects after the intravenous administration of 5 mg of propranolol and again after the additive effect of 0.03 mg/kg of atropine. Mean resting heart rate was decreased 15 beats/min by propranolol and then increased by 38 beats/min after atropine. Mean exercise heart rate was 157 for control exercise, 119 after propranolol and 143 after propranolol + atropine. The resting cardiac index was reduced 21% by propranolol and restored to control values after atropine. The mean control exercise cardiac index was 7.2 l/min per m2; this was reduced to 5.8 after propranolol and increased to 6.2 after atropine. The mean stroke index was not altered by control exercise, increased 3 ml/beat per m2 with exercise after propranolol and increased 6 ml/beat per m2 with exercise after propranolol + atropine. Resting pulmonary artery, aortic and left-ventricular end-diastolic pressures were not altered by propranolol or by propranolol + atropine. The mean control exercise left-ventricular end-diastolic pressure was 9 mm Hg, increased to 19 mm Hg after propranolol and fell to 12 mm Hg after propranolol + atropine. The mean exercise aortic systolic pressure was 10 mm Hg below the value for control exercise after propranolol and 8 mm Hg below control after propranolol + atropine. Atropine lessens the inhibition of the cardiac response to exercise with beta adrenergic inhibition, possibly by increasing the heart rate.

scholarly journals The Chronic Effects of Narghile Use on Males’ Cardiovascular Response During Exercise: A Systematic Review

2021 ◽  
Vol 15 (2) ◽  
pp. 155798832199770
Author(s):  
Faten Chaieb ◽  
Helmi Ben Saad
Keyword(s):  
Systematic Review ◽  
Heart Rate ◽  
Cardiovascular Response ◽  
Recovery Period ◽  
Cardiopulmonary Exercise Test ◽  
Negative Effects ◽  
Chronic Effects ◽  
Blood Pressures ◽  
Response To Exercise ◽  
Harmful Effects

Narghile use has regained popularity throughout the world. Public opinion misjudges its chronic harmful effects on health, especially on the cardiovascular system. This systematic review aimed to evaluate the chronic effects of narghile use on cardiovascular response during exercise. It followed the preferred reporting items for systematic reviews guidelines. Original articles from PubMed and Scopus published until January 31, 2020, written in English, and tackling the chronic effects of narghile use on human cardiovascular response during exercise were considered. Five studies met the inclusion criteria. Only males were included in these studies. They were published between 2014 and 2017 by teams from Tunisia ( n = 4) and Jordan ( n = 1). One study applied the 6-min walk test, and four studies opted for the cardiopulmonary exercise test. Narghile use was associated with reduced submaximal (e.g., lower 6-min walk distance) and maximal aerobic capacities (e.g., lower maximal oxygen uptake) with abnormal cardiovascular status at rest (e.g., increase in heart rate and blood pressures), at the end of the exercise (e.g., lower heart rate, tendency to chronotropic insufficiency) and during the recovery period (e.g., lower recovery index). To conclude, chronic narghile use has negative effects on cardiovascular response to exercise with reduced submaximal and maximal exercise capacities.

Cardiovascular response to cycle exercise during and after pregnancy

1989 ◽  
Vol 66 (1) ◽  
pp. 336-341 ◽  
Author(s):  
S. P. Sady ◽  
M. W. Carpenter ◽  
P. D. Thompson ◽  
M. A. Sady ◽  
B. Haydon ◽  
...  
Keyword(s):  
Heart Rate ◽  
Maximal Exercise ◽  
Cardiovascular Response ◽  
Work Load ◽  
Cycle Ergometry ◽  
Maximal Heart Rate ◽  
O2 Uptake ◽  
Cycle Exercise ◽  
Vascular Beds ◽  
Response To Exercise

Our purpose was to determine if pregnancy alters the cardiovascular response to exercise. Thirty-nine women [29 +/- 4 (SD) yr], performed submaximal and maximal exercise cycle ergometry during pregnancy (antepartum, AP, 26 +/- 3 wk of gestation) and postpartum (PP, 8 +/- 2 wk). Neither maximal O2 uptake (VO2max) nor maximal heart rate (HR) was different AP and PP (VO2 = 1.91 +/- 0.32 and 1.83 +/- 0.31 l/min; HR = 182 +/- 8 and 184 +/- 7 beats/min, P greater than 0.05 for both). Cardiac output (Q, acetylene rebreathing technique) averaged 2.2 to 2.8 l/min higher AP (P less than 0.01) at rest and at each exercise work load. Increases in both HR and stroke volume (SV) contributed to the elevated Q at the lower exercise work loads, whereas an increased SV was primarily responsible for the higher Q at higher levels. The slope of the Q vs. VO2 relationship was not different AP and PP (6.15 +/- 1.32 and 6.18 +/- 1.34 l/min Q/l/min VO2, P greater than 0.05). In contrast, the arteriovenous O2 difference (a-vO2 difference) was lower at each exercise work load AP, suggesting that the higher Q AP was distributed to nonexercising vascular beds. We conclude that Q is greater and a-vO2 difference is less at all levels of exercise in pregnant subjects than in the same women postpartum but that the coupling of the increase in Q to the increase in systemic O2 demand (VO2) is not different.(ABSTRACT TRUNCATED AT 250 WORDS)

The Role of the Aortic Body Chemoreceptors in the Cardiac and Respiratory Responses to Acute Hypoxia in the Anesthetized Dog

1973 ◽  
Vol 51 (4) ◽  
pp. 249-259 ◽  
Author(s):  
G. P. Biro ◽  
J. D. Hatcher ◽  
D. B. Jennings
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Acute Hypoxia ◽  
Control Period ◽  
Indirect Evidence ◽  
Minute Volume ◽  
Significant Rise ◽  
Cardiac Response ◽  
Cardiac Responses ◽  
Respiratory Parameters

The participation of the aortic chemoreceptors in the reflex cardiac responses to acute hypoxia is suggested only by the indirect evidence of pharmacological stimulation of these receptors. In order to assess their role more directly, the response to a 15 min period of hypoxia was determined after surgical denervation of the aortic chemoreceptors (A.D.), and compared with the response of sham-operated (S.O.) dogs, anesthetized with morphine–pentobarbital. In the control period, while breathing room air, the cardiovascular and respiratory parameters measured in the A.D. animals were not different from those of the S.O. dogs. Hypoxia (partial pressure of oxygen approximately 30 mm Hg) in the S.O. dogs was associated with a statistically significant rise in the heart rate (+71 ± 7 min−1, mean ± S.E.M.) and of the cardiac output (+25 ± 10 ml kg−1 min−1). In the A.D. animals, the significantly smaller increment in heart rate (+29 ± 6 min−1) was associated with a fall of the cardiac output (−16 ± 12 ml kg−1 min−1). The hypoxia-induced changes in heart rate and cardiac output in the S.O. animals were different (p < 0.05) from those in the A.D. group. The minute volume of ventilation was significantly augmented in both groups, and to a comparable extent. These findings indicate that the aortic chemoreceptors play a significant role in the cardiac response to hypoxia, but they do not affect, to a significant extent, the respiratory response.

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