Blood Pressure and Heart Rate Response to Isometric Exercise and Mental Arithmetic in Normotensive and Hypertensive Subjects

1976 ◽  
Vol 51 (s3) ◽  
pp. 681s-685s ◽  
Author(s):  
G. Nyberg

1. Sustained hand-grip exercise and mental arithmetic were performed by normal and hypertensive subjects. Blood pressure and heart rate were recorded with a device which allows blind and unbiased measurements, based on the conventional cuff method. 2. Both stimuli caused increases in heart rate and systolic and diastolic blood pressure, which were greater for isometric exercise than for mental arithmetic. 3. Normal females had a greater response to repeated exercise, and had a smaller systolic pressure elevation during mental arithmetic than the other groups. 4. Repeated testing showed good reproducibility in normal subjects.

1974 ◽  
Vol 47 (3) ◽  
pp. 249-257 ◽  
Author(s):  
D. F. Marcus ◽  
H. F. Edelhauser ◽  
M. G. Maksud ◽  
R. L. Wiley

1. Normal subjects performed fatiguing static hand-grip contraction at tensions of 20% and 55% of their maximum voluntary contraction (MVC). Intraocular pressure (IOP) was measured by applanation tonometry before, during and after the isometric exercise. Forearm blood samples were taken from the antecubital vein in both the exercised and non-exercised arm before and 2 min post-exercise for measurement of plasma lactate, osmolality, Pv,o2, Pv,co2 and pH. 2. During hand grip the heart rate and blood pressure increased significantly, whereas the IOP remained unchanged from control in both the 20% and 55% MVC experiments. 3. In the recovery period heart rate and blood pressure returned to control values within 3 min and the IOP decreased significantly from control in both the 20% and 55% MVC experiments. 4. When an occlusion cuff was inflated on the exercising arm just before release of the 55% MVC grip, the decreased IOP could be delayed until the cuff was released. 5. Post-exercise blood samples showed elevated lactate concentrations and Pv,o2 and decreased pH in the exercised arm; however, the values remained unchanged in the non-exercised arm. The decreased IOP after exercise may be related to an increased blood lactate concentration.


1979 ◽  
Vol 56 (3) ◽  
pp. 287-291 ◽  
Author(s):  
L. Hume ◽  
D. J. Ewing ◽  
I. W. Campbell ◽  
S. R. Reuben ◽  
B. F. Clarke

1. The heart-rate response during sustained hand grip was studied in four normal subjects before and after intravenous atropine, propranolol and combined cardiac autonomic blockade with both drugs. The results suggest that the increase in heart rate during the first 30 s is due to parasympathetic withdrawal, whereas the further increase between 30 s and 180 s is probably mediated by a combination of parasympathetic withdrawal and sympathetic stimulation. 2. The increases in heart rate during each minute of sustained hand grip were compared in 26 normal subjects, 37 diabetic subjects without and 24 diabetic subjects with proven autonomic neuropathy. In the diabetic subjects with autonomic neuropathy the increase in heart rate during the first minute was impaired, whereas the increases during the second and third minutes were similar in all three groups. 3. The initial increase in heart rate over the first 30 s of hand grip and the later increase between 30 s and 180 s were compared in nine normal subjects, ten diabetic subjects without and six diabetic subjects with autonomic neuropathy. The increase during the first 30 s was impaired in the diabetic subjects with autonomic neuropathy, whereas the later phase of the response was similar in all three groups. 4. It is concluded that impairment of the heart-rate response to sustained hand grip in diabetic autonomic neuropathy is mainly due to impairment of the early parasympathetic phase, but that the presence of cardiac sympathetic damage can also be detected.


1981 ◽  
Vol 60 (2) ◽  
pp. 145-155 ◽  
Author(s):  
G. Duncan ◽  
R. H. Johnson ◽  
D. G. Lambie

1. To investigate the stimulus to the cardiovascular and respiratory systems during isometric exercise, two patients with sensory neuropathies affecting forearm afferent nerves were studied and their circulatory and respiratory responses compared with those of normal subjects. The contribution of pain to the cardiorespiratory changes was also investigated in normal subjects by using hypnosis to relieve pain during and after isometric exercise. 2. The patients and normal subjects performed fatiguing isometric forearm exercises on a handgrip dynamometer on at least two occasions, once with normal forearm circulation and once with the forearm circulation occluded by an arterial cuff during and after exercise. Blood pressure, heart rate, minute ventilation, oxygen consumption and ventilatory equivalent were measured before, during and after exercise. 3. During exercises with and without occlusion increases in blood pressure and heart rate in patients and in subjects under hypnosis were similar to those in control subjects. Changes in oxygen consumption were also similar to those of controls, but the patients showed a smaller rise in ventilation and no increase in ventilatory equivalent. 4. After exercise in normal subjects occlusion of the forearm circulation produced continued elevation of blood pressure and respiration. Blood pressure also remained elevated after exercise with occlusion in subjects under hypnosis, but not in patients with sensory loss. Respiration did not remain elevated in either subjects under hypnosis or patients. 5. The results suggest that cardiovascular and respiratory changes during isometric exercise can occur without involvement of muscle sensory nerves and that pain contributes substantially to the increase in respiration. Normal sensory innervation is apparently necessary only for maintenance of raised blood pressure after exercise with occlusion.


2000 ◽  
Vol 39 (02) ◽  
pp. 200-203
Author(s):  
H. Mizuta ◽  
K. Yana

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3568
Author(s):  
Bernardita Cayupe ◽  
Carlos Morgan ◽  
Gustavo Puentes ◽  
Luis Valladares ◽  
Héctor Burgos ◽  
...  

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.


1992 ◽  
Vol 72 (3) ◽  
pp. 1039-1043 ◽  
Author(s):  
V. K. Somers ◽  
K. C. Leo ◽  
R. Shields ◽  
M. Clary ◽  
A. L. Mark

Recent evidence indicates that muscle ischemia and activation of the muscle chemoreflex are the principal stimuli to sympathetic nerve activity (SNA) during isometric exercise. We postulated that physical training would decrease muscle chemoreflex stimulation during isometric exercise and thereby attenuate the SNA response to exercise. We investigated the effects of 6 wk of unilateral handgrip endurance training on the responses to isometric handgrip (IHG: 33% of maximal voluntary contraction maintained for 2 min). In eight normal subjects the right arm underwent exercise training and the left arm sham training. We measured muscle SNA (peroneal nerve), heart rate, and blood pressure during IHG before vs. after endurance training (right arm) and sham training (left arm). Maximum work to fatigue (an index of training efficacy) was increased by 1,146% in the endurance-trained arm and by only 40% in the sham-trained arm. During isometric exercise of the right arm, SNA increased by 111 +/- 27% (SE) before training and by only 38 +/- 9% after training (P less than 0.05). Endurance training did not significantly affect the heart rate and blood pressure responses to IHG. We also measured the SNA response to 2 min of forearm ischemia after IHG in five subjects. Endurance training also attenuated the SNA response to postexercise forearm ischemia (P = 0.057). Sham training did not significantly affect the SNA responses to IHG or forearm ischemia. We conclude that endurance training decreases muscle chemoreflex stimulation during isometric exercise and thereby attenuates the sympathetic nerve response to IHG.


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