Electrocardiographic, Heart‐Rate and Subjective Responses to Prolonged Gravitational Stress and their Relation to some Dimensional and Functional Parameters of the Circulatory System

Bjurstedt, H.; Hansson, Lars‐Erik; Ström, Gunnar

doi:10.1111/j.1748-1716.1960.tb00059.x

Cited by 4 publications

(1 citation statement)

References 11 publications

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“…Our findings in subjects with vasoregulatory abnormalities are similar to those found in normal subjects by these workers. Electrocardiographic changes during positive acceleration in normal subjects have been attributed to myocardial ischaemia (Gauer, 1950;Gauer and Zuidema, 1961;Zuidema et al, 1956), to descent of the diaphragm (Browne, 1958(Browne, -1959, and related to heart rate (Bjurstedt et al, 1959). Nordenfelt (1961) was, however, unable to reverse these changes produced by orthostasis with rate slowing carotid massage.…”

Section: Basalmentioning

confidence: 99%

Effect of positive acceleration (+gz) on electrocardiogram of subjects with vasoregulatory abnormality.

Khanna¹,

Balasubramanian²,

Dham³

et al. 1977

Heart

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ST-T wave changes in the electrocardiogram detected during routine examination and aggravated by erect posture, hyperventilation, and exercise in apparently healthy young individuals have been termed vasoregulatory abnormalities. No evidence of ischaemic heart disease has been found in such subjects. Ten young healthy air crew with vasoregulatory abnormalities were subjected to maximal exercise on treadmill and procedure repeated after 120 mg propranolol daily for 3 days. After one week, they were subjected to a stress of positive acceleration (+gz) in a human centrifuge at 2-5 g and 3-5 g for 15 seconds each at a constant rate of rise of 0-1 g/s and the electrocardiogram was monitored during and in the post-acceleration phase. The procedure was repeated after propranolol 120 mg daily for 3 days. The stress of positive acceleration resulted in pronounced prominence of P waves and inversion of T waves (as has been reported in normal subjects) with minimal ST depression in the electrocardiogram. ST segment depression during exercise, at heart rates corresponding to those achieved during peak centrifuge runs, was significantly more pronounced. The ST, P, and T wave changes were returned to normal after propranolol. It is concluded that minimal ST segment depression after stress of positive acceleration as compared with conspicuous ST segment depression during exercise at corresponding heart rates, and their normalisation after propranolol, rules out ischaemia as an aetiological factor in subjects with vasoregulatory abnormalities.

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Section: Basalmentioning

confidence: 99%

Effect of positive acceleration (+gz) on electrocardiogram of subjects with vasoregulatory abnormality.

Khanna¹,

Balasubramanian²,

Dham³

et al. 1977

Heart

View full text Add to dashboard Cite

show abstract

Antigravity Effects of Leg Exercise

Rosenhamer

1968

Acta Physiologica Scandinavica

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To investigate the effects of leg exercise, on the overall tolerance to exaggerated gravitational stress, 8 subjects were exposed for 13 min to a threefold increase of the force of gravity in centrifuge experiments (+ 3 Gz) while in the sitting position, both during motionless resting and when exercising at 600 kpm/min on a bicycle ergometer. In all subjects, continuous leg exercise prevented the occurrence of circulatory collapse, which otherwise became imminent in 5 subjects after 5 to 12 min in the resting condition as evidenced by blackout or rapid increase in heart rate. Subjectively, exercise was experienced as less stressful than the resting condition. The improved circulatory stability with exercise was also reflected by uniformity of individual heart rate responses, the group mean value increasing from 152 to 160 beats/min during the 6th to 12th min.

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Antigravity Effects of Leg Exercise

Rosenhamer

1968

Acta Physiologica Scandinavica

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Rosenhamer, G. Antigravity effects of leg exercise. Acta physiol. scand. 1968. 72. 72–80, To investigate the effects of leg exercise on the overall tolerance to exaggerated gravitational stress, 8 subjects were exposed for 13 min to a threefold increase of the force of gravity in centrifuge experiments (+ 3 Gz) while in the sitting position, both during motionless resting and when exercising at 600 kpm/min on a bicycle ergometer. In all subjects, continuous leg exercise prevented the occurrence of circulatory collapse. which otherwise became imminent in 5 subjects after 5 to 12 min in the resting condition as evidenced by blackout or rapid increase in heart rate. Subjectively, exercise was experienced as less stressful than the resting condition. The improved circulatory stability with exercise was also reflected by uniformity of individual heart rate responses, the group mean value increasing from 152 to 160 beats/min during the 6th to 12th min.

show abstract

Electrocardiographic, Heart‐Rate and Subjective Responses to Prolonged Gravitational Stress and their Relation to some Dimensional and Functional Parameters of the Circulatory System

Cited by 4 publications

References 11 publications

Effect of positive acceleration (+gz) on electrocardiogram of subjects with vasoregulatory abnormality.

Effect of positive acceleration (+gz) on electrocardiogram of subjects with vasoregulatory abnormality.

Antigravity Effects of Leg Exercise

Antigravity Effects of Leg Exercise

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