No heartbreak at high altitude; preserved cardiac function in chronic hypoxia

Stembridge, Mike; Levine, Benjamin D.

doi:10.1113/ep087665

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…This response seems to be compensatory to maximise stroke volume (SV) when ventricular filling is impaired. Given that sub-endocardial function was maintained, the elevation in sympathetic activity was proposed as the most likely explanation for this phenomenon (Stembridge and Levine, 2019). In support to this hypothesis, findings have been recently provided that the increase in cardiac twist can be attenuated by the administration of specific β1-adrenergic antagonist, which appears to support the hypothesis that this is an appropriate response to sympathetic activation (Williams et al, 2019).…”

Section: Introductionmentioning

confidence: 93%

Systolic and Diastolic Functions After a Brief Acute Bout of Mild Exercise in Normobaric Hypoxia

et al. 2021

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Acute hypoxia (AH) is a challenge to the homeostasis of the cardiovascular system, especially during exercise. Research in this area is scarce. We aimed to ascertain whether echocardiographic, Doppler, and tissue Doppler measures were able to detect changes in systolic and diastolic functions during the recovery after mild exercise in AH. Twelve healthy males (age 33.5 ± 4.8 years) completed a cardiopulmonary test on an electromagnetically braked cycle-ergometer to determine their maximum workload (Wmax). On separate days, participants performed randomly assigned two exercise sessions consisting in 3 min pedalling at 30% of Wmax: (1) one test was conducted in normoxia (NORMO) and (2) one in normobaric hypoxia with FiO2 set to 13.5% (HYPO). Hemodynamics were assessed with an echocardiographic system. The main result was that the HYPO session increased parameters related to myocardial contractility such as pre-ejection period and systolic myocardial velocity with respect to the NORMO test. Moreover, the HYPO test enhanced early transmitral filling peak velocities. No effects were detected for left ventricular volumes, as end-diastolic, end-systolic, and stroke volume were similar between the NORMO and the HYPO test. Results of the present investigation support the hypothesis that a brief, mild exercise bout in acute normobaric hypoxia does not impair systolic or diastolic functions. Rather, it appears that stroke volume is well preserved and that systolic and early diastolic functions are enhanced by exercise in hypoxia.

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Section: Introductionmentioning

confidence: 93%

Systolic and Diastolic Functions After a Brief Acute Bout of Mild Exercise in Normobaric Hypoxia

et al. 2021

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“…Myocardial contractility as assessed by echocardiography is preserved in acute hypoxia 95 99 although subtle changes such as more rapid diastolic untwisting velocity 100 have been reported. Systemic blood pressure increases to a limited degree following ascent to high altitude, although there can be a significant interindividual variability in the observed responses.…”

Section: Other Systems: Cardiovascular Blood Renal and Tissue Responsesmentioning

confidence: 99%

High Altitude

Berger,

Luks

2023

Semin Respir Crit Care Med

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With ascent to high altitude, barometric pressure declines, leading to a reduction in the partial pressure of oxygen at every point along the oxygen transport chain from the ambient air to tissue mitochondria. This leads, in turn, to a series of changes over varying time frames across multiple organ systems that serve to maintain tissue oxygen delivery at levels sufficient to prevent acute altitude illness and preserve cognitive and locomotor function. This review focuses primarily on the physiological adjustments and acclimatization processes that occur in the lungs of healthy individuals, including alterations in control of breathing, ventilation, gas exchange, lung mechanics and dynamics, and pulmonary vascular physiology. Because other organ systems, including the cardiovascular, hematologic and renal systems, contribute to acclimatization, the responses seen in these systems, as well as changes in common activities such as sleep and exercise, are also addressed. While the pattern of the responses highlighted in this review are similar across individuals, the magnitude of such responses often demonstrates significant interindividual variability which accounts for subsequent differences in tolerance of the low oxygen conditions in this environment.

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“…Масса сердца животных групп О-1 и О-2 возросла к моменту окончания эксперимента на 62,4 и 38,4 % соответственно (p<0,05), что свидетельствует в пользу выраженных адаптивных перестроек организма, связанных со снабжением систем организма кислородом, что соотносится с литературными данными [7,8]. Но в условиях жесткой модели адаптации эти изменения более значительны.…”

Section: оригинальные исследованияunclassified

Bone mineral density of female rats in the process of adaptation to simulated durative intermittent hypobaric hypoxia

Belyaev¹,

Rzhepakovsky²,

Piskov³

et al. 2020

Medical news of the North Caucasus

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Bone mineral densiTY of female raTs in The process of adapTaTion To simulaTed duraTiVe inTermiTTenT hYpoBaric hYpoXia Belyaev n. g., rzhepakovsky i. V., piskov s. i., plyuiko V. V. north-caucasus federal university, stavropol, russian federation Представлена оценка минеральной плотности бедренной кости методом рентгеновской компьютерной микротомографии и показателей адаптивных процессов самок крыс при моделировании хронической прерывистой гипобарической гипоксии. Увеличение массы сердца и надпочечников, повышение количества эритроцитов и гемоглобина явились маркерами компенсаторных процессов. Полученные результаты указывают на то, что длительное прерывистое воздействие гипобарической гипоксии как в условиях жесткой адаптации, так и с постепенным наращиванием стресс-фактора служит фактором, способствующим остеопоротическим изменениям в костной ткани. Ключевые слова: гипоксическая гипоксия, гипобарическая хроническая гипоксия, минеральная плотность костной ткани, самки крыс, адаптация The estimation of femoral mineral density by Х-ray computer microtomography and indicators of adaptive processes in female rats in the simulation of chronic intermittent hypobaric hypoxia is presented. An increase in heart and adrenal mass, an increase in the number of red blood cells and hemoglobin were markers of compensatory processes. The obtained results indicate that long-term intermittent exposure to hypobaric hypoxia, both in conditions of severe adaptation, and with a gradual build-up of the stress factor, can lead to osteoporotic changes in the bone tissue.

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No heartbreak at high altitude; preserved cardiac function in chronic hypoxia

Cited by 4 publications

References 5 publications

Systolic and Diastolic Functions After a Brief Acute Bout of Mild Exercise in Normobaric Hypoxia

Systolic and Diastolic Functions After a Brief Acute Bout of Mild Exercise in Normobaric Hypoxia

High Altitude

Bone mineral density of female rats in the process of adaptation to simulated durative intermittent hypobaric hypoxia

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