Baseline Values of Cardiovascular and Respiratory Parameters Predict Response to Acute Hypoxia in Young Healthy Men

Abstract

The majority of the available works have studied distinct hypoxic responses of respiratory and cardiovascular systems. This study examines how these systems interact while responding to hypoxia and whether baseline metrics moderate reactions to a hypoxic challenge. Central hemodynamic, aortic wave reflection, and gas exchange parameters were measured in 27 trained young men before and after 10-min normobaric isocapnic hypoxia (10 % O2). Associations were assessed by correlation and multiple regression analyses. Hypoxic changes in the parameters of pulse wave analysis such as augmentation index (-114 %, p=0.007), pulse pressure amplification (+6 %, p=0.020), time to aortic reflection wave (+21 %, p<0.001) report on the increase in arterial distensibility. Specifically, initially compliant arteries blunt the positive cardiac chronotropic response to hypoxia and facilitate the myocardial workload. The degree of blood oxygen desaturation is directly correlated with both baseline values and hypoxic responses of aortic and peripheral blood pressures. The hypoxia-induced gain in ventilation (VE), while controlling for basal VE and heart rate (HR), is inversely associated with HR and systolic blood pressure. The study suggests that cardiovascular and respiratory systems mutually supplement each other when responding to hypoxic challenge.

“Exercise with facemask; Are we handling a devil's sword?” – A physiological hypothesis

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Effect of Acute Hypoxia on Cardiorespiratory Coherence in Male Runners

“…It has been shown earlier in our laboratory (Divert et al, 2015) that cardiorespiratory reactions to hypoxic and hypercapnic tests divide athletes into the clusters depending on the type of sports performance they are specialized in. This finding has initiated subsequent studies that led to the conclusion of a close, mutually substitutional relationship between respiratory and cardiovascular systems under hypoxic conditions (Melnikov et al, 2017). For example, it has been shown that the parameters of the training process and the features of the respiration pattern that appear as a consequence of training modulate the sensitivity of brain structures to hypoxia as reflected in changes in the EEG α-rhythm under conditions of hypoxia (Balioz and Krivoshchekov, 2012).…”

Effect of chronic intermittent hypobaric hypoxia on heart rate variability in conscious rats

“…After 42 days of CIHH treatment, animals were placed into a custom‐made, closed container where they received a ten‐minute acute normobaric hypoxia (10% O 2 ). Electrocardiograms of conscious rats were continuously recorded before (normal oxygen), during (hypoxia), and after hypoxia (reoxygenation).…”