| Botek et al.,2121 Botek M, Krejcí J, De Smet S, Gába A, McKune AJ. Heart rate variability and arterial oxygen saturation response during extreme normobaric hypoxia. Auton Neurosci. 2015;190:40-5. 2015 |
29 young moderately active healthy individuals (26 ± 4.9 years of age), |
10 min NH (FiO2= 9.6% at ~6200 m). Two groups: (RG) SpO2≥ 72.2% or (SG) ≤ 72.2% |
Controlled breathing (12 breaths/min) |
RG (↓80.8 ± 7.0); SG (↓67.2 ± 2.9) |
LnHF ↓ (RG and SG); LnHF (SG < RG);Ln LF/HF (↑ SG) and (↔ RG); Ln LF/HF (SG > RG); LFnu ↑ (SG); LFnu (SG > RG); HFnu ↓ (SG); HFnu (SG < RG) |
| Buchheit et al.,88 Buchheit M, Richard R, Doutreleau S, Lonsdorfer-Wolf E, Brandenberger G, Simon C. Effect of acute hypoxia on heart rate variability at rest and during exercise. Int J Sports Med. 2004;25(4):264-9. 2004 |
12 young moderately active healthy individuals (30.9 ± 2.3 years of age) |
6-min NH (11.5% O2 at ~4800 m) |
Spontaneous breathing |
ΔSaO2 (7.80±0.59) |
rMSSD ↓; SDNN ↔; LF ↔; HF ↓; LFnu and HFnu ↔ |
| Iwasaki et al.,1010 Iwasaki K, Ogawa Y, Aoki K, Saitoh T, Otsubo A, Shibata S. Cardiovascular regulation response to hypoxia during stepwise decreases from 21% to 15% inhaled oxygen. Aviat Space Environ Med. 2006;77(10):1015-9. 2006 |
18 young healthy individuals (22 ± 2 years of age |
NH (21%, 19%, 17%, 15% O2). Ten minutes at each level |
Spontaneous breathing |
SpO2 19% O2 (↓97,4 ± 0.2); 17% O2 (↓95.6 ± 0.3); 15% O2 (↓92.4 ± 0.5) |
LF ↔ (21%, 19% O2); LF ↑ (17%, 15%); HF ↔ (21%, 19%, 17%, 15% O2); LF/HF ↔ (21%, 19%, 17%); LF/HF ↑ (15%) |
| Zużewicz et al.,3232 Zuzewicz K, Biernat B, Kempa G, Kwarecki K. Heart rate variability in exposure to high altitude hypoxia of short duration. Int J Occup Saf Ergon. 1999;5(3):337-46. 1999 |
6 healthy individuals (25-28 years of age) |
HH Chamber in 4500 m. Six 30-min assessment periods at 4-hour intervals. Control situation (normoxia) on a different day |
Spontaneous breathing |
Absent data |
R-R ↓, SDNN ↓, pNN50 ↓, LF ↔, HF ↓, LF/HF ↔;(HRV during the day) |
| Zhang et al.,2626 Zhang D, She J, Zhang Z, Yu M. Effects of acute hypoxia on heart rate variability, sample entropy and cardiorespiratory phase synchronization. Biomed Eng Online. 2014;13:73. 2014 |
12 young healthy individuals (29 ± 7 years of age) |
HH Chamber in 3000 m and 4000 m. Fifteen minutes each level.Gradual rise (0-3000 m; 3000-4000 m) |
Spontaneous breathing |
SpO2 (↓90 ± 3) 3000m; (↓84 ± 4) 4000m |
LF ↓ (4000 m); LF (4000 < 3000 and normoxia); HF ↓ (4000 m); HF (4000 < 3000 and normoxia); LF/HF ↑ 4000 m; LF/HF (4000 m > normoxia) |
| Rupp et al.,2828 Rupp T, Leti T, Jubeau M, Millet GY, Bricout VA, Levy P, et al. Tissue deoxygenation kinetics induced by prolonged hypoxic exposure in healthy humans at rest. J Biomed Opt. 2013;18(9):095002. 2013 |
11 young healthy individuals (29 ± 6 years of age) |
NH (12% O2 at ~4000 m) sudden exposure. Two 4-hour sessions on different days. 3-min in normoxia (baseline), 4h 21% or 12% O2, 15-min recovery.Temperature (23 ± 1)°C and humidity (43 ± 9)% |
Spontaneous breathing |
SpO2↓ and stabilized at ~85% after 20-min exposure to hypoxia |
RR ↓ (relative to baseline and control session); rMSSD ↔; pNN50 ↓ (relative to control session); LFnu ↑ and ↓ HFnu (relative to the control session and baseline from 80 min.); LF/HF ↑ (relative to baseline) |
| Basualto-Alarcón et al.,1111 Basualto-Alarcon C, Rodas G, Galilea PA, Riera J, Pagés T, Ricart A, et al. Cardiorespiratory parameters during submaximal exercise under acute exposure to normobaric and hypobaric hypoxia. Apunts Med Esport. 2012;47(174):65-72. 2012 |
7 young healthy individuals (22.7 ± 5.8 years of age) |
15-min exposure to HH chamber in 3000 m and 15-min exposure to NH tent in 3000 m (different days) |
Spontaneous breathing |
SpO2↓ in both HH (91.6 ± 4.2) and NH (89.1 ± 3.8) |
In HH: rMSSD ↔; pNN50 ↔; LF% ↔; HF% ↓; LFnu ↑;HFnu ↓; LF/HF ↑;In NH: HRV ↔ |
| Bhaumik et al.,1414 Bhaumik G, Dass D, Bhattacharyya D, Sharma YK, Singh SB. Heart rate variability changes during first week of acclimatization to 3500 m altitude in Indian military personnel. Indian J Physiol Pharmacol. 2013;57(1):16-22. 2013 |
6 healthy young military servicemen (24.83 ± 2.93 years of age) |
HH (actual altitude 3500 m) after 48 hours and after 5 days |
Spontaneous breathing |
SpO2↓ after 2 days (92.83 ± 0.47); ↓ after 5 days (96.5 ± 0.22) |
Day 2nd: LF ↔; HF ↓; LFnu ↑; HFnu ↓; LF/HF ↑; 5th day: LF ↔; HF ↓; LFnu ↔; HFnu ↔; LF/HF ↔ |
| Guger et al.,1212 Guger C, Krausert S, Domej W, Edlinger G, Tannheimer M. EEG, ECG and oxygen concentration changes from sea level to a simulated altitude of 4000 m and back to sea level. Neurosci Lett. 2008;442(2):123-7. 2008 |
10 healthy males (21-33 years of age) |
A rise to 4000 m was reached after 1 hour and kept for 12 hours in HH chamber |
Spontaneous breathing |
After 1 hour SpO2↔; After 5h SpO2 ↓ (82.7 ± 6,8); and after 11h SpO2 ↓ (84.9 ± 4.5) |
After 1 hour HRV ↔; After 11 hours rMSSD ↓, SDANN ↓; SDNN ↓; LFnu ↑; HFnu ↓; LF/HF ↑ |
| Giles et al.,2323 Giles D, Kelly J, Draper N. Alterations in autonomic cardiac modulation in response to normobaric hypoxia. Eur J Sport Sci. 2016;16(8):1023-31. 2016 |
11 physically active males (21.8 ± 0.9 years of age) |
Five visits for 5 levels of FiO2 (20.3%; 17.4%; 14.5%; 12%; 9.8%) in NH, temperature (20°C) and 50% humidity. The length of exposure was 10 min |
Spontaneous breathing recorded (RF = 15.6 ± 3.4, 16.2 ± 2.7, 14.8 ± 3.0, 12.4 ± 4.2, 12.9 ± 4.2 breaths/min), respectively |
SpO2= 20.3% FiO2 (96.8 ± 2.1); 17.4% FiO2 (95.8 ± 1.7); 14,5%FiO2 (91.6 ± 1.7); 12% FiO2 (84.1 ± 4.0); 9.8% FiO2 (77.7 ± 5.8%) |
SDNN ↔; Ln rMSSD ↔; Ln VLF ↔; Ln LF ↔; Ln HF ↔; Ln LF/HF ↔ LFnu ↔; HFnu ↔ (in all conditions). The HR ↑ and Ln TP ↓ only in 9.8%FiO2
|
| Krejčí, et al.,2424 Krejcí J, Botek M, McKune A. Dynamics of the heart rate variability and oxygen saturation response to acute normobaric hypoxia within the first 10 min of exposure. Clin Physiol Funct Imaging. 2016 Jul 6. [Epub ahead of print]. 2016 |
29 young moderately active healthy individuals (26 ± 4.9 years of age), |
10 min NH (FiO2= 9.6% at ~6200m), in supine position |
Controlled breathing (12 breaths/min) |
SpO2↓ for 10 min: (96.4 ± 2.3 min in the first minute and reaching 71.9 ± 10% in the tenth minute) without stabilizing |
ΔHR ↑ (from 1 min); ΔLn rMSSD ↓ (from the 2nd min); ΔLn SDNN ↓ and ΔLn SDNN/rMSSD ↑ (both from the 3rd min); |
| Brown et al.,2222 Brown SJ, Barnes MJ, Mündel T. Effects of hypoxia and hypercapnia on human HRV and respiratory sinus arrhythmia. Acta Physiol Hung. 2014;101(3):263-72. 2014 |
10 healthy young individuals (aged 22 – 42) |
6 min HN (FiO2= 10% at ~5500 m), in supine position |
Spontaneous breathing |
Absent data |
HR ↑; LFnu ↔; HFnu ↔ |
| Haddad et al.,2525 Haddad H, Mendez-Villanueva A, Bourdon PC, Buchheit M. Effect of acute hypoxia on post-exercise parasympathetic reactivation in healthy men. Front Physiol. 2012;3:289. 2012 |
10 healthy, physically active males (32.7 ± 4 years of age), |
At rest: 10 min HN (FiO2= 15.4% at ~2400m), sit down. At 20-23°C) |
Spontaneous breathing |
Absent resting SpO2
|
At rest: RR ↔; Ln rMSSD ↔; Ln HF ↔; LF/HF ↔ |
