Intermittent hypobaric hypoxia applicability in myocardial infarction prevention and recovery

Abstract

Intermittent hypobaric hypoxia (IHH) has been the focus of important research in cardioprotection, and it has been associated with several mechanisms. Intermittent hypobaric hypoxia inhibits prolyl hydroxylases (PHD) activity, increasing the stabilization of hypoxia-inducible factor-1 (HIF-1) and activating crucial adaptative genes. It has been hence suggested that IHH might be a simple intervention, which may offer a thoughtful benefits to patients with acute myocardial infarction and no complications. Nevertheless, several doubts exist as to whether IHH is a really safe technique, with little to no complications in post-myocardial infarction patients. Intermittent hypobaric hypoxia might produce instead unfavourable changes such as impairment of vascular hemodynamics and hypertensive response, increased risk of hemoconcentration and thrombosis, cardiac rhythm perturbations, coronary artery disease and heart failure, insulin resistance, steatohepatitis and even high-altitude pulmonary oedema in susceptible or nonacclimatized patients. Although intermittent and chronic exposures seem effective in cardioprotection, IHH safety issues have been mostly overlooked, so that assorted concerns should be raised about the opportunity to use IHH in the post-myocardial infarction period. Several IHH protocols used in some studies were also aggressive, which would hamper their widespread introduction within the clinical practice. As such, further research is needed before IHH can be widely advocated in myocardial infarction prevention and recovery.

Oxidative and carbonyl stress in pregnant women with obstructive sleep apnea

“…Animal experiments have shown that antioxidants could be beneficial in OSA confirming the role of oxidative stress in this sleep-related disorder [18]. On the other hand, intermittent hypoxia has also been suggested to have some protective effects against some cardiovascular complications [19] and may even have some therapeutic benefit in patients with COPD as it may improve ventilation [20]. Given the complicated hormonal and physiological milieu of pregnancy, which includes a higher inflammatory state, it is unclear how OSA would impact oxidative stress.…”

Intermittent hypoxia training as non-pharmacologic therapy for cardiovascular diseases: Practical analysis on methods and equipment

“…It was suggested that intermittent hypobaric hypoxia may produce harmful biochemical changes, including decreased antioxidant capacity and increased lipid peroxidation, which may lead to suppression of vascular endothelial function and impairment of vascular hemodynamics. 67…”

Altitude et système cardiovasculaire

“…Ainsi, l'utilisation de l'hypoxie intermittente par inhalation de mélanges hypoxiques se développe sans que les limites, bénéfices et dangers de cette technique ne soient encore clairement établis [15,16].…”