Effects of Slow Deep Breathing at High Altitude on Oxygen Saturation, Pulmonary and Systemic Hemodynamics

Abstract

Slow deep breathing improves blood oxygenation (SpO2) and affects hemodynamics in hypoxic patients. We investigated the ventilatory and hemodynamic effects of slow deep breathing in normal subjects at high altitude. We collected data in healthy lowlanders staying either at 4559 m for 2–3 days (Study A; N = 39) or at 5400 m for 12–16 days (Study B; N = 28). Study variables, including SpO2 and systemic and pulmonary arterial pressure, were assessed before, during and after 15 minutes of breathing at 6 breaths/min. At the end of slow breathing, an increase in SpO2 (Study A: from 80.2±7.7% to 89.5±8.2%; Study B: from 81.0±4.2% to 88.6±4.5; both p<0.001) and significant reductions in systemic and pulmonary arterial pressure occurred. This was associated with increased tidal volume and no changes in minute ventilation or pulmonary CO diffusion. Slow deep breathing improves ventilation efficiency for oxygen as shown by blood oxygenation increase, and it reduces systemic and pulmonary blood pressure at high altitude but does not change pulmonary gas diffusion.

Self-Regulation of Breathing as a Primary Treatment for Anxiety

“…Electron acceptors, such as oxygen, are responsible for the proton gradient and hyperpolarization that occur in the electron transport chain during mitochondrial cellular respiration (Alberts et al 2002) suggesting that fluctuations in oxygen, even minor fluctuations that occur during inspiration and expiration, may affect the degree of mitochondrial hyperpolarization and subsequently affect the rate of cellular respiration (Jerath et al 2015). Slow deep breathing, which has been shown to increase oxygenation (Bernardi et al 1998;Bilo et al 2012), may therefore lead to a slight but widespread increase in hyperpolarization of cellular membranes (Jerath et al 2015). In addition, the existence of voltage dependent channels that transfer ions between the mitochondrial outer membrane and the cytosol (Fieni et al 2010;Kmita and Stobienia 2006) suggests that mitochondrial membrane potential changes may affect the entire cell.…”

Exercise ventilatory inefficiency in heart failure: some fresh news into the roadmap of heart failure with preserved ejection fraction phenotyping

“…Evidence is lacking but some speculation may derive from the observed physiological ventilatory adaptations obtained at high altitude, where hypoxia (and the associated high VE/VCO 2 slope) can be partially corrected by a voluntarily imposed high tidal volume at low VE frequencies. 25 This way of breathing is typical of some relaxing activities such as rosarium, yoga, and listening to music that might overall benefit VE efficiency, at least in HFrEF. 26,27 In HFpEF, the recent greater molecular understanding of endothelial damage and oxidative stress due to the proinflammatory state would imply the concept of a pulmonary microvessel vasculopathy susceptible to benefits by interventions targeting the impaired nitric oxide-cGMP bioavailability pathway by improving the regional lung perfusion and, for instance, the VD/VT pattern during exercise.…”

“…Considering the different underlying pathophysiology, with a prevailing higher reflex‐induced inefficiency of VE in HFrEF as the major reason for exercise hyperventilation and a high VD/VT as the major cause of hyperpnoea in HFpEF, should we start to consider ventilatory abnormalities during exercise a more focused target of therapy and treat them accordingly? Evidence is lacking but some speculation may derive from the observed physiological ventilatory adaptations obtained at high altitude, where hypoxia (and the associated high VE/VCO 2 slope) can be partially corrected by a voluntarily imposed high tidal volume at low VE frequencies . This way of breathing is typical of some relaxing activities such as rosarium, yoga, and listening to music that might overall benefit VE efficiency, at least in HFrEF .…”

Thoraco-abdominal coordination and performance during uphill running at altitude

“…Specifically, ventilatory patterns characterized by a higher tidal volume (VT) and reduced respiratory rate (RR) have been found to be the most efficient due to the reduction in dead space ventilation [11–14]. This ventilatory pattern can play an important role in SpO 2 and therefore can influence respiratory and cardiac responses and exercise performance at altitude [10,12]. …”