Physiological Changes to the Cardiovascular System at High Altitude and Its Effects on Cardiovascular Disease

Abstract

Riley, Callum James, and Matthew Gavin. Physiological changes to the cardiovascular system at high altitude and its effects on cardiovascular disease. High Alt Med Biol. 18:102-113, 2017.-The physiological changes to the cardiovascular system in response to the high altitude environment are well understood. More recently, we have begun to understand how these changes may affect and cause detriment to cardiovascular disease. In addition to this, the increasing availability of altitude simulation has dramatically improved our understanding of the physiology of high altitude. This has allowed further study on the effect of altitude in those with cardiovascular disease in a safe and controlled environment as well as in healthy individuals. Using a thorough PubMed search, this review aims to integrate recent advances in cardiovascular physiology at altitude with previous understanding, as well as its potential implications on cardiovascular disease. Altogether, it was found that the changes at altitude to cardiovascular physiology are profound enough to have a noteworthy effect on many forms of cardiovascular disease. While often asymptomatic, there is some risk in high altitude exposure for individuals with certain cardiovascular diseases. Although controlled research in patients with cardiovascular disease was largely lacking, meaning firm conclusions cannot be drawn, these risks should be a consideration to both the individual and their physician.

Interaction between Cardiac Functional Indices during Incremental Exercise Test Reveals the Peculiarities of Adaptation to Exercising

“…Factors such as duration or intensity of exercise [4], training status [5], gender [6], and environment [7] are indistinguishable components that determine the extent of post-exercise dysfunctions [8]. Furthermore, physical exertion that leads to structural cardiac changes vary depending on the type of training and may affect the function of the heart, i.e., long-term physical activity may lead to an athlete developing “athlete’s heart” [9].…”

Telomere elongation protects heart and lung tissue cells from fatal damage in rats exposed to severe hypoxia

“…It has been well documented that acute exposure to hypoxia at high altitude will cause serious damage to a wide variety of human organs, in particular the heart and lung tissues. High-altitude pulmonary edema and heart disease are the most common high-altitude-related illnesses in otherwise healthy lowlanders at altitudes typically above 2500 m, with a high mortality rate in the absence of adequate treatment [ 1 , 2 ]. However, the prevention and treatment of high-altitude-related heart and lung diseases remain challenging.…”

Hydration Status and Cardiovascular Function

“…Acute hypobaric hypoxia (i.e., high-altitude) increases BP [213] and alters body water balance via fluid shifts and changes in hormonal control of body fluid and electrolytes [214,215,216]. The increases in BP during acute exposure to altitude is thought to occur through endothlin-1-mediated increases in heart rate and systemic sympathetic activation.…”

“…The increases in BP during acute exposure to altitude is thought to occur through endothlin-1-mediated increases in heart rate and systemic sympathetic activation. With chronic altitude exposure, there is potential to develop chronic arterial and pulmonary hypertension, the mechanisms and evidence for which are discussed in depth by Riley et al [213]. Specific to changes in body water balance, acute altitude exposure (3500 m for 12 days) elicits reductions in extracellular water and total body water [214].…”