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The standard drug treatment of dexamethasone does not alter the hypoxia or the consequent vasoconstriction, but stimulates fluid reabsorption in the lungs to reverse the edema. Additionally, several studies on native populations remaining at high altitudes have demonstrated to varying degrees the blunting of the HPV response.
Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure in the arteries of the lungs. [7] Symptoms include shortness of breath, fainting, tiredness, chest pain, swelling of the legs, and a fast heartbeat. [7] [1] The condition may make it difficult to exercise. [7] Onset is typically gradual. [8]
The physiological responses to high altitude include hyperventilation, polycythemia, increased capillary density in muscle and hypoxic pulmonary vasoconstriction–increased intracellular oxidative enzymes. There are a range of responses to hypoxia at the cellular level, shown by discovery of hypoxia-inducible factors (HIFs), which determine ...
By contrast, in the lungs, the response to hypoxia is vasoconstriction. This is known as hypoxic pulmonary vasoconstriction, or "HPV", and has the effect of redirecting blood away from poorly ventilated regions, which helps match perfusion to ventilation, giving a more even oxygenation of blood from different parts of the lungs. [81]
To be classified as pulmonary heart disease, the cause must originate in the pulmonary circulation system; RVH due to a systemic defect is not classified as pulmonary heart disease. Two causes are vascular changes as a result of tissue damage (e.g. disease, hypoxic injury), and chronic hypoxic pulmonary vasoconstriction. If left untreated, then ...
Feb. 13—Sweating, nausea, dizziness and unusual fatigue may not sound like typical heart attack symptoms. However, they are common for women and may occur more often when resting or asleep.
Re-entry HAPE is also an entity that has been described in persons who normally live at high altitude but who develop pulmonary edema after returning from a stay at low altitude. [3] If HAPE is not treated, there is a 50% risk of mortality. [4] Symptoms include crackling sounds when breathing, dyspnea (at rest), and cyanosis. [4]
Many people with chronic obstructive pulmonary disease have a low partial pressure of oxygen in the blood and high partial pressure of carbon dioxide.Treatment with supplemental oxygen may improve their well-being; alternatively, in some this can lead to the adverse effect of elevating the carbon dioxide content in the blood (hypercapnia) to levels that may become toxic.