Chronic mountain sickness (CMS) represents a variably reversible asynchronous syndrome of secondary polycythemia along with erythrocytosis, erythrocyte aggregation, hemoglobinemia, hemoconcentration, thrombocytopenia, increased whole blood viscosity, fibrinogenemia, prothrombotic state, pulmonary and systemic hypertension, and congestive heart failure, occurring due to hypobaric hypoxia-anoxia-...

Chronic mountain sickness (CMS) is a disease that affects many high-altitude dwellers, particularly in the Andean Mountains in South America. The hallmark symptom of CMS is polycythemia, which causes increased risk of pulmonary hypertension and stroke (among other symptoms). A prevailing hypothesis in high-altitude medicine is that CMS results from a population-specific "maladaptation" to the h...

High-altitude pulmonary oedema (HAPE) occurs in predisposed individuals at altitudes >2,500 m. Defective alveolar fluid clearance secondary to a constitutive impairment of the respiratory transepithelial sodium transport contributes to its pathogenesis. Hypoxia impairs the transepithelial sodium transport in alveolar epithelial type II cells in vitro. If this impairment is also present in vivo,...

Patients with respiratory diseases may be at risk during flight because at cruising altitude an important hypobaric hypoxia may occur. The only absolute contraindications to flying in these patients are pneumothorax, bronchogenic cyst and severe pulmonary hypertension. In order to evaluate the risks related to air travel in patients with respiratory diseases, an evaluation of their fitness to f...

Electrocardiograims of healthy men both native and long-term residents at 14,900 feet above sea level have been obtained and classified according to their dominant pattern. Most of the tracings showed signs of either right ventricular hypertrophy or right bundle-branch block, incomplete and complete. Some of the mechanisms responsible for these electrocardiographic changes found at high altitud...

Broilers of 4 different commercial strains were kept during winter at an altitude of 1,350 m. The birds were slaughtered at weekly intervals and their relative right ventricular mass (pulmonary arterial pressure index = API values) determined. In addition, the incidence of ascites was recorded. Two of the strains suffered high losses from ascites, while the other 2 showed a certain degree of re...

cor triatriatum is an acyanotic congenital heart disease. we present a rare case of cor triatriatum sinistrum in a 6-month-old female infant who was presented with cyanosis and failure to thrive. the 2d transthoracic echocardiography and the doppler color flow imaging showed a proximal venous chamber communicating to the distal left atrium  through restrictive opening to the low-pressure, dista...

Localized alveolar hypoxia causes constriction of the small resistance pulmonary arteries, thus diverting the desaturated, mixed-venous blood to better ventilated areas of the lung. Although modulated by endothelial vasoactive substances, the constrictor response to hypoxia is intrinsic to the smooth muscle cell. Ion channels are important elements in two of the three components of the response...

The pulmonary hypertensive response to chronic hypoxia varies markedly among mammalian species. An explanation for this variability was sought by exposing seven species to hypobaric hypoxia (PB equal to 435 mmHg) for 19-48 days. Control animals were studied at 1,600 m (PB equal to 630 mmHg). The pulmonary hypertension that developed varied in the following order of decreasing severity: calf and...

We have studied the pulmonary circulation of three closely related animals, the llama, alpaca, and guanaco. The mean pulmonary arterial pressure of 12 llamas and one alpaca indigenous to high altitude in the Andes was found to be slightly but significantly higher than that of three llamas and three guanacos born and bred at low altitude in England. On the other hand, the medial thickness of the...