PURPOSE Postprandial myocardial ischemia has been observed in frail older adults with postprandial hypotension and in patients with severe coronary artery disease, especially after high doses of carbohydrates. The impact of oral glucose on myocardial oxygen supply and demand in healthy older adults without postprandial hypotension or postprandial angina remains unexamined. We hypothesized that ...

High temperatures can stress animals by raising the oxygen demand above the oxygen supply. Consequently, animals under hypoxia could be more sensitive to heating than those exposed to normoxia. Although support for this model has been limited to aquatic animals, oxygen supply might limit the heat tolerance of terrestrial animals during energetically demanding activities. We evaluated this model...

FOR MORE THAN A CENTURY a large body of evidence has accumulated in the physiological and pathophysiological literature to support the close relationship between the demand of oxygen by the tissues and the supply of oxygen by the cardiorespiratory system. When the demand for oxygen changes, how is its supply altered to match the increased demand and what are the signals by which the increased d...

Ischemia is the most common cause of acute renal failure. Ischemic-induced renal tissue hypoxia is thought to be a major component in the development of acute renal failure in promoting the initial tubular damage. Renal oxygenation originates from a balance between oxygen supply and consumption. Recent investigations have provided new insights into alterations in oxygenation pathways in the isc...

OBJECTIVES We sought to study the effects of catecholamines on myocardial oxygen consumption (VO2), regional blood flows and total body VO2 in lambs with circulatory congestion. BACKGROUND Catecholamines are often used to support cardiovascular function in children with circulatory congestion because they increase contractility as well as heart rate. However, these changes increase myocardial...

a pulmonary embolus clogs the artery that provides blood supply to a part of the lung. the embolus not only prevents the exchange of oxygen and carbon dioxide but also decreases blood supply to the lung tissue itself, potentially causing the tissue to die (infarct). a 52-year-old man presented with syncope and anxiety. he had sinus tachycardia and dilated right ventricle with trabeculations. a ...

the acute diffuse hypoxia in dogs by general hypoxia, ligation of the coronary arteries and perfusion of the coronaries in the diffuse hypoxic hear ts. t he results of our experiments suggest that the quantitative diminu tion of oxygen and bloo d supply to the myocardium is, rather than oxygen differential , a determining fa ctor for development of ventr icular fi brillat ion or cardiac arrest.

Patients with aortic stenosis are susceptible to myocardial ischemia during hemodynamic stress, which may be caused by two mechanisms. First, vascular abnormalities inherent in myocardial hypertrophy may impair coronary vasodilation, limiting the ability to increase coronary blood flow to meet increased metabolic demands. Second, aortic stenosis itself may cause an imbalance between oxygen supp...

Mass casualty events and disasters, both natural and human-generated, occur frequently around the world and can generate scores of injured or ill victims in need of resources. Of the available medical supplies, oxygen remains the critical consumable resource in disaster management. Strategic management of oxygen supplies in disaster scenarios remains a priority. Hospitals have large supplies of...