Background: Cardiorenal anemia syndrome (CRAS) is an evolving global epidemic associated with increased morbimortality and cost of care. The management of patients with CRAS remains a challenging undertaking worldwide and the lack of evidence-based clinical guidelines adds to the challenge. We aimed to explore the prevalence and survival rates of heart failure patients with CRAS in Tanzania.
View Article and Find Full Text PDFThe effect of physical training on an individual's ability to withstand an orthostatic stress is unclear. This study was undertaken to determine the effects on orthostatic tolerance in healthy volunteers of training at a level appropriate for unfit subjects and cardiorespiratory patients. In 11 asymptomatic, untrained subjects the following assessments were made: plasma volume by Evans Blue dye dilution and blood volume derived from haematocrit; carotid baroreceptor sensitivity from the slope of the regression of change in cardiac interval against pressure applied to a neck chamber; orthostatic tolerance as time to presyncope in a test of head-up tilting combined with lower body suction; exercise test relating heart rate to oxygen consumption.
View Article and Find Full Text PDFObjective: To determine whether a programme of simple, moderate exercise training increases blood volume and improves orthostatic tolerance in patients with attacks of syncope or near syncope related to orthostatic stress.
Design: An open study in 14 patients referred with unexplained attacks of syncope, who were shown to have a low tolerance to an orthostatic stress test. Measurements were made of plasma and blood volumes, orthostatic tolerance to a test of combined head up tilt and lower body suction, and baroreceptor sensitivity by applying subatmospheric pressures to a chamber over the neck.
Salt loading of patients with orthostatic-related syncope has been shown to increase plasma volume and orthostatic tolerance and to decrease baroreceptor sensitivity. This study aims to define the time course of these changes and reveal indications as to the likely mechanisms involved. We measured plasma volume by Evans blue dilution, orthostatic tolerance by time to presyncope in a test of combined head-up tilt and lower body suction, and baroreceptor sensitivity as the cardiac interval prolongation to neck suction.
View Article and Find Full Text PDFAviat Space Environ Med
June 1996
Background And Hypothesis: Orthostatically-induced syncope is accompanied by venous pooling and vasodilatation. Loss of consciousness during head-to-foot acceleration (G-LOC) in aviators may be caused by a different mechanism, as venous pooling should be prevented through the use of an anti-G suit. This research was conducted to test the hypothesis that in individuals wearing a well-fitted anti-G garment, no important changes occur in the volume of dependent regions during loss of consciousness resulting from rapid onset acceleration stress.
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