Calculation of the velocity of body displacement and of the momentum of the body from 100 normal ballistic tracings shows that the values of the velocity of body displacement present a small scatter (mean value 68.3 + 13.9 mm. per second) and are independent of body weight and surface area. For uniformity of values and simplicity of calculation, which can be effected also on many abnormal traci...

BACKGROUND Symptomatic hypotension is the most frequent complication in patients receiving haemodialysis (HD). Previous studies have reported that the use of modulating dialysate sodium concentration or ultrafiltration (UF) rates, or the combination use of sodium profile and UF profile may better preserve blood volume and reduce the incidence of hypotensive episodes. The aim of this study was t...

Lower body negative pressure (LBNP), a model of hemorrhage (Hem), shifts blood to the legs and elicits central hypovolemia. This study compared responses to LBNP and actual Hem in sedated baboons. Arterial pressure, pulse pressure (PP), central venous pressure (CVP), heart rate, stroke volume (SV), and +dP/dt were measured. Hem steps were 6.25%, 12.5%, 18.75%, and 25% of total estimated blood v...

Ten healthy human volunteers were subjected to progressive lower body negative pressure (LBNP) to the onset of cardiovascular collapse to compare the response of noninvasively determined skin and fat corrected deep muscle oxygen saturation (SmO2) and pH to standard hemodynamic parameters for early detection of imminent hemodynamic instability. Muscle SmO2 and pH were determined with a novel nea...

BACKGROUND Although characteristics such as heart rate (HR) and blood pressure (BP) are commonly reported in studies of the relationship between fatigue and cardiac functioning, few reports examine how cardiac function parameters such as cardiac output (CO) and stroke volume (SV) relate to fatigue. This study examined the relationship between self-reported fatigue and hemodynamic functioning at...

BACKGROUND Noninvasive quantification of regurgitation is limited because Doppler measures velocity, not flow. Because backscattered Doppler power is proportional to sonified blood volume, power times velocity should be proportional to flow rate. Early studies, however, suggested that this held only for laminar flow, not for regurgitant jets, in which turbulence and fluid entrainment augment sc...

Cardiac output (CO) and stroke volume (SV) are parameters of key clinical interest. Many techniques exist to measure CO and SV, but are either invasive or insufficiently accurate in clinical settings. Electrical impedance tomography (EIT) has been suggested as a noninvasive measure of SV, but inconsistent results have been reported. Our goal is to determine the accuracy and reliability of EIT-b...

We identified the cardiovascular stress encountered by superimposing dehydration on hyperthermia during exercise in the heat and the mechanisms contributing to the dehydration-mediated stroke volume (SV) reduction. Fifteen endurance-trained cyclists [maximal O2 consumption (VO2max) = 4.5 l/min] exercised in the heat for 100-120 min and either became dehydrated by 4% body weight or remained euhy...

The purpose of this study was to determine whether the reduction in stroke volume (SV), previously shown to occur with dehydration and increases in internal body temperatures during prolonged exercise, is caused by a reduction in left ventricular (LV) function, as indicated by LV volumes, strain, and twist ("LV mechanics"). Eight healthy men [age: 20 ± 2, maximal oxygen uptake (VO₂max): 58 ± 7 ...

1. The renal artery to a lone remaining kidney was constricted in fourteen concious dogs. The following variables were measured in all animals: blood pressure (BP), cardiac rate (CR), plasma renin concentration (PRC), plasma volume (PV), extracellular fluid volume (ECFV) and plasma non-protein nitrogen (NPN). Sodium balance was estimated in eleven dogs. Cardiac output (CO), total peripheral res...