A comparison of the effects of lower body positive pressure and head-down tilt on cardiovascular responses in humans.
Both lower body positive pressure (LBPP) and head-down tilt (HDT) can induce fluid shifts from the lower body to the thorax and result in a loading of cardiopulmonary baroreceptors. The aim of this study was to compare the effects of LBPP and HDT on cardiovascular responses in humans. To accomplish this, a graded LBPP test of 10, 20 and 30 mmHg, as well as a 6 degrees HDT was applied. It has been suggested that <20 mmHg LBPP and <30 degrees HDT load the cardiopulmonary baroreceptors by translocation of blood volume from the lower body to the thorax, while >20 mmHg LBPP activates the intramuscular pressure-sensitive receptors.
Fu
Q
Q
Dept. of Autonomic Neuroscience, Nagoya University, Japan.
Sugiyama
Y
Y
Kamiya
A
A
Iwase
S
S
Mano
T
T
D000328:Adult; D017704:Baroreflex; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D002307:Cardiography, Impedance; D002320:Cardiovascular Physiological Phenomena; D018495:Fluid Shifts / Q000502:physiology*; D018475:Head-Down Tilt; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008150:Lower Body Negative Pressure; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D011312:Pressure; D013318:Stroke Volume / Q000502:physiology