Changes of Cardiovascular Indices during Head up Tilt Plus Lower Body Negative Pressure
Abstract：Objective To understand the change of the cardiovascular function and to evaluate the usefulness of sphygmography and heart rate variability (HRV) spectrum techniques on estimating cardiovascular function during HUP+LBNP. Method Blood pressure, ECG, cerebral oxygen saturation and sphygmogram of 16 subjects were studied during 75° head up tilt plus lower body negative pressure (HUP+LBNP). Result (1) During HUP+LBNP, heart rate, blood pressure, normalized low frequcncy component(LFn), LFn/HFn increased significantly, the cerebral blood oxygen saturation, T wave (ECG), HFn decreased significantly；(2) Blood pressure, heart rate and cerebral blood oxygen saturation decreased significantly in presyncopal state；(3)The heart rate in low tolerance group was higher than that in high tolerance group during the initial stage of HUT+LBNP;(4) The shape of pulse wave changed enormously during HUP+LBNP,so that no analysis could be made. Conclusion HUP+LBNP was an effective approach to examine the regulatory function of cardiovascular system,and the sphygmogram could not be used in studying the regulatory function of cardiovascular system during HUP+LBNP.
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Publication Date：2001-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 36-40 )