UNASSIGNED:动脉压波形反映了心脏与动脉系统之间的相互作用,并携带有关循环状态的潜在相关信息。根据普遍接受的“波传输模型”,净BP波形来自离散的前向和后向压力波的叠加,收缩期的前向波主要由左心室(LV)射血功能决定,后向由外周反射波决定,其时间和振幅取决于动脉硬度,波的传播速度和下游导纳失配的程度。然而,这种方法掩盖了弹性动脉的“Windkessel功能”。最近,提出了“储层超压”模型,将动脉血压波形解释为与容积相关的“储层”压力和与波相关的“超压”压力的复合。
UNASSIGNED:在这项研究中,我们将水库超压方法应用于分析10名年轻健康志愿者的颈动脉压力波形(压平眼压测量),在进行5周的头下倾斜卧床休息之前和之后,导致每搏输出量(SV)显着减少,舒张末期左心室容积和左心室纵向功能无中心血压显著变化,心输出量,总外周阻力和主动脉硬度。还通过波分离分析确定了前向和后向压力分量。
UNASSIGNED:与基线状态相比,卧床休息导致左心室射血时间(LVET)显着减少,舒张时间(DT),后向压力振幅(BP)和压力库积分(INTPR)。INTPR与LVET直接相关,DT,到达后波峰值的时间(BT)和每搏输出量,而超压积分(INTXSP)与中心压直接相关。此外,Δ。INTPR与Δ直接相关。LVET,和Δ。DT,在多变量分析中,INTPR与LVET和DT以及INTXSP与中心收缩压独立相关。
UNASSIGNED:这是一篇假设生成论文,为应用于非侵入性获得的颈动脉压力波形的储层波假设具有潜在的临床应用提供了支持。
UNASSIGNED: The arterial pressure waveform reflects the interaction between the heart and the arterial system and carries potentially relevant information about circulatory status. According to the commonly accepted \'wave transmission model\', the net BP waveform results from the super-position of discrete forward and backward pressure waves, with the forward wave in systole determined mainly by the left ventricular (LV) ejection function and the backward by the wave reflection from the periphery, the timing and amplitude of which depend on arterial stiffness, the wave propagation speed and the extent of downstream admittance mismatching. However, this approach obscures the \'Windkessel function\' of the elastic arteries. Recently, a \'reservoir-excess pressure\' model has been proposed, which interprets the arterial BP waveform as a composite of a volume-related \'reservoir\' pressure and a wave-related \'excess\' pressure.
UNASSIGNED: In this study we applied the reservoir-excess pressure approach to the analysis of carotid arterial pressure waveforms (applanation tonometry) in 10 young healthy volunteers before and after a 5-week head down tilt bed rest which induced a significant reduction in stroke volume (SV), end-diastolic LV volume and LV longitudinal function without significant changes in central blood pressure, cardiac output, total peripheral resistance and aortic stiffness. Forward and backward pressure components were also determined by wave separation analysis.
UNASSIGNED: Compared to the baseline state, bed rest induced a significant reduction in LV ejection time (LVET), diastolic time (DT), backward pressure amplitude (bP) and pressure reservoir integral (INTPR). INTPR correlated directly with LVET, DT, time to the peak of backward wave (bT) and stroke volume, while excess pressure integral (INTXSP) correlated directly with central pressure. Furthermore, Δ.INTPR correlated directly with Δ.LVET, and Δ.DT, and in multivariate analysis INTPR was independently related to LVET and DT and INTXSP to central systolic BP.
UNASSIGNED: This is an hypothesis generating paper which adds support to the idea that the reservoir-wave hypothesis applied to non-invasively obtained carotid pressure waveforms is of potential clinical usefulness.