Medical Center, Miyagi University of Education.
Division of Nephrology, Endocrinology, and Vascular Medicine, Department of Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
J Hypertens. 2022 Feb 1;40(2):338-347. doi: 10.1097/HJH.0000000000003014.
Blood pressure fluctuates during diastole to create a dicrotic wave but the mechanistic origin remains poorly understood. We sought to investigate the characteristics and determinants of diastolic pressure and flow fluctuations with a focus on stiffness gradients between the central aorta and peripheral arteries.
Using applanation tonometry and duplex ultrasound, pulse waveforms were recorded on the femoral artery in 592 patients (age: 55 ± 14 years) to estimate the diastolic pressure fluctuation as a residual wave against the mono-exponential decay and the diastolic flow fluctuation as a bidirectional (forward and reverse) velocity wave. The radial, carotid, and dorsalis pedis pressures were also recorded to measure the peripheral/aortic pulse pressure (PP) and pulse wave velocity (PWV) ratios.
There were close resemblances between the femoral pressure and flow fluctuation waveforms. The pressure and flow fluctuations were mutually correlated in relative amplitude as indexed to the total pulse height (r = 0.63), and the former temporally followed the latter. In multivariate-adjusted models, higher peripheral/aortic PP and PWV ratios were independently associated with greater pressure and flow fluctuation indices (P < 0.001). Mediation analysis revealed that the associations of PP and PWV ratios with the pressure fluctuation index were largely mediated by the flow fluctuation index [indirect/total effect ratio: 57 (95% CI 42-80)% and 54 (30-100)%, respectively].
These results suggest that central-to-peripheral pulse amplification and stiffness gradients contribute to triphasic flow fluctuations and dicrotic pressure waves. Diminished or inverted stiffness gradients caused by aortic stiffening may thus reduce diastolic runoff leading to ischemic organ damage.
血压在舒张期波动以产生双向压力波，但机械起源仍知之甚少。我们试图研究舒张期压力和流量波动的特征和决定因素，重点关注中心主动脉和外周动脉之间的僵硬度梯度。
应用平板张力测定法和双功能超声，在 592 例患者（年龄：55±14 岁）的股动脉上记录脉搏波形，以估计舒张期压力波动作为单指数衰减的残余波，以及舒张期流量波动作为双向（正向和反向）速度波。还记录了桡动脉、颈动脉和足背动脉的压力，以测量外周/主动脉脉搏压（PP）和脉搏波速度（PWV）比值。
股动脉压力和流量波动波形非常相似。压力和流量波动在相对幅度上相互关联，以总脉搏高度为指标（r=0.63），前者在时间上紧随后者。在多变量调整模型中，较高的外周/主动脉 PP 和 PWV 比值与较大的压力和流量波动指数独立相关（P<0.001）。中介分析显示，PP 和 PWV 比值与压力波动指数的关联主要由流量波动指数介导[间接/总效应比：57（95%置信区间 42-80）%和 54（30-100）%]。
这些结果表明，中心至外周的脉搏放大和僵硬度梯度有助于三相血流波动和双向压力波。主动脉僵硬引起的递减或反转的僵硬度梯度可能会减少舒张期血流，导致缺血性器官损伤。
