Evaluation of aortic wall assessed by strain rate in exercise therapy and drug medication

背景：虽然肱-踝脉波速度（PWV）是一种广泛使用的动脉硬度指标，但该方法存在一些局限性。用于测量PWV的动脉的实际长度是根据解剖校正值来估计的，而肱-踝PWV直接受到全身血压或血管闭塞的影响。因此，本研究的目的是确定组织多普勒超声心动图测量的主动脉壁应变率是否比肱-踝PWV更有助于评估局部主动脉顺应性。方法：72例心功能正常、无大血管并发症的患者（年龄18 ~ 79岁）入选本研究。结果：肱-踝关节PWV与年龄呈显著正相关，且随年龄增长而增加（r=0.73, p<0.05）。应变率与年龄呈显著负相关，应变率随年龄的增长而下降（r=-0.44, p<0.05）。肱-踝PWV与收缩压之间也存在显著相关性（r=0.45, p<0.001），但应变率与收缩压之间无显著相关性。高脂血症和正常脂血症受试者的肱-踝PWV无显著差异。而高脂血症组的应变率低于正常脂血症组（p<0.05）。结论：升主动脉壁应变率是一种新的、比肱-踝PWV更准确的区域主主动脉壁顺应性指标。

Background : Although brachial-ankle pulse wave velocity (PWV) is a widely used index of arterial stiffness, there are several limitations of this method. The actual length of an artery used for measuring PWV is estimated based on an anatomical correction value, and brachial-ankle PWV is directly affected by systemic blood pressure or vascular occlusion. Thus, the aim of this study to determine whether aortic wall strain rate as measured by tissue Doppler echocardiography is a more useful modality for evaluating regional aortic compliance than brachial-ankle PWV. Methods: Seventy-two patients (18- to 79- years- old) with normal cardiac function and without large vessel complications were enrolled in this study. Results : A significant positive correlation was found between brachial-ankle PWV and age, and brachial-ankle PWV increased with age (r=0.73, p<0.05). A significant negative correlation was found between strain rate and age, and strain rate decreased with age (r=-0.44, p<0.05). A significant correlation also was found between brachial-ankle PWV and systolic blood pressure (r=0.45, p<0.001), but not between strain rate and systolic blood pressure. There was no significant difference in brachial-ankle PWV between hyperlipidemic and normolipidemic subjects. However, strain rate was lower in hyperlipidemic than in normolipidemic subjects (p<0.05). Conclusion : Strain rate on the ascending aortic wall is a novel and more accurate index of regional main aortic wall compliance than brachial-ankle PWV.