Ye Zi, Coutinho Thais, Pellikka Patricia A, Villarraga Hector R, Borlaug Barry A, Kullo Iftikhar J
Division of Cardiovascular Diseases and the Gonda Vascular Center, Mayo Clinic, Rochester, Minnesota, USA.
Am J Hypertens. 2015 Nov;28(11):1325-31. doi: 10.1093/ajh/hpv039. Epub 2015 Apr 3.
Increased arterial stiffness leads to increased pulsatile load on the heart. We investigated associations of components of pulsatile load with a measure of left ventricular (LV) systolic function-global longitudinal strain (GLS), in a community-based cohort ascertained based on family history of hypertension.
Arterial tonometry and echocardiography with speckle tracking were performed in 520 adults with normal LV ejection fraction (EF) (age 67±9 years, 70% hypertensive) to quantify measures of pulsatile load (characteristic aortic impedance (Zc), total arterial compliance (TAC), and augmentation index (AI)) and GLS. The associations of log-Zc, log-TAC, and AI with GLS were assessed using sex-specific z-scores for each measure of arterial load.
In univariable analyses, higher Zc was associated with worse GLS (less negative) and higher TAC and AI were associated with better GLS (all P < 0.001). In a multivariable model including age, sex, heart rate (HR), LVEF, mean arterial load (systemic vascular resistance), and measures of pulsatile load, Zc remained associated with GLS (β = 0.28, P < 0.001), while the associations of TAC and AI were no longer significant (P > 0.5). Additional adjustment for cardiovascular risk factors and history of coronary heart disease and stroke did not attenuate the association of Zc with GLS; Zc, sex, HR, LVEF remained associated with GLS after stepwise elimination (all P < 0.001).
Greater proximal aortic stiffness, as manifested by a higher Zc, is independently associated with worse LV longitudinal function.
动脉僵硬度增加会导致心脏搏动负荷增加。我们在一个基于高血压家族史确定的社区队列中，研究了搏动负荷各成分与左心室（LV）收缩功能指标——整体纵向应变（GLS）之间的关联。
对520名左心室射血分数（EF）正常的成年人（年龄67±9岁，70%为高血压患者）进行动脉张力测定和斑点追踪超声心动图检查，以量化搏动负荷指标（特征性主动脉阻抗（Zc）、总动脉顺应性（TAC）和增强指数（AI））和GLS。使用针对每种动脉负荷指标的性别特异性z评分评估log-Zc、log-TAC和AI与GLS之间的关联。
在单变量分析中，较高的Zc与较差的GLS（负值较小）相关，较高的TAC和AI与较好的GLS相关（所有P<0.001）。在一个包括年龄、性别、心率（HR）、左心室射血分数、平均动脉负荷（全身血管阻力）和搏动负荷指标的多变量模型中，Zc仍与GLS相关（β = 0.28，P<0.001），而TAC和AI的关联不再显著（P>0.5）。对心血管危险因素以及冠心病和中风病史进行额外调整并未减弱Zc与GLS之间的关联；在逐步排除后，Zc、性别、HR、左心室射血分数仍与GLS相关（所有P<0.001）。
较高的Zc所体现的更大的近端主动脉僵硬度与较差的左心室纵向功能独立相关。
