Department of Physiology, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France
Centre de Diagnostic et Thérapeutique Cardiovasculaire, Hôpital Hôtel-Dieu, Assistance Publique-Hôpitaux de Paris, Paris, France.
J Am Heart Assoc. 2018 Feb 28;7(5):e007427. doi: 10.1161/JAHA.117.007427.
Left ventricular (LV) torsion plays a key role in cardiac efficiency. In hypertension, aortic stiffening augments cardiac afterload. However, little is known about the links between LV regional contraction and aortic stiffness. We, therefore, investigated these relationships and their contribution to LV diastolic function.
The study included normotensive and hypertensive individuals with normal LV ejection. Apical, basal, and global LV rotation rate and LV global longitudinal strain were measured (2-dimensional speckle tracking echocardiography). Aortic stiffness was calculated from carotid-femoral pulse wave velocity, and LV relaxation was calculated from early diastolic mitral annulus motion. The ratio of basal or apical untwist/twist rates was calculated to assess relationships between aortic stiffness and LV torsion parameters. LV twist and untwist rates were greater in hypertensive than normotensive individuals because of increased basal twist (<0.001) and untwist (<0.001) rates. LV relaxation was reduced (early diastolic mitral annulus motion=7.4±1.9 versus 10.4±2.3 cm/s; <0.001). In the whole population, basal untwist rate increased with aortic stiffening (=0.43; <0.001) and LV relaxation (=0.41; =0.001). The ratio of basal untwist/twist rate was positively correlated with carotid-femoral pulse wave velocity, and in the hypertensive group, was greater than in the control group and positively correlated to carotid-femoral pulse wave velocity(<0.001). Results were independent of age, treatment, mean blood pressure, and indexed LV mass.
In hypertensive individuals, greater basal LV torsion was associated with increased aortic stiffness and improved diastolic function. These changes may compensate for the deleterious effects of aortic stiffening on LV relaxation.
左心室（LV）扭转在心脏效率中起着关键作用。在高血压中，主动脉僵硬度增加了心脏的后负荷。然而，对于 LV 局部收缩与主动脉僵硬度之间的联系知之甚少。因此，我们研究了这些关系及其对 LV 舒张功能的贡献。
本研究包括血压正常和高血压且左心室射血分数正常的个体。测量心尖、基底和整体 LV 旋转率和 LV 整体纵向应变（二维斑点追踪超声心动图）。从颈股脉搏波速度计算主动脉僵硬度，从舒张早期二尖瓣环运动计算 LV 松弛度。计算基底或心尖解旋/扭转率的比值，以评估主动脉僵硬度与 LV 扭转参数之间的关系。由于基底扭转（<0.001）和解旋（<0.001）率增加，高血压患者的 LV 扭转和解旋率高于血压正常者。LV 松弛度降低（舒张早期二尖瓣环运动=7.4±1.9 与 10.4±2.3cm/s；<0.001）。在整个人群中，基底解旋率随主动脉僵硬度（=0.43；<0.001）和 LV 松弛度（=0.41；=0.001）的增加而增加。基底解旋/扭转率的比值与颈股脉搏波速度呈正相关，且在高血压组中大于对照组，与颈股脉搏波速度呈正相关（<0.001）。结果独立于年龄、治疗、平均血压和指数化 LV 质量。
在高血压患者中，较大的基底 LV 扭转与主动脉僵硬度增加和舒张功能改善相关。这些变化可能补偿了主动脉僵硬度对 LV 松弛的有害影响。
