Department of Cardiovascular Diseases, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
Department of Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
BMC Cardiovasc Disord. 2020 Jan 30;20(1):33. doi: 10.1186/s12872-020-01336-0.
Aortic stenosis (AS) causes left ventricular (LV) pressure overload, leading to adverse LV remodeling and dysfunction. Identifying early subclinical markers of LV dysfunction in patients with significant AS is critical as this could provide support for earlier intervention, which may result in improved long-term outcomes. We therefore examined the impact of severe AS and its consequent increase in LV afterload on myocardial deformation and rotational mechanics by 2-dimensional (2D) and 3-dimensional (3D) speckle-tracking echocardiography.
We prospectively measured various strain parameters in 168 patients (42% female, mean age 72 ± 12 years) with severe AS and LV ejection fraction (EF) ≥50%, and compared them to normal values found in literature. 2D and 3D images were analyzed for global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), basal rotation, apical rotation, and peak systolic twist. We further assessed the degree of concordance between 2D and 3D strain, and examined their association with measures of LV preload and afterload.
Patients with severe AS exhibited significantly lower GLS and GRS but higher GCS, apical rotation, and twist by 2D and 3D echocardiography compared with published normal values (P = 0.003 for 3D twist, P < 0.001 for all others). Agreement between 2D- and 3D-GLS by concordance correlation coefficient was 0.49 (95% confidence interval: 0.39-0.57). GLS was correlated with valvulo-arterial impedance, a measure of LV afterload (r = 0.34, p < 0.001 and r = 0.23, p = 0.003, respectively).
Patients with severe AS demonstrated lower-than-normal GLS and GRS but appear to compensate with higher-than-normal GCS, apical rotation, and twist in order to maintain a preserved LVEF. GLS showed a modest correlation with valvulo-arterial impedance.
主动脉瓣狭窄（AS）导致左心室（LV）压力超负荷，导致 LV 不良重构和功能障碍。在严重 AS 患者中识别早期亚临床 LV 功能障碍的标志物至关重要，因为这可能为早期干预提供支持，从而可能改善长期预后。因此，我们通过二维（2D）和三维（3D）斑点追踪超声心动图检查，研究严重 AS 及其导致的 LV 后负荷增加对心肌变形和旋转力学的影响。
我们前瞻性测量了 168 例严重 AS 且左心室射血分数（EF）≥50%的患者的各种应变参数，并将其与文献中发现的正常值进行比较。对 2D 和 3D 图像进行整体纵向应变（GLS）、整体圆周应变（GCS）、整体径向应变（GRS）、基底旋转、心尖旋转和收缩期峰值扭转的分析。我们进一步评估了 2D 和 3D 应变之间的一致性程度，并研究了它们与 LV 前负荷和后负荷测量值的相关性。
与文献中的正常值相比，严重 AS 患者的 2D 和 3D 超声心动图显示 GLS 和 GRS 显著降低，但 GCS、心尖旋转和扭转较高（3D 扭转的 P=0.003，所有其他的 P<0.001）。二维和三维 GLS 的一致性相关系数为 0.49（95%置信区间：0.39-0.57）。GLS 与 valvulo-arterial 阻抗呈正相关，后者是 LV 后负荷的一种测量方法（r=0.34，p<0.001 和 r=0.23，p=0.003）。
严重 AS 患者的 GLS 和 GRS 低于正常值，但为了维持正常的 LVEF，似乎通过较高的 GCS、心尖旋转和扭转来代偿。GLS 与 valvulo-arterial 阻抗呈中度相关。
