Department of Ultrasound Diagnostics, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
Nephrol Dial Transplant. 2012 Dec;27(12):4422-9. doi: 10.1093/ndt/gfs090. Epub 2012 May 4.
Multidirectional myocardial strain analysis can provide mechanistic insight into the ventricular systolic function and pathophysiology. The aim of this study was to assess the multidirectional systolic function of the left ventricle (LV) and its relationship to LV geometry in hemodialysis patients with preserved left ventricular ejection fraction (LVEF).
A total of 98 end-stage renal disease patients (age 46 ± 10 years, 60% men) with preserved LVEF (≥50%) on a maintenance hemodialysis program and 18 healthy volunteers were enrolled. The patients were divided into non-hypertrophic groups (classified as normal LV geometry and concentric remodeling) and hypertrophy groups (classified as eccentric and concentric hypertrophy) according to their LV geometries assessed from LV mass/height(2.7) and relative wall thickness in combination. Multidirectional strain analysis was performed by two-dimensional speckle tracking echocardiography.
Myocardial systolic strain (longitudinal and circumferential) and stress-corrected midwall fraction shorting (sc-MWFS) were lower in the hypertrophy groups compared with non-hypertrophic groups. Longitudinal strain and strain rate were even lower in the concentric hypertrophy group than the eccentric hypertrophy group (-15.5 ± 2.2% versus -17.8 ± 2.6%, P = 0.001; -0.7 ± 0.2 versus -0.9 ± 0.2s(-1), P = 0.016). Impaired longitudinal strain correlated with higher LV mass index (LVMI), relative wall thickness, pre-dialysis systolic blood pressure (SBP), calcium-phosphate product and lower sc-MWFS (all P < 0.0001) and weakly correlated with higher interdialytic weight gain (P = 0.004). Using multivariate linear regression, the independent predictors of LV longitudinal strain were pre-dialysis SBP, LVMI, relative wall thickness and sc-MWFS. There were no differences in LVEF and myocardial function in radial direction among all groups.
In hemodialysis patients with LV hypertrophy, myocardial function was impaired not only in longitudinal direction but also in circumferential direction despite preserved LVEF. Low longitudinal strain is related to LV hypertrophy, concentric geometry and pre-dialysis blood pressure.
多方向心肌应变分析可以为心室收缩功能和病理生理学提供机制上的见解。本研究旨在评估左心室（LV）的多向收缩功能及其与左心室射血分数（LVEF）保留的血液透析患者 LV 几何形状的关系。
共纳入 98 名终末期肾病患者（年龄 46 ± 10 岁，60%为男性），在维持性血液透析计划中保留 LVEF（≥50%），并纳入 18 名健康志愿者。根据 LV 质量/身高（2.7）和相对壁厚度的组合，将患者分为非肥厚组（分为正常 LV 几何形状和同心重塑）和肥厚组（分为偏心肥厚和同心肥厚）。使用二维斑点追踪超声心动图进行多方向应变分析。
与非肥厚组相比，肥厚组心肌收缩应变（纵向和环向）和校正壁中层缩短分数（sc-MWFS）较低。与偏心肥厚组相比，同心肥厚组的纵向应变和应变率更低（-15.5 ± 2.2%与-17.8 ± 2.6%，P=0.001；-0.7 ± 0.2 与-0.9 ± 0.2s(-1)，P=0.016）。纵向应变受损与较高的 LV 质量指数（LVMI）、相对壁厚度、透析前收缩压（SBP）、钙磷乘积和较低的 sc-MWFS 相关（均 P<0.0001），与透析间体重增加呈弱相关（P=0.004）。多元线性回归分析显示，LV 纵向应变的独立预测因子为透析前 SBP、LVMI、相对壁厚度和 sc-MWFS。所有组之间的 LVEF 和径向心肌功能无差异。
在 LV 肥厚的血液透析患者中，尽管保留了 LVEF，但心肌功能不仅在纵向方向受损，而且在环向方向也受损。低纵向应变与 LV 肥厚、同心几何形状和透析前血压有关。
