Department of Cardiac Imaging, Baker Heart and Diabetes Institute, Melbourne, Australia; School of Public Health and Preventative Medicine, Monash University, Melbourne, Australia.
Department of Cardiac Imaging, Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
J Am Soc Echocardiogr. 2017 Jul;30(7):659-666. doi: 10.1016/j.echo.2017.03.014. Epub 2017 May 2.
Left atrial (LA) strain imaging enables the quantitative assessment of LA function. The clinical relevance of these measurements is dependent on the provision of information incremental to the left ventricular (LV) evaluation. The aim of this study was to test the hypothesis that LA pump function but not reservoir function is independent of measurement of LV mechanics.
Echocardiography was undertaken in a community-based study of 576 participants ≥65 years of age with one or more risk factors (e.g., hypertension, diabetes mellitus, obesity). Strain analysis was conducted using a dedicated software package, using R-R gating. LV function was classified as normal in the presence of global longitudinal strain (GLS) (≤-18%) or global circumferential strain (GCS) (≤-22%). The associations between GLS or GCS and LA reservoir, conduit, and pump strain were assessed using univariate and multivariate linear regression.
Patients (mean age 71 ± 5 years, 54% women) with reduced GLS had higher blood pressure and rates of diabetes and obesity (P < .05). LA reservoir strain and conduit strain were lower in the group with impaired GLS (38.2 ± 7.3% vs 39.9 ± 6.4% [P = .004] and 18.7 ± 5.7% vs 20.5 ± 5.1% [P < .001], respectively), but there was no difference in LA pump strain (19.5 ± 5.5% vs 19.3 ± 4.6%, P = .72). GLS was independently associated with LA reservoir and conduit strain (P < .05) but not independently associated with LA pump strain (P = .91). Reduced GCS was associated with a larger body mass index, male sex, and diabetes (P < .05). There were no differences in LA reservoir, conduit, and pump strain in patients with normal and abnormal GCS (P > .05).
The application of LA strain is specific to the component measured. LA pump strain is independent of LV mechanics.
左心房（LA）应变成像可实现 LA 功能的定量评估。这些测量的临床相关性取决于提供的信息是否对左心室（LV）评估有补充作用。本研究旨在验证假设，即 LA 泵功能而非储备功能与 LV 力学测量无关。
在一项针对≥65 岁且有一个或多个危险因素（如高血压、糖尿病、肥胖症）的社区人群的研究中进行了超声心动图检查。使用专用软件包，采用 R-R 门控技术进行应变分析。LV 功能正常的标准为整体纵向应变（GLS）（≤-18%）或整体环向应变（GCS）（≤-22%）。使用单变量和多变量线性回归评估 GLS 或 GCS 与 LA 储备、传导和泵应变之间的关系。
GLS 降低的患者（平均年龄 71±5 岁，54%为女性）血压更高，且糖尿病和肥胖症发病率更高（P<0.05）。GLS 受损组的 LA 储备应变和传导应变更低（分别为 38.2±7.3%与 39.9±6.4%[P=0.004]和 18.7±5.7%与 20.5±5.1%[P<0.001]），但 LA 泵应变无差异（19.5±5.5%与 19.3±4.6%，P=0.72）。GLS 与 LA 储备和传导应变独立相关（P<0.05），但与 LA 泵应变无关（P=0.91）。GCS 降低与更大的体重指数、男性和糖尿病有关（P<0.05）。GCS 正常和异常的患者 LA 储备、传导和泵应变无差异（P>0.05）。
LA 应变的应用取决于所测量的成分。LA 泵应变与 LV 力学无关。
