室壁分层分析技术评价超重及肥胖患者左室纵向应变的研究

Evaluating left ventricular longitudinal strain in overweight and obese population by layer-specific deformation analysis

目的应用室壁分层分析技术评价超重及肥胖患者左室心肌纵向应变特征,分析其影响因素。方法根据体质量指数(BMI)将102例受试者分为正常组、超重组及肥胖组,每组34例,应用二维斑点追踪成像(2D-STI)技术比较各组左室整体三层心肌纵向应变;逐步回归分析心功能影响因素。结果各组三层心肌纵向应变均存在梯度特征,其测值从大到小依次为心内膜下心肌、中层心肌及心外膜下心肌,两两比较差异均有统计学意义(均P<0.01)。与正常组比较,肥胖组左室整体各层心肌纵向应变均减低(均P<0.05);超重组左室整体各层心肌纵向应变与正常组和肥胖组比较差异均无统计学意义。逐步回归分析发现,BMI与心内膜下心肌纵向应变、中层心肌纵向应变及心外膜下心肌纵向应变均独立相关,腰臀比与心内膜下心肌纵向应变和中层心肌纵向应变均独立相关(均P<0.05)。结论超重和肥胖患者左室壁三层心肌纵向应变均存在梯度特征,肥胖患者左室心肌纵向收缩功能受损。BMI和腰臀比可能是超重和肥胖患者左室纵向收缩功能的独立影响因素。

Objective To evaluate left ventricular longitudinal strain（LS） characteristics in overweight and obese population by layer-specific deformation analysis,and to analyze possible influence factors of LS.Methods One hundred and two enrolled subjects were divided into healthy,overweight and obese groups according to body mass index（BMI）,each group has 34 subjects.The left ventricular global three-layer LS were compared by two-dimensional speckle tracking imaging（2 D-STI）in all groups.Cardiac function factors were analyzed by stepwise regression analysis.Results Gradient feature of three-layer LS across left ventricular wall was showed among three groups,the measured value in descending order were subendocardial myocardial layer（Endo）,mid-myocardial myocardial layer（Mid）and subepicardial myocardial layer（Epi）,there were significant difference among three groups（all P〈0.01）.Compared with healthy group,the three-layer LS decreased in obese group（all P〈0.05）.Compared with healthy group and obese group,there were no significant differences in three-layer LS in overweight group.Stepwise regression analysis revealed that BMI was independently correlated with LS-Endo,LS-Mid,LS-Epi,and waist to hip ratio was independently correlated with LS-Endo and LS-Mid（all P0.05）.Conclusion Gradient feature of three-layer LS across left ventricular wall is showed in overweight and obese population.Myocardial longitudinal systolic functon was impaired in obese group.BMI and waist to hip ratio may be independent influence factors of left ventricular longitudinal systolic function in overweight and obese population.