应用二维斑点追踪分层应变技术评价单纯2型糖尿病患者左室收缩功能的研究

目的 探讨单纯2型糖尿病患者左室各层及各节段心肌收缩功能的早期变化情况。方法 选取60例血压和冠状动脉正常的单纯2型糖尿病患者和60例健康志愿者作为正常对照，应用二维斑点追踪分层应变技术测量两组研究对象内层、中层和外层及基底段、中间段和心尖段心肌的纵向应变峰值（GLS）和圆周应变峰值（GCS），以及各节段的径向应变峰值（GRS），比较两组研究对象纵向、圆周和径向应变的差异。结果 两组研究对象左室心肌GLS和GCS均由内而外逐层递减、从基底段至心尖段逐段增加（P<0.01），GRS对照组心尖段较中间段及基底段明显减低（P<0.05），病例组GRS心尖段较基底段明显减低（P<0.05）；病例组各层及各节段GLS均较对照组对应层次和对应节段明显减低（P<0.05）,GCS中间段较对照组明显减低（P<0.05）,GRS心尖段较对照组明显减低（P<0.05）。结论 2型糖尿病患者在射血分数降低前已存在左室心肌和收缩功能损伤，心脏长轴方向的收缩功能和中下份心肌受损更明显。

Evaluation of left ventrieular systolic function in patients with type 2 diabetes mellitus using two-dimensional layer-specific speckle-tracking imaging

Objective To evaluate the early change of left ventricular systolic function in patients with type 2 diabetes mellitus (T2DM)using two-dimensional layer-specific speckle-tracking imaging. Methods The study included 60 T2DM patients without hypertension and coronary artery disease, and 60 normal controls. Global longitudinal strains (GLS) and global circumferential strains (GCS) of three myocardial layers (endocardial, mid-myocardial andepicardial) and three segments (basal, middle and apex) were measured usinglayer-specific speckle-tracking imaging.Globalradial strains (GRS) of three segments were also assessed. Results Among all the subjects, GLS and GCS decreased gradually from the endocardiallayerto the epicardial layer but increased gradually from the basal segment to the apex segment (all p<0.01).Moreover, in both groups,GRS were lower in the apex segment than in the basal segment(all p<0.05). Compared with control subjects, patients with T2DM had lower GLS of the three myocardial layers, the basal segment and the middle segment (all p<0.05). Patients with T2DM tend to have lower GLS of the apex segment thancontrol subjects (p=0.058). The GCS of the middle segment and the GRS of the apex segment were higher in patients with T2DM than in control subjects (p=0.014 and p=0.006, respectively). Conclusion Patients with T2DM have had left ventricular systolic dysfunction prior to decreased ejection fraction. The long-axis global systolic function and the middle-apex segments of the left ventricle may damage more easily.