左室应变及扭转评价冠心病临床心功能的初步研究

Preliminary evaluation of left ventricular strain and torsion in clinical cardiac function classification in coronary artery disease

目的应用二维超声斑点追踪技术(2D-STI)检测冠心病心肌应变和扭转改变与临床心功能分级进行比较,初步评价心肌应变及扭转定量判断冠心病临床心功能的价值。方法将56例冠心病患者分为临床心功能接近正常或正常组(30例)及心功能异常(26例),比较受检者临床心功能积分(NYHA-AP)、左室射血分数(LVEF)、左室心肌整体径向应变(GRS)、纵向应变(GLS)、左室心肌收缩期心肌扭转角度(TA)。结果两组比较:GLS、GRS、TA减低(P<0.05);心功能正常组GLS、GRS、TA与NYHA-AP及LVEF相关性不大,LVEF与NYHA-AP也相关性不大,而心功能异常组呈相关关系;以GLS-15.05%截断点判定患者心功能符合临床NYHA分级Ⅰ~Ⅱ级,灵敏度为88%、特异度为70%。结论 2D-STI技术检测心肌应变及扭转与临床心功能分级相关,有较好的灵敏度和特异度。

AIM To study left ventricular myocardial strain and torsion using 2D speckle tracking technology （2D-STI） and to explore the value of myocardial strain and torsion in quantitative assessment of the New York Heart Association （classification） accumulated points （NYHA-AP） in coronary artery disease （CAD）. METHODS Fifty-six patients with CAD were divided into normal clinical heart function group （group A, n=30） and dysfunctional clinical cardiac group （group B, n=26）. Thirty subjects without CAD were recruited as normal control group （group C）. Left ventricular ejection fraction （LVEF）, left ventricular myocardial global longitudinal strain （GLS）, global radial strain （GRS） and left ventricular myocardial systolic torsion angle （TA） were detected and compared between groups. RESULTS LVEF, GLS, GRS and TA in CAD group were lower （P〈0.05） than those in the control group. There was no correlation between LVEF and GLS in group A （P〉0.05）, GLS and LVEF were positively correlated in group B, and GLS, GRS and TA in group B were lower than those in group A （P〈0.05）. LVEF had no correlation with NYHA-AP in group A but were positively correlated in Group B. Sensitivity and specificity of the cut-off point of GLS-15.05% for determining NYHA class I-II grade were, respectively, 88.45% and 70%. CONCLUSION 2D-STI has unique advantages in evaluating regional myocardial function. Clinical cardiac function classification and LVEF are not synchronized and myocardial strain and torsion are correlated with clinical cardiac function. Regional myocardial function variation develops simultaneously with clinical cardiac function. Myocardial strain and torsion decreases even if NYHA is still good or to a lesser degree. Decreased myocardial strain and torsion indicate the development of heart dysfunction.