分层应变评估冠心病单纯左前降支显著狭窄心肌收缩功能的研究

Study on the evaluation of myocardial systolic function in patients with coronary heart disease of significant left anterior descending branch stenosis by layer-specific strain technique

目的分析应用二维斑点追踪成像(2D-STI)评价冠状动脉粥样硬化性心脏病(冠心病)单纯左前降支显著狭窄患者左心室3层心肌收缩的功能。方法选取临床疑似冠心病并行冠状动脉造影(CAG)提示左前降支单支病变且狭窄率大于或等于75%的61例患者为研究对象,分为狭窄组(n=30)和冠状动脉未见狭窄组(对照组,n=31)。应用2D-STI测量左前降支供血的3层心肌节段的纵向及圆周应变峰值[心内膜下层心肌节段纵向应变(endo-RLS)、中层心肌节段心肌纵向应变(mid-RLS)、心外膜下层节段心肌纵向应变(epi-RLS)、心内膜下层节段心肌圆周应变(endo-RCS)、中层心肌节段心肌圆周应变(mid-RCS)及心外膜下层节段心肌圆周应变(epi-RCS)],并计算心内膜下层与心外膜下层区域纵向及圆周应变峰值差值(ΔRLS、ΔRCS)。结果与对照组比较,狭窄组各节段心肌endo-RLS、mid-RLS、epi-RLS、endo-RCS、mid-RCS、ΔRLS、ΔRCS绝对值减低(P<0.05)。受试者工作特征(ROC)曲线显示endo-RLS预测左前降支显著狭窄的曲线下面积最大,诊断效能最好。结论2D-STI分层应变技术能够有效评价左前降支显著狭窄的冠心病患者左心室3层心肌的收缩功能,较早预测左前降支的显著狭窄。

Objective To evaluate the left ventricular three-layer myocardium systolic function by speckle tracking imaging(2D-STI)layer-specific strain in coronary heart disease patients with significant left anterior descending artery stenosis.Methods Sixty-one patients with clinically suspected coronary heart disease and coronary angiography(CAG)suggesting a single-vessel lesion of the left anterior descending artery and with a stenosis rate greater than or equal to 75%were selected and divided into the stenosis group(n=30)and the non-coronary stenosis group(the control group,n=31).2D-STI was used to measure the peak longitudinal and circumferential strain of the three-layer myocardial segment supplied by the left anterior descending branch[longitudinal strain of subendocardial myocardial segment(endo-RLS),longitudinal strain of middle myocardial segment(mid-RLS),myocardial longitudinal strain of subepicardial segment(epi-RLS),subendocardial segmental myocardial circumferential strain(endo-RCS),middle myocardial segmental myocardial circumferential strain(mid-RCS)and subepicardial segmental myocardium circumferential strain(epi-RCS)],and calculate the difference between the longitudinal and circumferential peak values of the subendocardial and subepicardial regions(ΔRLS,ΔRCS).Results Compared with the control group,the absolute values of endo-RLS,mid-RLS,epi-RLS,endo-RCS,mid-RCS,ΔRLS andΔRCS in each segment of the stenosis group decreased(P<0.05).ROC curve showed that endo-RLS predicts the largest area under the curve for the significant stenosis of the left anterior descending branch,and the diagnostic efficiency was the best.Conclusion 2D-STI layer-specific strain technique can quantitatively evaluate the systolic function of three-layer myocardium in patients with coronary artery disease and early predict patients with significant left anterior descending artery stenosis.