超声背向散射技术研究慢性缺血性功能异常心肌跨壁异质性的临床意义  

Clinical Significance of Investigating Myocardial Transmural Heterogeneity by Integrated Backscatter in Patients with Chronic Ischemic Dysfunctional Myocardium

作　　者：潘晓芳[1] 王珂[2] 赵晓兰[1] 郭然 

机构地区：[1]大连市中心医院医学影像部,辽宁省大连市116033 [2]大连医科大学附属一院心内科

出　　处：《中国超声医学杂志》2005年第3期175-179,共5页Chinese Journal of Ultrasound in Medicine

基　　金：大连市重点科技攻关项目 [大科技发 No.(2 0 0 0 ) 1 57]

摘　　要：目的　利用超声背向散射 (IBS)技术研究慢性缺血性功能异常心肌在血管成功再灌注前后跨壁异质性的变化特征 ,探讨其临床应用价值。方法　分别在血管重建术前及术后 ,检测 5 8例慢性冠心病伴有左室壁节段功能障碍患者 (共 88个异常心肌节段 ,4 3个正常心肌节段 )相关心肌节段心内膜下层及心外膜下层心肌的 IBS周期变化幅度 (CVIB) ,计算跨壁梯度 (TGCV)和跨壁梯度指数(TGI) ,并在常规超声下测量相应心肌节段的室壁增厚率 (WT% )。结果　正常心肌 CVIB具有跨壁梯度 [TGCV:(1.2 2± 0 .4 6 ) d B,TGI:(2 0 .8± 6 .6 ) % ]。血管重建术前 ,存活心肌节段 TGCV、TGI减低并逆转为负值分别为 (- 0 .5 9± 0 .2 7) d B和 (- 16 .8± 8.5 ) % ;而非存活心肌节段 CVIB跨壁梯度基本消失 [TGCV:(- 0 .0 6 4± 0 .16 ) d B,TGI:(- 3.2 2± 6 .84 ) % ]。存活心肌节段的跨壁异质性 (|TGCV|、 |TGI|)明显小于正常心肌节段 (P<0 .0 0 1)、大于非存活心肌节段 (P<0 .0 0 1)。异常心肌节段的 |TGCV|、 |TGI|与血管重建术后 6～ 8周相应心肌节段的 WT%均呈正相关 (分别为 r=0 .6 35 ,P<0 .0 0 1和 r=0 .4 5 9,P<0 .0 1)。结论　利用 CVIB检测人体心肌的跨壁收缩异质性 ,可以评价慢性缺血性功能障碍心肌的收缩储备 。Objective To investigate the characteristics of myocardial transmural contraction heterogeneity on chronic ischemic dysfunctional myocardium before and after revascularization using integrated backscatter technique(IBS),and furthermore to assess the value of clinical application Methods The magnitude of the cardiac cycle variation of integrated backscatter (CVIB) of the layers in subendocardium and subepicardium were measured in fifty eight patients with chronic coronary heart disease accompanying left ventricular segmental dysfunction(altogether 88 abnormal myocardial segments,43 normal myocardial segments) before and after intervention,and the transmual gradient(TGCV) and transmural gradient index(TGI) of CVIB,as well as percent wall thickening(WT%)by conventional echocardiography were calculated Results In normal myocardial segments,there was a transmural gradient of CVIB TGCV:1 22±0 46 dB,TGI:20 8±6 6 % Before revascularization,the TGCV and TGI all were decreased and reversed to negative in viable myocardial segments[( -0 59±0 27) dB,-(16 8±8 5) %,respectively];in nonviable segments,the transmural gradient of CVIB almost disappeared [TGCV:(-0 064±0 16) dB,TGI:(-3 22±6 84)%] The transmural heterogeneity(|TGCV|,|TGI|) in viable myocardial segments was lower than that in normal myocardial segments( P <0 001),and greater than that in nonviable myocardial segments( P <0 001) All |TGCV|and|TGI| in chronic ischemic dysfunctional myocardium before revascularization positively correlated with WT% of the corresponding segments 6-8 weeks after coronary recanalization( r =0 635, P <0.001; r =0 459, P <0 01,respectively) Conclusions The detection of human intramyocardial contraction heterogeneity using CVIB could assess segmental myocardial contractile reserve on chronic ischemic dysfunctional myocardium,which provided more useful informations for clinical application in predicting the restoration of cardiac function after reperfusion and performing medical or surgical interve

关 键 词：超声背向散射技术 慢性缺血性功能异常 心肌跨壁异质性 冬眠心肌 心肌缺血 

分 类 号：R445.1[医药卫生—影像医学与核医学]