三维斑点追踪成像评价心肌存活性的临床研究

摘要

目的 探讨三维斑点追踪成像技术超声心动图评价心肌存活性的临床价值.方法 病例均为2010年4月至2012年12月间于南京医科大学附属南京医院心内科、心外科收住就诊患者,均根据心电图、心肌酶学及冠状动脉造影确诊为心肌梗死.受检患者静息状态下均存在不同程度的节段性室壁运动异常,其中部分患者已接受经皮腔内冠状动脉成形术和冠脉内支架置入术或冠状动脉旁路移植术,入选患者均排除糖尿病、心肌病及严重瓣膜病.选取图像清晰者进行图像采集,应用二维超声心动图观察入选45例心肌梗死患者心肌运动,二维斑点追踪成像及三维斑点追踪成像技术分别检测患者各节段径向、纵向及环向收缩期峰值应变(Rs、Ls、Cs)和(或)面积应变、3D应变.以核素心肌灌注/代谢显像结果作为金标准将各节段划分为存活组及非存活组心肌,并分析三维斑点追踪成像技术评定存活心肌的敏感度及特异度.所有测值均采用均数±标准差(-x±s)表示,两组间及组内比较采用t检验,特异度及敏感度分析采用受试者工作特征曲线(ROC)分析.结果 ①所观察的720个节段中,368个节段表现为运动异常,其中存活心肌节段204,梗死心肌节段164;②存活组与非存活组比较,二维应变Rs、Ls及Cs两组比较差异无统计学意义;③三维应变Cs于存活组及非存活组差异无统计学意义,Ls、Rs及3D应变、面积应变于非存活组较存活组应变值显著减低;④以Rs、Lss及3D应变、面积应变作为观察对象,Rs值为11.1％评价存活心肌的敏感度为95.1％,特异度为53.4％;Ls值为14.3％评判存活心肌的敏感度为65.2％,特异度为65.7％;3D应变值为17.4％评判存活心肌的敏感度为70.6％,特异度为77.2％;面积应变值为23.2％评判存活心肌的敏感度为91.5％,特异度为78.8％.结论 三维斑点追踪成像技术超声心动图能够作为临床提供有效区分存活与非存活心肌的新途径.%Objective To investigate the role of three-dimensional speckle tracking echocardiography (3D-STE) in providing a novel approach to assessing myocardial viability in patients with myocardial infarction (MI).Methods The subjects from the Department of Cardiology and the Department of Cardiac Surgery admitted from April 2010 through December 2012 were diagnosed as MI by electrocardiogram,myocardial enzymes and angiography.The clear imaging of angiography was selected out and collected.All patients had different degrees of segmental wall motion abnormalities,and some already had percutaneous transluminal coronary angioplasty and coronary stenting or coronary artery bypass grafting.Patients with diabetes,heart disease and severe valvular disease of heart were excluded.A total of 45 MI patients were checked with routine echocardiography,two-dimensional speckle tracking echocardiography (2D-STE) and 3D-STE.Then,radionuclide myocardial perfusion/metabolic imaging was served as a "golden standard" to distinguish the viable from nonviable myocardium in each patient within a day.In order to determine the most sensitivity and specificity threshold values of circumferential peak-systolic strain (Cs),longitudinal peak-systolic strain (Ls),radial peak-systolic strain (Rs),3D strain and area strain for viability detection from 3D-STE,the receiver operating characteristic curve was used to investigate the sensitivity and specificity of the detection of viable myocardium with strain parameters in the study.Comparisons between viable and non-viable groups were carried out with t test.Data were expressed as the mean value ± standard deviation (-x ± s).Results The ventricular wall motion abnormality by visual assessment was observed in 368 segments from 720 segments in 45 patients.Furthermore,204 segments were confirmed to be viable by radionuclide myocardial perfusion/metabolic imaging whereas the rest 164 segments were identified as nonviable among 368 abnormal segments.There were no significant differences in circumferential peaksystolic strain (Cs),longitudinal peak-systolic strain (Ls) and radial peak-systolic strain (Rs) by 2D-STE between viable and nonviable group.Compared with those in viable group,there wasn' t any difference in Cs,but Rs and Ls decreased significantly by 3D-STE in nonviable group.The 3D strain and area strain in absolute value decreased in nonviable group compared with viable group.According to 3D-STE,when Rs higher than 11.1％,the sensitivity was 95.1％ and the specificity was 53.4％ for identification of viable myocardium,whereas Ls higher than 14.3％ resulted in sensitivity of 65.2％ and a specificity of 65.7％.Besides,3D strain higher than 17.4％ had a sensitivity of 70.6％ and a specificity of 77.2％ for detection of viable myocardium,while area strain higher than 23.2％ allowed a sensitivity of 91.5％ and a specificity of 78.8％.Conclusions The 3D-STE might have potential reliability of myocardial viability detection in the patients with left ventricular dysfunction after MI.