小剂量腺苷超声心动图试验检测急性心肌梗死后患者存活心肌

目的 评价小剂量腺苷超声心动图试验(LDAE)对急性心肌梗死早期存活心肌检出的准确性.方法 对36例急性心肌梗死患者于发病后3～10 d行剂量递增的LDAE(腺苷80、100和110μg·kg-1·min),所有患者在LDAE前后接受经皮冠状动脉介入术.采用17节段半定量分析法分析二维超声图像.心肌梗死后2～3个月随访二维超声,以局部室壁运动改善作为心肌存活标准,评价LDAE检测存活心肌的敏感性、特异性和小剂量腺苷对血液动力学的影响.结果 腺苷110μg·kg·min时与用药前比较,心率轻度增快[(78.1±10.9)次/min比(70.7±10.8)次/min,P<0.01],左室收缩末期容积减小[(20.1±9.3)ml比(30.4±1.9)ml,P<0.01]和射血分数升高(74.7%±9.8%比62.6%±10.4%,P<0.01).腺苷不良反应总发生率38.9%(14/36),但症状轻微.LDAE检出存活心肌的敏感性、特异性、诊断准确性、阳性预测值和阴性预测值分别为90.3%、80.8%、86.0%、84.8%和87.5%.腺苷剂量100μg·kg·min时敏感性(88.5%)和特异性(86.0%)好而不良反应无明显增加.结论 LDAE是检测急性心肌梗死后患者存活心肌的较好而安全的新方法 ,有较高的敏感性和特异性,腺苷剂量100μg·kg·min可作为LDAE进一步研究的推荐剂量.     

组织多普勒腺苷负荷超声心动图定量评估心肌缺血的应用

目的 评价定量腺苷负荷超声心动图技术诊断冠心病的准确性.方法 40例患者行常规剂量(140μg·ks-1·min-1持续6 min静脉滴注)腺苷负荷超声心动图试验以评估心肌缺血.基于常规二维图像之上的组织多普勒成像采集基线状态和药物负荷状态下的心肌运动图像(美国GE VIVID7超声诊断仪),在ECHOPAC软件上进行后处理分析测量16节段心肌运动速度、应变、应变率.结果 以冠状动脉造影或CT冠状动脉成像为标准,共有缺血节段159个节段,非缺血节段465个.腺苷负荷峰值后,除缺血心肌的舒张早期应变(Se)无明显变化外,缺血心肌和非缺血心肌的收缩期速度(Sm)、舒张早期速度(Em)、舒张晚期速度(Am)和收缩期应变(Smax)以及收缩期应变率(SRs)、舒张早期应变率(SRe)、舒张晚期应变率(SRa),以及非缺血心肌的舒张早期应变(Se)均明显增加(P＜0.05).缺血心肌的基线Sm和Em均显著低于非缺血心肌[分别为(3.16±1.20)cm/s和(4.03±1.27)cm/s,P＜0.01;(3.75±1.67)cm/s和(4.66±1.70)cm/s,P＜0.05],峰值负荷下,两组间Sm和Em差异更加显著[分别为(3.98±1.63)cm/s和(5.07±1.52)cm/s;(4.51±2.32)cm/s和(6.52±2.56)cm/s;均P＜0.01];缺血心肌的收缩期应变(Smax)和舒张早期应变(Se)均明显低于非缺血心肌(分别为16.91%±3.35%和19.56%±5.47%,P＜0.01;9.53%±2.89%和13.06%±4.63%,P＜0.001).操作者工作特性(ROC)曲线所得曲线下面积以负荷峰值的Se最大(曲线下面积=0.740,敏感性为67%,特异性为83%).结论 组织多普勒负荷超声心动图参数可定量评估心肌缺血,是临床非创伤性诊断冠心病准确可靠的方法.     

腺苷负荷心肌灌注显像对冠状动脉介入治疗的临床意义

目的:探讨腺苷负荷心肌灌注显像对冠状动脉(冠脉)介入治疗的临床意义。方法:66例冠心病患者,行腺苷负荷心肌灌注显像和冠脉造影,根据需要进行介入治疗,介入治疗后3～7天复查腺苷负荷心肌灌注显像。腺苷负荷心肌灌注显像采用单光子发射断层显像图像采集系统,腺苷注射液总量为840μg/kg,6分钟匀速静脉泵入,腺苷泵入3分钟时静脉推注99锝-2-甲氧基异丁基异腈核素(99mTc-MIBI);1.5h后进行心肌灌注断层显像。若异常,次日行静息心肌显像。核素显像左心室心肌分为9个节段,心肌灌注评分分4级。结果:66例患者的腺苷负荷心肌灌注显像与冠脉造影结果相比,双支病变腺苷负荷心肌灌注显像阳性率(87.5%,28/32)和三支病变腺苷负荷心肌灌注显像阳性率(100%),与冠脉造影阳性率(100%)比较差异均无统计学意义(P0.05);单支病变腺苷负荷心肌灌注显像阳性率为54.5%(12/22),与冠脉造影阳性率(100%)比较差异有统计学意义(P0.01)。双支病变和三支病变腺苷负荷心肌灌注显像阳性率分别与单支病变相比,差异均有统计学意义(P均0.05)。冠脉介入后心肌核素显像血流灌注改善率为94.1%(32/34),与冠状动脉介入前(0%,0/34)自身对照,差异有统计学意义(P=0.003)。结论:腺苷负荷心肌灌注显像对于冠心病患者冠脉介入前病变程度分析以及介入后疗效判断有一定的临床意义。     

实时三维斑点追踪成像结合实时心肌声学造影预测心肌梗死后患者心肌存活性的临床研究

摘要 目的 探讨实时三维斑点追踪成像技术（RT-3D-STI）结合实时心肌声学造影（RT-MCE）技术评价心肌梗死后患者心肌存活性的临床应用价值。方法 选取 25 例根据心电图、心肌酶学及冠脉造影确诊,且成功进行冠状动脉血运重建术的心肌梗死患者。所有患者于术前 1 周内行 RT-MCE 检查,对心肌灌注结果进行半定量评价;分别于术前及术后 6 个月行二维超声分析左室各节段心肌进行室壁运动,根据术后室壁运动是否改善将室壁运动异常的心肌节段分为两组：存活心肌组和非存活心肌组;同时行 RT-3D-STI 技术测得左室心肌整体及各节段三维峰值长轴应变 (3D-LPS) 、环向应变 (3D-CPS) 、面积应变 (3D-APS) 及径向应变 (3D-RPS) 参数指标。结果 血运重建术前,存活心肌组 3D-PLS、3D-PAS、3D-PCS、3D-PRS 明显高于无存活心肌组（P <0.05）;单参数 ROC 曲线分析结果显示,静息状态下,以术前 3D-PAS ≤ -16.5% 作为截断值判断心肌梗死后存活心肌的 AUC 为 0.944,敏感性为 91.3%,特异性为 93.8%,明显高于其它应变值;多参数联合分析结果显示,三维应变参数联合判断心肌梗死后存活心肌的 AUC 为 0.969,灵敏度及特异度分别为 95.7%、 90.6%。血运重建术前,RT-MCE 评价存活心肌的敏感度及特异度分别为 93.1％、 68.8％,一致性分析得出 Kappa 值为0.645。结论 在静息状态下, RT-3D-STI 技术预测心肌梗死后心肌的存活性地价值高于 RT-MCE 技术,其中三维应变参数以 3D-PAS ≤ -16.5% 作为截断值判断心肌梗死后心肌存活性的价值最高,且两种技术联合应用能更好地评价心肌存活性。     

腺苷负荷超声心动图识别存活心肌的应用研究

目的探讨腺苷超声心动图负荷试验(ATE)在识别存活心肌中的应用价值及安全性.方法59例心肌梗死后患者静脉注射腺苷,剂量为90 μg/min持续3 min,加量至110 μg/min持续3 min,检出二维超声室壁改善节段作为存活心肌节段,与治疗后随访结果--"金标准"比较,分析两者的符合率及试验中患者发生的不良反应的情况.结果腺苷负荷后,患者心率增加、血压下降,但幅度较小;ATE识别存活心肌的敏感性90.4%,特异性90.5%;未发生严重不良反应.结论ATE识别存活心肌是一种可靠、安全、有效的方法.     

腺苷负荷试验心肌灌注显像在老年人冠心病中的临床应用

目的 评价腺苷负荷试验心肌灌注显像在诊断老年人冠心病的准确性及临床应用的特点.方法 63例临床疑诊冠心病或已诊断但病情不稳定需介入治疗老年患者,住院后分别行腺苷负荷试验心肌灌注显像和冠状动脉(冠动)造影检查.腺苷负荷试验心肌灌注采用单光子发射断层显像图像采集系统,腺苷以140μg·kg-1·min-1静脉注射,用药时间6 min,注射过程中全程监测心电图、血压及患者的症状.于注射腺苷3 min末,静脉注射核素显像剂99cm Tc-MIBI 925 MBq,1.5 h后行心肌灌注断层显像,若显像异常,次日行静息心肌显像.冠脉造影按常规程序,在腺苷负荷试验心,肌灌注显像前后1周内进行.结果 63例中,53例冠脉造影阳性,10例阴性,而腺苷负荷试验心肌灌注显像51例阳性,7例阴性.腺苷负荷试验心肌灌注显像诊断老年人冠心病的总体敏感性为96.2%,特异性为70.0%,阳性预测值94.4%,阴性预测值77.8%,准确性为92.1%.53例冠脉造影显示,冠脉狭窄病变中,单支病变29例,二支14例,三支10例;累及左前降支(LAD)44支,左回旋支(LCX)18支,右冠脉(RCA)25支.腺苷负荷试验心肌灌注显像判断血管病变以LAD敏感性最高,达到95.5%;RCA次之,为84.0%;LCX最差,仅为55.6%;但特异性可达100%.监测过程中,32例(50.0%)患者发生胸闷、胸痛、头晕、头痛等不良反应,无严重事件发生.结论 腺苷负荷心肌灌注显像诊断老年人冠心病的敏感性、特异性高,尤其对探查和定位严重的冠脉病变准确性更高;腺苷负荷试验过程中副作用小,且因检查无创,因此在老年人冠心病的临床诊断应用中具有重要的价值.     

心脏腺苷负荷磁共振成像在冠心病早期诊断中的应用

目的:评价心脏腺苷负荷磁共振成像在冠心病早期诊断中的作用。方法: 选择临床无急性冠脉综合征,选择性冠状动脉造影（CAG）证实冠脉有不同程度狭窄的患者34例,根据CAG结果将患者分为3组,第1组管腔狭窄＞75%、第2组狭窄50%~75%以及第3组狭窄<50%。在3.0T磁共振成像仪上分别行静息和腺苷负荷磁共振心脏灌注扫描和延迟增强成像,对比分析不同状态下磁共振（MR）成像心肌灌注变化。结果: 在未发生急性冠脉综合征患者,静息磁共振心肌灌注成像显示心肌缺血主要表现为心肌灌注减少,总阳性率38%(13/34),不同冠状动脉狭窄组间无显著性差异。磁共振腺苷负荷试验可增加患者心肌灌注降低检测的阳性率［62%(21/34)］。统计结果显示,对于心肌缺血的检测,心脏磁共振腺苷负荷试验与静息心脏磁共振心肌灌注之间有显著性差异(P<0.01)。延迟扫描成像在34例患者中无延迟增强改变。结论: 腺苷负荷MR灌注成像可以显著提高心肌缺血诊断的阳性率,有助于冠心病的早期诊断。     

腺苷负荷心肌灌注显像在老年冠心病患者诊断中的价值

目的评价腺苷负荷心肌灌注显像试验对老年人冠心病的诊断价值以及对病变血管部位、血管支数、狭窄程度所作的评估。方法选择116例可疑冠心病的老年患者,行腺苷负荷心肌灌注显像。腺苷注射液按140μg/(kg.min)在6min内匀速静脉泵入。当腺苷泵入3min时经三通管快速静推99m锝-2-甲氧基异丁基异腈(99mTc-MIBI);1.5h后进行心肌灌注断层显像。若显像异常,次日行静息心肌显像。所有患者腺苷负荷心肌灌注显像后行冠状动脉造影。结果在116例患者中,73例冠状动脉造影显示明显的冠状动脉狭窄病变,其中单支病变22例,两支病变32例,三支病变19例。腺苷负荷心肌灌注显像试验诊断冠心病的敏感度、特异度和准确度分别为87.7%、72.1%和65.5%。诊断单支、两支和三支冠状动脉病变患者的敏感度分别为59.1%、84.4%和89.5%(P0.05)。对管径狭窄为50%～75%组的敏感度为57.1%,管径狭窄≥75%组的敏感度为89.4%,两组间比较有统计学意义(P0.05)。无论是单支病变、两支病变还是三支病变,累及前降支血管病变的心肌核素的阳性率均高(P0.05)。行血管内超声检查的17例患者中,有7例病变斑块面积狭窄率50%或管腔面积4mm2,有偏心或不稳定性斑块,给予冠脉介入治疗,而此7例腺苷负荷心肌核素均为阳性。结论腺苷负荷心肌灌注断层显像诊断老年患者冠心病的敏感度与冠脉狭窄程度和病变支数相关。对重度狭窄和两支、三支病变的患者有较高的敏感度,但对轻中度狭窄和单支病变的患者敏感度较低。腺苷负荷心肌灌注断层显像预测左前降支病变的阳性符合率高于左回旋支和右冠状动脉,且对临界病变的预测有一定价值。     

计算机辅助心肌造影负荷超声定量评价心肌灌注及局部收缩功能

目的 探讨计算机辅助心肌造影负荷超声(MCSE)定量评价心肌灌注和局部收缩功能的应用价值.方法 采用急性阻断再灌注左室支建立兔模型,根据阻断和再灌注时间分为两组:阻断30 min后再灌注60 min(Ⅰ组)和阻断120 min后再灌注60 min(Ⅱ组).分别在基础状态、阻断、再灌注和多巴酚丁胺负荷(5、10、15和20 μg·kg-1·min-1)行心肌造影超声心动图,造影图像经自制计算机辅助软件处理后,自动标出每个节段的标化造影剂密度(CI),根据标化CI值,彩色编码标记为:0～ -20像素(pix)黄色、-21～ -40 pix蓝色、-41～ -70 pix绿色以及＜-70 pix红色.分别计算出阻断时和再灌注后红色编码区面积,并与荧光微球染色和氯化三苯基四氮唑染色面积对照分析.同时测量各阶段危险心肌的收缩期室壁增厚率(WT).结果 (1)阻断时,危险心肌的WT降到零点或呈负值,CI明显低于基础状态,红色编码区面积与荧光染色危险心肌面积呈正相关(r=0.91,P＜0.01).(2)再灌注和多巴酚丁胺5μg·kg-1·min-1后,各组危险心肌的WT和标化CI仍减低.以标化CI-70 pix为截断值,识别梗死节段的敏感性为95%,特异性为87%.红色编码面积与氯化三苯基四氮唑染色梗死心肌面积呈正相关(r=0.89,P＜0.01).(3)随着多巴酚丁胺剂量的增加,Ⅰ组的标化CI恢复至基础状态,WT逐渐增加超过基础水平,但Ⅱ组仍保持较低水平.结论 计算机辅助心肌造影负荷超声可以定量评价心肌灌注和局部收缩功能,是识别顿抑和梗死心肌安全可行的方法.     

冠状动脉介入治疗前后腺苷负荷心肌灌注显像在临床中的价值

目的:探讨腺苷负荷心肌灌注显像在冠状动脉介入治疗前后中的临床价值。方法:116例冠心病可疑患者住院,行腺苷负荷心肌灌注显像和冠状动脉造影,根据需要进行介入治疗,介入治疗后3~7d复查腺苷负荷心肌灌注显像。腺苷负荷心肌灌注显像采用单光子发射断层显像图像采集系统,腺苷注射液按140ug.kg-1.min-1,6min匀速静脉泵入,腺苷泵入3min时静脉推注99锝-2-甲氧基异丁基异腈核素(99mTc-MIBI);1.5h后进行心肌灌注断层显像。若异常,次日行静息心肌显像。核素显像左室心肌分为17个节段,心肌灌注分4级。结果:73例冠心病患者中,66例行介入处理,其中32例患者冠状动脉介入处理后复查     

Two-dimensional strain combined with adenosine stress echocardiography assessment of viable myocardium

The objective of this study was to explore a new method for the identification of viable myocardium by means of two-dimensional (2D) strain imaging combined with adenosine stress echocardiography. A total of 15 anesthetized open-chest healthy mongrel dogs underwent left anterior descending coronary artery occlusion for 90 min followed by 120-min reperfusion. Adenosine was infused at 140 μg kg⁻¹ min⁻¹ over a period of 6 min. Images were acquired at baseline (when pericardial cradle was made), after reperfusion (when reperfusion finished) and after adenosine administration (while administration stopped). Measurements of the regional peak-systolic strain in radial, circumferential, and longitudinal motion on anterior wall and anterior septum were, respectively, performed under different conditions. The dogs were killed after the echocardiographic studies finished and then the area of infracted myocardium was defined by triphenyltetrazolium chloride histology. A segment with equal or less than 50% area of infracted myocardium was considered to be viable. As a result, 37 regions were viable whereas 53 were non-viable among 90 regions in 15 dogs. At baseline, there was no significant difference in peak-systolic radial strain (Rs), circumferential strain (Cs), and longitudinal strain (Ls) between the viable and non-viable groups. After reperfusion, Rs, Cs, and Ls in absolute value decreased compared to those at baseline in both groups, although there was no significant difference between these groups. Rs and Ls increased after adenosine administration compared to reperfusion (p < 0.01; p < 0.05) in viable group while there were no changes in non-viable group. Compared with non-viable group Rs, Cs and Ls in viable group increased significantly (p < 0.01; 0.05) after adenosine administration. There was a negative correlation between Rs and infarct size (r = −0.72). Cs and Ls correlated well with infarct size, respectively (r = 0.40; 0.67). A change of Rs more than 13.5% has a sensitivity of 83.8% and a specificity of 83.0% for viable whereas a change of Ls more than 11% allowed a sensitivity of 78.4% and a specificity of 88.7%. Combined with these two variables, the sensitivity and specificity could reach 91.9 and 79.2%. Two-dimensional strain imaging combined with adenosine stress echocardiography can provide a new way to distinguish viable myocardium from the non-viable.     

Usefulness of ultrasonic strain measurements to predict regional wall motion recovery in patients with acute myocardial infarction after percutaneous coronary intervention

Strain Doppler echocardiography can detect systolic regional myocardial dysfunction. This study assessed whether strain could predict recovery of regional left ventricular function in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention. Forty-three patients with anterior AMI undergoing successful percutaneous coronary intervention of the left anterior descending coronary artery were studied. Longitudinal myocardial strain was measured at the left anterior descending coronary artery territory in the apical long-axis view within 24 hours after percutaneous coronary intervention. Regional wall motion was analyzed by the anterior wall motion score index (A-WMSI). Viable myocardium was defined as a decrease < or = 2.0 in A-WMSI. Patients were categorized as A-WMSI at 4 weeks into a viable group (n = 24) and a nonviable group (n = 19). End-systolic strain and peak strain were significantly lower in the nonviable group than in the viable group (-4.8 +/- 4.8% vs -9.9 +/- 4.7 %, p <0.005; -9.9 +/- 4.6 vs -13.5 +/- 4.1 %, p <0.05). Moreover, corrected time to peak strain (cTPS; time delay from end-systolic to peak strain/RR interval) was significantly longer in the nonviable group than in the viable group (0.19 +/- 0.04 vs 0.13 +/- 0.03, p <0.0001). For prediction of viable myocardium, cTPS <0.15 had a sensitivity of 95% and a specificity of 85%. In conclusion, strain, especially cTPS, is useful for predicting recovery of regional left ventricular function in patients with AMI after percutaneous coronary intervention.     

小剂量多巴酚丁胺超声心动图联合心肌声学造影对心肌梗死后存活心肌的诊断价值

目的前瞻性评价小剂量多巴酚丁胺超声心动图(LDDE)联合心肌声学造影(MCE)对心肌梗死后存活心肌的诊断价值。方法对24例心肌梗死者进行静态MCE、LDDE及3个月后静态超声心动图随访分析。MCE和室壁运动均用16段划分法进行目测半定量计分。心肌造影计分(MCS)回声均匀性增强为1分,回声低淡不均匀为0.5分,缺损为0分。室壁运动计分(WMS)用常规计分法。结果随访时,运动改善的心肌节段中MCS1分占49.4%、0.5分占50.6%,对LDDE均有反应;运动无改善的节段MCS0.5分占9.5%,0分占90.5%,对LDDE有反应者占13.3%,无反应占86.7%。预测存活心肌的敏感性、特异性及准确率分别为LDDE86%、86.7%、86.4%;MCE100%、89.7%、94.6%;LDDE联合MCE86.1%、100%、94.0%。结论心肌微血管结构与功能的完善是心肌存活的基本条件。MCE灌注正常和低灌注,且对多巴酚丁胺有反应的心肌有收缩力储备;而对多巴酚丁胺无反应的低灌注或无灌注心肌则多不能恢复收缩功能。LDDE联合MCE能提高检测存活心肌的特异性及准确率。     

Tissue velocity imaging during dobutamine stimulation for assessment of myocardial viability: segmental analysis in patients after myocardial infarction

BACKGROUND: Dobutamine stress echocardiography (DSE) is an established method for the detection of viable myocardium, but evaluation of this method is subjective. Tissue velocity Imaging (TVI) allows quantitative analysis of regional myocardial wall motion by assessment of systolic myocardial velocities. The aim of this study was to evaluate the diagnostic value of DSE and TVI for detection of viable myocardium. METHODS: In 56 patients (58+/-12 years) with previous myocardial infarction (130+/-42 days, mean ejection fraction 42+/-15%) low-dose DSE was combined with analysis of peak systolic myocardial velocities (Vpeak) by TVI for assessment of myocardial viability. As reference served a follow-up echocardiography after successful revascularization (mean 91+/-3 days). RESULTS: Of a total of 896 segments 200 showed abnormal wall motion (31 mildly hypokinetic, 50 severely hypokinetic, 115 akinetic, 4 dyskinetic). In 125 of these 200 segments regional improvement of regional wall motion was observed (62.5% viable). An increase of Vpeak>1 cm/s during dobutamine stimulation allowed the identification of viable myocardium with a sensitivity of 82% and a specificity 82% (DSE: 77% and 80%). By receiver operating characteristic (ROC) curve analysis, a cut-off value of 1.0 cm/s was the best parameter to differ viable from nonviable myocardium (area under the curve 0.85; p<0.01; 95% CI 0.79 to 0.90). Improvement of global ejection fraction after revascularization (47+/-13%, p=0.11) corresponded with three TVI viable segments with a sensitivity of 92% and a specificity of 89% (p=0.012). CONCLUSIONS: TVI allows the identification of viable myocardium during dobutamine stimulation and enables a quantitative interpretation of DSE.     

硝酸酯、小剂量多巴酚丁胺及其合用超声心动图试验识别急性心肌梗死存活心肌的对比研究

目的对比硝酸酯、小剂量多巴酚丁胺(Dob)及其合用二维超声心动图(2DE)试验识别急性心肌梗死(AMI)存活心肌的准确性和安全性。方法AMI患者31例,于发病后7～14(10±3)d行硝酸酯、小剂量Dob及其合用2DE试验,后行冠状动脉血运重建(CRV)术成功,术后6个月左右(167±18)d复查2DE。用16节段半定量分析法对左室各节段收缩运动和增厚情况给予分级记分。将2DE试验所检的存活心肌与CRV术后其收缩功能改善的实际对比,评价识别AMI存活心肌的准确性和安全性。结果31例AMI患者共有221个异常节段。与硝酸酯和Dob3μg单用时相比,两者合用2DE试验对AMI区存活心肌节段的检出率均显著提高（50.2%对37.6%和40.7%,P均<0.05）,识别敏感性和准确性也均显著提高（77.6%对56.8%和61.6%,81.0%对70.1%和72.4%,P<0.05～0.01）;而硝酸酯合用Dob5μg2DE试验对存活心肌的检出率、识别敏感性和准确性均已达Dob10μg单用时的水平（55.7%对55.8%,87.2%对89.5%和86.4%对87.9%,P均>0.05）,而又无Dob10μg诱发心肌缺血的副作用。结论硝酸酯与小剂量(3、5μg     

Use of echocardiography for predicting myocardial viability in patients with reperfused anterior wall myocardial infarction

Dobutamine stress echocardiography (DSE), myocardial contrast echocardiography (MCE), and ultrasonic tissue characterization with integrated backscatter are useful methods for assessing myocardial viability in acute myocardial infarction. In this study, we compared the potential of 3 methods for predicting myocardial viability in 38 patients with reperfused anterior wall acute myocardial infarction. We performed MCE shortly after coronary reperfusion with an intracoronary injection of microbubbles. We recorded 2-dimensional integrated backscatter images at rest and, then, performed low-dose (10 microg/kg/min) DSE 3 days later. In integrated backscatter images, we placed the region of interest in the midwall of the myocardial segment to reconstruct the cyclic variation of myocardial integrated backscatter. The myocardial segment was judged viable when it showed active contraction 3 months later. Among 74 segments analyzed, 34 were judged viable. Presence of contractile response during DSE predicted segmental viability with 91% sensitivity and 78% specificity. Intense and homogenous contrast enhancement with MCE predicted viability with 82% sensitivity and 73% specificity. The presence of synchronous contraction of cyclic variation predicted myocardial viability with 79% sensitivity and 83% specificity. There were no differences in sensitivity and specificity among the 3 methods. Thus, MCE and ultrasonic tissue characterization can predict myocardial viability as accurately as DSE in patients with acute myocardial infarction. The logistics of the methods may determine clinical application.     

小剂量多巴酚丁胺超声心动图试验和双核素心肌显像检测急性心肌梗死后患者存活心肌比较

目的比较小剂量多巴酚丁胺超声心动图试验（LDDE）和^99mTc-甲氧基异丁腈（MIBI）／^18F-脱氧葡萄糖（FDG）双核素同时采集法（DISA）单光子发射型断层显像（SPECT）对急性心肌梗死早期存活心肌检出的准确性。方法对44例急性心肌梗死患者于发病后5～10天内行LDDE和DISA—SPECT,所有患者在LDDE和DISA检查后接受经皮冠状动脉介入术。两种方法均采用16节段半定量法分析图像。心肌梗死后3个月随访二维超声,以局部室壁运动改善作为心肌存活标准,比较两种方法检测存活心肌的敏感性和特异性。结果LDDE检出存活心肌的敏感性、特异性、诊断准确性、阳性预测值和阴性预测值分别为77％、82％、79％、82％和77％。DISA检出存活心肌的敏感性、特异性、诊断准确性、阳性预测值和阴性预测值分别为85％、62％、74％、71％和79％。LDDE和DISA两者对运动异常节段检出存活心肌的一致性为70％。对于运动减低节段,LDDE和DISA对存活心肌检出率差异无统计学意义（74．1％比77．6％,P〉0．05）;对于无运动节段,LDDE对存活心肌检出率低于DISA（29％比53％,P〈0．01）。结论对急性心肌梗死后的患者,DISA检出存活心肌的敏感性高于LDDE,而特异性低于LDDE,联合应用起互补作用,提高检测存活心肌的能力。     

Strain rate measurement by doppler echocardiography allows improved assessment of myocardial viability inpatients with depressed left ventricular function

OBJECTIVES: This study sought to evaluate whether objective assessment of the myocardial functional reserve, using strain rate imaging (SRI), allows accurate detection of viable myocardium. BACKGROUND: Strain rate imaging is a new echocardiographic modality that allows quantitative assessment of segmental myocardial contractility. METHODS: In 37 patients (age 58 +/- 9 years) with ischemic left ventricular dysfunction, myocardial viability was assessed using low-dose (10 microg/kg body weight per min) two-dimensional dobutamine stress echocardiography (DSE), tissue Doppler imaging, SRI and (18)F-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET). The peak systolic tissue Doppler velocity and peak systolic myocardial strain rate were determined at baseline and during low-dose dobutamine stress from the apical views. RESULTS: A total of 192 segments with dyssynergy at rest were classified by (18)FDG PET as viable in 94 and nonviable in 98. An increase of peak systolic strain rate from rest to dobutamine stimulation by more than -0.23 1/s allowed accurate discrimination of viable from nonviable myocardium, as determined by (18)FDG PET with a sensitivity of 83% and a specificity of 84%. Receiver operating characteristic (ROC) curve analysis showed an area under the curve for prediction of nonviable myocardium, as determined by (18)FDG PET using SRI, of 0.89 (95% confidence interval [CI] 0.88 to 0.90), whereas the area under the ROC curve using tissue Doppler imaging was 0.63 (95% CI 0.61 to 0.65). CONCLUSIONS: The increase in the peak systolic strain rate during low-dose dobutamine stimulation allows accurate discrimination between different myocardial viability states. Strain rate imaging is superior to two-dimensional DSE and tissue Doppler imaging for the assessment of myocardial viability.     

急性心肌梗死急诊经皮冠状动脉介入治疗后评价心肌组织再灌注方法的对比研究

目的应用TIMI心肌灌注分级、单个导联ST段回落幅度、单个导联ST段最大偏移幅度和超声心动图四种方法评价急性心肌梗死急诊经皮冠状动脉介入治疗后心肌水平再灌注。方法50例急性心肌梗死患者急诊介入治疗后采用TIMI心肌灌注分级、单个导联ST段回落幅度、单个导联ST段最大偏移幅度及随访1个月超声心动图观察室壁运动改善四种方法评价心肌灌注,并于术后7±2天行核素心肌灌注显像。结果与核素心肌灌注显像比较,TIMI心肌灌注分级敏感性为94.7,特异性为16.7,准确性为76.0;单个导联ST段回落幅度敏感性为89.5,特异性为83.3,准确性为88.0;单个导联ST段最大偏移幅度敏感性为84.2,特异性为83.3,准确性为84.0;超声心动图敏感性为78.9,特异性为83.3,准确性为80.0。心电图(单个导联ST段回落幅度、单个导联ST段最大偏移幅度)和超声心动图与核素检查存在一致性,且一致性良好;TIMI心肌灌注分级未显示与核素检查存在一致性。结论心电图和超声心动图可较好地评价急性心肌梗死后心肌组织再灌注水平。