小剂量多巴酚丁胺超声心动图对存活心肌及介入治疗的评价

目的　利用小剂量多巴酚丁胺超声心动图 (LDDE)显示心肌梗死部位存活心肌的存在及介入治疗术后整体心脏收缩功能的变化 ,评价介入治疗对存活心肌的作用。方法　选择前降支(LAD)单支闭塞病变拟行介入治疗患者 2 5例 ,均在术前做LDDE ,然后行经皮冠状动脉腔内成形术(PTCA)和支架术 ,术后 2～ 4个月复查二维超声心动图 (2DE) ,LDDE及二维超声心动图 (2DE)均采用16阶段半定量分析法 ,将LDDE显示≥ 2个相邻室壁运动不良节段 (RWMA)收缩功能改善者定为多巴酚丁胺阳性 ,并与介入治疗术后室壁运动改善相对比。术后RWMA改善定为存活心肌 ,并进行心肌收缩功能改善的评价。结果　多巴酚丁胺试验阳性 (持续改善和双向反应 )对存活心肌具有较高的预测价值 ,即在LDDE阳性的 118个室壁运动异常节段中有 10 3个节段介入治疗术后恢复 ,而LDDE阴性的 5 0个室壁运动异常节段仅有 11个节段恢复。此外 ,整体心功能的改善也与室壁运动异常的改善相一致 ,即术后射血分数 (EF)、心排血量 (CO)、心脏指数 (CI)等反映整体心脏功能的指标也有明显改善。结论　LDDE可以发现心肌梗塞部位存活心肌的存在 ,并可预测介入治疗后存活心肌的恢复和心脏整体收缩功能的改善     

低剂量多巴酚丁胺超声心动图和心电图ST段抬高预测血管重建术后存活心肌

目的采用低剂量多巴酚丁胺超声心动图(LDDE)和负荷心电图ST段抬高评价梗塞心肌节段于血管重建术前后的存活心肌.方法心肌梗死患者35例,于术前行低剂量多巴酚丁胺超声心动图和负荷心电图检查,术后一个月重复基础超声心动图检查.采用16节段和4分法评估左室功能,在术前和术后随访时有1个或1个以上节段室壁运动评分≥1为功能改善.结果 35例心肌梗死患者, 术后有18例室壁运动改善.有14例患者在行低剂量多巴酚丁胺试验时出现ST段抬高,其中术后有11例室壁运动改善, ST段抬高预测术后室壁运动改善的敏感性和特异性分别为61%和82%.同样,在术前LDDE心肌收缩力储备阳性的16例患者中,术后有14例功能改善,则LDDE对术后室壁运动改善的敏感性和特异性分别为77%和88%.结合术前负荷试验ST段抬高和LDDE心肌收缩力储备阳性,对术后室壁运动改善的敏感性和特异性分别为61%和94%.结论负荷试验ST段抬高和LDDE均是检测存活心肌安全、易行及有价值的方法.     

静息与负荷心肌造影超声心动图识别存活心肌的对比研究

目的探讨负荷心肌造影超声心动图(MCSE)对心肌梗死后存活心肌评价的疗效和安全性。方法选择冠状动脉造影证实的心肌梗死患者30例。首先在静息状态下行心肌造影超声心动图(MCE),MCE心肌灌注结果采用半定量评价。多巴酚丁胺负荷静脉滴注剂量分别为5、10、20μg·kg~(-1)·min~(-1),每期3 min观察心率、血压变化于达到负荷剂量后再次行MCE,并以~(18)F-脱氧葡萄糖正电子发射计算机体层扫描(PET)作为金标准评价其敏感性和特异性。结果 MCE总共评价360个梗死节段,静息MCE评价1、0.5、0分为264、22、74个节段。多巴酚丁胺负荷MCSE评价1、0.5、0分为286、30、44个节段,评价MCE敏感性和特异性分别为38.10%、88.89%,kappa=0.285(P0.01)。评价MCSE敏感性和特异性分别为86.21%、88.89%,kappa=0.746(P0.05)。结论MCE及MCSE安全性良好。MCE及MCSE均与冠状动脉造影心肌梗死部位有较好的相关性,以PET作为金标准,MCSE具有较高的敏感性和特异性,是评价梗死节段内存活心肌的较好方法。     

多巴酚丁胺负荷超声心动图对急性心肌梗死后心肌存活性的评价

目的：采用多巴酚丁胺负荷超声心动图评价急性心肌梗死后梗死区域心肌的存活性。方法：３６例急性心肌梗死病人进入本研究，分别采用５μｇｋｇ－１／ｍｉｎ和１０μｇｋｇ－１／ｍｉｎ的多巴酚丁胺静脉滴注，体表超声心动图观察梗死区域心肌收缩心室壁运动和厚度的变化，以识别有无存活心肌。结果：对３６例病人分析了５７６段心肌，基础状态时９４段心肌运动消失；１１９段心肌运动减低；３６３段心肌为正常心肌。静脉滴注５μｇｋｇ－１／ｍｉｎ多巴酚丁胺后，运动消失的９４段心肌中，３０段心肌心室壁运动及收缩心室壁增厚率得到了改善，其中２３段心肌变为运动减弱心肌，７段心肌变为正常心肌，将多巴酚丁胺增量至１０μｇｋｇ－１／ｍｉｎ后，由第１次剂量无反应的运动消失的６４段心肌中，有５段心肌心室壁运动和收缩心室壁增厚率得到改善。结论：采用多巴酚丁胺负荷超声心动图对急性心肌梗死后存活心肌的识别是安全的，而且具有十分重要的临床意义。     

小剂量多巴酚丁胺超声心动图与硝酸甘油介入~(99m)Tc-MIBI的心肌灌注显像估测存活心肌

目的　探讨小剂量多巴酚丁胺超声心动图 (LDDE)与含服硝酸甘油 (NTG)介入99mTc 甲氧基异丁基异睛 (MIBI)的心肌灌注显像在心肌存活估测中的价值。方法　对 17例心肌梗死患者分别行静息 NTG介入99mTc MIBI和小剂量多巴酚丁胺超声心动图的检查 ,经皮冠状动脉腔内成形术或冠状动脉旁路移植术后一个月重复基础超声心动检查 ,并进行对比分析。结果　 17例患者于基础超声心动检查 ,共有 94个心肌节段运动异常 ,在其中 5 0个低动力心肌节段中 ,两种方法一致性节段 2 9个 (5 8% ,P >0 .0 5 ) ;在 44个无动力心肌节段中两种方法一致性节段 16个 (36 % ,P<0 .0 5 )。两种方法对低动力心肌节段功能恢复的预测差异无显著性意义 (P>0 .0 5 ) ;而对无动力心肌节段 ,LDDE较NTG介入 99m　Tc MIBI心肌灌注显像有较高的特异性 (90 .9%vs 6 4.7% ,P <0 .0 5 )和较低的敏感性 (6 3.6 %vs88.9% ,P <0 .0 5 )。对整个运动障碍节段功能恢复的预测 ,LDDE较NTG介入99mTc MIBI心肌灌注显像有较高的特异性 (87.2 %vs 6 8.2 % ,P <0 .0 5 )。结论　两种方法对低动力心肌节段的预测有良好的一致性 ,LDDE对整个运动障碍节段功能恢复的预测有较高的特异性。     

经静脉心肌声学造影评价心肌梗死后存活心肌的价值

目的　探讨经静脉心肌声学造影 (MCE)对心肌梗死后存活心肌的诊断价值。方法　 2 4例心肌梗死患者用二维超声评价室壁运动情况 ,同时经静脉进行MCE ,以 3个月后静态超声心动图左室心肌节段性运动改善为依据评价MCE对心肌梗死后存活心肌的诊断价值。结果　在 2 4例病人的 384个心肌节段中 ,运动异常节段 184个。在运动异常的 184个节段中 ,MCE1分 39段 ,0 5分 5 0段 ,0分 95段。 3个月复查 79个节段有运动改善 ,其中 39段来自MCE1分的心肌 ,4 0段来自MCE0 5分的心肌。MCE对预测心肌梗死后室壁运动改善的敏感性、特异性、阳性预测值、阴性预测值及准确率分别为 :10 0 %、89 7%、84 8%、10 0 %和 94 6 %。结论　MCE能比较准确地预测心肌梗死后心肌的存活性     

在负荷多巴酚丁胺超声心动图中T波假正常化预测血管重建术后存活心肌

目的在负荷多巴酚丁胺超声心动图试验中，评估T波假正常化及收缩储备对存活心肌的检测价值。方法41例近期心肌梗死患者，于血管重建术前行低剂量多巴酚丁胺超声心动图(Low—Dose Dobutamine Echocardiography，LDDE)和负荷心电图检查，术后两个月重复静息超声心动图检查。采用16节段和4分法评估左室功能，在术前和术后随访时有1个或1个以上梗死节段室壁运动评分≥1为功能改善；T波的假正常化的定义为在≥2个梗死相关的心电图导联上T波由倒置变为直立。结果术后对所有心肌梗死患者进行了随访，其中有22例(54％)室壁运动改善，术前负荷超声心动图与负荷心电图总的符和率为71％，T波假正常化预测术后室壁运动改善的敏感性和特异性分别为77％和79％；LDDE预测术后室壁运动改善的敏感性和特异性分别为82％和84％；两种方法共同预测术后室壁运动改善的敏感性和特异性分别为64％和95％。结论负荷试验中T波假正常化和LDDE均是检测存活心肌安全、易行及有价值的方法。     

超声心动图诊断存活心肌新进展

近年来人们认为缺血除引起心肌坏死外 ,仍有部分心肌可能存活 ,是心肌为免受坏死的一种保护反应。准确地判断心肌存活性对缺血性心脏病治疗方案的选择、危险程度分级、正确估价再灌注治疗的疗效以及对预后的估测均具有重要的临床意义。近年来超声心动图在诊断存活心肌方面取得长足进展 ,本文将对这些新方法和新技术作一综述。1　药物负荷超声心动图二维超声是目前观察节段室壁运动异常较可靠的方法 ,利用药物负荷超声心动图是评价心肌存活性较实用的方法 ,常用的药物有多巴酚丁胺及硝酸酯等。1.1　小剂量多巴酚丁胺 :兴奋 β1及β2 、α1受…     

不同小剂量多巴酚丁胺超声心动图与18F-脱氧葡萄糖心肌代谢显像对比检测冠心病左心室收缩功能严重受损患者存活心肌

目的 :与18F 脱氧葡萄糖单光子发射计算机断层摄影术 (SPECT)心肌代谢显像对比 ,评价不同小剂量多巴酚丁胺超声心动图 ,检测冠心病左心室收缩功能严重受损患者存活心肌的准确性和安全性。方法 :冠心病心肌梗死伴左心室收缩功能严重受损 (平均左心室射血分数 0 3 8± 0 0 5 )的患者 3 3例 ,1周内分别进行不同小剂量多巴酚丁胺 [3、5、10 μg/(kg·min) ]超声心动图和99m锝 甲氧基异丁基、18F 脱氧葡萄糖SPECT心肌灌注及代谢显像。图像分析均采用 16节段半定量法。以18F 脱氧葡萄糖SPECT检测结果为标准 ,评价不同小剂量多巴酚丁胺超声心动图检测存活心肌的敏感性、特异性、准确性和安全性。结果 :3 3例患者的 3 65个运动异常节段中存活心肌检出率 :18F 脱氧葡萄糖SPECT心肌代谢显像检出的存活心肌节段为 67 4% ,多巴酚丁胺 3、5和 10 μg/(kg·min)分别为 3 8 9%、61 4%和 70 4%。多巴酚丁胺 3 μg/(kg·min)检出的存活心肌节段显著低于18F 脱氧葡萄糖SPECT心肌代谢显像检出的存活心肌节段 (P <0 0 0 1)。多巴酚丁胺 3、5、10μg/(kg·min)超声心动图检出存活心肌的敏感性分别为 5 1 6%、82 9%和 91 8% ,准确性分别为 63 6%、81 6%和87 8% ,均显著递增 (P <0 0 5～ 0 0 0 1) ;副作用发生率分别     

小剂量多巴酚丁胺超声心动图对可逆心肌的诊断价值

多巴酚丁胺超声心动图试验是临床开展较为广泛的检测冠心病的药物负荷试验 ,利用多巴酚丁胺兴奋 β1及 β2 、α1受体的特性 ,逐渐增加剂量 ,增加心肌收缩力、收缩压和心率 ,增加心肌耗氧量 ,扩张正常冠状动脉 ,引起血流再分配 ,从而使缺血区心肌室壁运动及增厚率异常 ,判断冠心病的存在。近年来对缺血和缺血后心肌功能障碍有新的认识 ,认为缺血除引起心肌坏死以外 ,尚有可逆心肌即顿抑心肌(Stunned Mycardium;SM)和冬眠心肌 (Hibernat-ing mycardium;HM)存在。小剂量多巴酚丁胺超声心动图 (Low- dose dobutamine echocardigraphy;LDDE…     

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。     

Usefulness of myocardial contrast echocardiography using low-power continuous imaging early after acute myocardial infarction to predict late functional left ventricular recovery

Microvascular perfusion is a prerequisite for ensuring viability early after acute myocardial infarction (AMI). For adequate assessment of myocardial perfusion, both myocardial blood volume and velocity need to be evaluated. Due to its high frame rate, low-power continuous myocardial contrast echocardiography (MCE) can rapidly assess these parameters of myocardial perfusion. We hypothesized that the technique can accurately differentiate necrotic from viable myocardium after reperfusion therapy in AMI. Accordingly, 50 patients underwent low-power continuous MCE using intravenous Optison (Amersham Health, Amersham, Middlesex, United Kingdom) 7 to 10 days after AMI. Myocardial perfusion (contrast opacification assessed over 15 cardiac cycles after the destruction of microbubbles with high energy pulses) and wall thickening were assessed at baseline. Regional and global left ventricular (LV) function was reassessed after 12 weeks. Out of the 297 dysfunctional segments, MCE detected no contrast enhancement during 15 cardiac cycles in 172 segments, of which 160 (93%) failed to show improvement. MCE demonstrated contrast opacification during 15 cardiac cycles in 77 segments, of which 65 (84%) showed recovery of function. The greater the extent and intensity of contrast opacification, the better the LV function at 3 months (p <0.001, r = -0.91). Almost all patients (94%) with <20% perfusion in dysfunctional myocardium (assessing various cut-offs) failed to demonstrate an improvement in LV function. MCE and peak creatine kinase proved to be independent predictors of functional recovery (p <0.001). In conclusion, low-power continuous MCE is an accurate and rapid bedside technique to identify microvascular perfusion after AMI. This technique may be utilized to reliably predict late recovery of function in dysfunctional myocardium after AMI.     

Comparison of myocardial contrast echocardiography with NC100100 and (99m)Tc sestamibi SPECT for detection of resting myocardial perfusion abnormalities in patients with previous myocardial infarction

OBJECTIVE—To determine whether myocardial contrast echocardiography (MCE) following intravenous injection of perfluorocarbon microbubbles permits identification of resting myocardial perfusion abnormalities in patients who have had a previous myocardial infarction.
PATIENTS AND INTERVENTIONS—22 patients (mean (SD) age 66 (11) years) underwent MCE after intravenous injection of NC100100, a novel perfluorocarbon containing contrast agent, and resting ^99mTc sestamibi single photon emission computed tomography (SPECT). With both methods, myocardial perfusion was graded semiquantitatively as 1 = normal, 0.5 = mild defect, and 0 = severe defect.
RESULTS—Among the 203 normally contracting segments, 151 (74%) were normally perfused by SPECT and 145 (71%) by MCE. With SPECT, abnormal tracer uptake was mainly found among normally contracting segments from the inferior wall. By contrast, with MCE poor myocardial opacification was noted essentially among the normally contracting segments from the anterior and lateral walls. Of the 142 dysfunctional segments, 87 (61%) showed perfusion defects by SPECT, and 94 (66%) by MCE. With both methods, perfusion abnormalities were seen more frequently among akinetic than hypokinetic segments. MCE correctly identified 81/139 segments that exhibited a perfusion defect by SPECT (58%), and 135/206 segments that were normally perfused by SPECT (66%). Exclusion of segments with attenuation artefacts (defined as abnormal myocardial opacification or sestamibi uptake but normal contraction) by either MCE or SPECT improved both the sensitivity (76%) and the specificity (83%) of the detection of SPECT perfusion defects by MCE.
CONCLUSIONS—The data suggest that MCE allows identification of myocardial perfusion abnormalities in patients who have had a previous myocardial infarction, provided that regional wall motion is simultaneously taken into account.


Keywords: myocardial contrast echocardiography; NC100100; single photon emission computed tomography; perfusion     

Detection of viable myocardium by transvenous myocardial contrast echocardiography using harmonic power Doppler: canine model of acute coronary occlusion and reperfusion

STUDY OBJECTIVE: To assess whether myocardial contrast echocardiography (MCE) using harmonic power Doppler (HPD) in conjunction with the transvenous contrast agent SHU 563A would be useful in detecting stunned but viable myocardium. DESIGN: Acute coronary occlusion (2 to 3 h) followed by 1 h of reperfusion was created in 10 dogs in an open-chest model. Measurements and results: Continuous harmonic B-mode for wall motion analysis and ECG triggered HPD for assessment of myocardial perfusion was employed during coronary occlusion and after reperfusion. Postmortem 2,3,5-triphenyltetrazolium chloride (TTC) staining was performed to verify infarction. Extent of wall motion abnormality (WMA), perfusion defect size, and anatomic infarct size (myocardial infarction [MI]) were analyzed in a 5-segment model. All 10 dogs showed WMA in 23 of 50 segments during coronary occlusion. In eight dogs, HPD detected perfusion defects in 18 of 50 segments. The concordance rate between WMA and perfusion defect was 86%. Mean linearized power (MLP) in segments with WMA was significantly lower compared to normal segments (60.7 +/- 38.9 vs 110.5 +/- 108.8, p < 0.05). After reperfusion, the extent of WMA was larger than the area of perfusion defect (percentage of left ventricular slice area): 30 +/- 13% vs 9 +/- 8%, p < 0.01. Eventual infarct size was 6 +/- 7%. WMAs were seen in 18 of 50 segments. TTC confirmed MI in 7 of 18 segments. MLP in segments with WMA but no MI was significantly higher compared to segments with WMA and MI (84.5 +/- 67.3 vs 13.2 +/- 9.6, p < 0.01). Thus, the extent of WMA after reperfusion was greater than the size of perfusion defect and eventual MI, indicating the presence of stunned but viable myocardium. CONCLUSION: MCE using HPD and the contrast agent SHU 563A can demonstrate the efficacy of reperfusion, identify necrotic regions, and aid in the recognition of stunned but viable myocardium. This approach could be useful clinically in patients with acute MI undergoing reperfusion therapy.     

Comparison of low-dose dobutamine echocardiography and thallium-201 reinjection for the determination of myocardial viability in the early post myocardial infarction period

OBJECTIVE: Determination of viability in the infarction zone in the early post Ml period is an important parameter in clinical decision making. METHODS: In an attempt to compare the places of low-dose dobutamine echocardiography (LDDE) and thallium-201 reinjection SPECT (TI-SPECT) in the determination of viability in dyssynergic myocardial segments, 17 patients (mean age: 54.6 +/- 12.8 years, 16 male, 1 female) with a recent myocardial infarction and an uneventful early clinical course underwent both tests within 5-13 days of infarction. The 16-segment model was utilised to evaluate the left ventricular wall motion and each segment was graded as 1) normokinetic, 2) hypokinetic, 3) akinetic and 4) dyskinetic or aneurysmal on a 4-scale basis. A dyssynergic segment of myocardium was considered to be viable by LDDE if it showed an improvement in wall motion of at least one grade with low-dose dobutamine infusion (10 microg/kg/min). On the other hand, mild to moderate (< 50%) fixed perfusion defects and reversible (at least a 10% improvement in perfusion on either redistribution or reinjection images) severe (50% or more) perfusion defects were considered positive for viability by TI-SPECT. RESULTS: Of the 76 segments with resting dyssynergy (10 dyskinetic/aneurysmal, 33 akinetic, 33 hypokinetic), 51 (67%) were shown to be viable by LDDE and 61 (80%) by TI-SPECT. There was an agreement of 76% (p = 0.03, K = 0.63) between the two methods. CONCLUSION: This study disclosed a moderate degree of agreement between LDDE and TI-SPECT for the determination of viability in dyssynergic myocardial segments in the early post-myocardial infarction period.     

Detection of functional recovery using low-dose dobutamine and myocardial contrast echocardiography after acute myocardial infarction treated with successful thrombolytic therapy

OBJECTIVE: We studied the value of low-dose dobutamine stress echocardiography (LDDE) and myocardial contrast echocardiography (MCE) in early prediction of left ventricular functional recovery (LVFR) after acute myocardial infarction (AMI) treated with successful thrombolysis. DESIGN: LDDE and MCE using second-harmonic intermittent imaging were performed in first week after AMI. LVFR was defined as an absolute > or =5% increase in ejection fraction, from early to 6 months of follow-up by Technetium-99m-Sestamibi single-photon emission computed tomography. PATIENTS: Out of 50 patients studied, 19 evolved with LVFR (group 1) and 31 without LVFR (group 2). Regional dysfunction was detected in 103 (37%) infarcted-related segments in group 1 and in 173 (63%) segments in group 2. RESULTS: Sensitivity, specificity, positive, and negative predictive values and accuracy for detecting LVFR by LDDE were 94.7% (18/19), 87.1% (27/31), 81.8% (18/22), 96.4% (27/28), and 90% (45/50), respectively, and by MCE were 94.7% (18/19), 51.6% (16/31), 54.5% (18/33), 94.1% (16/17), and 68% (34/50). In group 1, functional improvement was observed in 86.9% (53/61) of segments with contractile reserve by LDDE and in 65.8% (52/79) of segments with microvascular perfusion by MCE. In group 2, functional improvement was observed in 78.3% (18/23) of segments with contractile reserve by LDDE and in 25.5% (25/98) of segments with microvascular perfusion by MCE. All segments without perfusion by MCE evolved without functional recovery. CONCLUSION: LDDE was an accurate predictor of late left ventricular function recovery after AMI, while MCE was sensitive and has a high negative predictive value demonstrating that microvascular perfusion is essential for LVFR.     

Combined assessment of microvascular integrity and contractile reserve improves differentiation of stunning and necrosis after acute anterior wall myocardial infarction

OBJECTIVES: We sought to determine the relative accuracy of myocardial contrast echocardiography (MCE) and low-dose dobutamine echocardiography (LDDE) in predicting recovery of left ventricular (LV) function in patients with a recent anterior wall myocardial infarction (MI). BACKGROUND: Left ventricular dysfunction after acute MI may be secondary to myocardial stunning or necrosis. Myocardial contrast echocardiography allows real-time echocardiographic perfusion assessment from a venous injection of a fluorocarbon-based contrast agent. Although this technique is promising, it has not been compared with LDDE. METHODS: Forty-six patients underwent baseline wall motion assessment, MCE, and LDDE two days after admission, as well as follow-up echocardiography after a mean period of 53 days. RESULTS: Perfusion by MCE predicted recovery of segmental function with a sensitivity of 69%, specificity of 85%, positive predictive value of 74%, negative predictive value of 81%, and overall accuracy of 78%. Contractile reserve by LDDE predicted recovery of segmental function with a sensitivity of 50%, specificity of 88%, positive predictive value of 72%, negative predictive value of 73%, and overall accuracy of 73%. Concordant test results occurred in 74% of segments and further increased the overall accuracy to 85%. The mean wall motion score at follow-up was significantly better in perfused versus nonperfused segments (1.9 vs. 2.6, p < 0.0001) and in segments with contractile reserve, compared with segments lacking contractile reserve (1.9 vs. 2.5, p < 0.0001). CONCLUSION: Myocardial contrast echocardiography compares favorably with LDDE in predicting recovery of regional LV dysfunction after acute anterior wall MI. Concordant contractile reserve and myocardial perfusion results further enhance the diagnostic accuracy.     

Real-time myocardial contrast echocardiography for the detection of stress-induced myocardial ischemia. Comparison with 99mTc-sestamibi single photon emission computed tomography

BACKGROUND: Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects. METHODS: Real-time MCE based on continuous infusion of Optison (8-10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg x 4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (kappa=0.72) for rest- and 86% (kappa=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, kappa=0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, kappa=0.59), LCX (86%, kappa=0.64) and RCA (80%, kappa=0.68) perfusion territories. CONCLUSIONS: These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.     

Potential clinical applications of myocardial contrast echocardiography in evaluating myocardial perfusion in coronary artery disease

Myocardial contrast echocardiography (MCE) is a relatively new technique that uses microbubbles to produce myocardial opacification. Recent advances in echocardiography have resulted in improved detection of microbubbles within the myocardium allowing combined acquisition of function and perfusion data, thus making MCE suitable for bedside use. Regardless of the imaging modality chosen or the type of stress used, MCE detects changes developing in the coronary microcirculation, providing important information for the evaluation of severity of coronary artery disease and for the detection of viable myocardial tissue in acute or chronic coronary artery disease.