Assessment of myocardial viability in patients with acute myocardial infarction by two-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography

It is clinically important to determine the myocardial viability of regional wall motion abnormality segments in patients with acute myocardial infarction (AMI). The purpose of this study was to ascertain the ability and value of a combination of speckle tracking echocardiography (STE) and low dose dobutamine stress echocardiography (LDDSE) for the evaluation of viable myocardium in patients with AMI. Forty-two hospitalized patients with AMI and left ventricular systolic dysfunction (left ventricular ejection fraction <50 %) were underwent STE in conjunction with LDDSE and dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT). Percutaneous coronary intervention (PCI) was performed subsequently in all patients. STE was used to measure radial, circumferential, and longitudinal end-systolic strain and peak systolic strain rate. The movement of each segment was observed by routine echocardiography 1, 3, and 6 months after PCI, and its improvement over time was the criterion of viable myocardium. The sensitivity, specificity and accuracy of DISA-SPECT for the assessment of viable myocardium were 83.6, 74.4, and 80.7 %, respectively. Among the radial, circumferential, and longitudinal strain and strain rate parameters, only longitudinal strain (LS) and longitudinal strain rate (LSr) at rest and LDDSE emerged as independent predictors of viable myocardium, When combining LS and LSr at LDDSE, the sensitivity, specificity and accuracy for the assessment of viable myocardium rose to 89.8, 90.2 and 89.9 %, respectively. The sensitivity of STE in conjunction with LDDSE was similar to DISA-SPECT for detecting viable myocardium in patients with AMI, but the specificity and accuracy of STE performed with LDDSE were higher than DISA-SPECT.     

多巴酚丁胺负荷超声心动图与背向散射积分对陈旧性心肌梗死患者心肌存活性的研究

目的：探讨小剂量多巴酚丁胺负荷超声心动图与背向散射技术评估陈旧性心肌梗死患者的心肌存活性。方法：分别测量28例心肌梗死患者在不同负荷阶段时(注药剂量分别为0，5，10，20μg.kg^-1.min^-1)，胸骨旁左心室乳头肌水平短轴观的4个节段(前室间隔、前壁、后壁和下壁)的背向散射积分周期变异(CVIB)和标化背向散射积分周期变异(CVIB％)，并在冠状动脉重建术后随访常规超声心动图。结果：非心肌梗死组及非存活心肌组的CVIB和CVIB％在小剂量多巴酚丁胺负荷过程中无显著变化，而存活心肌组CVIB和CVIB％均在5—10μg.kg^-1.min^-1时增加并保持较高水平至负荷终点。结论：陈旧性心肌梗死患者的心肌背向散射积分参数在小剂量多巴酚丁胺负荷状态下呈现出有意义的改变，两种方法的结合可用于定量检测存活心肌。     

谐波成像后应用超声背向散射积分评价陈旧性心肌梗塞心肌残存收缩能力

目的:探讨组织谐波成像(THI)后应用超声背向散射积分(IBS)评价陈旧性心肌梗塞(OMI)心肌残存收缩能力的优点。方法:前壁陈旧性心肌梗塞20例定为OMI组,健康人22例定为对照组。应用Agilent-5500型超声仪,获取两组左室乳头肌水平短轴观的THI和基波成像(FI)画面,记录左室前间隔心肌组织IBS值和IBS值心动周期变动量(CVIBS)。运用t检验进行两组IBS参数的显著性检验。结果:THI后和FI时,OMI组左室前间隔IBS值均显著高于对照组(P<0.05,P<0.01),CVIBS均显著低于对照组(P<0.01,P<0.01)。与FI时比较THI后OMI组左室前间隔IBS值显著增高(P<0.05),CVIBS显著增大(P<0.05)。结论:THI后应用IBS评价OMI心肌残存收缩能力敏感度增高。     

背向散射技术结合多巴酚丁胺负荷试验检测不同部位冠状动脉狭窄

目的探讨背向散射技术结合多巴酚丁胺负荷试验(DSE)能否提高对不同部位冠状动脉狭窄的检测率。方法记录32例临床疑诊为冠心病的患者在不同剂量多巴酚丁胺负荷下左室乳头肌水平短轴观的背向散射积分,按冠状动脉造影结果将心肌节段分组,比较各组心肌在各剂量负荷下背向散射积分周期变异(CVIB)值的变化。结果和正常冠状动脉供血心肌节段相比,狭窄冠状动脉供血心肌节段的CVIB值在静息状态和小剂量多巴酚丁胺负荷下无显著差异,但在大剂量负荷下明显降低。以DSECVIB<4.8dB作为检测冠状动脉狭窄的阈值,对于左前降支病变,DSECVIB法可提高敏感性、特异性和准确率;对于左旋支和右冠状动脉病变,DSECVIB法未能提高检测的敏感性,而提高了特异性和准确率。结论背向散射技术与传统DSE联合应用可提高DSE对不同部位冠状动脉狭窄的检测率,尤其对于左前降支的病变。     

应用定量组织速度成像技术结合小剂量多巴酚丁胺负荷试验评价心肌存活性

目的　探讨应用定量组织速度成像 (QTVI)技术结合小剂量多巴酚丁胺负荷超声心动图试验 (LDDSE)评价心肌存活性的价值。方法　 2 0例心肌梗死患者均行经皮腔内冠状动脉成形术 (PTCA)或PTCA 支架术。术前 1周内进行LDDSE ,术后 ( >6周 )复查超声心动图。应用QTVI技术获取LDDSE各阶段及术后梗死心肌范围内相邻两取样点的组织速度和位移曲线 ,测量其收缩期最大速度和位移 ,算出其心肌应变 (S)和应变率 (SR)。结果　在术后室壁运动有改善组中 ,LDDSE各阶段以及术后各取样点的收缩期最大速度和最大位移均较术前静息状态时有不同程度提高。LDDSE在 5 μg·kg-1·min-1剂量结束时 ,SR、S均较静息状态时提高 [SR :( 0 .4± 0 .3 )s-1对 ( 0 .2± 0 .2 )s-1,P <0 .0 5 ;S :0 .0 5± 0 .0 4对 0 .0 3±0 .0 1,P <0 .0 5 ] ,而较术后稍低 [SR :( 0 .4± 0 .3 )s-1对 ( 0 .8± 0 .2 )s-1,P <0 .0 5 ;S :0 .0 5± 0 .0 4对 0 .10±0 .0 4,P <0 .0 5 ]。LDDSE在 10 μg·kg-1·min-1剂量结束时 ,SR、R均较静息状态时明显提高 [SR :( 1.0±0 .4)s-1对 ( 0 .2± 0 .2 )s-1,P <0 .0 1;S :0 .10± 0 .0 5对 0 .0 3± 0 .0 1,P <0 .0 1] ,与术后差异无显著性意义[SR :( 1.0± 0 .4)s-1对 ( 0 .8± 0 .2 )s-1,P >0 .0 5 ;S :     

超声背向散射积分对急性心肌梗死早期诊断的临床研究

目的 研究心肌组织背向散射积分（IBS）及IBS心动周期变化幅度（CVIB）用于临床早期诊断急性心肌梗死的价值。方法 选30例正常人,15例急性心肌梗死患者（24h以内）、15例旧性心肌梗死患者（心肌梗死在3个月以上）,应用HPB5500型超声诊断仪,在胸骨旁左室乳头肌短轴切面,分别测量左心室前间隔,前壁、侧壁,后壁,下壁和后间壁心肌组织的IBS,并将其与心包IBS的比值作为心肌IBS的校正值（IBS％）;舒张末期与收缩末期的IBD差值即CVIB,并将其与心包IBS的比值作为心肌CVIB的校正值（CVIB％）。同时作心电图的比较对照。结果 15例急性心肌梗死患者心肌梗死部位及正常人（21．4vs8．1,21．4vs7,2,均P＜0．001）,而CVIB明显小于非梗死部位及正常人（6．5vs10．16．5vs7．5,均P＜0．001）。与心电图变化一致。陈旧性心肌梗死部位的IBS明显高于急性心肌醒梗死部位（25．6vs2.4,P＜0．05）,CVIB则明显低于急性心肌梗死部位（3．9vs6．5,P＜0．05）。结论 IBS对临床上诊断急性心肌梗死有很高的特异性和敏感性,并可判断病变心肌的范围和功能状况,可作为早期诊断急性心肌梗死的可靠指标。     

Enoximone very low-dose dobutamine stress echocardiography: a new test for detecting viability in severe myocardial dysfunction after acute myocardial infarction.

Relying on the synergistic action on contractility of enoximone and dobutamine when concomitantly infused, 25 patients with their first acute Q-wave anterior myocardial infarctions underwent conventional low-dose dobutamine echocardiography (LDE) and enoximone very-LDE to assess myocardial viability in severely dysfunctioning areas. Images were recorded at peak of pharmacodynamic effect of drugs and 4 months after revascularization. At peak-dose stage of LDE and enoximone very-LDE the regional infarct zone wall-motion score significantly decreased from the basal value of 25.6 +/- 2.9 to 16 +/- 6.0 (P <.001) and to 14.5 +/- 5.2 (P <.001), respectively. A high correlation was found by comparing the wall-motion score of each patient calculated at peak effect of combined drug administration with follow-up values (r(s) = 0.9). Enoximone very-LDE has proven to be a new test useful to evaluate viability in asynergic segments especially when the results of conventional tests are questionable.     

多巴酚丁胺负荷超声结合心肌背向散射积分评价存活心肌

目的探讨多巴酚丁胺负荷超声(DSE)结合心肌背向散射积分(IBS)检测存活心肌的临床应用价值.方法冠心病组:22例患者,经冠状动脉定量造影术(QCA)确诊为冠心病(CAD),并进一步行经皮冠脉介入治疗术(PCI),术前1周内行DSE(5,10,20,40 μg/kg·min)检查,于静息、DSE每级负荷5 min采集全心尖切面(长轴、二腔、四腔)IBS图像,术后3个月复查二维超声和IBS检查.对照组:18例患者,QCA结果正常,行2DE,DSE,IBS检查.根据CVIB在DSE过程中的变化特点,探索CVIB最大变化率K值定义存活心肌,并检测K值识别存活心肌的敏感性、准确性,与单纯DSE进行比较.结果与单纯DSE相比,DSE结合IBS的K值检测存活心肌敏感性、准确性明显提高(90.0% vs 73.3%;90.4%vs77.4%、P＜0.05～0.01).结论DSE结合IBS技术较单纯DSE使用能提高检测存活心肌的敏感性和准确性.     

超声背向散射积分和回声强度在急性心肌梗死诊断中的？…

目的 探讨心肌组织背向散射积分（ＩＢ）和回声强度（ＥＩ）是否可用于临床急性心肌梗死的诊断及其应用价值。方法 在３５例急性心肌梗死患者发病２周内,用ＨＰ－５５０型超声诊断仪和ＤＦＹ型超声图像定量分析诊断仪,在胸骨旁左室乳头肌短轴切面,分别测量冠状动脉左前降支,左回旋支和右冠动脉支配区域心肌组织（分别相当于左室乳头肌短轴切面上１２、４、８点的位置）的ＩＢ和ＥＩ心动周期变化幅度（ＣＶＩＢ和ＣＶＥＩ）值,     

小剂量多巴酚丁胺负荷下运用校正背向散射声学参数检测存活心肌

目的探讨在小剂量多巴酚丁胺负荷(LDDSE)下运用校正背向散射声学参数能否提高检测存活心肌的敏感性和特异性.方法心肌梗死患者46例,按照PTCA术后室壁运动改善状况将心肌节段分为存活心肌组和非存活心肌组,比较2组在PTCA前LDDSE下的心肌背向散射指标.结果 LDDSE下存活心肌的CVIB及校正CVIB值均高于静息状态,而非存活心肌的CVIB与校正CVIB值在两种状态下无明显差异.以CVIB＞5.0 dB和校正CVIB＞3.8 dB作为判断存活心肌的标准,敏感性、特异性、准确性分别为82.1%和85.7%、68.9%和72.4%、77.6%和81.2%.二维室壁运动评分法判断存活心肌的敏感性、特异性、准确性分别为76.9%、75.9%、76.5%.结论背向散射技术结合小剂量多巴酚丁胺负荷超声心动图能较好地定量评价存活心肌,相对于二维室壁运动评分法,是更为客观准确的评价室壁运动的方法.     

小剂量多巴酚丁胺负荷超声评价急性心肌梗死后存活心肌

目的 探讨小剂量多巴酚丁胺负荷超声(LDDSE)评价急性心肌梗死(AMI)后存活心肌的价值及安全性.方法 选择25例行急诊经皮冠状动脉介入治疗(PCI) AMI患者,PCI后14天进行LDDSE试验,以PCI术后3个月超声心动图检查室壁运动改善为评价存活心肌的金标准,观察LDDSE评价存活心肌的准确度,同时观察AMI早期行LDDSE的安全性.结果 LDDSE检测存活心肌的敏感度为82.5％,特异度78.5％,准确度为80.9％.在LDDSE过程中未见严重不良反应.结论 LDDSE可用于AMI患者存活心肌的评估,是一种较为安全、简便的评价存活心肌的方法.     

Low-level exercise echocardiography identifies contractile reserve in patients with a recent myocardial infarction: comparison with dobutamine stress echocardiography.

Contractile reserve (CR) during dobutamine stress echocardiography (DSE) identifies patients with coronary artery disease whose left ventricular function and prognosis may improve after revascularization. To test the hypothesis that the early stages of upright bicycle-exercise echocardiography (LLEx) result in CR comparable with DSE, 30 patients 1 week after myocardial infarction underwent multistage LLEx and DSE. At low and peak LLEx, heart rate and systolic blood pressure were higher than DSE. Identification of CR by LLEx was concordant with DSE when analyzed by infarct zone or by individual patient. We conclude that CR can be demonstrated during LLEx that correlates with DSE in patients with a recent MI. Low-level exercise is a promising alternative to DSE for identifying contractile reserve after MI.     

速度向量成像联合小剂量多巴酚丁胺负荷实验评价兔心肌梗死后存活心肌

目的 评价速度向量成像(VVI)联合小剂量多巴酚丁胺负荷实验检测兔心肌梗死模型存活心肌的价值。方法 结扎新西兰大白兔冠状动脉左心室支,建立心肌梗死兔模型。于术后8周对实验动物行小剂量多巴酚丁胺负荷实验,采用VVI检测局部室壁给药前后应变及应变率的改变;处死实验动物后,取心脏进行氯化三苯四氮唑(TTC)染色观察坏死心肌,以TTC结果为金标准,计算VVI诊断存活心肌的敏感度和特异度。结果 给予小剂量多巴酚丁胺后,非存活心肌节段应变和应变率较给药前均无明显改变(P均>0.05);存活节段收缩期应变和应变率随剂量增加而增加,与给药前比较差异均有统计学意义(P均<0.05),舒张期应变率亦有增加趋势,与给药前比较差异无统计学意义(P>0.05)。VVI联合小剂量多巴酚丁胺负荷实验诊断存活心肌的敏感度和特异度在左心室长轴切面为77.42%(24/31)和82.35%(42/51),在左心室短轴切面为84.31%(43/51)和88.73%(126/142)。结论 VVI联合小剂量多巴酚丁胺负荷实验评价心肌梗死后存活心肌准确、无创,具有潜在临床应用价值。     

Sensitive detection of myocardial viability in chronic coronary artery disease by ultrasonic integrated backscatter analysis.

BACKGROUND: Myocardial viability is not synonymous with contractile reserve and identifiable in a significant percentage of dysfunctional myocardial segments without contractile reserve. The usefulness of ultrasonic tissue characterization by the phase-corrected magnitude of cyclic variation of integrated backscatter (MVIB) in chronic coronary artery disease is not fully validated. Thus, whether MVIB predominantly reflects the contractile reserve or myocardial viability of chronically dysfunctional myocardium was determined. METHODS: The MVIB of severely dysfunctional interventricular septum or posterior wall was measured in 34 consecutive patients with previous myocardial infarction. Dobutamine stress echocardiography and fluorine-18 fluorodeoxyglucose positron emission tomography were used as the standards of contractile reserve and myocardial viability, respectively. RESULTS: Among 44 dysfunctional segments, only 15 were judged as having contractile reserve and 29 were judged as not by dobutamine stress echocardiography, whereas 26 segments showed myocardial viability using fluorine-18 fluorodeoxyglucose positron emission tomography and 18 did not. MVIB was greater in segments with than in those without contractile reserve (4.7 +/- 2.2 vs -1.4 +/- 4.9 dB, P < .0001), but there was considerable overlap between the groups. On the other hand, MVIB of segments with and without myocardial viability (4.1 +/- 2.6 vs -4.3 +/- 3.3 dB, P < .0001) was distinctly different and predicted myocardial viability with a sensitivity of 92% and a specificity of 94%. CONCLUSIONS: For patients with chronic coronary artery disease, MVIB better reflects myocardial viability than it does contractile reserve. Ultrasonic tissue characterization, in concordance with fluorine-18 fluorodeoxyglucose positron emission tomography, is a sensitive method for detecting myocardial viability.     

Very early stage detection of acute myocardial infarction by harmonic ultrasonic integrated backscatter

To study the very early diagnosis of acute myocardial infarction (AMI) by harmonic imaging ultrasonic integrated backscatter (IBS). Thirty normal persons, 68 cases with AMI, of whom 28 cases were at the very early stage of acute myocardial infarction (in 2 h), and 40 cases with acute myocardial infarction (in 2 to 12 h) were examined by IBS and the cyclic variation of integrated backscatter (CVIB) with HP-5500 ultrasonic system in different segment (the segment of myocardial infarction and no myocardial infarction). In the segment of AMI of the very early stage (in 2 h) the IBS (dB) is much higher than that of the segment of no AMI (18.7 versus 8.3), p < 0.001, the CVIB (dB) are lower (6.1 versus 7.6), p < 0.001. But at that time there are no obvious changes in ECG. In the other 40 cases with AMI in 2 to 12 h, IBS in the segment of AMI is obviously higher than the normal person and no infarction segment in the same heart (21.3:8.3, 20.2:8.5) p < 0.05, but CVIB (dB) is obviously lower than the normal person and no infarction segment in the same heart (5.8:7.6, 5.9:9.4) p < 0.05 the changes of the ultrasonic is coincidence with ECG. IBS (dB) are very obvious just as in ECG. The result demonstrates that ultrasonic tissue characterization with harmonic imaging integrated backscatter can be used for diagnosis in the very early stage of AMI, and can judge the segment range of AMI and function of the whole heart.     

多巴酚丁胺超声心动图负荷试验与放射性核素心肌灌注显像对心肌存活性的对比研究

目的 评价小剂量多巴酚丁胺超声心动图负荷试验(DSE)和放射性核素心肌灌注显像(SPECT)预测心肌存活性的价值。方法 以15例成功行经皮冠脉介入治疗(PCI)患者术后6个月室壁运动改善为检验标准，进行小剂量多巴酚丁胺超声心动图负荷试验及SPECT检查，比较两者检测心肌存活性的准确性。结果 小剂量多巴酚丁胺超声心动图负荷试验峰剂量期与低剂量期在预测心叽存活敏感性、阴性预测差异具有显著性意义；与DSE相比，SPECT具有较高的敏感性但其特异性较低。结论 DSE与SPECT检测心肌存活性的准确性各有优点，但DSE更具实用性。     

多巴酚丁胺负荷超声下斑点追踪与组织多普勒技术检测存活心肌的临床价值

目的 探讨超声斑点追踪技术(STE)与组织多普勒技术(TDI)分别联合多巴酚丁胺负荷试验检测存活心肌的临床价值.方法 左心室收缩功能下降(左心室射血分数＜50％)冠心病患者37例,在血运重建之前进行联合多巴酚丁胺负荷超声心动图(DSE)的STE与TDI检查,分析计算室壁运动异常节段(RWMA)的静息及DSE后纵向应变率(LSR)和收缩期峰值速度(PSV).血运重建后1、3、6个月分别复查超声心动图,室壁运动改善为判定存活心肌的金标准,分析STE与TDI检测存活心肌的价值.结果 检查RWMA214个,金标准检测119个节段为存活心肌,95个节段为非存活心肌.存活心肌与非存活心肌的LSR和PSV在静息状态下比较差异有统计学意义(P＜0.01),存活心肌组的LSR和PSV在DSE前后比较差异有统计学意义(P＜0.01),而非存活心肌组的LSR和PSV在DSE前后差异无统计学意义(P＞0.05).受试者工作特征(ROC)曲线判定以△LSR(％)≥7.14％为截断点,检测存活心肌的敏感度88.2％,特异度80.0％;以△PSV(％)≥8.04％为截断点,检测存活心肌的敏感度74.8％,特异度83.2％.联合运用LSR和PSV两项指标,检测存活心肌的敏感度和特异度分别提高至89.8％、88.7％.结论 STE与TDI联合DSE检测存活心肌的敏感度和特异度有明显提高,适宜在临床推广使用.     

Left ventricular twist during dobutamine stress echocardiography after acute myocardial infarction: association with reverse remodeling

Left ventricular (LV) twist is emerging as a marker of global LV contractility after acute myocardial infarction (AMI). This study aimed to describe stress-induced changes in LV twist during dobutamine stress echocardiography (DSE) after AMI and investigate their association with LV reverse remodeling at 6 months follow-up. In 82 consecutive first AMI patients (61 ± 12 years, 85 % male) treated with primary percutaneous coronary intervention, DSE was performed at 3 months follow-up. Two-dimensional speckle-tracking-derived apical and basal rotation and LV twist were calculated at rest, low- and peak-dose stages. LV reverse remodeling was defined as ≥10 % decrease in LV end-systolic volume between baseline and 6 months follow-up. Patterns of LV twist response on DSE consisted of either a progressive increase throughout each stage (n = 18), an increase at either low- or peak-dose (n = 53) or no significant increase (n = 11). LV reverse remodeling occurred in 28 (34 %) patients, who showed significantly higher peak-dose LV twist (8.51° vs. 6.69°, p = 0.03) and more frequently progressive LV twist increase from rest to peak-dose (39 vs. 13 %, p < 0.01) compared to patients without reverse remodeling. Furthermore, increase in LV twist from rest to peak-dose was the only independent predictor of LV reverse remodeling at 6 months follow-up (OR 1.3, 95 % CI 1.1?1.5, p = 0.005). Both the pattern of progressive increase in LV twist and the stress-induced increment in LV twist on DSE are significantly associated with LV reverse remodeling at 6 month follow-up after AMI, suggesting its potential use as a novel marker of contractile reserve.     

心肌梗死患者背向散射积分变化及临床意义

目的 探讨背向散射积分技术(IBS)定量评价心肌存活和左心室重构的临床应用。方法 记录18例健康志愿者和36例接受经皮冠脉支架置入术的初发急性心肌梗死患者的心尖左心室长轴、心尖四腔和两腔观超声背向散射图像，对比观察正常对照组与心肌梗死患者术后1周内、1个月及3个月时不同室壁节段心肌IBS值及其周期变异幅度(CVIB)的动态变化，并分析其与患者左心室形态及心功能改变之间的关系。结果 无左心室重构的A组，再灌注后1周内梗死与非梗死节段的IBS与正常组差异无显著性意义，梗死节段的CVIB较正常组明显减低；1个月及3个月时，CVIB随心功能恢复而逐渐改善。发生左心室重构的B组，再灌注后1周内梗死节段的IBS较正常组明显增高，梗死与非梗死节段的CVIB均显著减低；1个月及3个月时梗死与非梗死节段IBS均逐渐增高，而CVIB仅非梗死节段恢复。结论 心肌梗死患者的心肌背向散射积分参数与正常对照组明显不同，可作为评价心肌活性、预测左心室重构和心功能恢复程度的客观指标。     

背向散射积分超声组织定征识别存活心肌的实验

目的探讨背向散射积分检测技术识别存活心肌的敏感性和准确性。方法应用商品化的背向散射积分联机分析处理系统检测活体开胸犬重度缺血、晕厥和梗死心肌模型的标化背向散射积分（ＩＢＳ）、标化背向散射积分周期变异（ＣＶＩＢ）及室壁增厚率。结果重度缺血心肌ＩＢＳ明显增高,ＣＶＩＢ明显减低。再灌注后ＣＶＩＢ的恢复幅度高于室壁增厚率。晕厥心肌的ＩＢＳ和ＣＶＩＢ基本正常,但室壁增厚率明显减低。梗死心肌的ＩＢＳ明显增高,ＣＶＩＢ消失或呈反相,再灌注后无改善。结论背向散射积分超声组织定征能敏感反映不同程度缺血心肌的散射特性变化,为无创判定心肌存活性和评价心肌功能提供了一个新的技术手段