Evaluation of immediate post-stress wall motion on adenosine stress/rest Thallium-201 Gated Myocardial SPECT

As early as 10 min after adenosine stress, immediate post-stress wall motion can be evaluated on adenosine stress/rest Tl-201 gated myocardial SPECT. To widen the applications of Tl-201 in gated SPECT, we investigated the reproducibility of LV parameters (EF, EDV, and ESV), and the diagnostic competency of immediate post-stress wall motion evaluations obtained by adenosine stress/rest Tl-201 gated myocardial SPECT. Myocardial perfusion and wall motion were evaluated using a 5-point scoring system in 20-segment model using Cedas automatic gated software (AutoQUANT 4.3.1). The reproducibilities of LV parameters were examined through repeated acquisition (n=31). Diagnostic competency was evaluated vs. coronary angiography, and multivariate logistic regression analysis was used to determine whether stress abnormal perfusion (SSSp), stress abnormal wall motion (SSSwm), or reversible abnormal wall motion (SDSwm) predict coronary stenosis (> 70%) (n=60). Two standard deviations for immediate post-stress wall motion were smaller than those for rest at EF (8.6 vs. 10.7%) and ESV (6.0 ml vs 8.4 ml). Univariate logistic regression analysis identified SSSp (p=0.006), SSSwm (p=0.016), and SDSwm (p=0.020) are significant predictors, but only SSSp (p=0.013) and SDSwm (p=0.039) were found to be significant by multivariate analysis. In addition, SSSwm or SDSwm were able to find undetected coronary artery disease in 54.5% (6/11) of patients with normal perfusion. We conclude that Tl-201 can be successfully applied to gated SPECT for immediate post-stress wall motion evaluation, and that reversible wall motion abnormality on adenosine stress/rest Tl-201 gated myocardial SPECT is an independent predictor of significant coronary artery disease.     

Comparison of dobutamine stress echocardiography and exercise stress Thallium-201 SPECT for detection of myocardial ischemia after acute myocardial infarction treated with thrombolysis

In order to compare the ability of dobutamine stress echocardiography (DSE) and exercise Thallium-201 SPECT to detect myocardial ischemia in patients with myocardial infarction (Ml) treated with thrombolysis, 43 prospectively selected patients with Ml treated with thrombolysis underwent within 1 month from Ml DSE, stress-redistribution-reinjection Thallium-201 SPECT and coronary angiography. The echocardiographic and scintigraphic images were analyzed for the presence of myocardial ischemia using a 11-segment left ventricular model. DSE and exercise Thallium-201 SPECT detected myocardial ischemia in the infarct zone in 72 and 72 (31/43) of patients and ischemia at a distance in 12 (5/43) and 19 (8/43) of patients with a concordance of 67 and 88 , respectively. A significant agreement between DSE and exercise Thallium SPECT was found in the evaluation of the extent of both myocardial necrosis and stress-induced myocardial ischemia. DSE and exercise Thallium SPECT showed similar sensitivity (79 vs 76), specificity (60 vs 60) and accuracy (77 vs 74) for detection of a critical stenosis of the infarct-related artery; there was also no significant difference between the tests in sensitivity, specificity and accuracy for detection of the multivessel disease. In conclusion, initially after thrombolyzed MI, DSE and exercise Thallium-201 SPECT detect myocardial ischemia in the infarct zone in a high proportion of patients and show a similar accuracy for the diagnosis of a critical stenosis of the infarct-related coronary artery and of the multivessel disease.     

Factors Affecting Accuracy of Ventricular Volume and Ejection Fraction Measured by Gated Tl-201 Myocardial Perfusion Single Photon Emission Computed Tomography

The electrocardiogram-gated single photon emission computed tomography (SPECT) measurement of left ventricular end-diastolic volume, end-systolic volume and ejection fraction may contain substantial errors. We evaluated whether patient-related factors affect the accuracy of left ventricular volume and ejection fraction measured by gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. Left ventricular volume and ejection fraction were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated end-diastolic and end-systolic volume, and overestimated ejection fraction, but 4D-MSPECT overestimated all those values (P<0.001). Independent variables associated with increasing the difference in end-diastolic volume between echocardiography and gated SPECT were decreasing left ventricular end-diastolic wall thickness, decreasing body surface area, female sex and increasing end-diastolic volume (P<0.001). Those for end-systolic volume were decreasing left ventricular end-systolic wall thickness, female sex, and decreasing end-systolic volume (P<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in ejection fraction (P<0.001). Adenosine stress SPECT showed significantly higher end-diastolic and end-systolic volume values and a lower ejection fraction than did redistribution SPECT (P<0.001). Patient-related factors affect the accuracy of left ventricular volume and ejection fraction measured by gated Tl-201 SPECT. Modification of gated SPECT measurements by taking account of these factors would lead to reduce systemic errors.The authors do not have any financial associations that might pose a conflict of interest in connection with the submitted article. None of the authors has a financial interest in any cardiac software package, and this study was not supported by any vendor or cardiac software producer.     

Thallium-201 SPECT and low-dose dobutamine stress cine MRI for predicting functional recovery of regional myocardial contraction in patients with myocardial infarction.

OBJECTIVES: The purpose of this study was to compare the diagnostic performances of Tl-201 single photon emission computed tomography (SPECT) and dobutamine stress cine magnetic resonance imaging (MRI) for predicting functional recovery of regional myocardial contraction in patients after myocardial infarction. METHODS: Twenty patients underwent Tl-201 SPECT and MRI 3-4 weeks after onset of myocardial infarction. Cine MR images were acquired in the resting state and during dobutamine stress. Tl-201 uptake and systolic wall thickening (SWT) on cine MRI were analyzed on short-axis images by using a 14-segment model. Follow-up cine MR images were obtained 187.1+/-33.5 days after onset. RESULTS: The averaged Tl-201 uptake in 54 segments with impaired SWT was 47%+/-20%, being significantly lower than that in 226 segments with preserved SWT (75%+/-18%; p<0.0001). The sensitivity, specificity, and accuracy of dobutamine MRI and Tl-201 SPECT for predicting preserved SWT after 6 months were 89% vs. 80%, not significant (NS); 89% vs. 72%, p<0.01; and 89% vs. 79%, NS, respectively. In the anterior wall and apex, the sensitivity and specificity of SPECT were not significantly different from those of MRI. In the inferior wall and posterolateral wall, however, the specificity of SPECT was substantially lower than that of MRI (53% vs. 88%, p<0.001), resulting in significantly lower accuracy (75% vs. 90%, p<0.01). CONCLUSIONS: Both SPECT and dobutamine MRI showed excellent sensitivity for predicting myocardial viability in all left ventricular segments. Decreased specificity of SPECT in the inferior and posterolateral segments resulted in lower overall specificity in comparison with dobutamine MRI.     

多巴酚丁胺负荷超声心动图结合舒张功能应变率评价冠心病的临床研究

目的探讨多巴酚丁胺负荷超声心动图(DSE)结合应变率显像(SRI)技术中舒张功能参数变化诊断冠心病的临床价值。方法28例临床疑诊为冠心病的患者接受DSE试验并行舒张期SRI参数分析,以冠状动脉造影结果为金标准,比较DSE负荷下二维目测法及SRI检出冠心病患者舒张功能异常的敏感性及特异性。结果狭窄冠状动脉供应心肌节段在峰值剂量(40μg·kg-1·min-1)DSE负荷下与静息状态及小剂量(10~20μg·kg-1·min-1)DSE负荷相比,舒张早期应变率显著降低,舒张开始时间显著延长。DSE检出冠心病患者舒张功能异常的敏感性、特异性、准确率分别为84%、86%及86%,DSE-舒张早期应变率和舒张开始时间检出冠心病患者舒张功能异常的敏感性分别为91%和93%,特异性分别为87%和85%,准确率分别为89%和90%。结论DSE结合SRI中舒张功能参数变化可提高DSE检出冠心病患者舒张功能异常的敏感性,能定量评价冠心病患者DSE状态下的心肌舒张运动状态,具有一定的临床价值。     

多巴芬酊胺超声心动图与心肌缺血

与冠脉造影及铊－２０１心肌ＳＰＥＣＴ显像对照研究疑冠心病患者２３例，评估多巴芬酊胺超声心动图在心肌缺血中的应用价值。结果表明多巴芬酊胺超声心动图检测冠脉狭窄及缺血后存活心肌的敏感度、特异度及符合率分别为７３％，７６％；７２％，８８％及７２％，８３％。评估左前降支供血节段缺血及缺血后存活心肌的能力较左旋支和右冠脉支供血节段强。     

Which is the better method in detecting significant left anterior descending coronary artery stenosis during contrast-enhanced dobutamine stress echocardiography: coronary flow velocity reserve or wall-motion assessment?

The diagnostic accuracy of dobutamine stress echocardiography (DSE) depends on wall-motion assessment. Coronary flow velocity reserve (CFVR) during DSE can be measured by transthoracic Doppler echocardiography. To investigate comparative diagnostic accuracy between wall-motion and CFVR assessment in the detection of significant left anterior descending coronary artery (LAD) stenosis, 274 patients underwent both contrast-enhanced DSE and coronary angiography. Intravenous contrast agent, Levovist, was injected to enhance left ventricular endocardial border delineation and coronary flow velocity in the LAD. Wall motion was assessed by standard technique, and CFVR was calculated as coronary flow velocity at peak dobutamine stress divided by baseline coronary flow velocity by transthoracic Doppler echocardiography. CFVR could be successfully obtained in 232 patients (feasibility, 85%). After excluding 14 patients with isolated diagonal stenosis, CFVR was significantly lower in 65 patients with significant LAD stenosis than it was in 153 patients without stenosis (1.62 +/- 0.56 vs 2.72 +/- 0.94, P <.001). CFVR < or = 2.0 had a 75% sensitivity, a 81% specificity, and a 79% diagnostic accuracy for detecting significant LAD stenosis, and these values were comparable with those by wall-motion analysis (sensitivity, 78%; specificity, 89%; and diagnostic accuracy, 86%). The measurement of CFVR in the LAD during DSE was feasible and the diagnostic accuracy of CFVR was equivalent to wall-motion assessment in the detection of LAD stenosis.     

Simultaneous dobutamine stress echocardiography and dobutamine scintigraphy (99mTc-MIBI-SPET) for assessment of coronary artery disease

Background: Simultaneous dobutamine stress echocardiography (DSE) and^99mTc-MIBI-SPET (DMS) for the evaluation of the presence and the extent of coronary artery disease (CAD) were assessed for a head to head comparison regarding the diagnostic accuracy of the two tests. Methods and Results: Forty-five consecutive patients (33 males and 12 females: 53±6.8 yr.) underwent exercise electrocardiography and simultaneous dobutamine stress echocardiography and MIBI-SPET imaging. Coronary angiography was performed in all patients (significant coronary stenosis > 50%). On the basis of the results of exercise electrocardiogram the pre-test probability for coronary artery disease (Diamond's algorithm) was low (45.6±12.7 %). The overall specificity, sensitivity and predictive accuracy of Echo-dobutamine stress test for diagnosis of the presence or absence of CAD were: specificity 82%, sensitivity 76%, diagnostic accuracy 80%, positive predictive value 90%, negative predictive value 40%. The overall specificity, sensitivity and predictive accuracy of MIBI-SPET-dobutamine test for diagnosis of the presence or absence of CAD were: specificity 86%, sensitivity 87%, diagnostic accuracy 84%, positive predictive value 97%, negative predictive value 54%. MIBI-SPET-dobutamine test showed a significantly higher sensitivity in comparison with ECHO-dobutamine test (P<0.05). Conclusion: Both noninvasive methods for the detection of CAD showed a good diagnostic accuracy. Nevertheless the SPET model showed an higher sensitivity in comparison with DSE model, essentially in the presence of a lower extent of CAD and during submaximal test.     

Increased myocardial wall thickening as index of viability assessment: a preliminary report on delayed contrast MRI

Purpose : Regional wall thickening measurement by delayed contrast MRI may assess myocardial viability and functional recovery of ischemic cardiomyopathy. Materials and methods : Delayed contrast MRI data was used in 40 patients with significant coronary artery disease and severe left ventricular dysfunction. Regional wall thickening on follow‐up MRI served as an index of functional recovery in patients receiving revascularization. For comparison, myocardial viability was assessed by MRI and ²⁰¹Tl SPECT in 10 patients using a 17‐segment method. Results : On 480 segments, MRI hyperintensities showed positive correlation with ²⁰¹Tl reduction (r = 0.71, p < 0.0001) in the inferior wall and apex. Delayed MRI detected myocardial viability better than ²⁰¹Tl SPECT. Delayed contrast‐enhanced MRI showed diagnostic accuracy 65%, sensitivity 95%, specificity 25%, positive predictive value 65% and negative predictive value 75%, whereas ²⁰¹Tl SPECT showed diagnostic accuracy 54%, sensitivity 72%, specificity 25%, positive predictive value 52% and negative predictive value 54%. Areas under the ROC curves by MRI and ²⁰¹Tl SPECT were 0.59 ± 0.04, 0.52 ± 0.05, respectively (p = 0.07). The viability concordance was 80% between ²⁰¹Tl SPECT and MRI. Conclusion : Delayed contrast‐enhanced MRI may detect the inferior wall thickening and apex as an index of viable myocardium better than ²⁰¹Tl SPECT. Myocardial viability may predict functional recovery after revascularization in ischemic cardiomyopathy. Copyright © 2009 John Wiley & Sons, Ltd.     

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。     

Diagnostic accuracy of quantitative cardiac MRI evaluation compared to stress single-photon-emission computed tomography

Background: Cardiac MRI (cMRI) perfusion is a promising non-invasive tool to assess myocardial ischemia. The accuracy of quantitative cMRI perfusion has been recently demonstrated, but to date no previous study has compared this technique with stress single-photon-emission computed tomography (SPECT). The aim of this study was to evaluate the diagnostic accuracy of myocardial perfusion reserve (MPR) based on cMRI compared with SPECT. Methods: We examined 24 patients who underwent coronary angiography, stress SPECT and cMRI perfusion. Qualitative assessment of both SPECT and cMRI images, quantification of cMRI perfusion, and quantitative coronary angiography (QCA) were independently performed. MPR was calculated using Fermi deconvolution technique. Accuracy of quantitative and qualitative data was examined to detect > 50% diameter stenosis (DS) by QCA. Results: Qualitative analysis was obtained in 198 segments and quantitative analysis was performed in 171 segments. Significant coronary artery disease (CAD) was present in 81.8% of patients. Visual cMRI assessment yielded sensitivity of 74.4% and specificity of 79.4% to predict > 50%DS, while SPECT showed sensitivity of 67.4% and specificity of 81.3%. The sensitivity for SPECT in the right coronary artery territory and apex was low compared to cMRI. Sensitivity and specificity for detection of significant CAD were 89.5% and 46.6% for MPR (cutoff 1.92). Area under the curve was 0.75 for MPR (P < 0.01). Conclusions: The diagnostic accuracy of qualitative examination of perfusion cardiac MRI and stress SPECT were comparable. The high sensitivity and low operator dependency of quantitative cMRI makes it an attractive tool to evaluate myocardial perfusion.     

Tl-201 myocardial SPECT in silent myocardial ischemia and angiographically proven coronary heart disease

Silent myocardial ischemia is defined as true myocardial ischemia without angina pectoris in patients with angiographically detected coronary artery disease. In this study 52 patients (46 male, 8 female: mean age 53 years) with a pathological exercise test but no symptoms were investigated. They showed stenosis of 75% or more of the diameter in at least one coronary segment on angiography. Prior to or after catheterization (within 14 days) Tl-201 SPECT was done and evaluated independently of angiography. A clear correlation between angiographically confirmed stenosis and reversible perfusion defects with Tl-201 SPECT was established (62 out of 76 lesions). Furthermore, there was a significant relation between angiographically detected subtotal or total occlusions of coronary vessels and irreversible perfusion defects using Tl-201 SPECT (35 in 44 lesions) (p less than 0.001). In patients with ST depression but without angina pectoris during the exercise test, the Tl-201 SPECT is highly suited to determine the hemodynamic effect of coronary stenoses.     

Simultaneous assessment of wall motion and coronary flow velocity in the left anterior descending coronary artery during dipyridamole stress echocardiography.

OBJECTIVES: This study was designed to assess the feasibility and clinical meaning of simultaneous assessment of wall motion and coronary flow velocity (CFV) reserve in the left anterior descending coronary artery (LAD) by transthoracic approach for detecting LAD stenosis during dipyridamole stress echocardiography. BACKGROUND: Coronary flow reserve plays an important role, which can be evaluated by transthoracic Doppler echocardiography during vasodilator stress. METHODS: Dipyridamole stress test was performed in 110 patients with known or suspected coronary artery disease. CFV in the distal LAD was obtained at baseline and after dipyridamole infusion, and wall motion was also assessed up to the administration of atropine, if required. All patients underwent quantitative coronary angiography within 2 days of the stress test, and significant LAD stenosis was defined as > 50% stenosis. RESULTS: The success rate of both measurements was 92%. CFV reserve < 2 had a higher sensitivity (94% vs 72%, P <.01) and a lower specificity (65% vs 95%, P <.01) than wall-motion assessment for detecting significant LAD stenosis, and diagnostic accuracy between 2 methods was comparable (81% vs 82%). A total of 69 patients (73%) showed concordant results of the 2 methods, and diagnostic accuracy for detecting significant LAD stenosis was high (94%) in this subset of patients. CONCLUSIONS: The simultaneous assessment of CFV and wall motion was feasible in the majority of cases during dipyridamole stress echocardiography. Although diagnostic accuracy between the 2 tests was comparable, concordant results of the 2 methods provided accurate diagnosis in detecting significant LAD stenosis.     

A comparative evaluation of Tl-201 and Tc-99m sestamibi myocardial perfusion spect imaging in diabetic patients

Aim Myocardial perfusion scintigraphy (MPS) is an effective tool for early diagnosis of coronary artery disease (CAD) in type II diabetes mellitus (DM). The purpose of this study was to review the comparative findings of Tc-99m MIBI and Tl-201 MPS in defining normal and abnormal myocardial segments, type and extent of the perfusion defects with reference to coronary angiography findings in diabetic patients. Methods Thirty patients with type II DM who had abnormal Tc-99m MIBI MPS findings and underwent coronary angiography were included this study (20 male, 10 female; mean age was 64 ± 11 years). Those patients were also investigated with Tl-201 MPS thereafter. All scintigraphic images were evaluated semiquantitatively using a 20-segments myocardial model. The perfusion of myocardial segments, reversibility and severity of defects based on defect score were compared using the MIBI and Tl-201 images in relation to coronary angiography. Diffuse slow-washout of Tl-201 was also noted. Results A total of 600 myocardial segments were comparatively analyzed. Diagnostic concordance between both tracers in defining normal and abnormal perfusion on a segmental basis was 88% (κ = 0.71). The percentage of normal, reversible and non-reversible segments in the Tc-99m MIBI and Tl-201 study were 67–61%, 11–20% and 22–19% respectively. While the number of irreversible defects were similar for both tracers, more number of reversible defects were identified by Tl-201 MPS than Tc-99m MIBI (65 vs. 123, p = 0.001). No significant difference between the defect scores of both tracers was found. Conclusion MPS using both tracers offered agreement in defining or excluding perfusion abnormalities in a major part of the data. However, Tl-201 MPS yielded better detection rate of myocardial ischemia than Tc-99m MIBI MPS in diabetic patients.     

彩色室壁运动与声学定量技术评价多巴酚丁胺负荷超声心动图对冠心病的诊断价值

目的：应用智能声学定量（AQi)和彩色室壁运动（CK）技术，对多巴酚丁胺负荷超声心动图（DSE）诱发的冠心病室壁运动异常（WMA）及左室功能改变进行检测，旨在为冠心病早期诊提供更准确的可定量方法。方法：对临床可疑冠心病患者45例，进行AQi-CK-DSE检查，并与冠脉造影结果进行对照。结果：用药后心率、收缩压、心率与收缩压的乘积均明显增高；冠心病病组身血分数、峰值充盈率减少，峰值充盈时间延长。室壁运动计分指数明显增加（P＜0．001）。DSE诊断冠心病的敏感性、特异性、准确性及一致性指标分别为96．5％、93．7％、95．5％及90．3％。阳性、阴性预测值分别为96．5％和93．7％。结论AQi-CD－DSE检测冠心病患者WMA及左心功能的改变，为冠心病病早期诊断提供了一定种安全准确可定量的方法。     

仰卧位蹬车运动及多巴酚丁胺负荷超声心动图检测冠心病的对比研究

目的比较仰卧位蹬车运动负荷超声心动图(SBE)和多巴酚丁胺负荷超声心动图(DSE)检测冠心病的价值.方法43例疑为冠心病患者随机在同一时间内进行SBE和DSE检测,先做SBE检查,当心率、血压、心电图检测恢复至静息状态水平再做DSE检查.本组患者经冠状动脉造影证实为冠心病25例,正常者18例.结果SBE和DSE检测冠心病的敏感性、特异性和准确性分别为84.0%vs80.0%、88.9%vs83.3%和86.0%vs76.7%(P>0.05).结论SBE与DSE检测冠心病价值相当,SBE为生理负荷,临床上检测冠心病应首选SBE.     

应变率显像检测心肌舒张起始时间对多巴酚丁胺负荷试验诱发心肌缺血的诊断价值

目的探讨心肌舒张起始时间（TR）对多巴酚丁胺负荷试验（DSE）所诱发心肌缺血的检测价值。方法选择冠心病患者35例及年龄、性别相匹配的健康志愿者20例,检测静息状态下心肌各节段TR值,冠心病组另行多巴酚丁胺负荷试验并检测最大负荷状态的TR值。结果对照组中间段TR短于心尖段（P〈0.05）及基底段TR（P〉0.05）。冠心病组静息状态运动异常的心肌与对照组比较TR值明显延长（P〈0.01）;DSE过程中各节段心肌TR普遍有所缩短,但非缺血心肌与缺血心肌相比,TR缩短程度差异有统计学意义（32%对18%,P〈0.05）,如果将DSE过程中TR变化率≤20%作为判断心肌缺血的标志,其敏感性90%,特异性78%。结论作为评价局部心肌舒缩功能的指标,TR的检测方便、快捷;DSE过程中TR变化率可以作为判断心肌缺血与否的一个定量指标。     

多巴酚丁胺负荷定量组织追踪技术诊断老年冠心病的临床研究

目的探讨多巴酚丁胺负荷超声心动图(DSE)与定量组织追踪技术(TT)相结合诊断老年冠心病的临床价值。方法 98例疑似冠心病老年患者行DSE+TT检查,测定不同多巴酚丁胺负荷剂量时各室壁中段收缩期心肌峰值位移(Dpeak),2周内行冠状动脉造影后将所有患者分成冠心病组与正常组,并将两组Dpeak进行比较研究。结果冠心病组在10、20μg·kg-1·min-1这两个负荷剂量时前壁、前间隔、侧壁、后壁Dpeak小于正常组,差异有统计学意义(P<0.05),而两组下壁Dpeak在其他任何负荷剂量时差异均无统计学意义(P>0.05);与冠状动脉造影比较,Dpeak诊断老年人冠心病的敏感度、特异度、准确性分别为82.4%、61.7%、72.4%,Dpeak在多巴酚丁胺40μg·kg-1·min-1负荷剂量时其诊断的敏感度和特异度最高,分别为88.2%、69.5%。结论多巴酚丁胺负荷定量组织追踪成像是一项安全、有效、无创诊断老年冠心病的方法。     

Mechanisms of regional wall motion abnormalities in contrast-enhanced Dobutamine Stress Echocardiography

BACKGROUND: In the diagnosis of coronary artery disease (CAD) with Dobutamine Stress Echocardiography (DSE), regional wall motion abnormalities (RWMA) are assumed to indicate a perfusion deficit. METHODS AND RESULTS: For a more particular examination of RWMAs, we compared simultaneous echo-contrast (Optisone)-enhanced DSE (0-40 microg/kg Dobutamine, 16-segment- model) and MiBi-SPECT in a prospective double-blinded study design in 69 non-selected consecutive patients (44 male, 25 female, age 64+/-12 years). Additionally, all patients were examined by coronary-angiography. The prevalence of significant CAD (stenosis >50% lumen diameter) was 52%. DSE had a sensitivity of 78% and a specificity of 66% for the detection of significant CAD with a positive and negative predictive value of 72 and 73%, respectively. Among 28 patients with significant CAD and positive DSE study (true positive), 78% displayed a corresponding perfusion deficit in MiBi-SPECT. Among 11 patients with a positive DSE study but no current significant coronary stenosis (false positive), 82% showed stress-induced RWMAs in the inferior/posterior region, 73% displayed left ventricular hypertrophy, 54% resting-ECG abnormalities and 45% resting-RWMA (3 previous MI, 2 previous CABG surgery). Among 8 patients with negative DSE study but significant coronary stenosis (false negative), 75% had a stenosis of the LCX, 63% displayed resting- WMA, 63% displayed left bundle branch block or ST-segment depression, 50% displayed only peripheral coronary stenosis, and DSE visualization was suboptimal in 38%. CONCLUSION: This prospective study in non-selected patients shows that the majority of RWMAs in DSE are matched to a perfusion deficit detectable by nuclear imaging. Nevertheless, pre-existing cardiac abnormalities may also lead to stress-induced RWMA not associated with a perfusion deficit or mask a perfusion deficit upon DSE. Particularly in patients with LV hypertrophy, resting-RWMA, bundle branch block or ST segment depression, the predictive value of DSE may, therefore, be limited.     

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。