平板运动试验时的QT离散度诊断冠心病的价值

为了解ＱＴ离散度（ＱＴｄ）在运动试验中的变化对冠心病心肌缺血的诊断价值，对３０例临床诊断或疑诊为冠心病的病人先后行平板运动试验（简称运动试验）及冠状动脉（简称冠脉）造影检查。１７例运动试验阳性者中１０例确诊为冠心病；１３例运动试验阴性者中１０例冠状动脉正常。运动试验诊断冠心病的敏感性７６．９％、特异性５８．８％、准确性６６．７％。冠心病组与冠脉正常组运动前、中、后ＱＴｄ分别为４６．２５±２０．１３ｍｓ、７１．９２±２０．３７ｍｓ、５１．２５±１４．４８ｍｓ及３２．３５±６．６４ｍｓ、３０．８８±９．２３ｍｓ、２９．３８±８．５４ｍｓ，两者比较，Ｐ均＜０．０１。冠心病组运动前、后与运动中ＱＴｄ比较，差异有显著性，Ｐ＜０．００５；而冠脉正常组ＱＴｄ变化无显著性。以运动中ＱＴｄ≥６０ｍｓ为异常，诊断冠心病的敏感性为９２．３％、特异性１００％、准确性９６．７％。提示运动试验中ＱＴｄ增加可作为诊断冠心病心肌缺血的敏感而特异的指标     

Usefulness of Seismocardiography for the Diagnosis of Ischemia in Patients with Coronary Artery Disease

Background: Seismocardiography (SCG) is a useful method for the detection of exercise‐induced changes in cardiac muscle contractility which may occur during myocardial ischemia. The aim of this study was to compare the diagnostic accuracy of SCG with electrocardiographic exercise test (ETT) for diagnosis of ischemia in patients with angiographically proved coronary artery disease (CAD). Methods: Seventy‐seven male patients with CAD without myocardial infarction (MI), mean age 51 ± 9 years, were subjected to SCG and ETT. A gender‐matched control group consisted of 30 healthy volunteers aged 34 ± 7 years. SCG was done simultaneously with resting supine 12‐lead electrocardiography before and immediately after a symptom‐limited ETT. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of SCG were compared with ETT. Moreover, the diagnostic accuracy of both the methods was compared, with coronary angiography being the reference for the analysis. Results: SCG was more sensitive (61.1% vs 44.2%, P < 0.05) and accurate (70% vs 61%, P < 0.05) method for detecting ischemia caused by coronary stenosis ≥50%, at least in one coronary artery compared to the ETT. However, ETT had better specificity than SCG (82.4% vs 76%, P < 0.05). The PPV and NPV of SCG were significantly better than those obtained with ETT (77.9% vs 76%, P < 0.05 and 63.4% vs 53.8%, P < 0.05, respectively). Moreover, the concordant results of SCG and ETT improved the diagnostic accuracy of both methods. Conclusions: SCG appeared to be more sensitive for detecting ischemia caused by more than ≥50% stenosis of the main coronary artery compared to an electrocardiographic stress test. SCG was a useful ETT adjunct for selecting patients requiring coronary angiography.     

Relation Between Ambulatory Electrocardiographic Monitoring and Myocardial Perfusion Imaging to Detect Coronary Artery Disease and Myocardial Ischemia: An ACIP Ancillary Study

Objectives. This study sought to explore the relation between markers of ischemia detected by ambulatory electrocardiographic (AECG) monitoring and stress myocardial perfusion single-photon emission computed tomography (SPECT).Background. Stress myocardial SPECT and AECG monitoring are both utilized in evaluating patients with coronary artery disease. However, information is limited regarding the relation between the presence and extent of ischemia as detected by these two modalities.Methods. This was an ancillary study of the Asymptomatic Cardiac Ischemia Pilot (ACIP) trial. One hundred six patients with previous coronary angiography underwent AECG monitoring and stress SPECT within a close temporal time period. The frequency and duration of ischemia as assessed by AECG monitoring and the total and ischemic stress-induced myocardial perfusion defect sizes as assessed by SPECT were quantified in separate core laboratories. Multivariate logistic regression and linear regression analysis were used to determine associations between AECG and SPECT abnormalities with regard to angiographic, demographic and treadmill exercise variables.Results. Seventy-four percent of patients with significant (≥50%) coronary artery stenosis had SPECT abnormalities, whereas 61% had ischemia by AECG monitoring. The most important predictors of SPECT abnormalities were severity (p < 0.001) of coronary artery stenosis, followed by total exercise duration (p = 0.016) and patient age (p = 0.04). The only predictor of AECG abnormalities was the presence of ST segment depression on the initial exercise treadmill test (p = 0.021). Only a 50% concordance for normalcy or abnormalcy was observed between the SPECT and AECG results, and no relation was observed between the frequency or duration of AECG ischemia and the quantified total or ischemic myocardial perfusion defect size as assessed by SPECT.Conclusions. Ischemia as detected by AECG monitoring does not correlate with the presence and extent of ischemia as quantified by stress SPECT. Because these techniques appear to detect different pathophysiologic manifestations of ischemia, they may be complementary in more fully defining the functional significance of coronary artery disease and, in particular, which patients are at highest risk for adverse cardiac events.(J Am Coll Cardiol 1997;29:764–9)     

What Percent Luminal Stenosis Should Be Used to Define Angiographic Coronary Artery Disease for Noninvasive Test Evaluation?

Background: There has been controversy over what is the best angiographic luminal dimension criterion associated with ischemia for evaluating diagnostic tests. If one assumes that ST‐segment depression or scores are indicators of ischemia, then whatever angiographic criteria best discriminates those with ischemic and nonischemic responses would be the best angiographic marker for ischemia. To study this, we calculated the area under the ROC curves for ST depression and scores at different angiographic cut‐points in order to determine the best angiographic cut‐point for defining ischemia‐producing coronary disease. Methods: Twelve hundred and seventy‐six consecutive males without prior Ml with a mean age of 59 ± 11 years who had undergone exercise testing and coronary angiography were analyzed in this study. We calculated the number of patients of this population that would be considered to have coronary artery disease at different cut‐points for angiographic luminal stenosis. For example, 59% of the patients had significant CAD when disease was defined as 50% or greater coronary lumen stenosis of any coronary vessel while 49% of the patients had significant CAD when disease was defined as 70% or greater coronary lumen stenosis. Cut‐points were considered between 40 to 100% coronary lumen stenosis. ROC analysis was then performed comparing ST depression and treadmill scores at each of these cut‐points. Results: The cut‐point for coronary lumen stenosis that returned the highest AUC for ST depression and scores was between 70 and 80% coronary luminal stenosis. However, the difference between the 50% and 75% luminal stenosis criteria was minimal. Conclusion: It appears that the best cut‐point for defining significant angiographic disease when evaluating diagnostic tests of ischemia is 75% or greater coronary luminal stenosis. A.N.E. 2002;7(2):98–105     

Reevaluation of routine invasive strategy versus noninvasive testing following uncomplicated ST-elevation myocardial infarction

BACKGROUND AND AIMS: While current guidelines recommend a selective invasive approach after low-risk ST-elevation myocardial infarction (STEMI) treated by thrombolysis, based on noninvasive identification of patients with residual or inducible myocardial ischemia, in many instances physicians employ a strategy of routine angiography. The present study was undertaken to reexamine the correlation between noninvasive testing and coronary angiography in patients recovering from uncomplicated STEMI with regard to detection and management of residual infarct artery stenosis and to identify patients with multivessel (MVD) or high-risk coronary disease. METHODS: We prospectively performed predischarge exercise testing (ETT) and myocardial perfusion scintigraphy (MPS) prior to routine predischarge coronary angiography in 83/276 consecutive STEMI patients, who after treatment with initial and early thrombolysis, were defined as low risk by ACC/AHA risk classification. RESULTS: ETT was positive for myocardial ischemia in 11/43 (26%) patients with single-vessel disease (SVD) and 11/22 (50%) patients with MVD, but normal or nondiagnostic in the remainder. MPS revealed significant reversible perfusion defects in 13/40 (32%) patients with SVD and 13/22 (59%) patients with MVD. A selective strategy of ETT followed by MPS for nondiagnostic ETT missed residual infarct-related artery stenosis and/or MVD in 31/81 (38%) of the cohort. Among patients who may not otherwise have been referred for angiography, severe (> or =70%) residual stenosis of the infarct-related artery was present in 56% and MVD in 16%. CONCLUSIONS: Early predischarge ETT and/or MPS had limited sensitivity for the detection of coronary disease in low-risk post-STEMI patients. The study supports a simpler strategy of routine coronary angiography in most patients after low-risk STEMI.     

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.     

Dobutamine stress magnetocardiography for the detection of significant coronary artery stenoses - a prospective study in comparison with simultaneous 12-lead electrocardiography

BACKGROUND: Exercise electrocardiography is an imperfect test for the detection of coronary artery disease (CAD). Magnetocardiography detects cardiac electrical disturbances associated with myocardial ischemia. We prospectively investigated the accuracy of high-dose dobutamine stress magnetocardiography (DS-MCG) and simultaneous electrocardiography (DS-ECG) for the detection of significant CAD. METHODS: 100 patients with an intermediate pre-test probability for CAD underwent DS-MCG using a multichannel magnetometer prior to invasive coronary angiography. Patients were examined at rest and during a standard dobutamine-atropine scheme. Significant reduction of epicardial current strength/density during stress, reconstructed from the magnetic field map and superposed on a virtual heart model indicates myocardial ischemia. A 12-lead DS-ECG was recorded simultaneously. Significant coronary artery stenosis was defined as > or = 70% of lumen reduction. RESULTS: Without beta-blocker all 100 patients reached the targeted heart rate. The image quality of DS-MCG and DS-ECG was sufficient for analysis in all patients. In 19 patients CAD was ruled out angiographically. Thirty two or seven patients revealed coronary artery stenoses of 30-49% or of 50-69%, respectively. In 42 patients we found significant stenoses of > or = 70%. In 41 of these patients DS-MCG revealed myocardial ischemia. The sensitivity of DS-MCG and DS-ECG for the detection of significant coronary artery stenosis was 97.6% and 26.2%, the specificity of DS-MCG and DS-ECG 82.8% and 82.8%, respectively. CONCLUSIONS: DS-MCG can be performed with a standard dobutamine/atropine stress protocol. DS-MCG yields a significantly higher accuracy for the detection of significant coronary artery stenosis than DS-ECG.     

Value of exercise electrocardiography in the detection of restenosis after coronary angioplasty in patients with one-vessel disease.

Exercise treadmill testing (ETT) is considered an unreliable method for detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA). The studies on which this belief is based have used quantitative coronary angiography (QCA) as a reference. The inherent limitations of angiography have been demonstrated by intravascular ultrasound (IVUS). To determine the value of ETT for detecting restenosis when IVUS criteria are used to define restenosis, we studied 29 patients with angiographically documented 1-vessel coronary disease (<35% stenosis in all nondilated segments) who underwent angioplasty. ETT was performed < or =2 weeks before follow-up angiography and IVUS imaging. Only patients without any abnormalities precluding an accurate reading of the ST segment during ETT were included. Restenosis was defined as a > or =50% diameter stenosis by QCA criteria and as a cross-sectional area narrowing of > or =75% by IVUS. The ETT was positive in 12 patients and restenosis was documented by QCA and IVUS in 38% and 48% of cases, respectively. Sensitivity, specificity, and positive and negative predictive values of ETT when QCA was used as a reference were 55%, 67%, 50%, and 71%, respectively. This corresponded to an accuracy of 62% when compared with QCA. Sensitivity, specificity, and positive and negative predictive values were 79%, 93%, 92%, and 82% when ETT was compared with IVUS, with an accuracy of 86% (p = 0.002). Thus, ETT is a reliable noninvasive method for detecting the presence of restenosis after PTCA in patients with 1-vessel coronary artery disease. The presence of > or =75% cross-sectional narrowing shown by IVUS is well correlated with > or =1-mm ST-segment depression at follow-up ETT after PTCA.     

平板运动试验中IQTd诊断冠心病的价值

目的　评价用心率调整QTd指标 (IQTd)在平板运动试验中对冠心病的诊断价值。方法　 4 3例患者在冠状动脉造影前行平板运动试验 (ETT) ,测量其运动前、运动中与ST段下移最大时或最大负荷心率时 (无ST段下移者 )QTd、校正QTd(QTdr、QTcdr、QTdp、QTcdp) ,分别计算IQTd和IQTcd。ETT后 1周内行冠状动脉造影 (CAG) ,根据CAG结果分为冠心病 (CAD)组 2 3例和冠状动脉正常 (NCAD)组 2 0例。结果　运动前的QTdr和QTc dr在CAD与NCAD组间无显著差别。在冠状动脉正常组 ,运动过程QTdp和QTcdp无显著增加 ,而在冠心病组QTdp和QTcdp有显著性增加 (P <0 0 0 1)。在运动过程中 ,QTdp、QTcdp、IQTd、IQTcd在CAD与NCAD组间有明显差异。在NCAD组QTdp、QTcdp、IQTd、IQTcd95 %上限值分别为 74ms、86ms、0 .17ms/bpm和0 2ms/bpm。用其界值作为诊断标准 ,其特异性显著高于ST段压低 ,IQTd和IQTcd的敏感性和准确性显著高于ST压低 (P <0 0 5 )。结论　提示IQTd、IQTcd可作为平板运动试验中诊断冠心病敏感、准确和特异的指标     

A comparison of treadmill scores to diagnose coronary artery disease

Background: Recently, several treadmill scores have been proposed as means for improving the diagnostic accuracy of the exercise treadmill test (ETT). Questions remain regarding the diagnostic accuracy of treadmill scores when applied to a different patient population than that from which they were derived; furthermore, many treadmill scores have not been compared with one another in the same population. Hypothesis: The diagnostic accuracy of treadmill scores may not be the same. Methods: A retrospective analysis of data collected prospectively was performed on consecutive patients referred for evaluation of chest pain. All patients underwent a standard ETT followed by coronary angiography. Using angiographic evidence of coronary artery disease (CAD) as a reference, the area under the curve (AUC) of receiver operator characteristic (ROC) plots of the ST response alone, the Duke Treadmill Score (DTS), the Morise score, the Detrano score, the VA score, and a Consensus score consisting of the Morise, Detrano, and VA scores together were calculated and compared. The predictive accuracies of the DTS and the Consensus score to stratify patients for the likelihood of CAD were calculated and compared. Results: In all, 1,282 patients without a prior myocardial infarction had an ETT and coronary angiography. The AUC (± standard error) was 0.67 ± 0.01 for the ST response, 0.73 ± 0.01 for DTS, 0.76 ± 0.01 for Detrano score, 0.77 ± 0.01 for Morise score, 0.78 ± 0.01 for VA score, and 0.78 ± 0.01 for Consensus score. The AUC for each treadmill score was significantly higher (z‐score > 1.96) than for the ST response alone. The AUC of DTS was significantly lower than all other treadmill scores (z‐score > 1.96). The predictive accuracy (± 95% confidence interval) of the DTS to risk stratify patients into high and low likelihood for CAD was 71 (65‐77)%, versus 80 (74‐86)% for the Consensus score (p < 0.0001). Conclusion: In this population, the DTS remains useful for diagnosing CAD and stratifying for the likelihood of CAD, although it is less accurate than other treadmill scores.     

锝-氮-氮欧乙替心肌灌注显像对冠心病的诊断评价

目的评价锝-氮-氮欧乙替（^99mTc-N—NOET）心肌灌注显像检测冠心病的价值。方法对42例临床疑诊冠心病患者,行^99mTc-N-NOET运动负荷和再分布心肌灌注显像,所有患者行冠状动脉造影检查。结果在42例患者中,26例冠状动脉造影显示有冠状动脉狭窄病变,其中单支病变10例,二支病变7例,三支病变9例.^99mTc-N-NOET心肌显像检出心肌缺血或心肌梗死21例,未检出异常5例;16例冠状动脉造影正常患者,^99mTc-N-NOET心肌显像正常14例,异常2例.^99mTc-N-NOET心肌灌注显像诊断冠心病的敏感性为81％、特异性为88％、阳性预测值91％,阴性预测值74％,预测准确性为83％。诊断单支、二支和三支冠状动脉病变的敏感性分别为60％（6／10）、86％（6／7）、100％（9／9）。42例均无干扰心肌分辨的肺、肝重度摄取增高者。15min运动负荷显像肺脏摄取高,尤以冠状动脉狭窄患者增高明显。结论 ^99mTc-N-NOET心肌灌注显像检测冠心病敏感性、特异性较高,早期显像肺摄取增加与有意义的冠状动脉病变有关。     

活动平板运动试验诱发ST段抬高的临床意义

为探讨活动平板运动试验诱发ST段抬高的临床意义 ,分析了 9例无心肌梗死 (简称心梗 )而运动诱发ST段抬高的静息心电图、运动试验及冠状动脉 (简称冠脉 )造影检查结果。结果 :5 0 5 5例行平板运动试验者中 ,有 11例未患心肌梗死而运动诱发心绞痛伴ST段抬高 ,发生率 0 .2 2 %。其中 ,8例患者作了进一步检查 ,冠脉造影显示均有程度不等的血管病变 ,缺血相关血管的狭窄达到 5 0 %～ 10 0 %。ST段抬高导联与缺血相关血管有良好对应关系。另有 1例患者于运动试验 1周后死于心脏性猝死。结论 :无心梗患者运动诱发心电图ST段抬高是冠脉痉挛或冠脉严重狭窄所致心肌局部缺血的标志。     

The Value of Upsloping ST Depression in Diagnosing Myocardial Ischemia

We evaluated the value of upsloping ST‐segment depression in predicting the severity of myocardial ischemia. Comparison of the exercise electrocardiographic changes was made to myocardial perfusion images and coronary angiograms as the criteria for ischemia. We retrospectively reviewed 621 patients who underwent exercise technetium‐99m tetrofosmin single photon emission computed tomography (SPECT) for the assessment of suspected or known coronary artery disease followed by coronary angiography within a 3‐month period. The test sensitivity and specificity of 1 mm horizontal or downsloping ST depression in predicting reversible ischemia as assessed by gated SPECT imaging (GSI) were 65% and 87%, respectively. The corresponding values were 67% and 94% compared to coronary angiography. The sensitivity and specificity of gated SPECT imaging compared to coronary angiography were 78% and 89%. On the other hand when 1 mm upsloping ST depression at 70 ms past the J‐point was regarded as abnormal, along with horizontal and downsloping, the sensitivity and specificity were 82% and 90% compared to myocardial perfusion imaging, and 77% and 92% as assessed by coronary angiography. We conclude that upsloping ST‐segment depression is associated with an increased risk of coronary artery disease and is a valuable predictor of myocardial ischemia.     

三种无创检查方法诊断冠心病的价值

目的16层螺旋CT(16-SCT)、12导联动态心电图(AECG)和平板运动试验(EET)三种无创性诊断冠心病方法进行比较,并以冠状动脉造影(CAG)为金标准",评价其对冠心病的诊断价值。方法60例患者均行16-SCT、12导联AECG、EET和CAG检查。计算16-SCT、AECG、EET诊断冠心病的灵敏度、特异性。结果根据CAG结果,16-SCT诊断冠状动脉狭窄的灵敏度、特异性和准确率分别为91.0%,90.1%,90.4%;AECG诊断心肌缺血的灵敏度、特异性分别为54.8%,66.7%;EET诊断冠心病心肌缺血灵敏度、特异性为69.0%,72.2%。16-SCT与AECG及16-SCT与EET联合检测可使灵敏度提高到92.9%和95.2%,16-SCT与AECG、EET串联可使特异性提高到94.4%。结论16-SCT是一项新的有发展前途的冠心病诊断方法,能通过高的空间分辩率结合心电门控技术有效诊断冠心病,并结合AECG、EET检查提高冠心病的检出率。     

Acoustic cardiography to improve detection of coronary artery disease with stress testing

AIM: To assess if performance of 12-lead exercise tolerance testing (ETT) can be improved by simultaneous acoustic cardiography and to compare the diagnostic performances of electrocardiography (ECG) during ETT and acoustic cardiography for detection or exclusion of angiographically proven coronary artery disease (CAD).METHODS: We conducted an explorative study with retrospective data analysis using a convenience sample of consecutive patients (n = 59, mean age: 62 years) from an outpatient clinic in Switzerland, who were referred for ETT by their general practitioner on suspicion of CAD, and in whom, coronary angiography was carried out. Measurements included sensitivity, specificity, likelihood ratios and receiver operating characteristic curves. A standard, symptom-limited, 12-lead ECG exercise tolerance test was performed by independent persons with simultaneous acoustic cardiography and subsequent cardiac angiography for determination of significant CAD.RESULTS: Thirty-four of the 59 adult subjects (58%) had a final diagnosis of CAD by angiography, and in 25 subjects, CAD was excluded by angiography. Sensitivity/specificity of ST segment depression in the group was 29%/92%, whereas the most powerful acoustic cardiographic parameter was the strength of the fourth heart sound (S4), with corresponding sensitivity/specificity of 53%/92%. The disjunctive combination of the S4 and ST depression had sensitivity/specificity of 68%/84%.CONCLUSION: In this preliminary pilot study, the use of acoustic cardiography alone during ETT or disjunctively with ST depression has been shown to be a simple and convenient method for the detection of CAD, which was superior to ST depression on the standardized ECG.     

腺苷负荷心肌灌注显像评价中年女性心肌供血异常的临床价值

目的:评价国产腺苷负荷99Tcm-MIBI心肌灌注显像对65岁以下的中年女性患者心肌供血异常的判断临床价值。方法:2007年1月至2008年7月临床怀疑冠心病的中年女性109例,年龄40～65岁,平均年龄(54.9±6.1)岁,所有患者均在1个月内施行常规2d法腺苷负荷-静息心肌灌注显像(MPI)和冠状动脉造影术(CAG)检查。MPI和CAG图像由2名以上核医学/放射科医师共同读片;MPI评价标准:供血区某一心肌节段负荷时,出现放射性稀疏或缺损,静息时消失或改善,判定为心肌缺血;如静息时仍为放射性缺损,判定为心肌梗死。CAG评价标准:3支主要冠状动脉血管中至少有1支主要冠状动脉管径狭窄≥50%,判定为阳性。MPI与CAG对照,评价腺苷MPI对冠心病的诊断效能(敏感性、特异性和准确性)。结果:109例受检者中,MPI显示:阴性62例,阳性47例,心肌缺血42例,心肌梗死5例;累及59个室壁段,其中前降支供血区32段,回旋支供血区12段,右冠状动脉供血区15段。CAG显示:冠状动脉正常72例,冠状动脉异常37例,其中单支病变23例,双支病变7例,3支病变7例;冠状动脉异常37例中核素心肌灌注显像阳性31例,阴性6例;冠状动脉正常72例中核素心肌灌注显像56例阴性,16例阳性。腺苷负荷MPI对65岁以下女性患者诊断冠心病的灵敏度为83.8%(31/37例),特异性为77.8%(56/72例),准确性为79.8%(87/109例),阳性预测值为65.9%(31/47例),阴性预测值为90.3%(56/62例)。结论:腺苷负荷心肌灌注显像用于中年女性冠心病的诊断有较高的诊断效能,具有较高的临床应用价值。可作为中年女性早期诊断冠心病在运动心电图之外有效的、优先考虑的选择。     

Isolated post exercise delayed ST depression as a sign of severe ischemia: the influence of percutaneous transluminal coronary angioplasty.

The clinical implications of isolated late recovery ST depression were tested in patients with scintigraphically defined ischemia (coronary artery disease [CAD], n = 18) compared with patients without ischemia (n = 25). Spontaneous (78.4 versus 12.0%, P < 0.008) and exercise-induced angina (44.4 versus 0%, P < 0.0001) were more frequently seen in patients with CAD. Histories of unstable angina (33.3%), prior myocardial infarction (27.8%), ST elevated angina (22.2%) and significant stenosis in the left anterior descending artery (17 of 18, 94.4%) were almost exclusively seen in the CAD group. There was no significant difference between the two groups in capacity for exercise, maximum deviation of ST level or TV2 amplitude. Balloon angioplasty abolished late recovery ST changes in 63.6% of CAD patients. These results suggest that isolated late recovery ST depression, when accompanied with typical chest pain, may be considered as an indicator of myocardial ischemia, but this phenomenon is difficult to distinguish electrocardiographically.     

平板运动试验诱发ST段抬高对冠状动脉病变部位定位诊断的意义

目的探讨平板运动试验诱发ST段抬高对冠心病的诊断价值及对冠状动脉病变部位定位诊断的意义。方法分析8例无心肌梗死而运动诱发ST段抬高的运动心电图及冠状动脉造影检查结果。结果8例患者冠脉造影均显示有程度不等的血管狭窄(50%￣100%);ST段抬高导联与缺血相关血管有良好对应关系。结论无心梗患者运动诱发心电图ST段抬高是冠脉痉挛或冠脉严重狭窄所致心肌局部缺血的标志,且对预测冠状动脉病变部位有一定意义。     

Accuracy of the Master's exercise test in detecting significant coronary artery disease

To assess the significance and accuracy of noninvasive tests in detecting significant coronary artery disease (CAD; greater than 50% stenosis), the Master's exercise test, treadmill exercise test and dipyridamole-loading myocardial perfusion scintigraphy were performed and their results were compared with coronary angiographic findings in 60 patients with angina but without myocardial infarction. Among these, 27 patients had significant CAD. The Master's test performed in outpatient clinics had an 85% sensitivity and a 76% specificity in detecting significant CAD, when the degree of ST depression was equal to or exceeded 1 mm. The sensitivity further improved to 96% by adding chest pain to the criteria; then all patients with multivessel disease or critical ischemia were identified by the Master's test. Treadmill tests performed after admission had a 78% sensitivity and a 67% specificity. When the severity of ischemia was judged either by exercise capacity or the degree of ST depression or the coronary T wave, the treadmill test was superior to the Master's test. Although patients without significant CAD had longer exercise capacity and the higher maximum heart rate in the treadmill test than did those in the Master's test, these trends were similar but less marked in patients with significant CAD. Dipyridamole-loading myocardial perfusion scintigraphy showed an excellent sensitivity and specificity; 96% and 94%, respectively, in detecting significant CAD. It was particularly useful in distinguishing false positive exercise results due to left ventricular hypertrophy and coronary spasm and that in women, from true positive results. In conclusion, the Master's test is a simple and useful method for screening CAD in community hospitals and in outpatient clinics.     

Silent myocardial ischemia during daily activities in asymptomatic men with positive exercise test responses

The usefulness of prolonged ambulatory electrocardiographic monitoring (AEM) for detecting ischemia was investigated in 17 asymptomatic men who had ischemic-type ST-segment depression (greater than or equal to 2.0 mm) during treadmill exercise testing. No patient took anti-ischemic medications and all patients underwent coronary angiography. A total of 1,154 hours (range 64 to 72 hours/patient) of high-quality AEM recordings was obtained. Silent ischemia (episodes of asymptomatic ischemic-type ST depression of 60 seconds or longer) occurred in 11 patients during daily activity detected by AEM. In 6 other patients, no myocardial ischemic episodes were found. But 1 of these patients withdrew after only 24 hours of AEM and the remaining 5 had no significant coronary artery disease (CAD). All 11 patients who had silent ischemia had significant CAD (at least 50% stenosis) on angiography. There was wide intrapatient variability in the frequency of silent ischemic episodes. Silent ischemia was identified in 6 of these 11 patients after 24 hours of AEM, in 2 after 48 hours and in 3 after 72 hours. Thus, asymptomatic men with positive exercise test responses and CAD have silent ischemic episodes during daily activity. AEM may be useful in helping to predict which patients with asymptomatic positive exercise test responses have CAD; however, extended AEM periods are required.