等负荷运动心电图、二维超声心动图及心肌灌注断层显像对冠心病的诊断价值

对28例冠状动脉造影阳性和18例冠状动脉造影阴性患者进行等负荷运动心电图(运动ECG)、二维超声心动图(2-DE)及心肌灌注断层显像(SPECT)试验。结果表明:单项负荷试验以SPECT敏感性最高、2-DE的特异性最高,而运动ECG的敏感性及特异性则介于二者之间;联合负荷试验三项均阳性诊断冠心病的可靠性最大,二项阳性有诊断冠心病的可能.一项阳性诊断冠心病的可能性小,阳性意义需结合临床考虑,三项阴性者可排除冠心病。认为三项等负荷试验联合判定是筛选和诊断冠心病的准确、可靠的无创性检查方法。     

心脏磁共振与核医学负荷心肌灌注显像探测冠心病心肌缺血的对比研究

目的:对比心脏磁共振成像(CMR)与核医学单光子计算机断层扫描(SPECT)负荷心肌灌注显像探测冠心病心肌缺血的诊断效能。方法:前瞻性入选51例疑似或确诊冠心病患者,所有患者在冠状动脉造影(CAG)检查之前或之后4周内进行了CMR和SPECT负荷心肌灌注显像,三种检查之间无任何再血管化治疗。以CAG作为参考标准,将CMR与SPECT分析结果进行比较,计算其诊断效能。结果:基于患者个体分析,CMR和SPECT负荷心肌灌注成像检测狭窄50%以上冠状动脉的敏感性及特异性分别为:90%和75%;74%和75%。CMR的诊断效能0.879,与SPECT 0.818相似(P=0.3377);基于血管分析,CMR和SPECT负荷心肌灌注成像检测狭窄50%以上冠状动脉的敏感性及特异性分别为:78%和83%;75%和86%。CMR的诊断效能0.827,略好于SPECT 0.767(P=0.1284)。其中基于分支血管进行分析,CMR探测左前降支(LAD)分支血管病变的诊断效能0.849好于SPECT 0.688(P=0.0141)。CMR探测左旋支及右冠状动脉分支血管的诊断效能与SPECT相似,两者间差异无统计学意义。结论:CMR与SPECT负荷心肌灌注成像均能有效检测冠心病心肌缺血,基于患者个体分析,CMR与SPECT相比敏感性高,特异性相同;基于血管分析,CMR的敏感性和特异性均好于SPECT,尤其对于LAD分支血管病变。     

运动负荷201铊单光子发射型计算机断层显像判断经皮冠状动脉腔内成形术后再狭窄的价值

目的 :探讨运动负荷 2 0 1铊 (2 0 1 Tl)单光子发射型计算机断层显像 (Ex- 2 0 1 Tl SPECT)判断经皮冠状动脉腔内成形术(PTCA)后再狭窄的价值。　　方法 :对 PTCA术后 3～ 6个月的 12 8例患者 (心绞痛 74例 ,陈旧性心肌梗塞 5 4例 )进行 Ex- 2 0 1 Tl SPECT及运动负荷心电图 (Ex- ECG)。将左心室划分为 9个节段 ,采用 4级评分法对 2 0 1 Tl分布进行视觉评价 ,比较延迟像与负荷像的核素分布。　　结果 :12 8例冠心病患者 ,Ex- 2 0 1 Tl SPECT判断冠状动脉再狭窄的敏感性及特异性分别为 79%、89% ,明显高于 Ex-ECG(Ex- ECG 为 5 9%、6 8% ,Ex- ECG 为 5 2 %、74% ) ;心肌梗塞患者的 Ex- 2 0 1 Tl SPECT敏感性明显高于 Ex- ECG (P<0 .0 1) ,其特异性无显著差别。冠状动脉再狭窄程度越重 (狭窄 <10 0 % ) ,其检出率越高。　　结论 :Ex- 2 0 1 Tl SPECT使心肌显像对判断 PTCA术后再狭窄具有较大的临床应用价值。     

多巴酚丁胺负荷~(99m)Tc-MIBI心肌断层显像诊断冠心病的价值

56例多巴酚丁胺负荷~(99m)锝-甲氧基异丁基异腈(~(99m)Tc-MIBI)门控心肌灌注断层显像(DBA-SPECT),并进行多巴酚丁胺负荷心电图(DBA-ECG)及平板运动心电图.21例行冠脉造影.DBA负荷血液动力学效应曲线与平板运动试验之曲线相似.DBA-SPECT诊断冠心病的敏感性、特异性、准确率分别为87.5%、76.9%、81.0%;DBA-ECG诊断冠心病的敏感性、特异性、准确率分别为75.0%、92.3%、85.0%;平板运动心电图诊断冠心病的敏感性、特异性、准确率分别为87.5%、46.2%、61.9%.表明DBA-SPECT是诊断冠心病的一种具有较高敏感性和特异性的方法.且安全可靠,可部分代替运动负荷试验.     

多巴酚丁胺负荷超声与平板运动心电图诊断冠心病的临床研究

目的评价多巴酚丁胺超声心动图负荷试验(DSE)和平板运动心电图(TET)负荷试验诊断冠心病的价值。方法 46例可疑冠心病患者,行冠状动脉造影(CAG)、DSE及TET检查,以CAG作为诊断冠心病的金标准,比较多巴酚丁胺超声心动图负荷试验及平板运动心电图负荷试验诊断冠心病的准确性。结果多巴酚丁胺超声心动图负荷试验和平板运动心电图负荷试验对冠心病诊断的敏感性是86.2%vs 62.1%(P<0.05),特异性是88.2%vs 76.5%(P>0.05),准确性是87.0%vs 67.4%(P<0.05)。结论多巴酚丁胺超声心动图负荷试验对诊断冠心病有较高的敏感性、特异性和准确性。     

心电图负荷试验、动态心电图、心脏超声、核素心肌显像与冠脉造影对冠心病诊断价值的对比分析

目的对比分析心电图负荷试验、动态心电图(AECG)、心脏超声、核素心肌断层显像(SPECT)4种无创伤诊断与有创冠脉造影对冠心病的诊断价值。方法对拟诊断的230例患者进行心电图负荷试验,动态心电图监测,心脏超声检查,放射核素心肌显像及冠状动脉造影的冠心病诊断检查,记录结果并进行比较分析。结果以冠状动脉造影为金标准进行对比分析发现,心电图负荷试验诊断冠心病的敏感性最高为82.2%,超声心动图最低为43.8%;心电图负荷试验诊断冠心病特异性最高为71.4%,超声心动图最低为52.8%;心电图负荷试验诊断冠心病准确性最高为78.3%,动态心动图为75.7%,核素心肌断层显像为59.1%,超声心动图最低为46.9%。结论 4种对冠心病无创检查中,心电图负荷试验的敏感性,特异性、准确性比较高,在没有造影条件的情况下可为临床诊断冠心病提供可靠的证据。     

心肌缺血总负荷对可疑冠心病患者的诊断价值

目的分析心肌缺血总负荷(TIB)单独或联合冠心病危险因素对可疑冠心病患者的诊断价值。方法选择可疑冠心痛患者89例,同期行同步动态心电图监测及冠状动脉造影(CAG)后将患者分为:CAG阳性组52例,CAG阴性组37例。对2组TIB及危险因素进行logistic回归分析,计算TIB和(或)有意义指标检出冠心病的敏感性、特异性、阳性预测值和阴性预测值。结果 TIB检测冠心病的敏感性32.7%,特异性84.5%,阳性预测值77.3%,阴性预测值47.8%;男性与TIB阳性比较,诊断冠心病的敏感性升高(P<0.01);TIB阳性+糖尿病与TIB阳性比较,敏感性降低、特异性及阳性预测值升高(P<0.05,P<0.01)。年龄、男性和糖尿病是冠心病的独立危险因素。结论中老年男性及糖尿病患者发生冠心病的危险性明显升高;TIB与相关危险因素联合可以提高冠心病的诊断价值。在对可疑冠心病患者进行鉴别诊断时,TIB阳性、中老年男性及糖尿病具有重要参考价值。     

64层螺旋CT冠状动脉成像对冠心病诊断的应用价值

目的 通过探讨64层螺旋CT冠状动脉成像(64-SCTCA)对冠心病诊断的应用价值以明确临床上适于该项检查的人群.方法 回顾性分析285例接受64-SCTCA检查、并于4周内接受冠状动脉造影(CAG)检查的冠心病疑诊患者的临床资料.依照冠心病概率Duke模型,将受检者分为冠心病低危(n=80)、中危(n=92)和高危(n=113)3组,以CAG为"金标准",判断64-SCTCA诊断冠心病的准确性以及冠状动脉钙化、不同部位血管节段等因素对诊断准确性的影响.结果 64-SCTCA诊断冠心病的敏感性、特异性、阳性预测值、阴性预测值和诊断准确指\数分别为81.2%、93.3%、68.0%、96.6%和74.5%.冠心病概率Duke模型的低危组、中危组和高危组,其冠心病检出率分别为46.3%、72.8%和82.3%;64-SCTCA在低危组诊断冠心病的敏感性及阳性预测值明显低于中危组和高危组.对于冠状动脉Agatston钙化积分＞400分组,64-SCTCA诊断冠心病的敏感性(95.0%)明显高于0～100分组和101～400分组(77.4%和77.3%,P均＜0.05),特异性(82.2%)明显低于上述两组(94.0%和95.3%,P均＜0.05).其诊断远端血管病变的敏感性、阳性预测值均明显低于近、中段血管(P均＜0.05).结论 64-SCTCA主要适用于冠心病概率Duke模型临床分层的中危人群.其诊断准确性受冠状动脉钙化、病变部位、管腔直径等因素影响.     

同时行平板运动试验、QT离散度检查对冠心病诊断价值的研究

探讨同时行平板运动试验 (ETT)和测量QT间期离散度 (QTd)对反映冠状动脉病变的价值及应用前景。与冠状动脉造影结果对照分析 83例临床诊断或疑诊为冠心病患者的ETT、QTd(试验中ST段下移最大时或最大负荷心率时 )的结果。结果 :①ETT、QTd和系列法双项复合试验的灵敏性分别为 71.7%、79.2 %和 5 6 .6 % ;特异性分别为70 %、80 %和 96 .7% ;阳性预测值分别为 80 .9%、87.5 %和 96 .8% ;阴性预测值分别为 5 8.3%、6 8.6 %和 5 5 .8%。②ETT和QTd的灵敏性主要取决于受检人群、冠状动脉病变的支数和位置 ,QTd诊断单支、三支和前降支血管病变的灵敏性高于ETT(分别为 71.4 %vs 5 7.1% ;10 0 %vs 90 % ;92 .3%vs 76 .9% ) ,但均无统计学意义。结论 :同时行平板运动试验、QTd检查诊断冠心病较其单项检测具有更高的特异性和阳性预测值。     

201Tl运动负荷心肌显像、运动负荷心电图在冠心病诊断中的价值

目的:评价201Tl运动负荷心肌灌注显像(MPI),运动负荷心电图(ES-ECG)诊断冠心病(CAD)的临床价值。方法:首先以冠状动脉造影术(CAG)为标准(将冠脉管腔狭窄≥50%定为病变血管),96例做过CAG的患者被分为CAD组(n=55)和非CAD组(n=41)。所有患者均行运动负荷MPI和ES-ECG检查。对比分析运动负荷MPI和ES-ECG诊断CAD的灵敏度、特异性、准确性、阳性预测值。结果:运动负荷MPI和ES-ECG诊断CAD的敏感性分别为0.98、0.82;特异性分别为0.85、0.39;准确性分别为0.92、0.64;阳性预测值分别为0.90、0.64;阴性预测值分别为0.97、0.62。结论:运动负荷MPI与CAG有较好的一致性,而ES-ECG是一种较好的筛查方法。     

Dipyridamole-atropine stress echocardiography versus exercise SPECT scintigraphy for detection of coronary artery disease in hypertensives with positive exercise test

OBJECTIVES: Many different stress echocardiographic and radionuclide perfusion imaging tests have been proposed for detecting epicardial coronary artery disease (CAD) in hypertensive patients. Their relative diagnostic and prognostic value has not been exactly established. BACKGROUND: A positive exercise electrocardiography test has a low diagnostic specificity in hypertensive patients and warrants for a complementary imaging test to confirm the diagnosis of coronary artery disease. METHODS: Hypertensive patients (n = 53), (29 males, aged 58 +/- 10 years) with normal left ventricular function detected by echocardiography and previous positive exercise test ( > or = 0.15 mV of ST segment depression on 12 lead electrocardiogram) underwent dipyridamole-atropine stress echocardiography (DASE) and thallium-201 stress/ rest myocardial single-photon emission computed tomography (SPECT). All patients had coronary angiography within 15 days and independently of imaging test results. RESULTS: Coronary angiogram showed significant ( > or = 50% qualitatively assessed diameter reduction) epicardial coronary artery disease in 23 (43%) patients. Sensitivity for detection of coronary artery disease was significantly higher for scintigraphy (DASE = 78% versus SPECT = 100%, P < 0.05) while specificity was higher for echo (DASE = 100% versus SPECT = 47%, P < 0.00001). Diagnostic accuracy was also higher for echo (DASE = 91% versus SPECT = 70%, P < 0.01). CONCLUSION: In patients with exercise-nduced ST segment depression, dipyridamole stress echo and SPECT perfusion scintigraphy are both good diagnostic options, with DASE characterized by higher specificity, lower sensitivity, and at least comparable diagnostic accuracy than SPECT.     

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     

平板运动试验不同标准诊断冠心病的价值

目的探讨活动平板运动心电图ST段压低、QRS积分和ST／HR指数3种标准诊断冠心病的价值。方法选取可疑冠心病患者共177例,以冠状动脉造影结果为金标准,评价平板运动心电图3种标准诊断冠心病的敏感性和特异性。结果ST段压低、QRS积分和ST／HR指数诊断冠心病的敏感性和特异性均依次增高,ST／HR指数与ST段压低相比敏感性和特异性差异均有显著性意义（P〈0．05）,而QRS积分与ST段压低相比仅特异性差异有显著性意义（P〈005）。另外,ST／HR指数随着冠状动脉病变数目的增多而增高,QRS积分随着病变数目的增多而减少。结论①ST／HR指数可提高对冠心病的诊断价值;②当存在干扰性ST段压低时,采用QRS积分是较好的选择;③ST／HR指数、QRS积分可预计冠状动脉病变情况。     

Extent and severity of coronary heart disease. Determinations by thallous chloride Tl 201 myocardial perfusion scanning and comparison with stress electrocardiography.

Rest and exercise ECGs are the most widely used "noninvasive" tests for detecting coronary heart disease, but their sensitivity and specificity are suboptimal. Therefore, the diagnostic value of myocardial perfusion scanning using thallous chloride Tl 201 during rest and stress electrocardiography was examined in 95 patients with a chest discomfort syndrome. Overall, thallous chloride Tl 201 perfusion scanning had a sensitivity of 75% and a specificity of 91% for coronary heart disease compared with 56% sensitivity and 86% specificity with exercise-induced ST segment depression on the ECG. Combining rest and stress ECGs resulted in a sensitivity of 71%. In patients with coronary heart disease, perfusion scanning had a sensitivity of 93% for asynergy compared with 58% for exercise-induced ECG ST depression. Rest and stress myocardial perfusion scanning with thallous chloride Tl 201 provides improved sensitivity with good specificity in the diagnosis of coronary heart disease compared with exercise electrocardiography alone.     

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.     

24小时动态心电图对冠心病的诊断价值

对41例胸痛患者进行24小时动态心电图(AECG)及冠状动脉造影检查,其中24例在作上述检查2—3周内进行平板运动试验。10例正常冠状动脉患者AECG显示心肌缺血者仅1例,特异性90％;冠状动脉病变31例中显示心肌缺血20例,敏感性65％。心肌缺血检出敏感性与冠状动脉病变程度有关,多支病变为78％,单支病变为46％(P<0.01).AECG对单支病变患者,心肌缺血检出率明显低于平板运动试验(P<0.01);对多支病变患者,心肌缺血检出率与平板运动试验相同,均为88％。     

Diagnostic value of atrial pacing and thallium-201 scintigraphy for the assessment of patients with chest pain

Atrial pacing was performed either alone (n = 23) or in combination with thallium-201 scintigraphy (n = 113) in 136 patients referred for evaluation of chest pain. The presence of coronary artery disease (CAD) was excluded by cardiac catheterization in 12 patients and confirmed in 124. Both pacing-induced ST depression and angina had sensitivities of 48% for CAD; specificities were 75% and 83%, respectively. An abnormal thallium-201 scan (one or more reversible and/or fixed perfusion defects) was seen in 72% of patients with CAD (specificity 83%). Reversible perfusion defects were present in 47% of patients with CAD (specificity 83%), and fixed defects in 36% (specificity 100%). Pacing was associated with either ST depression or an abnormal perfusion scan in 81% of patients (specificity 67%). There were no significant differences in the results of atria pacing or thallium-201 scintigraphy in patients with or without a history of myocardial infarction, or in those with or without previous coronary artery bypass surgery. Pacing-induced ST depression, or both ST depression and a reversible perfusion defect occurred significantly less frequently in patients with peripheral vascular disease than in those without this diagnosis (p less than .05). With only one exception, there were no significant differences in the sensitivities of any indicators of ischemia (ST depression, angina, or perfusion scans), either individually or in combination, as the peak pacing rate or double product achieved increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of resting ST segment depression on the diagnostic characteristics of the exercise treadmill test

OBJECTIVES: The aim of this study is to demonstrate the effect of resting ST segment depression on the diagnostic characteristics of the exercise treadmill test. BACKGROUND: Previous studies evaluating the effect of resting ST segment depression on the diagnostic characteristics of exercise treadmill test have been conducted on relatively small patient groups and based only on visual electrocardiogram (ECG) analysis. METHODS: A retrospective analysis of data collected prospectively was performed on consecutive patients referred for evaluation of chest pain. One thousand two hundred eighty-two patients without a prior myocardial infarction underwent standard exercise treadmill tests followed by coronary angiography, with coronary artery disease defined as a 50% narrowing in at least one major epicardial coronary artery. Sensitivity, specificity, predictive accuracy and area under the curve of the receiver operating characteristic (ROC) plots were calculated for patients with and without resting ST segment depression as determined by visual or computerized analysis of the baseline ECG. RESULTS: Sensitivity of the exercise treadmill test increased in 206 patients with resting ST segment depression determined by visual ECG analysis compared with patients without resting ST segment depression (77 +/- 7% vs. 45 +/- 4%) and specificity decreased (48 +/- 12% vs. 84 +/- 3%). With computerized analysis, sensitivity of the treadmill test increased in 349 patients with resting ST segment depression compared with patients without resting ST segment depression (71 +/- 6% vs. 42 +/- 4%) and specificity decreased (52 +/- 9% vs. 87 +/- 3%) (p < 0.0001 for all comparisons). There was no significant difference in the area under the curve of the ROC plots (0.66-0.69) or the predictive accuracy (62-68%) between the four subgroups. CONCLUSIONS: The diagnostic accuracy and high sensitivity of the exercise treadmill test in a large cohort of patients with resting ST segment depression and no prior myocardial infarction support the initial use of the test for diagnosis of coronary artery disease. The classification of resting ST segment depression by method of analysis (visual vs. computerized) did not affect the results.     

Significance of treadmill stress testing in transmural myocardial infarction: Correlation with coronary angiography

To assess the usefulness of stress testing in predicting multivesselcoronary disease and left ventricular dysfunction, 83 male patientswith a myocardial infarction one to 84 months previously werestudied. In inferior infarction (45 patients), the ST segment depressionhad a sensitivity of 91% and a specificity of 77% to detectmultivessel disease. Patients with multivessel disease had significantlylower exercise capacity and maximal heart rates. ST segmentelevation showed a poor correlation with the number of affectedvessels. In anterior infarction (38 patients), both ST segment depressionand elevation were of little value to detect multivessel disease.However, the predictive value of an exercise test without STsegment changes to exclude multivessel disease was 89%; on theother hand, patients without ST segment changes had significantlyhigher ejection fractions, exercise capacity, maximal heartrates and rate-pressure products than patients with ST segmentchanges. Patients with ST segment elevation had significantly lower ejectionfractions in both groups. The sensitivity of ST segment elevationto detect severe segmental left ventricular dysfunction was84% for anterior infarction and 54% for inferior infarction.Specificity was 84 and 85%, respectively. We conclude that: (1) exercise-induced ST segment depression is useful to predictthe extent of coronary artery disease in inferior infarction,but it is of limited value in anterior infarction, (2) exercise-induced ST segment elevation correlates well withthe presence of severe left ventricular dysfunction in bothanterior and inferior infarction, and (3) an exercise test of considerable intensity without ST segmentchanges makes the existence of multivessel coronary diseaseand/or severe left ventricular dysfunction very improbable.     

Specificity of the stress electrocardiogram during adenosine myocardial perfusion imaging in patients taking digoxin

BACKGROUND: In patients taking digoxin, the exercise electrocardiogram has a lower specificity for detecting coronary artery disease. However, the effect of digoxin on adenosine-induced ST-segment depression is unknown. The purpose of this study was to evaluate the specificity of the electrocardiogram during adenosine myocardial perfusion imaging in patients taking digoxin. METHODS: Between May 1991 and September 1997, patients (n = 99) taking digoxin who underwent adenosine stress imaging with thallium-201 or technetium-99m sestamibi and coronary angiography within 3 months were retrospectively identified. Exclusion criteria included prior myocardial infarction, coronary artery angioplasty or bypass surgery, left bundle branch block, paced ventricular rhythm, or significant valvular disease. Twelve-lead electrocardiograms were visually interpreted at baseline, during adenosine infusion, and during the recovery period. The stress electrocardiogram was considered positive if there was > or =1 mm additional horizontal or downsloping ST-segment depression or elevation 0.08 seconds after the J-point compared with the baseline tracing. RESULTS: ST-segment depression and/or elevation occurred in 24 of 99 patients. There were only 2 false-positive stress electrocardiograms, yielding a specificity of 87% and positive predictive value of 92%. All 8 patients with > or =2 mm ST segment depression had multivessel disease by coronary angiography. CONCLUSIONS: ST-segment depression or elevation during adenosine myocardial perfusion imaging in patients taking digoxin is highly specific for coronary artery disease. Marked (> or =2 mm) ST-segment depression and/or ST-segment elevation is associated with a high likelihood of multivessel disease.