心率调整的ST段降低方法定性和定量检测冠心病的研究

目的探讨心率调整的ST段降低方法定性和定量检测冠心病的价值,并把ST/HR斜率和ST/HR指数两种指标和传统ST段指标进行了系统比较。方法选取2001年1月至2002年3月行平板运动ECG试验并在随后3周内住院行冠状动脉造影的可疑冠心病患者共173例,应用Cornell运动试验方案,分别测定并计算运动试验过程中ST段变化值及ST/HR斜率和ST/HR指数值,以冠状动脉造影结果作为诊断冠心病的标准。结果传统ST段指标、ST/HR斜率和ST/HR指数诊断冠心病的敏感性分别为68%、86%和81%,特异性分别为70%、85%和81%。ST/HR斜率和ST/HR指数诊断冠心病的敏感性、特异性均明显高于传统ST段指标(P<0.05)。传统ST段指标(ST段降低≥0.2mV)、ST/HR斜率和ST/HR指数定量识别冠心病3支血管病变的敏感性分别为30%、81%和64%,特异性分别为70%、65%和69%。ST/HR斜率和ST/HR指数识别冠心病3支血管病变的敏感性显著高于传统ST段指标(P<0.001),特异性无显著性差异(P>0.05)。结论心率调整的ST段降低指标、ST/HR斜率和ST/HR指数与传统ST段指标相比能明显提高运动ECG试验定性诊断冠心病的敏感性和特异性。与传统ST段指标相比,ST/HR斜率和ST/HR指数明显提高了运动ECG试验定量识别冠心病3支血管病变的敏感性。     

平板运动试验心率校正的ST段压低参数对冠心病诊断价值的探讨

探讨心率校正的ST段压低参数诊断冠状动脉 (简称冠脉 )病变的准确性 ,12 8例患者接受次极量平板运动试验和冠脉造影。观察各例患者运动中心率相关的ST段压低最大速度即最大ST段 /心率斜率 ,最大心率时ST段与静息时ST段压低值之差除以最大心率与静息心率之差即ΔST/HR指数 ,以及ST段压低 ,观察值与阳性判断标准比较。结果显示 ,最大ST/HR斜率诊断冠心病的敏感性、特异性及诊断符合率最高 ,分别为 94.1%、92 .3%、94.5 % ,ST段压低诊断冠心病的敏感性、特异性及诊断符合率最低 ,分别为 74.5 %、6 9.2 %、73.4%。最大ST/HR斜率在冠脉不同程度病变间无重叠 ,其它参数虽与冠脉病变程度有平行关系 ,但有较大程度的重叠。结论 :心率校正的ST段压低参数显著提高了对冠心病的诊断价值 ,其中最大ST/HR斜率对冠脉病变支数有定量诊断价值     

平板运动试验最大ST/HR斜率对冠心病的诊断价值

目的　探讨平板运动试验最大ST/HR斜率对冠心病的诊断价值。方法　对 10 6例患者进行冠状动脉造影和平板运动试验及 6 0例正常对照者进行平板运动试验 ,测定其最大ST/HR斜率及ST段压低值。结果　冠状动脉造影阳性组最大ST/HR斜率明显高于正常对照组 (分别为 3 8±2 3uV/bp .min和 0 9± 0 4uV/bp .min ,P <0 0 1) ;最大ST/HR斜率法诊断冠心病的敏感性和特异性明显高于ST段压低法 (分别为 95 5 % ,93 6 %和 6 2 5 % ,78% ,均为P <0 0 5 ) ;ST/HR斜率 >6 0uv/bp .min识别三支血管病变的敏感性和特异性较高 (分别为 83 3%和 97 5 % ) ;ST/HR斜率法女性假阳性率明显低于ST段压低法 (分别为 7 1%和 32 1% ,P <0 0 5 )。结论　最大ST/HR斜率对冠心病的临床诊断有较高的敏感性和特异性 ,优于ST段压低法 ,并对预示冠状动脉病变数目有一定的价值。     

性别对心率调整心电图ST段降低方法诊断冠心病的影响

目的　就性别对心率 (HR)调整心电图ST段降低方法诊断冠心病的影响进行探讨。方法　选取可疑冠心病患者共 173例 ,测定运动试验过程中心电图ST段变化值及ST/HR斜率和ST/HR指数 ,以冠状动脉 (冠脉 )造影结果作为诊断冠心病的标准。结果　ST/HR斜率和ST/HR指数诊断冠心病的敏感性、特异性均明显高于传统ST段指标 (P <0 0 5 )。ST/HR斜率和ST/HR指数诊断冠心病的敏感性男性患者分别提高 2 3%和 16 % ,女性患者分别提高 5 0 %和 4 2 % ,差异均有显著性意义 (P <0 0 5 ) ;而ST/HR斜率和ST/HR指数诊断冠心病的特异性 ,男性患者无明显提高 (P >0 0 5 ) ,女性患者分别提高 5 8%和 5 0 % (P <0 0 5 )。结论　ST/HR斜率和ST/HR指数与传统ST段指标相比 ,女性患者诊断冠心病的敏感性和特异性明显提高 ,男性患者敏感性有提高 ,特异性无明显变化     

持续性ST段压低的临床意义探讨

目的评价持续性ST段压低在冠状动脉病变中的作用及临床意义。方法具有心电图持续性ST段压低并伴有相应临床症状,临床拟诊冠心病患者87例,与活动平板运动试验及冠状动脉造影结果进行对照分析,评价其在诊断冠状动脉病变中的意义。结果心电图ST段持续性压低患者87例中,冠脉造影显示29例存在冠状动脉狭窄（33.3%）,其中单支病变12例,多支病变17例,58例冠脉正常或狭窄〈50%（66.67%）。结论持续性ST段压低并不是冠状动脉病变的特异性表现,对于持续性ST-T压低的患者,不能简单定论为冠心病心肌缺血,只有存在确定冠状动脉病变证据,临床又能除外其他病因时,才考虑诊断缺血性心肌病。     

心电图运动试验相关指数对冠状动脉介入术后再狭窄的预测研究

目的 探讨通过测定ST/HR斜率、ST/HR指数及常规ST段标准诊断冠状动脉介入术后再狭窄的敏感性和特异性.方法 对行冠状动脉介入治疗的224例,在术后3～6个月行次级量平板运动试验(TET),测量ST/HR斜率和ST/HR指数及常规ST段阳性标准诊断再狭窄,通过冠状动脉造影(CAG)确定有无再狭窄,评价其诊断再狭窄的价值.结果 ST/HR斜率联合ST/HR指数及常规ST段标准诊断再狭窄的敏感性和特异性分别为78.7% 和80.3% ,高于传统ST段标准(51.2% 和62.3% )(P＜0.05).结论 联合应用ST/HR斜率和ST/HR指数及常规ST段标准可作为诊断再狭窄的无创手段.     

平板运动试验的心率校正ST段下移指标对冠心病的预测价值

目的：探讨平板运动试验中ST段下移、△ST／△HR指数和最大ST／HR斜率预测冠心病的价值。方法：对已行冠脉造影检查并在造影前有平板运动试验资料的120例患者资料进行分析。研究ST段下移、△ST／△HR指数和最大ST／HR斜率诊断冠心病的敏感性、特异性。结果：120例患者冠脉造影阳性者66例。ST段下移、△ST／△HR指数和最大ST／HR斜率的（敏感性和特异性）分别为（69．7％、72．2％）、（92．4％、88．9％）和（93．9％、90．7％）。冠心病组△ST／△HR指数和最大ST／HR斜率敏感性、特异性均显著高于非冠心病组（P〈0．01）。结论：平板运动试验中采用心率校正的ST段指标能提高对冠心病的诊断价值。     

运动平板试验ST/HR斜率和心率恢复环在冠心病诊断中的价值

目的探讨运动平板试验中ST／HR斜率和心率恢复环在冠心病诊断中的价值。方法选择2006年1月至2007年6月于我科拟诊冠心病，接受运动平板试验的患者118例，应用Cornell方案，分别测定传统ST段指标、ST／HR斜率、心率恢复环，与1周内冠状动脉造影结果相比较，判断三种运动平板试验诊断指标对冠心病诊断的价值。结果ST／HR斜率诊断冠心病的敏感性为86．25％，特异性为89．47％，心率恢复环敏感性为81．25％，特异性为92．10％，两种指标的敏感性均明显高于传统ST段指标（56．25％，P〈0．05），特异性与传统ST段指标相比（86．84％），差异无统计学意义（P〉0．05）。结论ST／HR斜率和心率恢复环在冠心病诊断中较传统ST段下移诊断标准有较高的敏感性。     

平板运动试验中QRS时限延长对冠心病的诊断价值

目的 探讨平板运动试验中QRS时限延长对冠心病的诊断价值.方法 疑诊冠心病患者176例分别行冠状动脉造影术和活动平板运动试验,测定QRS时限和ST段下移值,分析上述指标对冠心病诊断的的敏感性、特异性和阳性预测值.结果 冠心病组运动后QRS时限明显延长(87.13±7.47ms vs 76.52±7.63ms,P<0.01),而对照组运动前后QRS时限无显著性差异(72.51±6.83ms vs 75.66±7.42ms,P>0.05).以运动中和运动后QRS延长>3ms 、ST段呈水平型或下斜型压低≥1 mm(J点后80 ms)作为阳性评定标准,预测冠心病的敏感性为81.6%、77.2%,特异性84.5%、70.7%,阳性预测值91.2%、83.8%.两者联合应用的敏感性、特异性和阳性预测值分别是76.3%、87.9%和92.6%.结论 QRS时限延长和ST段下移是可靠的诊断冠心病的运动心电图指标,两者联合应用可提高冠心病诊断的特异性和阳性预测值.     

平板运动试验恢复期与运动中ST段压低在冠心病中的诊断价值比较

目的 比较平板运动试验恢复期与运动中ST段压低的心电图表现在冠心病中的诊断价值.方法 选择可疑冠心病患者并行平板运动试验结果呈阳性者211例,将其分成运动中ST段压低组（A组,n=178）,恢复期ST段压低组（B组,n=33）,对两组的临床资料和冠状动脉造影结果进行对比分析.结果两组临床资料（除高尿酸）比较,差异均无统计学意义（均P ＞0.05）.两组对冠状动脉造影的阳性预测值相近（ 71.3%vs72.7%,P ＞0.05）,冠状动脉病变部位及单支、三支病变比较,差异无统计学意义（P ＞0.05）;冠状动脉病变重度狭窄率B组高于A组,差异有统计学意义（P＜0.05）.结论 平板运动试验恢复期ST段压低与运动中ST段压低在冠心病诊断中同样重要,可预示冠状动脉的重度病变.     

平板运动试验心脏变时功能不全对冠心病的诊断价值

目的探讨平板运动试验心脏变时功能不全对冠心病的诊断价值。方法将240例临床拟诊冠心病患者先后行平板运动试验及冠状动脉造影检查，并按冠状动脉造影结果分为冠心病组和非冠心病组，分析比较两组间心脏变时性指标。运动后最大心率〈预测最大心率的85％和变时性指数（CRI）〈0．8为心脏变时功能不全。结果冠心病组运动后最大心率、变时性指数两种变时功能不全的指标均低于非冠心病组（P〈0．01），与传统的ST段标准相比，变时功能不全诊断冠心病的敏感性、特异性、准确性无明显差异（P〉0．05），ST段标准伴变时功能不全诊断冠心病的特异性、准确性均较ST段标准明显增高，差异具有统计学意义（P〈0．05）。结论平板运动试验心脏变时功能不全是诊断冠心病的有用指标，与传统的ST段标准联合应用可提高对冠心病的诊断价值。     

Improved accuracy of the exercise electrocardiogram in detection of coronary artery and three-vessel coronary disease

The study objective was to assess the widespread applicability of ST/HR slope for the modified Bruce exercise test using a computerized electrocardiogram (ECG); compare the usefulness of the ST/HR slope with standard ECG criteria in detection of coronary artery disease (CAD) and identification of three-vessel or left main CAD; and then develop a new, modified ST/HR score (MSHS) for improving the diagnostic accuracy of ST/HR slope. The studies were retrospective and prospective in design, conducted in referral-based cardiology clinics at a national cardiovascular center. A selected sample of 142 patients underwent exercise ECG and coronary angiography, as did a normal control group of 402 patients who were apparently free from CAD. Sixty three other patients who underwent coronary angiography were also studied prospectively. No limitations of medical treatment were exacted for the test except digitalis treatment. Linear regression analysis, from which ST/HR slope was derived, was done with seven measurements of HR and ST displacement at 60 ms from J point in leads a VF and V5 during 6 min before the end of exercise. MSHS was derived from a multiple regression model with peak HR (% maximum HR), ST index (ST depression + ST slope), and ST/HR slope. Although the usual ST criteria (sensitivity = 63 percent, specificity = 73 percent), ST index (71 percent, 80 percent), and ST/HR slope (70 percent, 97 percent) were equally accurate in detection of CAD, MSHS showed significantly improved sensitivity (88 percent) with similar specificity (81 percent). In identification of three-vessel or left main CAD, when compared with other criteria, ST/HR slope and MSHS provided improved diagnostic accuracy: sensitivity (74 and 78 percent, respectively), specificity (88 and 93 percent) and overall test accuracy (85 and 89 percent). The improved accuracy of ST/HR slope and MSHS was prospectively validated in 63 other patients. ST/HR slope was applicable to computerized ECG data for the standard treadmill test, and showed improved accuracy in detection of three-vessel or left main CAD. The new, modified ST/HR score more accurately predicted not only the presence but also the severity of CAD.     

平板运动试验中室性早搏ST段下移诊断冠状动脉病变的价值

探讨平板运动试验中室性早搏(VPCs)ST段下移程度对反映冠状动脉(简称冠脉)病变的价值。将休息和平板运动试验中均发生VPCs并且在3个月内进行冠脉造影的92例患者按冠脉造影结果分成冠心病组和非冠心病组,比较两组VPCsST段下移程度,下移程度与冠脉狭窄程度的关系以及VPCsST段下移诊断冠心病的价值。结果:冠心病组运动中VPCsST段下移及ST/R均大于非冠心病组。其中ST/R>10%对冠心病诊断灵敏度为91%,特异度为75%;对单支、2支、3支血管病变诊断灵敏度分别为84%、91%、100%。冠脉狭窄≥90%组运动中VPCsST段下移和ST/R大于狭窄为50%~69%组。结论:运动试验中VPCsST段下移可作为诊断冠心病的有效参考指标,其下移程度可能与冠脉狭窄程度有关。     

QRS Score: A Composite Index of Exercise‐Induced Changes in the Q,R, and S Waves During Exercise Stress Testing in Patients with Ischemic Heart Disease

Background: To detect ischemic heart disease, the exercise‐induced ST‐segment displacement is the most frequently used ECG parameter. However, the value of this marker was proven to be limited with varying sensitivity and specificity. A new parameter, called QRS score, emerged to improve the efficacy of exercise testing. Methods: Our study aimed at evaluating the diagnostic value of QRS score in ischemic heart disease, investigating males and females separately, and examining the effects of heart rate and antiischemic medication. QRS score and cumulative ST depression were calculated in 212 patients and correlated to the findings of the stress myocardial perfusion SPECT (197 subjects) or coronary angiography (54 subjects). Results: An inverse correlation could be found between the QRS score and the results of myocardial SPECT and coronary angiography in the whole population, especially in males; females did not show a significant relationship. In patients with conclusive tests (achieving 85% of the maximal predicted heart rate) QRS score correlated significantly with the results of the stress myocardial perfusion SPECT and coronary angiography. The sensitivity, specificity, and validity of the QRS score surpassed those of the cumulative ST depression in the entire population as well as in patients with conclusive tests. The antiischemic medication did not affect correlation values. Conclusion: QRS score was significantly related to the extent of myocardial ischemia and the severity of coronary heart disease, thus along with the analysis of ST‐segment displacement may contribute to the more precise evaluation of exercise testing. A.N.E. 2001;6(4):310–318     

Improved accuracy of the exercise electrocardiogram: identification of three-vessel coronary disease in stable angina pectoris by analysis of peak rate-related changes in ST segments

Exercise electrocardiography has relatively poor specificity and predictive accuracy for 3-vessel coronary artery disease (CAD) when conventional diagnostic criteria are used. However, electrocardiographic evaluation using linear regression analysis of the heart-rate (HR)-related change in ST-segment depression (ST/HR slope) is reported to accurately distinguish patients with from those without CAD, and to accurately separate patients with 1-, 2- and 3-vessel CAD. To assess the applicability of this method and to compare it with conventional interpretation, retrospective evaluation of 50 patients in whom exercise electrocardiography and coronary cineangiography had been performed for suspected CAD was conducted using a modified ST/HR slope analysis limited to leads V5, V6 and aVF. Eighteen patients had 3-vessel, 22 had 2-vessel, 6 had 1-vessel and 4 had no CAD. Standard electrocardiographic criteria (1 mm or more of horizontal or downsloping ST depression) identified 3-vessel CAD with a sensitivity of 78%, specificity of 56% and positive predictive value of only 50%. Peak ST/HR slope criteria (greater than or equal to 6.0 microV/beat/min) identified 3-vessel CAD with a sensitivity of 78%, specificity of 97% and positive predictive value of 93%. The overall test accuracy using measured peak ST/HR slope was 90%, compared with 64% for standard ST-depression criteria. In conclusion, analysis of the peak ST/HR slope can greatly improve the diagnostic accuracy of exercise electrocardiography, and further prospective study of this method is indicated.     

New coronary artery disease index based on exercise-induced QRS changes

Exercise-induced changes in Q, R, and S wave amplitudes have been reported to detect coronary artery disease but with low specificity, low sensitivity, or both; it was hypothesized that their incorporation into a composite index (Athens QRS score) might improve specificity and sensitivity. For this purpose 246 patients were analyzed retrospectively and 160 prospectively. All patients underwent maximal exercise testing with a standard Bruce protocol and coronary arteriography as part of the diagnostic evaluation for possible or definite coronary artery disease. The Athens QRS score was decreased as the number of obstructed coronary arteries increased (normal coronary arteries = 7.85 +/- 5.23 mm, one-vessel disease = 5.2 +/- 5.3 mm, two-vessel disease = -0.85 +/- 5.4 mm, three-vessel disease = -3.5 +/- 5.8 mm; p less than 0.0001); the score was unrelated to exercise-induced ST segment depression, and negative (less than 0) scores were always associated with coronary artery disease. An Athens QRS score of 5 mm predicted coronary artery disease with sensitivity ranging from 75% to 86% and a specificity ranging from 73% to 79%, values higher than those of the Q wave (75% and 50%, respectively), R wave (65% and 55%), and S wave (70% and 10%) and of the ST segment depression (62% and 70%). It is concluded that exercise-induced changes in the QRS complex provide a useful index not only for the diagnosis but also for the assessment of severity of coronary artery disease.     

Heart rate adjustment of ST-segment depression for reduction of false positive electrocardiographic responses to exercise in asymptomatic men screened for coronary artery disease

The ability of heart rate (HR) correction of exercise-induced ST-segment depression (the delta ST/HR index) to reduce the number of false positive exercise electrocardiograms during initial screening for occult coronary artery disease (CAD) was examined in active, asymptomatic men from the Army Reserve. Among 606 consecutive men given treadmill tests, 62 asymptomatic subjects with normal results on resting electrocardiograms but abnormal outcomes on standard exercise electrocardiograms underwent rest and exercise radionuclide cineangiography, and the 10 subjects with abnormal radionuclide findings then underwent coronary angiography. A previously established delta ST/HR index less than 1.6 microV/beat/min correctly identified 34 of 52 subjects (65%) who, despite abnormal standard exercise electrocardiographic findings, had no rest or exercise radionuclide abnormalities. A delta ST/HR index greater than or equal to 1.6 microV/beta/min detected 7 of 7 subjects with abnormal radionuclide cineangiograms who had CAD at cardiac catheterization, but also identified 2 of 3 subjects with an abnormal radionuclide test who had no CAD. In contrast to the 7 of 62 subjects (11%) with abnormal standard exercise test criteria who had radionuclide and angiographic evidence of CAD, a delta ST/HR index partition of 1.6 microV/beat/min separated subjects into subgroups with 0% (0 of 35) vs 26% (7 of 27) prevalences of CAD by serial diagnostic evaluation (p less than 0.01). Thus, among asymptomatic subjects with abnormal electrocardiographic responses to exercise, simple HR correction of the magnitude of ST-segment depression reduced by 56% the number of subjects with standard exercise test criteria leading to referral for additional diagnostic evaluation, without loss of sensitivity for angiographically proven CAD and with accurate negative predictive value.(ABSTRACT TRUNCATED AT 250 WORDS)