最大ST/HR斜率法用于老年冠心病临床诊断的价值探讨

目的:探讨最大ST/HR斜率对老年冠心病临床诊断的价值。方法:用踏车运动试验测定30例老年冠心病和30例正常老年对照的最大ST/HR斜率及ST段压低值。结果:老年冠心病组的最大ST/HR斜率值明显高于对照组(分别为3.04±1.3及0.91±0.9uV/bpm,P<0.01),最大ST/HR斜率的敏感性和特异性高于ST段压低标准(分别为90％,86.6％和60％,73.3％;P<0.05)。随冠脉病变数目增多其最大ST/HR斜率值呈增大趋势。结论:最大ST/HR斜率法对老年冠心病的临床诊断有较高的敏感性和特异性,优于单纯ST段压低法,并对预测冠脉病变数目有一定的价值。     

最大ST段／心率斜率及其在冠心病康复中的应用（Ⅱ）

将37名冠心病患者随机分成两组,气功组22人,接受12周动功治疗;对照组15人,用安慰剂。疗程前后测CM_5ST段/心率斜率。结果发现气功组CM_5斜率减小,而对照组不变或增大,差异显著。ST段下移及常规运动试验其它指标在两组间无显著性差异。表明CM_5 ST段/心率斜率是一个与功能相关的心肌缺血指标,有望用于冠心病康复疗效评估。     

最大ST段／心率斜率对冠心病诊断价值的探讨

最大ＳＴ段／心率斜率对冠心病诊断价值的探讨湖北沙市市第三医院关美玲，袁宗富，曾晓常规心电图（ＥＣＧ）运动试验标准诊断冠心病因特异性和敏感性较低应用有所受限，我们在以往研究冠心病无创诊断方法学的基础上，观察运动中心率改变和相应ＳＴ段偏移与心肌缺血有关，...     

QT离散度联合ST/心率斜率及ST段标准诊断经皮冠状动脉介入术后再狭窄的研究

目的探讨心电图运动试验（EET）测定多项指标联合传统ST段标准诊断冠心病介入治疗后再狭窄的敏感性和特异性。方法2001年11月—2003年12月,对成功行经皮冠状动脉介入治疗（PCI）的129例患者在术后3-6个月进行随访,测量其EET、ST/心率斜率（ST/HRs）、QT离散度（QTd）及常规ST段阳性标准,将三者联合起来诊断PCI后再狭窄,通过冠状动脉造影确定有无再狭窄,评价其诊断再狭窄的价值。结果在传统ST段诊断标准基础上联合QTd及ST/HRs诊断再狭窄的敏感性和特异性分别为84.6%和80.4%,明显高于传统ST段诊断标准（敏感性为53.3%,特异性为66.7%,P〈0.05）。结论QTd联合ST/HRs及传统ST段标准可作为冠心病术后再狭窄的无创诊断手段。     

活动平板运动试验与冠状动脉造影结果对照分析

目的:探讨活动平板运动试验与冠状动脉病变的关系。方法:拟诊冠心病患者310例2周内行活动平板运动试验与冠状动脉造影检查,根据冠状动脉造影结果分为冠心病组和非冠心病组,比较2组活动平板运动试验开始后的运动第1分钟心率、运动能力总心率1/3、运动增加最大心率、运动后恢复2 min心率增加量。结果:冠心病组运动第1分钟心率、运动能力总心率1/3、运动增加最大心率、运动后恢复2 min心率均高于非冠心病组(P0.01);随冠状动脉病变严重程度增加,运动第1分钟心率、运动能力总心率1/3、运动增加最大心率、运动后恢复2 min心率逐渐增大(P0.01);运动第1分钟心率、运动能力总心率1/3、运动增加最大心率、运动后恢复2 min心率与ST段压低值及冠状动脉病变严重程度均呈正相关。结论:冠心病患者运动第1分钟心率、运动能力总心率1/3、运动增加最大心率、运动后恢复2 min心率增高可反映心肌缺血及冠状动脉病变程度。     

运动试验恢复期ST段压低的原因和特点

平板运动负荷试验（运动试验）目的是通过逐级增加运动量，检测冠脉储备能力，诱发心肌缺血。狭窄的冠脉不能随着运动量的增加而相应扩张，供血、供氧不能满足心肌需要时即出现缺血性胸痛和缺血型ST段改变，通常发生在运动中心率的峰值阶段。而我们工作中发现部分患缺血型ST段压低不是出现在运动中心率最快时，而是出现在运动试验恢复期，即运动停止以后。为分析判断运动试验恢复期缺血型ST段改变对冠心病的诊断价值。作将运动试验恢复期缺血型卵段压低的临床资料进行分析对比，旨在发现运动前和运动试验恢复期ST段压低的特点、原因和心脏超声的改变对冠心病的诊断价值。     

平板运动试验ST段抬高对冠心病诊断及定位分析

目的:对照平板运动试验与冠状动脉造影结果,探讨平板运动试验ST段抬高对冠心病诊断及定位的价值。方法:在846例行平板运动试验检查者中选择资料完整的78例行平板运动试验与冠状动脉造影的患者进行结果对照,观察运动引起ST段抬高与冠状动脉造影之间的联系。结果:846例平板运动试验中有8例ST段抬高,并且冠状动脉造影均为阳性。结论:在平板运动试验中ST段抬高能准确诊断冠心病,并且ST段抬高导联能定位冠状动脉狭窄部位。     

运动心电图试验ST/HR滞后(Hysteresis)与冠心病之间关系的研究

目的　探讨平板心电图运动试验ST/HR滞后与冠心病之间的关系及临床意义。方法　对可疑冠心病的136例患者在1周之内分别进行了平板运动试验和冠状动脉造影检查,并计算出心电图运动试验ST/HR滞后最大值。结果　136例患者,传统的ST段压低标准,阳性者86例,可疑阳性21例,其中真阳性78例;ST/HR滞后标准,阳性者83例,真阳性75例。传统的ST段压低标准与ST/HR滞后标准诊断冠心病的敏感性、特异性、准确性分别为714%、862%、758%和903%、868%、890%。结论　平板心电图运动试验ST/HR滞后标准能明显的改进心电图运动试验对冠心病的诊断作用,是检测心肌缺血有价值的指标。     

运动负荷中心电图ST段和QT间期离散度改变及对心脏功能的评估价值

目的:探讨活动平板运动试验(exercisetreadmilltesting,ETT)中ST段下移标准与心率校正的QT间期离散度(correctedQTdispersion,QTcd)对冠心病心肌缺血的诊断价值。方法:选择108例完成ETT的患者进行冠状动脉造影,将其分为非冠心病组(n=78)及冠心病组(n=30),分别测量各组运动前、中、后QT间期离散度(QTdispersion,QTd)及QTcd的变化,将运动后QTcd指标与ST段下移指标诊断冠心病心肌缺血的准确度进行比较。结果:冠心病组与非冠心病组无论运动前、运动中以及运动后,两组QTd及QTcd差异均有显著性意义。与ST段下移指标阳性(73.3%,61.1%)比较,QTcd≥50ms诊断冠心病的敏感性(86.7%)、阳性预测值(89.8%),差异有显著性意义(χ2=18.26,17.36,P<0.01)显著高于ST段下移法而特异性无显著差异;试用QTcd≥55ms为异常标准,则特异性显著提高(χ2=23.12,P<0.01),敏感性和阳性预测值都下降。结论:ETT中QTcd与ST段下移标准对心肌缺血的诊断价值相当。     

ST/HR指数联合常规ST段标准提高心电图运动试验对冠状动脉介入术后再狭窄诊断的研究

目的探讨通过心电图运动试验测定ST/HR指数联合常规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.方法对成功行冠状动脉介入治疗的129例患者,在术后3～6个月进行随访,心电图运动试验测量ST/HR指数及常规ST段阳性标准二者联合诊断再狭窄,通过冠状动脉造影确定有无再狭窄,评价其诊断再狭窄的价值.结果二者联合应用诊断再狭窄的敏感性和特异性分别为75.0%和83.3%,高于传统ST段标准（53.3%和66.7%）（均P＜0.05）.结论联合应用ST/HR指数及常规ST段标准可作为诊断再狭窄的无创手段.     

Diagnostic performance and partition values of exercise electrocardiographic variables in the detection of coronary artery disease – improved accuracy by using ST/HR hysteresis

Exercise electrocardiography is widely used for initial identification of patients with coronary artery disease (CAD). This study compares the measurements of ST‐segment changes during exercise and during early postexercise recovery in terms of diagnostic discrimination capacity and optimal partition values. Data from 1876 patients undergoing a routine bicycle exercise test were analysed. CAD was angiographically verified in 668 patients, and excluded by angiography (n = 119), myocardial scintigraphy (n = 250), and on clinical grounds (n = 839) in 1208 patients. Postexercise ST/HR hysteresis was calculated as normalized for heart rate (HR) ST/HR loop area during the first 3 min of recovery. ST/HR index was obtained by dividing the overall ST amplitude change during exercise by exercise‐induced HR change, and ST/HR slope was calculated using linear regression analysis of ST/HR data pairs during exercise. ST‐segment depression was measured during, and for 3 min after the exercise. Discriminating capacity of the methods was evaluated in terms of receiver operating characteristic areas and optimal partition values providing the combination of the best sensitivity and specificity were established. The best diagnostic discrimination was provided by ST/HR hysteresis at optimal partition value of ?15 μV, followed by postexercise ST amplitude measurements at gender‐specific partition values of ?10 to ?90 μV, ST/HR slope [partition value 2·4 μV (beats/min)^?1], ST/HR index [partition value 1·6 μV (beats/min)^?1], and ST‐segment depression during exercise (partition value 70 μV in men and 90 μV in women). The results demonstrate that analysis of postexercise ST/HR hysteresis offers the most accurate and gender indifferent identification of patients with CAD.     

Features of ST segment and T-wave in exercise-induced myocardial ischemia evaluated with multichannel magnetocardiography

BACKGROUND AND AIM: Magnetocardiography (MCG) is a novel, non-contact mapping technique to record cardiac magnetic field. We evaluated MCG criteria for myocardial ischemia in stress testing. METHODS: Multichannel MCG over frontal chest was performed in 44 patients with coronary artery disease (CAD) and 26 healthy controls during supine bicycle exercise test. Of the 44 patients 16 had anterior, 15 posterior, and 13 inferior ischemia documented by coronary angiography and exercise thallium scintigraphy. ST amplitude, ST slope, T-wave amplitude, and ST-T integral were measured. The optimal sites for detecting the ischemia-induced changes on MCG were sought. The orientation of the magnetic field was also determined. RESULTS: The optimal sites for the decrease of ST slope, ST amplitude, T-wave amplitude, and ST-T integral were over the abdomen. The reciprocal increase of these parameters was found over the left parasternal area. The optimal sites were approximately the same for all patient groups. In single-vessel disease patients without previous myocardial infarction (MI), ST slope increase and ST elevation performed the best (area under the receiver operating characteristic curve 92% and 90%, respectively). In post-MI patients with triple-vessel disease the decrease of T-wave amplitude and ST slope performed the best (area under curve 91%, for both). The magnetic field orientation at ST segment performed equally well as the other ST parameters. In stepwise logistic regression analysis, by use of the presence of CAD as the dependent parameter, ST slope increase and ST peak gradient orientation entered the model. CONCLUSIONS: Various ST segment and T-wave parameters detect ischemia in MCG. ST amplitude performs especially well in non-MI patients with less severe CAD. In advanced CAD late development of T-wave amplitude might be more sensitive to ischemia than ST amplitude.     

Features of ST segment and T-wave in exercise-induced myocardial ischemia evaluated with multichannel magnetocardiography

BACKGROUND AND AIM. Magnetocardiography (MCG) is a novel, non-contact mapping technique to record cardiac magnetic field. We evaluated MCG criteria for myocardial ischemia in stress testing. METHODS. Multichannel MCG over frontal chest was performed in 44 patients with coronary artery disease (CAD) and 26 healthy controls during supine bicycle exercise test. Of the 44 patients 16 had anterior, 15 posterior, and 13 inferior ischemia documented by coronary angiography and exercise thallium scintigraphy. ST amplitude, ST slope, T-wave amplitude, and ST-T integral were measured. The optimal sites for detecting the ischemiainduced changes on MCG were sought. The orientation of the magnetic field was also determined. RESULTS. The optimal sites for the decrease of ST slope, ST amplitude, T-wave amplitude, and ST-T integral were over the abdomen. The reciprocal increase of these parameters was found over the left parasternal area. The optimal sites were approximately the same for all patient groups. In single-vessel disease patients without previous myocardial infarction (MI), ST slope increase and ST elevation performed the best (area under the receiver operating characteristic curve 92% and 90%, respectively). In post-MI patients with triple-vessel disease the decrease of T-wave amplitude and ST slope performed the best (area under curve 91%, for both). The magnetic field orientation at ST segment performed equally well as the other ST parameters. In stepwise logistic regression analysis, by use of the presence of CAD as the dependent parameter, ST slope increase and ST peak gradient orientation entered the model. CONCLUSIONS: Various ST segment and T-wave parameters detect ischemia in MCG. ST amplitude performs especially well in non-MI patients with less severe CAD. In advanced CAD late development of T-wave amplitude might be more sensitive to ischemia than ST amplitude.     

Assessment of the effect of nifedipine on myocardial ischaemia by using the ST segment/heart rate slope

Nifedipine is used in patients with stable angina of effort and any resulting change in symptoms is attributed to several effects of nifedipine. However, there have been indications in such patients that one effect of nifedipine could be an increase in the severity of myocardial ischaemia, and the present report involves a trial the results of which could explain this effect. In the present trial, the effect of nifedipine on myocardial ischaemia was assessed by using the maximal ST/heart rate slope. This slope was used as an index of myocardial ischaemia because, in our hands in patients with angina, an increase or a decrease in the value of the slope respectively indicated an increase or a decrease in the severity of myocardial ischaemia as assessed by coronary arteriography. The maximal ST/heart rate slope was obtained at least twice in each of 23 patients with stable angina, with and without nifedipine; two patients were examined twice and three other patients were examined after an increased dose. Nifedipine resulted in an increase in the slope in 24 of the 28 comparisons, no change in three and a decrease in one comparison; there was a statistically significant (P less than 0.005; n = 28; paired t-test) increase in the maximal ST/heart rate slope. A further increase in the slope was obtained by increasing the dose of nifedipine in two out of three patients. The increase in the maximal ST/heart rate slope occurred in the absence of any effect of nifedipine on the initial level of ST segment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Exercise electrocardiography for diagnosis of coronary artery disease: impact of sampling rate on the diagnostic performance of ST/HR-loop based on data from early recovery phase

Quantitative analysis of electrocardiographic ST-segment/heart rate relationship (ST/HR loop) during early recovery phase of exercise stress test provides a sensitive tool for the detection of coronary artery disease (CAD). This study evaluates the effect of data sampling frequency on the diagnostic performance of ST/HR loop in 1876 patients undergoing a routine exercise test on a bicycle ergometer. CAD was verified angiographically in 668 patients and excluded by coronary angiography (n = 119), myocardial scintigraphy (n = 250) and on clinical grounds (n = 839) in 1208 patients. The normalized ST/HR loop area was calculated in all cases by integration of ST-segment amplitude difference from the end of exercise to the end of the first 3 min of recovery period over HR and dividing the integral by the HR difference over the integration period. The effect of different sampling rates (one, two and five samples per minute) on the CAD discrimination ability of ST/HR loop area was subsequently evaluated using receiver operating characteristic (ROC) curves. Reduction in ST/HR data sampling frequency from two to one sample per minute resulted in a significantly decreased diagnostic performance of the ST/HR loop whereas no differences in CAD discrimination capacity were observed between sampling frequencies of two and five samples per minute. The choice of ST/HR data sampling frequency may have a significant impact on the CAD diagnostic ability of the ST/HR loop. The use of sampling frequency below two samples per minute results in a significantly diminished diagnostic performance, a fact that should be taken into consideration when employing ST/HR diagnostic procedures.     

运动疗法在心脏术后康复中的作用

目的：探讨运动疗法在心脏术后康复中的作用。方法：21例心脏手术后患者均接受功率自行车或／和跑台训练为主的康复训练，并采用常规心电运动试验对康复训练前后的各项指标进行比较。结果：运动训练后，运动时间和最大运动负荷显著增加，安静时，心率、血压（包括收缩压和舒张压）、心率－血压乘积均显著下降（P＜0．05，P＜0．01），安静时心电图最大ST段压低明显改善（P＜0．01）；同等负荷量运动时，心率、血压、心率－血压乘积及运动诱发的最ST段压低与安静状态时有相似的改变(P＜0．05，P＜0．01）。结论：心脏术后的康复训练有助于增加体能，减轻心肌缺血，增加心肌储备功能，从而改善了患者的生活质量。     

冠心病患者等长收缩运动与心肌缺血的关系

目的　探讨冠心病患者等长收缩运动与心肌缺血的关系。方法　采用超声多普勒技术 ,比较 2 0例冠心病患者和 10例正常人极量短暂等长收缩运动 (briefisometricexercise ,BIE)、极量持续等长收缩运动(sustainedisometricexercise ,SIE)与动力性运动 (dynamicexercise ,DE)时的血流动力学反应和心功能表现。 结果　有心肌缺血的冠心病患者在DE运动终点时有心肌缺血表现 ,但BIE和SIE时无相应表现。心血管反应总体趋势为 :DE时心率和两项乘积运动增量均明显高于BIE和SIE ,各组间差异不显著。正常组DE时血流动力学多数指标的运动增量均高于BIE和SIE ,但有无心肌缺血的冠心病患者之间无明显差异。结论　在同等主观用力的前提下 ,冠心病患者等长收缩运动时心肌缺血发生率低于动力性运动。等长收缩运动时较高的舒张压和较长的灌注时间对心肌缺血有一定的保护作用。等长收缩运动在冠心病康复中的应用有合理的生理学基础。     

平板运动试验ST段压低恢复时期的假阳性表现

目的：对照平板运动试验与冠状动脉造影结果．探讨影响运动试验正确诊断冠心病的因素，从而提高冠心病诊断的准确性。方法：选择资料完整的156例行平板运动试验与冠状动脉造影的患进行结果对照。观察运动引起ST改变与冠状动脉造影之间的联系。结果：156例平板运动试验敏感性77％，特异性30％，假阳性率36％，其中36例女性平板运动试验敏感性71％，特异性27％．假阳性率61．5％。在42例假阳性患中，26例ST段压低在恢复期即刻恢复至原来状态。绝大多数女性运动试验假阳性ST段压低均在恢复期即刻恢复至原来状态。结论：平板运动试验是检测冠心病的有效方法。在平板运动试验中假阳性患大半数ST段压低在恢复期即刻恢复，提示假阳性与女性及ST段压低在恢复期即刻恢复有关。