Exercise-induced symptomatic ischaemia predicts a poor long-term prognosis after acute myocardial infarction

STUDY OBJECTIVES: To evaluate the long-term prognostic significance of symptomatic ischaemia during exercise testing performed 3 weeks after acute myocardial infarction (AMI). DESIGN: A prospective study with long-term follow-up. SETTING: A Cardiac Rehabilitation Clinic in a University Hospital. SUBJECTS: A total of 446 patients were allowed to perform exercise testing 3 weeks after AMI and followed for 72 +/- 20 months. MEASUREMENTS AND RESULTS: Patients were divided into three groups according to whether they had no ECG evidence of ischaemia during exercise testing (334 patients), silent ischaemia (90 patients) or symptomatic ischaemia (22 patients). Cardiac death was significantly more frequent in patients with symptomatic ischaemia when compared with silent ischaemia (31.8% vs. 7.8%, P < 0.01) or when compared with no ischaemia (31.8% vs. 10.2%, P < 0.01). The three groups had a low cardiac mortality during the first 48 months of follow-up. The prognosis of patients with symptomatic ischaemia worsens markedly thereafter. The results of exercise testing did not predict recurrence of myocardial infarction. Coronary revascularization was performed in 34.4% of those without ischaemia, 47.8% of those with silent ischaemia and 45.5% of those with symptomatic ischaemia (P < 0.01). CONCLUSIONS: Patients with symptomatic ischaemia have a good prognosis during the first 4 years of follow-up. Their prognosis worsens thereafter as opposed to patients with or without silent ischaemia. This high-risk group of patients with symptomatic ischaemia deserves optimal management including revascularization when appropriate.     

Interpretation and classification of microvolt T wave alternans tests

Measurement of microvolt-level T wave alternans (TWA) during routine exercise stress testing now is possible as a result of sophisticated noise reduction techniques and analytic methods that have become commercially available. Even though this technology is new, the available data suggest that microvolt TWA is a potent predictor of arrhythmia risk in diverse disease states. As this technology becomes more widely available, physicians will be called upon to interpret microvolt TWA tracings. This review seeks to establish uniform standards for the clinical interpretation of microvolt TWA tracings.     

Heart rate adjustment of magnetic field map rotation in detection of myocardial ischemia in exercise magnetocardiography

Aims We studied the capability of heart rate (HR) adjusted change in multichannel magnetocardiogram (MCG) to detect exercise-induced ischemia. Methods and results The MCG and 12-lead ECG were recorded simultaneously during supine exercise testing in 17 healthy controls and 24 patients with single vessel coronary artery disease (CAD). In the MCG analysis, we plotted the orientation of the magnetic field map (MFM) against the HR in each cardiac cycle during recovery. A regression line was fitted to the data and the line slope (degrees/bpm) was determined. In the ECG, the ST-segment depression vs HR (ST/HR) slope was evaluated. The HR adjusted MFM rotation was more extensive in the pooled CAD group, and in all subgroups with different stenosed vessel, than in the control group at the ST-segment (1.5 ± 2.1°/bpm vs 0.29 ± 0.25°/bpm, p < 0.0005) and at the T-wave apex (0.95 ± 0.81°/bpm vs 0.24 ± 0.25°/bpm, p < 0.0005). Areas under the receiver operating characteristic curves of the HR adjusted MFM rotation at the ST-segment (88.5 %) and the T-wave (86.0 %) were higher than the ones without HR adjustment (75.5 % and 68.1 %, respectively), and higher than the area of ST/HR slope in the ECG (80.2 %). Conclusion HR adjusted MFM rotation detects transient ischemia independent of the stenosed vessel. HR adjustment improves the performance of the MCG in ischemia detection by the analysis of the ST-segment and the T-wave. The MCG was superior to the 12-lead ECG. Received: 5 April 2001, Returned for 1. revision: 7 May 2001, 1. Revision received: 25 May 2001, Returned for 2. revision: 12 June 2001, 2. Revision received: 18 June 2001, Accepted: 20 June 2001     

早期活动对急性心肌梗死患者康复的影响

20世纪80年代以后，欧美国家对急性心肌梗死（AMI）无合并症患者于发病第5天开始下床活动，而且有些结果表明，这一方案不增加病死率及合并症的发生，能加快患者体力和心理状况的康复。但由于AMI病情凶险，并发症严重，医务人员对早期活动存在顾虑，所以当前临床上大多仍对AMI患者采用卧床3～4周的传统康复程序。本文进行对照观察，以探讨AMI患者早期下床活动对病情康复的影响.     

运动试验各阳性指标对冠心病的诊断价值

目的探讨运动试验各种阳性指标在诊断冠心病中的价值。方法选择行平板运动试验结果阳性的156例患者行冠状动脉造影检查,观察运动试验各种阳性指标与冠状动脉造影阳性之间的关系。结果156例中ST段抬高组8例患者冠状动脉造影均阳性,ST段压低组116例中冠状动脉造影阳性84例,T波正常化组22例中冠状动脉造影阳性14例,心律失常组10例中冠状动脉造影阳性4例。结论平板运动试验中ST段抬高能准确判定冠心病,T波正常化组与ST段压低组患者冠脉造影阳性率间无差别,可以作为运动试验阳性的新指标,心律失常诊断冠心病的价值较低,注意排除假阳性。     

平板运动试验阳性改变及QT离散度变化对诊断冠心病的临床意义

【目的】探讨平板运动试验阳性改变及QT离散度变化诊断冠心病的临床意义。【方法】对258例住院患者行平板运动试验并测量其运动前、运动中以及运动后QT离散度,并行冠状动脉造影检查,比较平板运动试验阳性改变、QT离散度变化和冠状动脉造影检查结果。【结果】258例平板运动试验阳性患者中冠状动脉造影异常者181例(占71%),冠状动脉造影狭窄程度>50%较狭窄程度<50%的患者平板运动试验QTcd明显增加(P<0.05),狭窄程度>50%组运动后QTcd较运动前明显增加(P<0.05)。【结论】平板运动试验阳性改变及QT离散度变化在冠心病诊断中具有重要的临床意义。     

推拿牵引配合患者主动锻炼治疗椎动脉型颈椎病

目的：观察颈椎主动锻炼配合牵引推拿治疗椎动脉型颈椎病.方法：对30例椎动脉型颈椎病患者采用牵引推拿配合颈部功能锻炼治疗,并与牵引推拿组进行疗效比较.结果：治疗组与对照组短期疗效无明显差异,但半年及1年随访复发率有明显差异.结论：主动功能锻炼可降低复发率.     

缓解期慢性阻塞性肺病患者的呼吸康复治疗

目的：观察呼吸康复治疗对缓解期(30PD患者呼吸系统症状、肺功能指标、膈肌移动范围的影响，以及近1a来急性发作次数．方法：缓解期出院的(X)PD患者共64例，随机分成对照组32例和康复治疗组32例，前者住院时未进行呼吸康复指导，后者出院前根据患者病情制订康复治疗方案，交给病人和家属参照执行，并留患者的联系电话号码以监督实施和随访．结果：呼吸康复治疗组与对照组比较．呼吸康复对缓解期(X)PD患者的临床症状、肺活量(VC)及1秒率(FEV1．0)、膈肌移动范围改善更为显著。急性发作次数明显少于对照组．结论：呼吸康复治疗在改善患者生存质量、减少住院和就诊次数等方面具备综合效果．     

煤工尘肺病人心肺功能运动试验研究

目的　了解I期尘肺病人体力能力和肺通气效率。方法　调查对象 14 3名 ,其中Ⅰ期煤工尘肺病人 6 4名 ,正常对照组 79名 ;所有对象进行心肺功能运动试验 ;运动设备为踏板 ,负荷方案采用非稳定状态的递增负荷法。结果　尘肺病人最大摄氧量 2 7.6 7ml·kg-1·min-1,显著低于正常人群 ;无氧阈位点和最大摄氧量水平位点的二氧化碳通气当量分别是 37.39和38.36 ,显著高于正常人群 ;6 4例尘肺病人中有 2 2人最大摄氧量小于 <2 5ml·kg-1·min-1。两组间无氧阈水平无显著性差别。结论　尘肺病人最大体力能力明显降低 ,通气效率明显降低 ,但体力耐力水平降低不明显 ;Ⅰ期煤工尘肺病人可胜任一般轻体力劳动     

运动状态下最大呼气流速和通气反应

目的本文探讨了最大呼气量对运动通气反应的影响。方法选择6名较高最大呼气量(FEV1>80%Pred;FEV1/FVC>72%)和5名较低最大呼气量(FEV1<80%Pred;FEV1/FVC<72%)者作为受试者。每名受试者尽最大力至疲劳,交替呼吸室内空气或含有3%CO2和76%N2的混合空气后用梯度循环测力仪进行测定。肺容量和流量环在每2min增加工作功率(20或30W)时进行测定,并对休息状态的数值进行分析。完成这两项测试后,分析通气阈(VTh)和最大运动值的最高等量工作率(HEWR)。结果在休息或VTh状态下呼吸CO2时,高流量者和低流量者的通气均增加(P<0.001)。呼吸CO2时,高流量者的HEWR增大(P<0.05)。而呼吸CO2时,如其对运动时的通气反应高于通气阈则使低流量者与呼吸室内空气者相比,其运动时的通气反应减少(P<0.05)。且吸入CO2运动时的通气反应高于通气阈者与FEV1(%Pred)(r=0.72,P<0.02)呈显著相关性。低流量者行最大运动的终末呼气肺容量和终末吸气肺容量在呼吸室内空气或CO2时较高,分别P<0.001、P<0.05。结论这些结果提示,低流量者吸入CO2来增强通气需求时,对较大或最大运动量的通气反应呈约束状态。这些结果可证实,高流量和低流量受试者在呼吸室内空气和3%CO2时的呼吸机制有显著性差别。