Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation

This study assesses the relationship between the distribution of thallium-201 and myocardial blood flow during coronary vasodilation induced by intravenous dipyridamole in canine models of partial and complete coronary artery stenosis. 10 dogs were chronically instrumented with catheters in the left atrium and aorta and with a balloon occluder and electromagnetic flow probe on the proximal left circumflex coronary artery. Regional myocardial blood flow was measured during control conditions with radioisotope-labeled microspheres, and the phasic reactive hyperemic response to a 20-s transient occlusion was then recorded. Dipyridamole was then infused intravenously until phasic coronary blood flow increased to match peak hyperemic values. The left circumflex coronary artery was either partially occluded to reduce phasic blood flow to control values (group 1) or it was completely occluded (group 2), and thallium-201 and a second microsphere label were injected. 5 min later, the animals were sacrificed, the left ventricle was sectioned into 1-2-g samples, and thallium-201 activity and regional myocardial blood flow were measured. Curvilinear regression analyses between thallium-201 localization and myocardial blood flow during dipyridamole infusion demonstrated a slightly better fit to a second- as compared with a first-order model, indicating a slight roll-off of thallium activity as myocardial blood flow increases. During the dipyridamole infusion, the increases in phasic blood flow, the distributions of regional myocardial blood flow, and the relationships between thallium-201 localization and regional blood flow were comparable to values previously observed in exercising dogs with similar occlusions. These data provide basic validation that supports the use of intravenous dipyridamole and thallium-201 as an alternative to exercise stress and thallium-201 for evaluating the effects of coronary occlusive lesions on the distribution of regional myocardial blood flow.     

老年冠心病患者抑郁程度与心肌缺血的关系

目的观察老年患者心肌缺血与抑郁程度的关系 ,了解老年冠心病患者发生抑郁的一般规律。方法根据流行病研究中心抑郁度量表 (CES D)评分 ,将完成冠状动脉造影确诊为冠心病的老年患者 12 1例分为无抑郁组 (A组 ,64例 ) ,轻中度抑郁组(B组 ,3 4例 )和严重抑郁组 (C组 ,2 3例 ) ,观察不同组别之间在日常生活和活动平板运动试验中心肌缺血发生状况。结果无抑郁组以单支冠状动脉病变为主 ,轻中度抑郁组单支、双支和 3支病变比例相近 ;严重抑郁组以 3支病变为主。日常生活中 ,轻中度抑郁组ST段下降 (4 2± 1 3 )次 ,ST段下降持续时间 (3 5 8± 9 2 )min ,ST段下降指数 (3 2 8± 0 9)min/h ,均高于无抑郁组的 (1 8±0 3 )次、(16 6± 4 2 )min、(1 76± 0 4)min/h和严重抑郁组的 (2 1± 0 7)次、(17 8± 5 8)min、(1 69± 0 5 )min/h(P <0 0 5 ) ;运动试验中 ,轻中度抑郁组心肌缺血阳性率与严重抑郁组相近 ,明显高于无抑郁组 (P <0 0 5 )。日常生活中缺血症状与无抑郁组相似 ,但活动后明显高于无抑郁组 (P <0 0 5 )。结论抑郁程度与冠脉病变程度有关 ,不同抑郁程度的患者心肌缺血的表现不同。     

心肌缺血与冠状动脉直径指数变化的关系

目的　研究高血压病心肌缺血与冠状动脉主干直径指数变化 (LCDI)的关系。方法　 2 2例高血压病心肌缺血性改变者 (A组 ) ,2 5例高血压病非缺血性改变者 (B组 )和 2 1例健康者 (C组 )加入本研究 ,比较各组的左室质量 ,左冠状动脉主干直径和直径指数及冠状动脉储备功能。结果　A组LCDI为(0 0 17± 0 0 0 4 )mm/g,显著小于B组的 (0 0 2 1± 0 0 0 5 )mm/g (P =0 0 11)和C组的 (0 0 2 3± 0 0 0 4 )mm/g (P =0 0 0 0 ) ,而后两组之间十分接近无差异。结论　高血压病心肌缺血性改变者左冠状动脉主干直径不能与左心室肥大成比例地扩大     

Tl-201 myocardial SPECT in silent myocardial ischemia and angiographically proven coronary heart disease

Silent myocardial ischemia is defined as true myocardial ischemia without angina pectoris in patients with angiographically detected coronary artery disease. In this study 52 patients (46 male, 8 female: mean age 53 years) with a pathological exercise test but no symptoms were investigated. They showed stenosis of 75% or more of the diameter in at least one coronary segment on angiography. Prior to or after catheterization (within 14 days) Tl-201 SPECT was done and evaluated independently of angiography. A clear correlation between angiographically confirmed stenosis and reversible perfusion defects with Tl-201 SPECT was established (62 out of 76 lesions). Furthermore, there was a significant relation between angiographically detected subtotal or total occlusions of coronary vessels and irreversible perfusion defects using Tl-201 SPECT (35 in 44 lesions) (p less than 0.001). In patients with ST depression but without angina pectoris during the exercise test, the Tl-201 SPECT is highly suited to determine the hemodynamic effect of coronary stenoses.     

心肌缺血总负荷与冠心病相关性研究

目的对"胸痛待查"患者的动态心电图进行分析,探讨心肌缺血总负荷(TIB)的临床意义。方法选择以"胸痛待查"住院的患者,行动态心电图(AECG)及冠状动脉造影(CAG)检查。按CAG结果分为冠心病(CAD)组与非CAD组。对比分析两组间AECG所获得的心肌缺血总负荷指标,研究TIB与冠心病的相关性。结果随冠心病Gensini积分的增加,TIB值增加,提示随着冠状动脉病变严重程度的增加,TIB逐渐增加。TIB筛查CAD的灵敏性为59.6%,特异性为97.9%,符合率为78.8%;Kappa值为0.553。结论TIB与冠心病严重程度呈正相关;TIB筛查冠心病与冠脉造影的符合率较高。     

双源CT冠状动脉血管成像评价心肌桥与冠状动脉粥样硬化性病变的关系

目的：双源CT冠状动脉血管成像评价心肌桥与冠状动脉粥样硬化性病变的关系。材料与方法：对767例疑冠心病患者进行双源CT冠状动脉血管成像。计算心肌桥的发生率,测量心肌桥长度、深度、确切的部位及合并冠状动脉粥样硬化改变。比较单纯心肌桥组与合并冠状动脉硬化组之间的关系。结果：767例中,发现心肌桥-壁冠状动脉401例（52.3%）,左前降支是最常见的部位（344/401）,左前降支心肌桥组和无心肌桥组近侧冠状动脉粥样硬化比较,有显著统计学意义（P<0.0001）,其中轻度P<0.0001,中度P<0.02,重度P<0.0001。左前降支心肌桥近侧狭窄与心肌桥的厚度有关,与长度无关。结论：心肌桥近侧冠状动脉硬化发生率高,表明心肌桥是冠状动脉病变解剖学上的危险因素。     

老年冠心病患者无症状心肌缺血阈的动态心电图分析

目的探讨24小时动态心电图对老年冠心病无症状心肌缺血阈值的临床意义。方法对78例老年冠心病患者进行24小时动态心电图检测，以观察心肌缺血阈值（MIT）、MIT的变异（IV）：以及每阵缺血发作持续时间（TMI）和ST段最大位移以及昼夜缺血阵数（IN）。结果共检出582阵心肌缺血，92．1％在ST段压低时心率加快，夜间心肌缺血阈值较低，但缺血时间及ST段压低程度明显重于昼间。结论高心肌缺血阈与心肌耗氧增加有关；低心肌缺血阈与冠状动脉张力有关。     

ATP负荷MR心肌灌注成像对冠心病心肌缺血诊断的临床应用研究

目的 研究ATP负荷MR心肌灌注成像对冠心病心肌缺血诊断的临床应用价值。方法将临床通过DSA冠脉造影诊断为冠心病患者30例，无症状健康志愿者5例，进行ATP负荷MR心肌灌注成像，ATP负荷MR心肌灌注成像应用真正快速稳态梯度回波序列（fast imaging employ steady state quisition，FIESTA）用于观察心肌的运动，快速梯度回波序列（fastcard gradient echo train，FGRE ET）用于心肌灌注首过时相MPd图像采集。反转恢复梯度回波序列（myocardial delay enhancement，MDE）用于完成心肌灌注延迟30分钟后MRI图像采集。应用GE AW4．0工作站DCEMI（Dynamic Contrast Enhanced Myocardial Imaging）心肌灌注图像分析软件，对左心室短轴心肌灌注首过时相图像进行分析，得到心肌灌注时间—信号强度曲线，观察曲线的上升斜率和信号强度的峰值。根据Brandt等描述的左心室短轴位与冠状动脉血管分布的对应关系，确定存在狭窄的冠状动脉血管。冠脉造影使用日本岛津公司DAR1200双C臂DSA机，以冠状动脉管径≤50％作为有临床意义的狭窄的诊断标准。结果 通过ATP负荷MR心肌灌注成像测定心肌低灌注区信号强度以及时间-信号强度曲线上升斜率可以判定心肌缺血区域，判定结果与冠脉造影结果比较，其中25例结果一致，5例结果不一致，符合率为83％。结论 ATP负荷MR心肌灌注成像通过测定心肌信号强度以及时间—信号强度曲线上升斜率量化指标，对于冠心病心肌缺血诊断结果与DSA冠脉造影检查结果具有高度的一致性，ATP负荷MR心肌灌注成像是一种无创性的测定心肌的血流的检查方法，通过这种无创性综合的检测技术可以为临床提供有价值的信息，为临床诊断及恰当治疗提供可靠的依据。     

无创性冠状动脉血流储备评价冠状动脉前降支病变心肌缺血

目的 探讨ATP负荷经胸多普勒超声心动图法(TTDE)无创性测量冠脉血流储备(CFR)评价冠脉左前降支病变心肌缺血、预测冠脉狭窄的临床价值.方法 选取胸痛发作、已知或疑似冠心病的左前降支单支病变患者54例,在TTDE冠脉血流显像模式下,于ATP注射前、注射中和注射后分别获取左前降支远段血流频谱,测定其静息时及最大冠脉扩张时峰值流速,计算CFR.进行冠脉造影(CAG)及单光子发射计算机断层成像术(SPECT)检查.结果 ①与SPECT心肌灌注显像对照,无创性CFR法评价心肌缺血差异无明显统计学意义(P＞0.05).CFR≤2.0评价左前降支病变相应供血区域心肌缺血的敏感性为93.3％,特异性为89.7％.②冠脉狭窄与CFR呈负相关(P＜0.001),随着狭窄程度加重,CFR逐渐减低.绘制ROC曲线,以CFR≤1.60为截断值预测冠脉显著狭窄的敏感性和特异性分别为92.3％和73.3％.结论 ATP负荷TTDE法CFR是评价冠心病心肌缺血的敏感指标并可以预测冠脉显著狭窄;CFR与CAG联合对稳定型冠心病治疗方案的选择具有重要临床价值.     

Ultrasonic tissue characterization evaluates myocardial viability and ischemia in patients with coronary artery disease

To evaluate whether or not ultrasonic tissue characterization (UTC) can detect jeopardized or salvageable myocardium in patients having chronic coronary artery disease, we studied 103 patients with sequential UTC, dobutamine stress echocardiography (DSE) and (201)thallium stress-reinjection single-photon emission computed tomography (T1-SPECT). This revealed that the weighted amplitude of the cyclic modulation of integrated backscatter was larger for the myocardium with less ischemia burden or greater viability (p<0.001). The segments with larger ischemia burden or the nonviable myocardium demonstrated the contrary result. Using the receiver-operating characteristic curve analyses to determine the cutoff value of weighted amplitude for various predictions, UTC can detect ischemia in normokinetic myocardium (kappa = 0.34 compared to DSE or T1-SPECT) and viability in dyssynergic myocardium (kappa = 0.57 compared to DSE and 0.45, to T1-SPECT). These observations show that UTC may prove useful in the identification and pathophysiological understanding of myocardial ischemia and viability.     

颈、股动脉内-中膜厚度及血管内皮舒张功能与冠心病的相关性

目的:探讨颈动脉、股动脉内-中膜厚度(IMT)及肱动脉流量介导的舒张功能(FMD)与冠心病的相关性.方法:经冠状动脉造影正常者29例(正常组),冠状动脉有病变者76例(冠心病组),利用高频超声检测颈动脉、股动脉IMT及肱动脉FMD.结果:单支病变组、多支病变组颈动脉、股动脉IMT明显高于正常组,肱动脉FMD则明显低于正常组(均P<0.01),单支病变组与多支病变组之间差异亦有统计学意义(P<0.01);冠状动脉病变积分(修正Gensini积分)与颈动脉、股动脉IMT呈明显正相关,与肱动脉FMD呈明显负相关(均P<0.000 1).结论:颈动脉、股动脉IMT及肱动脉FMD与冠心痛存在相关性,超声检测颈动脉、股动脉IMT及肱动脉FMD可为早期发现、治疗和预防冠心病提供依据.     

Relationships between exercise ECG and angiocardiographic indices of coronary insufficiency and myocardial fibrosis in coronary heart disease

Summary. Patients with coronary heart disease were examined with exercise ECG and angiocardiography. Maximum work capacity expressed as a percentage of the predicted normal exercise tolerance (Wmax%) was significantly associated with the angiocardiographic score of the myocardial mass subserved by obstructed coronary arteries (MCOS). Variables related to myocardial fibrosis (MF) such as post infarction ECG signs, the left ventricular wall motion score (LVMS) and the ejection fraction of the left ventricle (LVEF) correlated significantly as did variables related to reversible myocardial ischaemia or coronary insufficiency (CI), such as ST depression during exercise (STdepr), STAY and ST/HR indices, effort angina (EA/W) index, the extent of collaterals (CollS), and ‘MCOS-LVMS’. MF variables correlated weakly with CI variables. Wmax% covariated with the variables related to both CI and MF, and most closely with MCOS. Discrepancies between results of exercise ECG and angiocardiography have to some extent been overcome by comparing appropriate parameters.,     

Real-time 12-lead high-frequency QRS electrocardiography for enhanced detection of myocardial ischemia and coronary artery disease

Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.     

冠心病患者尿微量白蛋白水平及动脉硬化指数与冠脉狭窄程度的关系分析

目的研究动态动脉硬化指数(AASI)和尿微量白蛋白(MAU)与冠心病患者冠状动脉狭窄程度的相关性。方法选择冠心病130例患者,根据冠状动脉造影检查结果分为单支病变组(56例)、双支病变组(41例)、多支病变组(33例),同时选择冠脉正常患者为正常对照组(60例)。测定和比较各组的AASI、MAU;以Gensini积分表示冠状动脉狭窄程度,评价Gensini积分与AASI、MAU的相关性。结果多支病变组的AASI、MAU水平最高,其次为双支病变组、单支病变组,组间比较差异有统计学意义(P0.05),冠心病组AASI、MAU水平均显著高于正常对照组(P0.05)。相关性分析显示Gensini积分与AASI、MAU均呈显著正相关(r=0.674,0.732,P0.01)。结论AASI和MAU水平随冠脉病变支数的增加而上升,AASI和MAU水平与冠状动脉狭窄程度呈显著的正相关,可作为评价病变严重程度的参考指标。     

老年冠心病患者抑郁程度与心肌缺血的关系

目的:观察老年患者心肌缺血与抑郁程度的关系。方法:2002-01/2003-12深圳市南山人民医院及江西省人民医院心内科住院患者共193例。纳入标准:①年龄60～79岁,性别不限。②经冠状动脉造影证实冠脉单支或多支狭窄≥50%的患者。③静息血压≤180/120mmHg(1mmHg=0.133kPa)。排除心功能不全、慢性支气管炎、瓣膜病、心肌病及严重心律失常和右束支传导阻滞、急性心肌梗死和施行冠脉介入治疗的患者。实际纳入研究121例老年冠心病患者。采用流行病研究中心抑郁度量表评估结果将完成冠状动脉造影确诊为冠心病的老年患者121例分为无抑郁组(64例),轻中度抑郁组(34例)和严重抑郁组(23例),观察不同组别之间在日常生活和活动平板运动试验中心肌缺血发生状况。结果:无抑郁状态组以单支冠状动脉病变为主,轻中度抑郁组单支,双支和3支病变比例相近;日常生活中轻中度抑郁组ST段下降次数[4.2±1.3)次],ST段下降持续时间[(35.8±9.2)min],ST段下降指数(3.28±0.9)min/h]均高于无抑郁组[(1.8±0.3)次,(16.6±4.2)min,(1.76±0.4)min/h]和严重抑郁组[(2.1±0.7)次,(17.8±5.8)min,(1.69±0.5)min/h](t=3.531,5.167,2.047,P<0.05);运动试验中心肌缺血阳性率与严重抑郁组相近,但明显高于无抑郁组(χ2=3.274,P<0.05);严重抑郁组以3支     

左冠脉开口于右冠窦并急性心肌梗死1例

患者男,80岁,主因“胸闷5h,加重伴胸痛3h”入院。5h前日常活动时出现胸闷,呼吸困难,病人可耐受,未予重视。3h前无明显诱因出现胸闷加重,伴剧烈胸痛,呈压榨样疼痛,局限于前胸,不向周围放射,伴大汗,乏力,休息后症状无明显缓解。120大夫在家测不到血压,心率最慢为30次/分,神志清楚,急入院,查心电图示急性心肌梗死。患者无高血压、糖尿病、高血脂病史。吸烟60年,约20支/天。查体血压:96/55mmHg。神清,口唇紫绀,颈静脉无充盈,双肺底可闻及湿啰音,心率56次/分,律齐,无杂音,腹软,肝脾未及,双下肢不肿,辅助检查:血常规:WBC17.3×109/L,GRA:71%,B…     

应激性高血糖与急性心肌梗死冠脉病变程度及预后的关系

目的:探讨应激性高血糖(SHG)与急性心肌梗死冠脉病变程度及预后的关系.方法:根据心肌梗死初期血糖将90例急性心肌梗死患者分为两组,A组血糖≥8mmol/L,B组血糖＜8 mmol/L.对两组冠脉造影结果及预后进行比较分析.结果:A组梗死相关血管近端病变、梗死相关血管为前降支或右冠、心力衰竭、严重心律失常和梗死后心绞痛例数明显多于B组(P＜0.05),而左室射血分数明显低于B组(P＜0.05).结论:急性心肌梗死合并SHG的梗死相关血管多为前降支或右冠近端病变,预后不好.