急性心肌梗死QTc延长与心脏事件的关系

５８例急性心肌梗死（ＡＭＩ）发病２４ｈ首次心电图ＱＴｃ测定结果显示:ＱＴｃ＜４３０ｍｓ／ｓ１／２者３１例，无１例并发心脏事件（猝死、室颤或停搏、心力衰竭、心源性休克）；ＱＴｃ≥４５０ｍｓ／ｓ１／２者１６例，８１．２５％（１３／１６）并发心脏事件。ＡＭＩ心脏事件组与非事件组ＱＴｃ分别为４７８．１１±２５．８８ｍｓ／ｓ１／２与４１１．１３±３３．１１ｍｓ／ｓ１／２，Ｐ＜０．０１。提示:ＱＴｃ延长对预测ＡＭＩ并发心脏事件有参考价值     

超声二维心肌应变的变化与心肌梗死范围的相关性研究

目的评价心肌梗死患者超声二维心肌应变的变化与心肌梗死范围的相关性。方法选择71例急性心肌梗死患者,于心肌梗死后3～6个月行超声心动图和单光子发射计算机断层摄影(SPECT)检查,根据心肌梗死面积将患者分为A组28例(心肌梗死面积<12%),B组43例(心肌梗死面积≥12%)。所有患者行超声二维斑点追踪分析,测量心肌收缩期整体纵向应变(GLS)、收缩期整体径向应变(GRS)、收缩期整体圆周应变(GCS),对心肌应变与SPECT检测的左心室壁缺血坏死心肌的面积占左心室壁的百分比(Extent)进行相关分析,并应用ROC曲线评价3种心肌应变检测心肌梗死范围的价值。结果 B组的GLS、GCS及GRS均低于A组(P<0.05)。GLS、GCS与Extent均相关(r=0.721、r=0.504,P<0.01),GLS、GCS及GRS的ROC曲线下面积分别为0.818、0.749、0.678,诊断心肌梗死面积≥12%对应的界值分别为-13.83%、-11.65%、26.64%,敏感性和特异性分别为72.7%、88.9%,63.6%、88.9%,81.8%、55.6%。结论超声二维心肌应变的变化能够反映心肌梗死范围的改变,其中GLS能够较好地评价心肌梗死范围。     

门控心肌灌注显像相位分析评价陈旧性心肌梗死患者左心室收缩同步性

目的 应用单光子发射计算机断层成像(SPECT)/CT门控心肌灌注显像(GMPI)相位分析技术评价陈旧性心肌梗死(OMI)患者的左心室收缩同步性,并探讨影响收缩不同步的独立危险因素.方法 选择2010年10月至2013年9月在常州市第一人民医院确诊的OMI患者76例作为OMI组,同时选择健康者74例作为对照组,对其临床资料进行回顾性分析.所有研究对象均进行静息GMPI检查,应用Cedars Sinai QGS软件相位分析技术获得左心室收缩同步性参数[相位直方图带宽(BW)和相位标准差(SD)]以及心功能参数,应用QPS软件获得心肌灌注缺损范围.分别比较OMI组与对照组、左心室射血分数(LVEF)≤35％与LVEF＞ 35％ OMI患者之间的BW和SD值.以对照组BW值的x-±2s为异常临界阈值,大于该阈值定义为左心室收缩不同步,分析其独立危险因素.结果 (1)OMI组的BW[(91.3 ±58.6)°比(37.2±11.7)°,P＜0.001]和SD值[(27.3±20.8)°比(1 1.8±5.4)°,P＜0.001]均高于对照组,LVEF低于对照组(P＜0.001).LVEF≤35％的OMI患者BW[(136.0±52.9)°比(51.0±24.0)°,P＜0.001]和SD值[(38.7±21.3)°比(17.1±14.0)°,P ＜0.001]均高于LVEF＞ 35％的OMI患者.(2)在OMI患者中,左心室收缩不同步(BW ＞60.6°)的比例为57.9％ (44/76).与左心室收缩同步性正常OMI患者比较,不同步患者的LVEF较低(P＜0.0O1),左心室舒张末期容积、收缩末期容积、室壁运动异常总积分、室壁增厚异常总积分和心肌灌注缺损范围均较高(P均＜0.001).(3)LVEF≤35％的OMI患者合并左心室收缩不同步的比例高于LVEF＞35％的患者[91.7％ (33/36)比27.5％ (11/40),P＜0.001].(4)Pearson线性相关分析显示,LVEF与BW呈负相关(r=-0.807,P＜0.001).(5)多因素logistic回归分析显示,心肌灌注缺损范围是导致OMI患者发生左心室收缩不同步的独立危险因素(OR=1.076,95％ CI:1.015 ～1.141,P=0.015).结论 GMPI相位分析可客观反映左心室收缩同步性;OMI患者左心室收缩同步性减低,左心室收缩不同步与LVEF相关;心肌灌注缺损范围是OMI患者发生左心室收缩不同步的独立危险因素.     

三种无创性检查方法诊断冠心病的评价

作者以冠状动脉造影（ＣＡＧ）检查为金标准，１２７例病人以冠心病收入院，行ＣＡＧ检查，并行心电图（ＥＣＧ）、心脏Ｂ超和心肌灌注断层显像等无创伤检查，对其诊断效能进行评价。结果显示:ＥＣＧ，心脏Ｂ超和心肌灌注断层显像的敏感度分别为６０．３％、７０．９％和９０．５％，特异度分别为５４．７％、６２．３％和２１．４％；准确度分别为５７．５％、６６．７％和６２．９％。ＥＣＧ和心脏Ｂ超联合试验可使敏感度提高到７８．２％，特异度提高到８３．０％。心肌灌注显像的特异度较低，但对ＣＡＧ不能检出冠状动脉的微血管病变而心肌灌注显像对此类病人的敏感度却较高。心脏Ｂ超检出的舒张期功能障碍特别是同时合并节段性室壁运动异常对冠心病的诊断具有重要意义。     

99mTc-MIBI心肌灌注断层显像与心电图对冠心病的诊断价值

目的评估^99mTc—MIBI心肌灌注断层显像与心电图（ECG）在冠心病（CAD）诊断的价值。方法对28例冠心病和可疑冠心病患者进行心电图检查和^99mTc—MIBI心肌灌注断层显像（同时采用半定量方法分析患者左心室心肌血流灌注情况），其中13例患者行冠状动脉造影术（CAG）。结果心肌灌注断层显像与ECG阳性率分别为42．9％、53．6％，两者阳性率间差异无显著性意义（P〉0．05）。ECG诊断冠心病的敏感性为3／3，特异性为3／10，阳性预测值为3／10，阴性预测值为3／3，准确度为6／13。心肌灌注显像诊断冠心病的敏感性为3／3，特异性为8／10，阳性预测值为3／5，阴性预测值为8／8，准确度为11／13。心肌灌注断层显像和ECG与CAG阳性率间差异均无显著性意义（P〉0．05）。结论^99mTc—MIBI心肌灌注层显像与心电图是安全、无创伤、方便及费用低的检查方法，临床联合应用对冠心病的诊断、治疗和预后判断有重要的价值。     

无创心脏影像学检查在冠心病诊断中的临床应用价值

正以往对冠心病的诊断和治疗取决于冠状动脉解剖狭窄的程度,因此,有创的冠状动脉造影(coronary angiography,CAG)成为诊断冠心病的金标准。但是,近年研究结果显示,冠状动脉解剖学狭窄对心肌灌注和心肌灌注储备的影响更重要,心肌灌注异常是冠心病心肌缺血的第一个临床表现[1]。如何更早发现和确定患者是否存在心肌灌注和心肌灌注储备异常则成为近年学者们共同关注的一个焦点。随     

双嘧达莫负荷心肌201Tl和运动负荷心肌99Tcm-MIBI单光子发射计算机断层摄影在诊断心脏X综合征中的价值

目的 探讨双嘧达莫负荷心肌201T1单光子发射计算机断层摄影(SPECT)与运动负荷心肌99Tcm-甲氧基异丁基异腈(MIBI)SPECT显像在辅助诊断心脏x综合征中的价值.方法 选取临床符合心脏X综合征诊断标准患者共63例,将患者分为2组,一组行双嘧达莫负荷心肌201T1 SPECT显像,另一组行运动负荷心肌99Tcm-MIBI SPECT显像,评价两种核素心肌显像在诊断心脏X综合征中的符合率.结果 行双嘧达莫负荷心肌201T1 SPECT显像者35例,有31例出现病变部位的反向再分布,符合率为89%;行运动负荷心肌99Tcm-MIBI SPECT显像者28例,其中有24例出现负荷病变部位放射性稀疏或缺损,静息显像正常,符合率为87%.两种核素心肌灌注显像的符合率差异无统计学意义(P>0.05).结论 双嘧达莫负荷心肌201T1 SPECT显像能较直接反映心脏x综合征冠状动脉微循环病变.     

小剂量腺苷负荷超声心动图试验与双核素心肌显像检测急性心肌梗死后患者存活心肌比较

目的:比较小剂量腺苷负荷超声心动图试验(LDASE)与99mTc-甲氧基异丁腈(MIBI)/18F-脱氧葡萄糖(FDG)双核素同时采集法(DISA)单光子发射断层显像(SPECT)对急性心肌梗死(AMI)患者早期存活心肌检出的准确性.方法:对36例AMI患者于发病后3～10 d内行LDASE与DISA-SPECT.所有患者在LDASE前后接受经皮冠状动脉介入治疗术.AMI后3个月随访二维超声心动图,以局部室壁运动改善作为心肌存活的金标准,比较2种方法检测存活心肌的敏感性和特异性.结果:LDASE检出存活心肌敏感性为90.3%,特异性为80.8%,阳性预测值与阴性预测值分别为84.8%和87.5%,准确性为86.0%;DISA-SPECT检出存活心肌敏感性81.2%,特异性78.3%,阳性预测值81.1%,阴性预测值83.1%,准确性80.2%.2种方法对运动异常节段存活心肌检出一致性为72.6%,差异无统计学意义.结论:对AMI后患者,LDASE与DISA-SPECT均为检出存活心肌较敏感和特异的技术.     

心电前门控冠状动脉CT成像在快心率患者中的应用对策

目的探讨通过增加padding的方法,评估64层螺旋CT前门控冠状动脉CT成像在相对快心率患者的应用价值。方法选择心率>65/min患者30例(病例组),通过增加padding至180ms,重建40%⁸0%相位,评价冠状动脉图像质量,分析有效辐射剂量,并与30例(对照组)用回顾性心电门控螺旋CT冠状动脉重建方法辐射剂量进行对比。结果 98.3%的冠状动脉血管能够满足诊断要求,其中通过增加padding重建收缩期40%80%相位,评价冠状动脉图像质量,分析有效辐射剂量,并与30例(对照组)用回顾性心电门控螺旋CT冠状动脉重建方法辐射剂量进行对比。结果 98.3%的冠状动脉血管能够满足诊断要求,其中通过增加padding重建收缩期40%⁴5%相位窗,28.3%的冠状动脉血管图像质量改善,其中7例患者(23.3%)的12支血管(10.0%)图像质量由不能诊断改善为可以用于诊断;病例组平均辐射剂量明显低于对照组(3.5mSv vs 10.1mSv,P<0.01)。结论前门控轴扫增加padding用于相对快心率患者,可改善图像质量,避免用辐射剂量更高的回顾性心电门控螺旋CT扫描方法。     

两种电极导线在心室起搏临床应用中的比较

心内膜电极需长期安置在人体内,电极的稳定性和起搏阈值基本稳定至关重要,选择合适的起搏电极导线尤为重要.本文总结我院2000～2002年安装同一厂家生产的起搏器,采用两种不同结构起搏电极导线,即螺旋电极导线和楔形头电极导线,对它们的起搏阈值、电极阻抗和耗电量进行了对比观察.     

Comparison of myocardial contrast echocardiography with NC100100 and (99m)Tc sestamibi SPECT for detection of resting myocardial perfusion abnormalities in patients with previous myocardial infarction

OBJECTIVE—To determine whether myocardial contrast echocardiography (MCE) following intravenous injection of perfluorocarbon microbubbles permits identification of resting myocardial perfusion abnormalities in patients who have had a previous myocardial infarction.
PATIENTS AND INTERVENTIONS—22 patients (mean (SD) age 66 (11) years) underwent MCE after intravenous injection of NC100100, a novel perfluorocarbon containing contrast agent, and resting ^99mTc sestamibi single photon emission computed tomography (SPECT). With both methods, myocardial perfusion was graded semiquantitatively as 1 = normal, 0.5 = mild defect, and 0 = severe defect.
RESULTS—Among the 203 normally contracting segments, 151 (74%) were normally perfused by SPECT and 145 (71%) by MCE. With SPECT, abnormal tracer uptake was mainly found among normally contracting segments from the inferior wall. By contrast, with MCE poor myocardial opacification was noted essentially among the normally contracting segments from the anterior and lateral walls. Of the 142 dysfunctional segments, 87 (61%) showed perfusion defects by SPECT, and 94 (66%) by MCE. With both methods, perfusion abnormalities were seen more frequently among akinetic than hypokinetic segments. MCE correctly identified 81/139 segments that exhibited a perfusion defect by SPECT (58%), and 135/206 segments that were normally perfused by SPECT (66%). Exclusion of segments with attenuation artefacts (defined as abnormal myocardial opacification or sestamibi uptake but normal contraction) by either MCE or SPECT improved both the sensitivity (76%) and the specificity (83%) of the detection of SPECT perfusion defects by MCE.
CONCLUSIONS—The data suggest that MCE allows identification of myocardial perfusion abnormalities in patients who have had a previous myocardial infarction, provided that regional wall motion is simultaneously taken into account.


Keywords: myocardial contrast echocardiography; NC100100; single photon emission computed tomography; perfusion     

Dobutamine stress echocardiography versus quantitative technetium-99m sestamibi SPECT for detecting residual stenosis and multivessel disease after myocardial infarction

OBJECTIVE—To compare the relative accuracy of dobutamine stress echocardiography (DSE) and quantitative technetium-99m sestamibi single photon emission computed tomography (mibi SPECT) for detecting infarct related artery stenosis and multivessel disease early after acute myocardial infarction.
DESIGN—Prospective study.
SETTING—University hospital.
METHODS—75 patients underwent simultaneous DSE and mibi SPECT at (mean (SD)) 5 (2) days after a first acute myocardial infarct. Quantitative coronary angiography was performed in all patients after imaging studies.
RESULTS—Significant stenosis (> 50%) of the infarct related artery was detected in 69 patients. Residual ischaemia was identified by DSE in 55 patients and by quantitative mibi SPECT in 49. The sensitivity of DSE and mibi SPECT for detecting significant infarct related artery stenosis was 78% and 70%, respectively, with a specificity of 83% for both tests. The combination of DSE and mibi SPECT did not change the specificity (83%) but increased the sensitivity to 94%. Mibi SPECT was more sensitive than DSE for detecting mild stenosis (73% v 9%; p = 0.008). The sensitivity of DSE for detecting moderate or severe stenosis was greater than mibi SPECT (97% v 74%; p = 0.007). Wall motion abnormalities with DSE and transient perfusion defects with mibi SPECT outside the infarction zone were sensitive (80% v 67%; NS) and highly specific (95% v 93%; NS) for multivessel disease.
CONCLUSIONS—DSE and mibi SPECT have equivalent accuracy for detecting residual infarct related artery stenosis of  50% and multivessel disease early after acute myocardial infarction. DSE is more predictive of moderate or severe infarct related artery stenosis. Combined imaging only improves the detection of mild stenosis.


Keywords: myocardial infarction; dobutamine echocardiography; single photon emission computed tomography; SPECT; myocardial ischaemia     

Comparison of the effects of pirmenol and lidocaine on intraventricular conduction in canine myocardial infarction

Effects of pirmenol hydrochloride and lidocaine hydrochloride on intraventricular conduction were examined in the infarcted heart of anesthetized dogs. The effects of the drugs on the excitation induced by ventricular stimulations were determined with coupling intervals between 150 and 1,000 ms. Effects of the drugs on the His bundle electrocardiograms were also examined. Pirmenol in doses of 1-5 mg/kg prolonged the conduction time in the infarcted zones over a wide range of coupling intervals. Pirmenol at 5 mg/kg blocked the delayed conduction at a short coupling interval in the infarcted zones. The effect of pirmenol on the conduction time in the normal zone was slight. Lidocaine in doses of 3 and 10 mg/kg prolonged the conduction time in the infarcted zone at a short coupling interval. Pirmenol did not significantly prolong PQ or AH interval. In conclusion, pirmenol selectively depressed the delayed conduction in the infarcted zone, which could result in a reentrant pathway. The effect of pirmenol on delayed conduction was dependent on the coupling interval and was quite different from that of lidocaine.     

The accuracy of electrocardiographic Q waves for the detection of prior myocardial infarction as assessed by a novel standard of reference

BACKGROUND: The electrocardiogram (ECG) is valuable for the identification of prior myocardial infarction (MI) in individuals participating in epidemiologic studies or undergoing screening examinations. Although the Minnesota Code, a set of criteria for the interpretation of ECGs in such situations, is commonly used to identify MI in these settings, its accuracy is incompletely understood. HYPOTHESIS: We sought to test the accuracy of the Minnesota Code Q and QS criteria for MI against a new standard of reference, the presence of a perfusion defect on a resting myocardial scintigraphic image. METHODS: The resting myocardial scintigrams of all patients studied in our nuclear cardiology laboratory during 7 consecutive months were screened for the presence of perfusion defects. For each patient with such a defect, two individuals examined on the same day, who had no perfusion defect, were selected as controls. Electrocardiograms recorded within 30 days of the scintigraphy were read blindly by two of the authors using the Minnesota Code criteria for Q or QS waves indicative of MI. RESULTS: For 214 patients selected on the basis of their scintigraphic findings, a satisfactory ECG recorded within a month of the scintigraphy was also available. The overall sensitivity of the Q or QS criteria was 0.58 and the specificity was 0.75. As might be expected when only the most stringent criteria were applied, sensitivity was least and the specificity best. CONCLUSIONS: As in previous studies, in which necropsy material served as the standard of reference, sensitivity of the Q and QS criteria contained in the Minnesota Code is relatively modest and specificity is reasonable but not outstanding.     

心电图和超声心动图及左心室造影检查在心肌梗死合并室壁瘤患者中的诊断价值

目的探讨心电图和超声心动图及左心室造影对左心室室壁瘤的诊断价值。方法以手术发现为金标准,回顾性分析心肌梗死患者108例与室壁瘤患者17例,比较心电图和超声心动图及左心室造影检查对诊断左心室室壁瘤的敏感性、特异性、诊断准确率。结果心电图和超声心动图及左心室造影诊断室壁瘤的敏感性、特异性、诊断准确率分别为:58.8%,83.5%,40.0%;41.2%,95.6%,63.6%;86.7%,91.9%,65.0%。结论心电图对室壁瘤诊断具有简便,价廉,快速的特点,临床可作为首选方法。但确诊左心室室壁瘤,需要行超声心动图、左心室造影等检查。     

Electrocardiographic and echocardiographic detection of myocardial infarction in patients with left-ventricular hypertrophy. The LIFE Study

BACKGROUND: Left-ventricular hypertrophy (LVH) is a recognized risk factor for myocardial infarction (MI). However, detection of MI by standard electrocardiographic (ECG) criteria may be hampered in patients with LVH. In this setting of hypertensive LVH, the accuracy of two-dimensional (2D) echocardiography in detecting incident MI is unknown. Thus, we compared the accuracy of 2D echocardiography with Minnesota-code ECG criteria in detecting incident MI, adjudicated during serial evaluation in patients with hypertension and LVH. METHODS: In the ECG substudy of the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) Study, complete baseline wall-motion (WM) evaluation was obtained in 904 hypertensive patients with ECG LVH who did not have a left-bundle branch block. Electrocardiography and echocardiograms obtained at annual follow-up visits were evaluated for ECG Q-waves by Minnesota codes and WM abnormalities, respectively (mean follow-up, 4.8+/-0.9 SD years). Occurrence of incident clinical MI during follow-up was adjudicated by an expert end-point committee. RESULTS: In two logistic models adjusting for confounders, incident MI was independently associated with either incident Q-waves by the Minnesota code (odds ratio [OR], 6.1; 95% confidence interval [CI], 2.4-15.3) or incident and worsened WM abnormalities (OR, 11.9; 95% CI, 4.5-32.0), and the association was stronger for WM abnormalities than for Q-waves (P < .0001). Detection of incident MI by ECG or 2D echocardiography was obtained with sensitivities of 29% and 68% and specificities of 95% and 84%, respectively. CONCLUSIONS: Wall-motion abnormalities on serial 2D ECGs recognize incident MI better than do Minnesota-code ECG criteria during follow-up of patients with hypertension and LVH.     

The persistence of hibernating myocardium after acute myocardial infarction

Objective To establish the persistence of hibernating myocardium initiallydetected after myocardial infarction treated with thrombolysis. Methods and results Fourteen patients underwent gated positron emission tomographywith 18-fluoro-deoxyglucose and N13-ammonia at a median of 8days after first myocardial infarction. Repeat scans were performedat a median of 13 weeks post-infarction. A total of 148 (30·9%)myocardial segments showed reduced N13-ammonia uptake at thetime of the first scan compared with 154·5 (32·2%)segments at the time of repeat imaging. The median change inthe number of segments with reduced perfusion was –1·0.Initially 13 subjects had hibernating myocardium, seven patientshad large areas and six had smaller regions. Six (46·2%)subjects had repeat scans showing unchanged areas of hibernatingtissue and seven had second scans demonstrating changes in thesize of the region of hibernating myocardium. One patient hadno hibernating myocardium on either scan. Conclusions Positron emission tomography performed several months aftermyocardial infarction demonstrates significant changes in myocardialperfusion. However, a reduction in the number of segments withreduced perfusion does not always result in an improvement inmyocardial metabolism and contraction. Whilst most regions ofhibernating myocardium were still present several months afterinfarction, in only approximately half was the size of the mismatchedregion unchanged. Therefore it is not possible to predict thefate of hibernating myocardium which is present after infarction.     

骨骼肌干细胞移植对犬缺血心肌结构的影响

目的　观察自体骨骼肌干细胞移植于缺血心肌后对心肌结构变化的影响。方法　取 12只成年犬臀大肌 ,分离卫星细胞、培养、传代、用 4’ ,6 二乙酰基 2 苯基吲哚 (DAPI)标记卫星细胞 ;在已建立的急性心肌梗死动物模型基础上 ,将DAPI标记的卫星细胞 ,自左冠状动脉前降支灌入缺血心肌中。分别于 2、4、8周后取出心脏 ,对缺血心肌的纤维化程度及植入的卫星细胞进行观察。结果　在 2 4例标本中卫星细胞分化成为带有横纹德肌纤维 ;卫星细胞在缺血心肌中可分化成心肌细胞样细胞 ;在卫星细胞移植区域 ,原有心肌细胞由于得到保护而不发生玻璃样变性 ,且排列有序 ;对照组缺血心肌发生玻璃样变性 ,心肌细胞基本结构紊乱。结论　自体骨骼肌卫星细胞在缺血心肌中可分化成心肌细胞样细胞 ,并可抑制缺血心肌的纤维化 ,心肌的基本结构得到保护 ;干细胞移植有望为心肌损伤提供一条新的治疗途径     

Clinical decision-making and myocardial viability: current perspectives

Not all myocardium involved in a myocardial infarction is dead or irreversibly damaged. The balance between the amount of scar and live tissue, and the nature of the live tissue, determine the likelihood that contractile function will improve after revascularisation. This improvement (which defines viability) may be predicted with about 80% accuracy using several techniques. This review examines the determinants of functional recovery and how they may be integrated in making decisions regarding revascularisation.     

核素心肌灌注显像与三种心电方法诊断局灶性心肌梗死的对比研究

目的 :对比评价核素心肌灌注显像与心电图 （ECG）、高频心电图 （HFECG）及体表电位标测 （BSPM）三种心电方法对局灶性心肌梗死的诊断价值。方法 :采用结扎法 ,建立 10只局灶性心肌梗死犬动物模型。术后 2周 ,依次行核素心肌灌注显像、ECG,HFECG及 BSPM检查 ,术前行 HFECG和 BSPM检查 ,以作对比。结果 :ECG和HFECG检测局灶性心肌梗死的阳性率较低 ,仅为 5 0 % ,BSPM各单项参数检出的阳性率高于 ECG和 HFECG,多项指标平行试验诊断的敏感性与核素心肌显像相当 ,均为 90 %。结论 :BSPM和核素心肌显像对局灶性心肌显像均有较高的诊断价值 ,且核素心肌显像又能直观地反映梗死部位、范围和程度。