ST-T抬高的形态改变对急性心肌梗死早期诊断价值

目的探讨常规心电图中ST-T形态改变对急性心肌梗死(心梗)早期的诊断意义。方法回顾性分析116例发病0.5～4h有ST-T抬高并诊断为早期心梗的病例,与70例同期非心梗但有ST-T抬高的病例进行比较分析。结果早期心梗组与非心梗组的ST-T形态改变有显著性差异(p<0.05)。结论ST段不同程度的直线型或弓背型抬高、T波增高宽大,结合临床对诊断早期心梗有重要价值。     

急性前壁心肌梗死R波、Q波和ST段演变速度的观察

目的 通过心电图对急性心肌梗死的诊断提供更多的信息。方法 对21例急性前壁心肌梗死患者进行R波、Q波和ST段变化进行同步12导联心电图动态观察。将开始到结束的7次标测分成6个时间间隔．分别计算各个时间间隔的∑R、∑Q、和∑ST的平均值和标准差。结果∑R于胸痛发作后12h内迅速下降；∑Q逐渐增大，24h内变化最显著；EST 12h内迅速下降，48h后渐趋稳定。12例（57％）R波消失，Q波在发病后12h内形成；另9例（43％）于24h内形成。结论心肌梗死后ST段抬高、R波下降和Q波形成在快速型和慢速型心肌梗死患者中不同。     

碎裂QRS波

冠心病急性冠脉综合征治疗的新模式，包括更有效的溶栓治疗和更早期的冠脉介入治疗。使患者急性期的死亡率大为下降。临床病程及预后明显改善。这种治疗新模式还引起下述相应改变：①Q波型心肌梗死的发生率从原来66．6％下降到37．5％：②Q波型心肌梗死患者Q波的消失率从过去的6％上升到25％～63％：③非Q波型心肌梗死和非ST段抬高型心肌梗死的发生率相应增加；④发生过Q波或非Q波型心肌梗死的患者中。高达2／3的人经12导联心电图不能得到陈旧性心梗的诊断。     

“巨R波形”ST段抬高的特性及其临床意义

以往根据心电图出现病理性Q波、ST段移位及T波改变 ,将心肌梗死 (MI)分为急性、亚急性和陈旧性 3个时期。近年发现 ,MI早期心电图多不能显示 (MI)典型图形 ,往往只有ST T改变。本文旨在探讨超急性期MI罕见的“巨R波形”ST段抬高的特性及其临床意义。1　“巨R波形”(GRWS)ST段抬高的特性1993年Madias首先提出GRWSST段抬高的概念 ,其常见于MI超急性期 ,尤其是前壁MI[1] ,偶见于下壁[2 ] 。此外 ,还可见于心肌急性严重缺血时 ,如不稳定型、变异型心绞痛[3] 、运动负荷试验、心房起搏及PTCA术中[4、5] 。GRWSST段抬高的心电…     

缺血性J波:急性冠状动脉综合征超急性期的心电学指标

在2007年10月第十八届长城国际心脏病学会议上，北京大学人民医院郭继鸿教授介绍了有关缺血性J波的研究进展。 近几年，心血管医生根据心电图表现将急性心肌梗死分为超急性期、进展期（急性早期、sT段改变期）和确定期（Q波形成期）3个亚期。2000年急性心肌梗死分型从“Q波与非Q波型”转变为“ST段抬高与非ST段抬高型”。由于急性心肌梗死时坏死性Q波出现比较晚（平均需要9h），新分型将急性心肌梗死的诊断从确定期提前到进展期，     

"巨R波形"ST段抬高的特性及其临床意义

以往临床上根据心电图出现病理性Q波、ST段移位及T波改变,将心肌梗死分为急性、亚急性和陈旧性3个阶段。但近年来发现,在本病早期,心电图多不能显示心肌梗死的典型图形,往往只有ST-T改变。本文旨在探讨超急性期心肌梗死罕见的“巨R波形”ST段抬高(简称巨R形ST段)的特性及其临床意义。     

急性心肌梗死ST段抬高的形态和诊断误区

以往临床上根据心电图出现病理性Q波,ST段移位及T波改变,将心肌梗死分为急性期、亚急性期和陈旧性心肌梗死3个时期,但近年来发现,在本病早期多不能显示心肌梗死的典型心电图变化,往往只有ST-T改变,其中ST段抬高是急性心肌梗死最早期的心电图表现之一,     

犬急性透壁性心肌梗死极早期心电图变化的实验研究

目的:观察急性心肌梗死(AMI)极早期心电图的变化,并着重观察缺血性J波的发生情况及其与心律失常发生的关系,为临床早期诊断AMI提供依据。方法:杂种犬19只,开胸结扎前降支造成前壁急性心肌缺血,观察结扎前和结扎后2h内心电图变化。结果:超急性期约42%犬出现缺血性J波。T波高尖发生率为84%。ST段抬高发生率100%,全部累及胸前导联。巨R波发生率16%,出现晚于T波高尖和ST段抬高。以上心电图变化均出现在前壁,与梗死部位一致。AMI超急性期心电图变化中T波高尖和缺血性J波出现最早,ST段抬高次之,R波变化出现最晚。冠状动脉前降支结扎造成前壁心肌梗死后58%的犬至少有1次室性心动过速(VT)发生,26%发生心室颤动(Vf)死亡。前30min内发生的VT占总数的70%,与后90min比有显著性差异(P0.01)。出现J波的犬中全部发生VT,37.5%出现Vf;未出现J波的犬中27%出现VT,2只出现Vf。J波组VT较非J波组明显增加(P0.05)。结论:结扎前降支所致AMI超急性期心电图可出现缺血性J波、T波高尖、ST段抬高和巨R波型,缺血性J波是提示急性心肌缺血的心电图新指标,同时缺血性J波的出现常提示心电活动不稳定,易发生VT和Vf。     

急性心肌梗死的心电图分类与诊断

临床对急性心肌梗死的诊断一直沿用WHO的标准,即典型的胸痛症状、心肌酶学升高和心电图特征性的动态演变,这3个条件中满足2个即可诊断。尽管心电图在心梗极早期诊断、多支血管病变的冠状动脉定位等方面有一定的局限性,但由于其具有特异性和敏感性较高、无创、便捷、可多次重复等优点,在心梗的分类和诊断中仍具有不可忽视的重要地位。1.急性心肌梗死的心电图分类急性心肌梗死的心电图分类历经透壁性心梗和非透壁性心梗(20世纪80年代前)、Q波心梗和非Q波心梗(80年代),到近年随着再灌注治疗的临床应用已演变为ST段抬高型心梗和非ST段抬高型…     

心电图碎裂QRS波在急性心肌梗死诊断中的价值

目的:探讨心电图碎裂QRS波在急性心肌梗死诊断中的应用价值.方法:回顾性分析380例经冠状动脉(冠脉)造影确诊为冠心病者,其中162例急性心肌梗死中,根据是否ST段抬高分为:ST段抬高型急性心肌梗死(STEMI)组125例,非ST段抬高型急性心肌梗死(NSTEMI)组37例.根据入院3天内同步12导联心电图检查表现将其分为碎裂QRS波者36例、病理性Q波者42例、碎裂QRS波并病理性Q波者65例;另有19例为单纯ST段改变者,对比观察碎裂QRS波与病理性Q波在STEMI及NSTEMI患者中的发生率、敏感性、特异性、阳性预测值、阴性预测值.结果:162例急性心肌梗死者中,STEMI的发生率77.16%(125例/162例),NSTEMI的发生率22.84%(37例/162例).碎裂QRS波者在STEMI的发生率16.00%(20例/125例),低于病理性Q波者在STEMI的发生率28.80%(36例/125例),两者比较,差异有统计学意义(P<0.01).碎裂QRS波者在NSTEMI的发生率43.24%(16例/37例),高于病理性Q波者在NSTEMI的发生率16.22%(6例/37例),两者比较,差异有统计学意义(P<0.01).在STEMI诊断的敏感性、特异性、阳性预测值、阴性预测值病理性Q波者分别为28.80%、97.65%、85.71%、73.67%,碎裂QRS波者分别为16.00%、93.73%、55.56%、69.48%.在NSTEMI诊断的敏感性、特异性、阳性预测值、阴性预测值碎裂QRS波者分别为43.24%、94.17%、44.44%、93.90%,病理性Q波者分别为16.22%、89.50%、14.29%、90.83%.结论:在有急性心肌梗死诊断的其他证据时,碎裂QRS波可作为心电图诊断急性心肌梗死的一个新指标,尤其是对NSTEMI、非Q波型及无症状型急性心肌梗死,可避免漏诊.     

Myocardial viability in patients with thrombolyzed myocardial infarction: Is it assessable by predischarge exercise electrocardiography test?

BACKGROUND: Most studies concerning exercise electrocardiography (ECG) testing after acute myocardial infarction (AMI) were carried out in the prethrombolytic era. ST-segment elevation in the infarction area during exercise has usually been interpreted as indicating the presence of dyskinesia as a result of extensive left ventricle damage. HYPOTHESIS: This study was undertaken to evaluate the contributions of exercise-induced ST-segment elevation and T-wave pseudonormalization to the assessment of myocardial viability in patients with thrombolyzed myocardial infarction (MI), compared with low-dose dobutamine echocardiography. METHODS: The study comprised 52 consecutive patients with AMI treated with thrombolysis. All patients underwent low-dose dobutamine echocardiography and symptom-limited exercise testing before discharge. RESULTS: Nineteen patients showed ST-segment elevation (Group 1), 9 showed isolated T-wave pseudonormalization (Group 2), and 24 patients did not exhibit either of these ST-T segment changes (Group 3). Low-dose dobutamine echocardiography revealed evidence of viability in 16 patients (84%) in Group I (p = 0.01), 5 (56%) in Group 2 (p = NS), and 11 patients (46%) in Group 3 (p = NS). CONCLUSION: Exercise-induced ST-segment elevation may contribute to the evaluation of myocardial viability in patients with AMI treated with thrombolysis. However, in the absence of exercise-induced ST-segment elevation, further noninvasive studies might be indicated to assess myocardial viability.     

Quantitative T-wave analysis predicts 1 year prognosis and benefit from early invasive treatment in the FRISC II study population.

AIMS: To investigate the prognostic value of T-wave abnormalities in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), and whether such ECG changes may predict benefit from an early coronary angiography. Although ST-segment changes are considered the most important ECG feature in NSTE-ACS, T-wave abnormalities are the most common ECG finding. We hypothesize that a new quantitative approach to T-wave analysis could improve the prognostic value of this ECG abnormality. METHODS AND RESULTS: Quantitative T-wave analysis was performed on the admission ECG in 1609 patients with NSTE-ACS. Nine different categories of T-wave abnormality were analysed for their prognostic value concerning clinical outcome in patients not randomized to early coronary angiography. Also, the presence of one category (i.e. T-wave abnormality in > or =6 leads) was analysed for its predictive value concerning benefit from early coronary angiography. The combined study endpoint was death or myocardial infarction at 1 year follow-up. Patients with > or =6 leads with abnormal T-waves and concomitant ST-segment depression had a higher risk when not receiving early coronary angiography (24 vs. 12%, respectively; P=0.003), but could be brought to the same level of risk as the remaining patients with this treatment. For non-invasively treated patients five different categories of T-wave abnormality were significantly associated with an adverse outcome. CONCLUSION: New quantitative T-wave analysis of the admission ECG gives additional predictive information concerning clinical outcome and identifies patients who benefit from early coronary angiography.     

急性心肌梗死急诊经皮冠状动脉介入治疗后 ST段变化与临床预后的关系

目的 研究急性心肌梗死(AMI)成功急性介入术后ST段变化与临床预后的关系。 方法 回顾分析45例AMI患者的临床及造影情况,记录住院时、急诊介入术后90分钟、6小时、12小时、24小时12导联心电图,化验心肌CK值。介入治疗后在90分钟内抬高ST段回落>50％,CK峰值在12小时内,24小时内T波反转作为灌注组,不符合上述条件者为无灌注组。 结果45例AMI患者中36例(80％)再灌注,无再灌注组9例(20％);前壁心肌梗死无灌注组7例、而心肌再灌注组下壁心肌梗死20例。充血性心力衰竭、死亡,灌注组5例,无灌注组5例。 结论 AMI成功急性介入术后ST段变化与微循环障碍及住院期间的临床预后密切相关。     

Efficacy of thrombolysis in younger and older adult patients suffering their first acute q-wave myocardial infarction

OBJECTIVES: Advancing age is an independent predictor of increased mortality after acute myocardial infarction (AMI). Several hypotheses have been developed to try to explain this phenomenon, but data available about the efficacy of thrombolytic therapy in older patients are still not conclusive. The goal of this study was to investigate the efficacy of thrombolysis in adult and older patients who suffered their first AMI. DESIGN: Retrospective cohort study. SETTING: A coronary care unit. PARTICIPANTS: The sample included 244 younger (aged <65, n = 166) and older (age 65, n = 78) adult patients suffering their first Q-wave AMI, all receiving thrombolysis with human-recombinant tissue-type plasmin-ogen activator (100 mg total dose within 2.5 hours of the onset of AMI. MEASUREMENTS: Infarct size was estimated by isoenzyme creatine kinase-myoglobin (CK-MB) release, measuring the area under the curve as a function of time. ST elevation, the sum of ST elevation above the baseline, and the sum of R wave height in precordial leads V1-V6 were evaluated using 12-lead electrocardiograms. Myocardial reperfusion was calculated when ST-segment elevation decreased more than 60 with respect to the most abnormal peak detected.RESULTS: CK-MB peak level was significantly smaller in younger patients than in older ones (P< .01) and was significantly correlated with increasing age (P< .0001). Area under the 36-hour CK-MB curve was lower in younger patients than in older ones (P< .0001) and was well correlated with increasing age (P< .01). Reperfusion time was significantly shorter in younger patients (P< .05), and age was significantly correlated with reperfusion time (P< .001). CONCLUSIONS: Infarct size was greater and reperfusion time was longer in older patients than in younger ones with first Q-wave AMI treated with thrombolysis. Infarct size and reperfusion time were linearly correlated with increasing age. These findings may help explain the increase in mortality due to AMI observed with advancing age.     

Ischemic blocks during early phase of anterior myocardial infarction: correlation with ST-segment shift

Of 760 consecutive cases with anterior acute myocardial infarction (AMI), 55 developed acute bundle-branch block (BBB), fascicular block, or high-degree atrioventricular block during the hyperacute ECG stage of AMI. According to the direction of the ST segment during the acute ischemic episode, patients were divided into two groups. Group A consisted of 32 patients who developed BBB during ST-segment elevation, positive T wave, and absent or minimal Q wave. Group B consisted of 23 patients who developed BBB during ST-segment depression and evolved into anterior AMI. Group A was characterized by a higher incidence of right BBB and left anterior hemiblock [91% vs. 26% and 56% vs. 13%, respectively (p less than 0.005)]. Group B was characterized by a higher incidence of left BBB and left posterior hemiblock [57% vs. 9% and 26% vs. 12%, respectively (p less than 0.001)]. The BBB was transient (disappearing within hours to one day) in 14 patients in Group A and in 5 patients in Group B. The incidence of progression to high-degree atrioventricular block was almost equal in the two groups (25% and 26%). The mortality rate was very high in both groups, but higher in Group B [74% vs. 59% (p = NS)] especially in those with LBBB (85%). Most patients died on the day of occurrence of BBB [Group A, 50% vs. Group B, 70% (p = NS)]. The causes of death in both groups were cardiogenic shock and/or electromechanical dissociation.(ABSTRACT TRUNCATED AT 250 WORDS)     

A critique of the new ST-segment criteria for the diagnosis of acute myocardial infarction in patients with left bundle-branch block

BACKGROUND: Recently, electrocardiogram (ECG) criteria have been proposed for the diagnosis of acute myocardial infarction (AMI) in the presence of left bundle-branch block (LBBB). However, clinical experience indicates that such ECG changes indicative of AMI are occasionally noted in clinically stable patients with LBBB, raising concerns about the specificity of the proposed criteria. HYPOTHESIS: The aim of this study was to evaluate the frequency of ST-segment abnormalities suggestive of AMI in ambulatory patients with cardiovascular disease and chronic LBBB, who did not have an AMI. In addition, the ECG determinants of such ST-segment abnormalities were sought. METHODS: The files of all (4,193) patients followed in the outpatient cardiology clinic were reviewed to identify patients with LBBB. Electrocardiograms of these patients were evaluated as to the duration of the QRS complex, frontal QRS axis, amplitude of QRS in leads V1-V3, and the presence and magnitude of ST-segment depression (-ST) in leads V1-V3, and ST-segment elevation (+ST) in leads with predominantly positive or negative QRS complexes. Correlations of these ECG variables were carried out. RESULTS: In 124 patients with LBBB only 1 patient with -ST of 1 mm in leads V1-V3, and 1 patient with +ST of 1 mm in a predominantly positive ECG lead were found; the latter patient also had +ST of 6 mm in V3. Nine patients were detected with > or = 5 mm +ST in at least one ECG lead with predominantly negative QRS complex. Regression analysis of amplitude of +STs on corresponding QRS amplitudes in leads V1-V3 yielded Rs of 0.69, 0.68, and 0.69, all with a p value of 0.00005. A similar analysis of the amplitudes of +STs > or = 5 mm with the corresponding QRSs yielded an R = 0.76 and a p value of 0.0018. CONCLUSIONS: Thus, recently proposed ST-segment criteria for the diagnosis of AMI in patients with LBBB are appropriate. However, stable > or = 5 mm +STs are occasionally found in leads with predominantly negative QRS complexes, particularly of large amplitude (mean value 46.0, range [28.0-71.0] mm) in the absence of AMI. In such patients presenting with symptoms suggestive of AMI, further non-ECG confirmation of probable underlying AMI should be sought.     

aVR 导联对急性心肌梗死中左主干病变的诊断意义

目的：通过分析急性心肌梗死患者12导联心电图,探讨心电图对左主干病变的诊断意义。方法对急性心肌梗死并行冠脉造影术的4914例患者进行分层随机抽样,根据造影结果,将样本分为左主干病变组及非左主干病变组。记录两组一般临床资料,盲法测量两组心电图,对比两组得出预测左主干病变的指标。结果二元 logistic 回归分析表明,aVR 导联 ST 段抬高≥0．05 mV（OR：8．160,P ＜0．05）是左主干病变的独立预测因子。联合 aVR 导联ST 段抬高≥0．05 mV、V4～V6导联 ST 段压低、≥5个导联 ST 段压低、aVF 导联低电压、QRS 波群时限＞100 ms 这5个无创性指标,可将确诊左主干病变的概率从25．19％提高到69．24％。5个心电图指标的阳性预测值分别为52．63％、32．73％、26．39％、16．22％和22．22％。结论心电图对急性心肌梗死中左主干病变的预测是可行的。aVR 导联 ST 段抬高≥0．05 mV 是预测左主干病变良好的心电图指标,联合多指标可提高心电图对左主干病变的诊断价值。     

Acute non-Q wave cocaine-related myocardial infarction

Since our initial report in 1984 of six patients with AMI temporally related to cocaine use, we have observed 19 additional patients in whom ischemic chest pain syndromes occurred shortly after intranasal or IV use of cocaine or after smoking the drug. Seventeen patients (89 percent) developed non-Q wave infarction and two had Q-wave infarction. One patient manifested angina with striking ST-segment elevation. None of the patients had diabetes or hypertension, and all but one were cigarette smokers. The serum cholesterol level was 162 +/- 7 mg/dl. Four of the five patients who consented to coronary angiographic studies displayed normal coronary arteries, and one showed proximal stenosis of the right coronary artery. The cold pressor test was performed in seven patients; none had angina or ECG changes induced by cold stimulation. We conclude that T-wave infarction is a common form of an acute cardiac event related to cocaine abuse, and its pathogenesis may involve that of the cocaine-induced coronary vasospasm.     

Serial ECGs are less accurate than serial CK-MB results for emergency department diagnosis of myocardial infarction.

HYPOTHESIS: Serial creatine kinase-MB (CK-MB) levels provide more accurate predictive information regarding myocardial infarction than serial ECGs in emergency department patients with chest discomfort and no ST-segment elevation on the initial ECG. DESIGN: Prospective, observational study. SETTING: University hospital and university-affiliated Veterans Affairs Medical Center EDs. PARTICIPANTS: Two hundred sixty-one patients 30 years or older with chest discomfort warranting an ECG and consenting to observation. Exclusions included hemodynamic or rhythm instability and ST-segment elevation of 0.1 mV or more in two or more electrically contiguous leads at presentation. MEASUREMENTS: ECGs were obtained at presentation and three to four hours after presentation. Significant serial ECG changes sought on comparison of initial and three- to four-hour ECGs were 0.05 mV or more ST elevation or depression, Q-wave development, or T-wave inversion changes in two or more electrically contiguous leads. CK-MB levels were obtained at presentation and hourly for three hours (positive level, 8 or more ng/mL). Myocardial infarction was determined by record review and was based on independent CK-MB measurements. RESULTS: Twenty-eight (11%) patients were diagnosed with a myocardial infarction. Thirty-eight (15%) patients had a serial ECG change. Eleven of the myocardial infarction patients (39%) had a serial ECG change compared with 27 (12%) of the non-myocardial infarction patients (P < .001). Sensitivities and specificities of a serial ECG change versus serial CK-MBs for myocardial infarction were 39% versus 68% (sensitivity) and 88% versus 95% (specificity), respectively. Serial CK-MBs were more accurate than a serial ECG change for predicting myocardial infarction (P < .03). CONCLUSION: Serial changes in ECGs during a three- to four-hour interval were associated with the diagnosis of myocardial infarction but were infrequent and less accurate than serial CK-MB levels obtained for the same interval.     

心电图改变对急性下壁心肌梗死相关血管的预测价值

目的:对急性下壁心肌梗死患者的心电图资料进行回顾性研究,分析和比较心电图改变与冠状动脉造影及临床特点的对应性关系。探讨体表心电图改变对急性下壁心肌梗死患者的临床价值。方法:选取86例急性下壁心肌梗死患者,根据冠状动脉造影结果分为右冠状动脉(RCA)病变组和左冠状动脉(LCA)病变组。对比分析其心电图改变与冠状动脉造影结果及临床特点。结果:Ⅰ、Ⅱ、Ⅲ、aVR导联ST段及aVL导联波形改变对诊断梗死相关血管具有重要价值;V3与Ⅲ导联ST段改变比值预测梗死相关血管部位具有重要价值;伴aVR导联ST段压低患者病情重;伴胸前导联ST段压低者病情重、并发症发生率明显增高。结论:心电图对诊断下壁急性心肌梗死相关血管及其临床特点具有重要的预测价值。