Long-term prognosis of transient acute myocardial ischemia at rest

A medical approach to treatment was adopted in 652 patients with documented myocardial ischemia at rest during both the acute and follow-up phases. No patient underwent coronary revascularization during hospitalization and only 86 patients (13%) underwent coronary bypass surgery within 8 months from discharge. During hospitalization 13 patients died. In the remaining group (639 patients), the likelihood of death in the 10-year period after discharge was 28% for all patients and 20% for cardiac causes only. A series of factors studied during the acute stage were assessed in an effort to predict long-term outcome. The following noninvasive characteristics, listed in decreasing order of statistical significance, were found to be significant univariate predictors of survival: abnormal basal electrocardiogram, duration of coronary artery disease, previous myocardial infarction, pattern of ST-T changes during episodes of ischemia at rest, age and systemic hypertension. The average annual mortality rate for patients with T-wave changes, ST-segment elevation and ST-segment depression was 0.9, 1.8 and 3%, respectively. The Cox survival analysis identified abnormal basal electrocardiogram, duration of coronary artery disease and pattern of ST-T changes as significant, independent predictors of death. When invasive characteristics were entered in the model, number of greater than or equal to 50% narrowed coronary arteries, left ventricular ejection fraction, abnormal basal electrocardiogram and smoking habit were found to be independent and additive prognostic variables. Thus, long-term prognosis of patients with ischemia at rest is related to the severity of anatomic impairment, independent of the pattern of ST-T changes observed during the acute phase.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrocardiographic ST-segment changes during acute myocardial ischemia

The recognition and management of patients with acute coronary syndromes has relied to a large extent onthe standard 12-lead electrocardiogram (ECG) for assessing ST-segment changes associated with ischemia.The purpose of this review is to show both the capabilities and the limitations of the 12-lead ECG in recognizingischemia, and to seek alternative electrocardiographic leads, optimized for detection of ischemia originating indifferent regions of the ventricular myocardium. Three such leads are proposed—based on the results obtainedby electrocardiographic body-surface mapping performed during ischemia induced by balloon-inflation coronaryangioplasty. A survey of recent clinical studies shows that the electrocardiographic manifestations of acutemyocardial ischemia observed during coronary angioplasty are in agreement with the ST-segment measurements inadmission ECGs of patients with acute myocardial infarction.     

Predictors and in-hospital prognosis of recurrent acute myocardial infarction

Objective To investigate the contributing factors and in-hospital prognosis of patients with or without recurrent acute myocardial infarction (AMI). Methods A total of 1686 consecutive AMI patients admitted to Peking University People’s Hospital from January 2010 to December 2015 were recruited. Their clinical characteristics were retrospectively compared between patients with or without a recurrent AMI. Then multivariable logistic regression was used to estimate the predictors of recurrent myocardial infarction. Results Recurrent AMI patients were older (69.3 ± 11.5 vs. 64.7 ± 12.8 years, P < 0.001) and had a higher prevalence of diabetes mellitus (DM) (52.2% vs. 35.0%, P < 0.001) compared with incident AMI patients, they also had worse heart function at admission, more severe coronary disease and lower reperfusion therapy. Age (OR = 1.03, 95% CI: 1.02–1.05; P < 0.001), DM (OR = 1.86, 95% CI: 1.37–2.52; P < 0.001) and reperfusion therapy (OR = 0.74; 95% CI: 0.52–0.89; P < 0.001) were independent risk factors for recurrent AMI. Recurrent AMI patients had a higher in-hospital death rate (12.1% vs. 7.8%, P = 0.039) than incident AMI patients. Conclusions Recurrent AMI patients presented with more severe coronary artery conditions. Age, DM and reperfusion therapy were independent risk factors for recurrent AMI, and recurrent AMI was related with a high risk of in-hospital death.     

再发心肌梗死的危险因素及对短期预后的影响

目的探讨再发急性心肌梗死（AMI）的危险因素及对短期预后的影响。方法连续入选2006年1月至2010年12）1在北京大学人民医院住院治疗的AMI患者1447例。根据病史分为初发AMI组（n=1268）和再发AMI组（n=179）。记录患者性别、年龄、心血管相关危险因素、人院时心功能、心肌梗死类型、冠状动脉造影结果、住院期间死亡率、入院24h内的血脂、空腹血糖、血清肌酐等,并用logisticN归模型探寻再发AMI的危险因素。结果与初发AMI患者相比,再发AMI患者年龄较大,合并糖尿病的比例高。同时患者人院时心功能差,冠状动脉病变程度重。Logistic回归分析结果显示,年龄（OR1．03,95％CI：1．01～1．04,P〈0．01）、糖尿病（OR2．10,95％CI：1．51～2．91,P〈0．01）、吸烟（0R1．76,95％CI：1．20～2．57,P〈0．01）、血清肌酐水平（OR1．003,95％CI：1．001～1．004,P〈0．01）是再发AMI的独立危险因素。与初发AMI患者相比,再发AMI患者住院期间全因死亡率及心源性死亡率有升高趋势,但差异无统计学意义。结论年龄、糖尿病、吸烟、血清肌酐水平是再发AMI的独立危险因素。再发AMI患者住院期间短期死亡率并不明显增加。     

Comparison of the effect of heparin and aspirin versus aspirin alone on transient myocardial ischemia and in-hospital prognosis in patients with unstable angina

Objectives. This study compared the effects of heparin and aspirin versus aspirin alone on transient myocardial ischemia and in-hospital prognosis in patients with unstable angina.Background. Transient myocardial ischemia occurring in patients with unstable angina is associated with an adverse prognosis. Heparin and aspirin are two drugs used frequently in the treatment of this condition, but the effect of combination therapy versus aspirin alone on transient myocardial ischemia is unknown.Methods. Two hundred eighty-five consecutive patients with unstable angina were randomized to receive either intravenous heparin plus oral aspirin (150 mg once daily) (Group H + A) or aspirin alone (Group A). Patients also received a beta-adrenergic blocking agent, diltiazem and intravenous nitrates. ST segment monitoring was performed for the 1st 48 h of treatment. Patients were followed up for the duration of their in-hospital stay.Results. One hundred fifty-four patients (30 women, mean [±SEM] age 58.3 ± 0.8 years) received heparin and aspirin (Group H + A), and 131 patients (26 women, mean age 60.6 ± 0.8 years) received aspirin only (Group A). ST segment monitoring (11,622 h) yielded 244 episodes of transient myocardial ischemia of a total duration of 7,819 min. There were no significant differences between the two treatment arms in the number of patients with transient myocardial ischemia (27 [18%] in Group H + A vs. 31 [24%] in Group A), number of episodes (96 in Group H + A vs. 148 in Group A) or total duration of transient myocardial ischemia (2,911 min in Group H + A vs. 4,908 min in Group A). The incidence of in-hospital myocardial infarction or death was significantly higher in patients with transient myocardial ischemia (53% vs. 22%, p < 0.0001). Five of the six deaths occurred in patients with transient myocardial ischemia. Event-free survival from myocardial infarction or death was similar in both treatment groups. Preadmission therapy with aspirin was associated with a lower in-hospital infarction rate (19% vs. 34%, p = 0.01).Conclusions. The presence of transient myocardial ischemia in patients with unstable angina is associated with a significantly higher incidence of myocardial infarction or death in hospital. Combined therapy with heparin and aspirin compared with aspirin alone makes no difference in the development of these events, nor does it reduce the development of transient myocardial ischemia.     

Assessment of derived 12-lead electrocardiograms using general and patient-specific reconstruction strategies at rest and during transient myocardial ischemia

Twelve-lead ST-segment monitoring is a widely used tool for capturing focal ischemia and transient intermittent episodes. However, continuous registration of all 10 electrodes is impractical in clinical settings. This study investigated the accuracy of 2 derived 12-lead strategies that required 6 electrodes, including all limb leads, and 2 precordial leads by using population-based (generalized) and individualized (patient-specific) reconstruction coefficients to derive the additional 4 chest leads. A total of 26,880 simultaneous digital conventional 12-lead generalized and patient-specific electrocardiograms were monitored over 112 hours in 39 patients during percutaneous coronary intervention, including 159 balloon occlusions in 63 arteries, to test accuracy at rest and during ischemia. Occlusion duration was 78 seconds (range 42 to 96) in the left main coronary in 2 patients, the left anterior descending artery in 15, the right coronary artery in 10, the circumflex artery in 2, and graft segments in 5 patients. Average summated 12-lead ST deviation over the study population at baseline was 377 microV (range 104 to 1,718), which increased at peak ischemia to an average of 1,086 microV (range 282 to 4,099). Median absolute differences at peak ischemic ST deviation were 25 microV in lead V(1), 0 microV in lead V(2), 35 microV in lead V(3), 34 microV in lead V(4), 0 microV in lead V(5), 11 microV in lead V(6), and 114 microV for summated 12-lead ST deviation with the generalized method and 7 microV in lead V(1), 4 microV in lead V(2), 1 muV in lead V(3), 5 microV in lead V(4), 4 microV in lead V(5), 9 microV in lead V(6), and 83 microV for the summated 12-lead ST deviation with the patient-specific method. Limb leads (I, II, III, aVR, aVL, and aVF) were identical in all patients. Thus, generalized and patient-specific methods derived from 12-lead electrocardiography using actual limb and 2 precordial electrodes accurately derived the additional chest leads at rest and during ischemia. These approaches appear to be more practical than conventional 10-electrode monitoring but preserve high accuracy.     

急性肺栓塞的心电图变化

目的 　 探讨心电图在诊断急性肺栓塞中的作用。　方法　回顾性分析近两年收治的 13例急性肺栓塞患者入院时、溶栓后及治疗 2～ 4周后心电图的变化。　结果　 (1)入院时心电图变化 :心动过速 8例 ,右束支阻滞 3例 ,V1 导联T波、V1 ～V2 导联T波、V1 ～V3导联T波、V1 ～V4 导联T波、V1 ～V5导联T波、V1 ～V6 导联T波倒置为 10、 6、 4、 3、 2和 1例 ,SⅠ >0 1mV、TⅢ 、QⅢ 、SⅠQⅢTⅢ 分别为 7、 7、 9和 7例 ;(2 )溶栓后心电图变化 :心动过速消失 7例 ,右束支阻滞消失 1例 ,胸前导联T波倒置加深 4例 ,SⅠ 变浅 ,QⅢ 减小或消失 ,TⅢ 倒置变浅或直立 3～ 4例 :(3)治疗 2～ 4周后心电图变化 :心动过速消失 ;胸前导联T波直立数增加 ,ST段回基线 ,QⅢ 进一步减小或消失 ,TⅢ 倒置变浅或直立。　结论　急性肺栓塞心电图变化是多变的 ,需动态观察并密切结合临床加以识别。     

急性心肌梗死患者肾功能状态及对预后的影响

目的探评价急性ST段抬高型心肌梗死(STEMI)患者入院即刻肾功能状态及对院内预后的影响。方法多中心、前瞻性队列研究。入选自2005年12月至2007年1月,在发病后24小时内至北京市19家医院就诊的STEMI患者718例。入院即刻测定血清肌酐,根据改良的简化MDRD公式计算估计的肾小球滤过率(eGFR)。分为肾功能正常组(eGFR≥90ml/(min·1.73m2)、轻度肾功能不全组(60ml/(min·1.73m2≤eGFR90ml/(min·1.73m2)和中度肾功能不全组(eGFR60ml/(min·1.73m2),比较三组的临床特点和院内死亡和心血管事件发生情况,采用多元Logistic回归分析影响STEMI患者院内死亡和主要心血管事件的危险因素。结果 718例患者中共有280例(39.0%)已经存在不同程度的肾功能不全(eGFR90ml/min),其中61例(8.5%)为中度以上肾功能不全(eGFR60ml/min)。与肾功能正常组相比,轻度肾功能不全组和中度肾功能不全组患者年龄偏大(57±12)岁vs(66±13)岁vs(72±13)岁,P0.01),女性比例多(16.9%vs39.2%vs48.3%,P0.01),既往有高血压病(47.7%vs59.8%vs70.5%,P0.01),心力衰竭(0%vs2.7%vs6.6%,P0.01),脑卒中或一过性脑缺血(TIA)病史(8.9%vs10.6%vs19.3%,P0.05),入院时心功能Killip≥II级(34.7%vs37.0%vs65.5%,P0.01)较多。院内病死率(1.4%vs5.9%vs22.9%,P0.01)和心血管事件(18.0%vs27.4%vs63.9%,P0.01)显著增高。多因素Logistic回归分析显示入院即刻肾功能不全是STEMI患者发生院内死亡和心血管事件的独立危险因素(OR值分别为3.870;95%CI:1.767-8.474,P0.01和1.712;95%CI:1.217-2.408,P0.01)。结论 STEMI患者中肾功能不全发生率较高,院内死亡及心血管事件的发生率随肾功能恶化而增加,肾功能不全是院内死亡和心血管事件的独立危险因素。     

Holter-detected myocardial ischemia. Impact for prognosis and decision making after acute myocardial infarction

BACKGROUND: Aim of the study was to evaluate the prognostic and decision making value of Holter detected myocardial ischemia after acute myocardial infarction in comparison with clinically detected postinfarction angina and exercise test. METHODS: To this aim the patients consecutively admitted to our coronary care unit with acute myocardial infarction during one year were retrospectively evaluated. One hundred and eighty-nine patients (age 70+/-11 years, 137 male and 51 female) had a 24 hour Holter monitoring. One-year follow up of these patients was obtained. RESULTS: Myocardial ischemia was detected by Holter monitoring in 21 patients (11%), 4 with and 17 without angina. Symptom limited exercise test was obtained before discharge in 116 patients (62%): 45% were positive, 42% non-diagnostic and 13 negative for myocardial ischemia. Post infarction angina was present in 15 patients (9%). Patients with Holter detected myocardial ischemia were older (73+/-10 vs 66+/-11 years, p<0.05) and had higher prevalence of both angina and positive exercise test (p<0.01). One-year follow up was obtained in 186 patients. Holter detected myocardial ischemia positive predictive value for death or reinfarction was 15%, negative predictive value was 90%, similar to the absence of angina (90%) and the absence of positive exercise test (93%). Angina and exercise test identified 62% of patients with Holter detected myocardial ischemia. Residual myocardial ischemia was exclusively observed by Holter monitoring in 4% of the population, particularly in 1 patients with and 7 without exercise test. CONCLUSIONS: The additive contribution of Holter detected myocardial ischemia in the prognosis and decision making of post infarction patients is rather scanty.     

Role of myocardial scintigraphy with thallium-201 in the characterization of episodes of transient ischemia at rest. Clinical and electrocardiographic correlates

In the past ten years we studied 80 patients with angina at rest by 201-Thallium perfusion scintigraphy. According to ECG changes during episodes of transient ischemia at rest, the patients were divided into three groups. Thirty six patients showed transient ST segment elevation (Group 1); 33 ST segment depression (Group 2) and 11 normalization of negative T waves (Group 3). 201-TI scintigraphy was performed during spontaneous or ergonovine induced episodes of ischemia and at redistribution. Group 1 showed localized and severe perfusion defects, well correlated to the site of ECG changes. Group 2 showed more diffuse and less severe perfusion defects, less correlated to the site of ECG changes. Group 3 showed perfusion defects similar to those observed in Group 1 and associated in 54% with basal perfusion defects due to previous myocardial infarction. In conclusion: A) three main perfusion patterns are associated with the three types of ECG changes; B) relative to ECG, myocardial scintigraphy provides a more accurate definition of the site and extension of ischemia, particularly in Group 2 patients.     

胰岛素抵抗对急性ST段抬高心肌梗死患者院内预后的影响

目的:评估胰岛素抵抗(IR)对急性ST段抬高心肌梗死(STEMI)患者院内预后的影响。方法:入选148例STEMI患者,分为胰岛素抵抗组(IR组)和非胰岛素抵抗组(NIR组),比较两组的临床特点和院内预后。结果:IR组合并高血压较NIR组多,且入院时血压也较高。IR组患者冠脉狭窄程度较NIR组严重,心功能不全发生率、住院期间脑血管意外、院内死亡率也显著增高。结论:STEMI合并IR患者冠脉病变程度严重、住院死亡及脑血管意外发生率较NIR患者显著增高,提示IR是预测STEMI患者院内预后的重要因素之一。     

Timing and triggers of transient myocardial ischemia

Use of exercise tolerance testing and new techniques of ambulatory electrocardiographic monitoring to more objectively measure myocardial ischemia have enabled clinicians to better recognize the magnitude, timing and variable characteristics of transient ischemic events. These commonly occurring events in patients with coronary artery disease have a diurnal pattern strikingly similar to that reported for catastrophic cardiovascular events such as myocardial infarction, sudden cardiac death and stroke. Whether those factors that contribute to reversible ischemic events are similar to those causing infarction and sudden death has not been resolved. However, the parallel increase in morning activity for these related phenomena suggests that a better understanding of the triggers of reversible myocardial ischemia may help improve understanding of the causes of myocardial infarction and sudden cardiac death.     

Clinical evaluation of transient myocardial ischemia

Out of 432 patients with coronary heart disease, 106 (24.5%) were found to have transient myocardial infarction during ECG monitoring of ST segment for 10 hours of daily activity. High-grade ventricular arrhythmias were revealed in 74.6% of mainly male and middle-aged subjects. 63.4% of the patients exhibited congestive heart failure, 48.1% had postinfarct cardiosclerosis, and 25.5% presented with diabetes mellitus. Transient myocardial ischemia was more frequently detected during exercise and more rarely during emotional stress (21.7%), meal (19.8%), and smoking (7.8%). Asymptomatic episodes of ST segment elevation were recorded in 36.8%, while asymptomatic episodes of ST segment depression, in 29.2%. The duration of asymptomatic episodes of ST segment elevation and depression was twice and 1.5 times, respectively, less than that of symptomatic ones. Substantial myocardial perfusion and metabolic impairments were revealed with an asymptomatic ST segment depression frequency of at least one an hour, an amplitude of more than 2 mm, and a duration of no less than 40 min.     

Electrocardiographic diagnosis of myocardial infarction and ischemia during cardiac pacing

For the diagnosis of myocardial infarction (MI) using the QRS complex, the ECG provides only a low sensitivity (25%) but high specificity (close to 100%), but one cannot determine the age of an MI from the QRS complex. Although one cannot determine with certainty the age of an MI (hours, days or even years) from a single ECG, the presence of primary ST-segment abnormalities strongly suggests the diagnosis of acute MI or severe ischemia and the possible need for emergency revascularization. For acute MI, ST elevation>or=5 mm in predominantly negative QRS complexes is the best marker with a sensitivity of 53%, and specificity of 88%. A recent investigation suggests that T wave abnormalities from ischemia can be differentiated from those caused by cardiac memory related to pacing.