Unappreciable myocardial bridge causing anterior myocardial infarction and postinfarction angina

We report a case of anterior myocardial infarction in a middle-aged man without risk factors for atherosclerosis in whom myocardial bridge was diagnosed several years later. An abnormal wall motion during acute myocardial infarction masked the characteristic angiographic findings of myocardial bridge and rendered it unappreciable during the initial angiographic study.     

心肌桥致急性前壁心肌梗死的临床风险分析

目的探讨心肌桥致急性前壁心肌梗死的特征及临床风险。方法统计因急性胸痛疑心肌梗死行造影检查检出心肌桥的30例患者以及因急性胸痛造影检查无心肌桥的30例患者,分析心肌桥与急性前壁心肌梗死的关系,以及心肌桥致急性心肌梗死的特点。结果两组患者性别、年龄、高血压、高脂血症、家族史、吸烟史方面比较差异均无统计学意义。心肌桥患者在胸闷和胸痛方面无特异表现。在硝酸甘油疗效方面,30例心肌桥患者中3例(10.0%)有疗效;而无心肌桥患者11例(36.7%)有疗效。另外,30例心肌桥患者25例(83.3%)心功能在Ⅲ级或者Ⅳ级,而无心肌桥患者18例(60.0%)心功能在Ⅲ级或者Ⅳ级;心肌桥患者最终16例(53.3%)发生心肌梗死,而无心肌桥患者有8例(26.7%)发生心肌梗死。结论心肌桥患者服用硝酸甘油疗效很差,心肌梗死的风险有所提高,应早期防治。     

外伤性心肌损伤误诊急性心肌梗死一例

外伤性心肌损伤是钝性胸部外伤后的一种少见并发症,其最常见的症状是非特异性胸痛,其次为室性早搏和束支传导阻滞,伴有心肌坏死标志物轻度升高,需与急性心肌梗死鉴别。我院接收1例外伤性心肌损伤误诊为急性心肌梗死的病例,经过相应检查除外了急性心肌梗死,此类患者应引起各专业医生的关注,特别是老年患者,多合并基础心血管疾病,在临床工作中更应重视。     

经静脉实时心肌造影超声心动图评估心肌梗死后存活心肌

目的探讨经静脉实时心肌造影超声心动图（RT-MCE）评估心肌梗死后存活心肌。方法18例准备进行血运重建术心肌梗死患者,于术前1-5天行RT-MCE检查,并于术后3个月再次行常规超声心动图检查,室壁运动分析采用18节段分析法,分为运动正常、运动减弱、无运动和反常运动。心肌存活定义为术后超声检查室壁运动明显改善。将造影结果分为3种情况：充盈缺损,造影剂充盈延迟、回声稀疏不均匀或心内膜下充盈缺损,回声均匀性增强。其中后两种情况定义为存活心肌。结果在18例心肌梗死患者中共检出109个室壁运动异常节段,运动减弱为47个,无运动为56个,反常运动为6个。注射造影剂后回声均匀性增强的心肌节段中有2个节段术前室壁运动减弱,术后运动均改善;回声不均匀或心内膜下充盈缺损的心肌节段中术前室壁运动减弱有24个节段,术后运动改善14个,术前室壁无运动有24个节段,术后运动改善20个;充盈缺损的心肌节段中术前室壁运动减弱有21个节段,术后运动均未改善,术前室壁无运动32个,术后运动改善2个。RT-MCE检出存活心肌的敏感性、特异性分别为94.7%、78.9%。结论RT-MCE能比较准确的判断心肌梗死后心肌的存活性。     

Plasma zinc after myocardial infarction

Plasma levels of zinc and albumin have been measured for eight consecutive days in patients suffering chest pain due to myocardial infarction or myocardial ischaemia. A substantial diurnal variation has been found in both controls and patients. Plasma zinc falls after myocardial infarction reaching the lowest level on day 2, thereafter returning to normal by day 8. The lowest plasma zinc levels occur within 48 h of a myocardial infarction and in some patients herald the development of a serious cardiac arrhythmia. Plasma albumin falls progressively after myocardial infarction, being lowest on day 8. The fall in plasma zinc is not totally explained by the fall in plasma albumin.     

The acute myocardial infarction

Cardiovascular death is the number one cause of death in the United States, with a rate that is more than double that for cancer. Over half of these cardiovascular deaths are due to acute myocardial infarction. Management of the patient with acute myocardial infarction during and after hospitalization is discussed with an emphasis on primary and secondary prevention, patient autonomy and decision making. There is also a review of the directions that treatment of acute myocardial infarction will take in the future.     

Computed tomography imaging in myocardial infarction

Over recent decades, noninvasive imaging has become well established in the diagnostic work-up of patients suffering from myocardial infarction. It provides insights into the individual patient's prognosis and guides therapeutic decisions. MRI has long been considered the standard of reference in the noninvasive imaging of myocardial infarction. Only recently have different multidetector-row spiral computed tomography (MDCT) techniques successfully been evaluated for the visualization of myocardial infarction. This article describes different concepts of cardiac MDCT imaging in acute and chronic myocardial infarction. MDCT assessment of myocardial edema, myocardial perfusion and delayed myocardial contrast enhancement are introduced, with the latter evolving as key concept of viability imaging by means of MDCT. The current status of MDCT in the diagnostic work-up of myocardial infarction is reviewed.     

Stroke in patients with acute myocardial infarction

The analysis has been performed of 40 cases of acute myocardial infarction with concomitant stroke versus 26 cases of acute myocardial infarction alone. Being a complication of acute myocardial infarction in 0.94% of the cases, the stroke was ischemic in 95% and hemorrhagic in 5% of the patients. Association of the two events accounted for lethal outcomes in 80% of the cases. The principal factors of the stroke risk in myocardial infarction are suggested. They involve: an advanced age, cardiac arrhythmias, cardiogenic shock, diabetes mellitus, recurrent or transmural myocardial infarction, previous acute episodes of disturbed cerebral circulation, essential hypertension and hyperglycemia.     

心肌缺血预适应现象与心肌梗塞临床及预后关系的研究

目的：探讨心肌缺血预适应对心肌梗塞临床及预后的影响。方法：对３８５例心肌梗塞患者的临床及随访资料进行分析，按梗塞前有无心肌缺血表现分为Ａ、Ｂ两组。结果：Ａ组心肌梗塞时心肌坏死范围、心肌酶峰值、心律失常、左心衰竭、室壁瘤形成及病死率均明显低于Ｂ组，而梗塞后心绞痛及再次心肌梗塞的发生率却明显高于Ｂ组。两组差异显著（Ｐ＜０．０５或＜０．０１）。结论：心肌缺血预适应的临床意义有：①使再次缺血的程度减轻。②降低心律失常的发生率，提高室颤阈。③缩小梗塞范围。④维持梗塞后心脏功能。     

Adenosine myocardial perfusion single photon emission computed tomographic stress testing 24-72 h after uncomplicated myocardial infarction

Safety of performing adenosine myocardial perfusion stress testing as early as 24 h after acute uncomplicated myocardial infarction is not known. We evaluated 31 (14 females and 17 males, average age 72, range 46–89 years) consecutive patients with uncomplicated myocardial infarction, who underwent adenosine myocardial perfusion stress imaging, 24–72 h after infarction for risk stratification. Adenosine was infused at a rate of 140 g/kg/min for 6 min. Twenty patients were presented with non-ST-elevation myocardial infarction. Eleven patients were admitted with acute ST-elevation myocardial infarction. Patients were monitored for signs of complication during and immediately after the stress test. The average time from admission to performance of stress tests was 51 ± 19 h, ranging from the minimum of 24 h to maximum 72 h. No complications related to adenosine infusion were detected. In conclusion, our data suggest that a further large study of early adenosine myocardial perfusion SPECT imaging may be safe in a carefully selected group of patients after uncomplicated myocardial infarction.     

Acute coronary syndrome and myocardial infarct--new definitions

Until recently a general consensus existed for the clinical entity diagnosed as myocardial infarction using the world health organisation (WHO) definition. According to the WHO definition myocardial infarction was defined by a combination of two of three typical characteristics: typical symptoms, rise of cardiac enzymes (CK, CK-MB), and a typical ECG pattern involving the development of Q waves. New insights into the development of acute myocardial infarction, the superiority of the biochemical characteristics of cardiac troponin assays over CK and CK-MB measurements in blood, and new therapeutic concepts made a new definition of myocardial infarction, e.g. of the acute myocardial infarction, necessary. Timing of the diagnosis of myocardial necrosis is of outmost importance relative to the time of observation (acute, evolving, healing, healed MI), as is the classification of the extent of myocardial damage (microscopic, small, medium or large). The term "acute coronary syndrome" (ACS) has been established as a working diagnosis for choosing the appropriate therapeutic strategy. In patients with ACS and ST elevation ischemia (STEMI ACS, true posterior ischemia inclusive) as well as in patients with presumably new LBBB, immediate reperfusion therapy should be performed (primary PTCA or thrombolytic therapy), whereas in patients with ECG changes other than ST elevation or new LBBB (NSTEMIACS) additional antiplatlet therapy on top of aspirin and heparin is indicated. In contrast to the acute phase of infarction when troponin in blood often is not detectable yet, the diagnosis of definitive myocardial infarction is based primarily on troponin elevation. Hard criteria for established infarction are the development of pathologic Q waves or healing or healed myocardial necrosis in pathology; troponin may be normal then, depending of time relapsed.     

核素心肌灌注显像诊断无症状性心肌缺血价值

目的探讨核素心肌灌注显像诊断无症状性心肌缺血的临床应用价值。方法动态心电图或其他心电检测技术检测无症状性心肌梗死患者22例,均行核素心肌灌注显像与冠状动脉造影检查,并以冠状动脉造影结果为金标准,计算核素心肌灌注显像结果预测值。结果 22例患者中8例核素心肌灌注显像表现为不可逆性心肌缺血,14例表现为混合性心肌缺血,共检测出40个节段病变心肌。冠状动脉造影检出阳性血管45支(血管狭窄程度≥50%),其中28支狭窄程度>90%,15支狭窄程度>70%~90%,2支狭窄程度≤70%。核素心肌灌注显像阳性结果预测值为88.9%(40/45)。结论核素心肌灌注显像有助于无症状性心肌缺血诊断,并可用于评价心肌损害严重程度。     

冠状动脉完全闭塞无心肌梗死患者临床特点

目的探讨冠状动脉完全闭塞无心肌梗死患者的临床特点。方法选取冠状动脉造影显示冠状动脉完全闭塞而无心肌梗死发生的23例患者（无心肌梗死组）和冠状动脉造影显示冠状动脉完全闭塞有明显临床心肌梗死证据的27例患者（心肌梗死组），比较两组患者的临床特点。结果两组在高血压、年龄、性别等方面比较差异无显著性。无心肌梗死组在糖尿病、血脂异常、吸烟、心绞痛史等方面与心肌梗死组比较，差异均有显著性（均为P〈0．05）。无心肌梗死组冠状动脉病变血管支数较心肌梗死组多，侧支循环建立较好。但经皮冠状动脉介入治疗的成功率要低于心肌梗死组。结论冠状动脉造影显示有冠状动脉完全闭塞患者中，部分患者可无心肌梗死表现。除年龄、性别等不可控制因素外，糖尿病、血脂异常、吸烟等危险因素可能促进冠状动脉粥样硬化的发展。部分冠状动脉完全闭塞而无心肌梗死的患者常有较长的心绞痛史，冠状动脉病变弥散，侧支循环建立较好，所以在某支冠状动脉病变发展到完全闭塞时可不表现心肌梗死。     

心肌梗死后心肌存活面积与心功能的关系

目的探讨心肌梗死后心肌存活面积与心功能的关系.方法对98例曾患有心肌梗死的患者,用硝酸甘油介入、99Tc-甲氨基异丁基异氰(99TcmMIBI)二次扫描方法测定存活心肌面积,同时计算出心功能指标.结果存活心肌面积大组与存活心肌面积小组平均年龄及有无心力衰竭、心脏扩大等各项危险因素例数比较,差异无显著性意义(P＞0.05);前者的严重心律失常的发生率为58.2%,后者为25.6%,2组有显著差异(P＜0.01).结论提示心肌梗死后存活心肌面积与心功能和心率失常密切相关.     

心肌酶谱检测在急性心肌梗死诊断中的价值

[目的]探讨心肌酶谱测定在诊断急性心肌梗死中的应用价值。[方法]选取我院2009年1月一2010年1月住院的急性心肌梗死患者40例。测定其肌酸激酶（CK）、肌酸激酶同工酶（CK—MB）、乳酸脱氢酶（LDH）、同型半胱氨酸（HCY）含量,并与40例正常对照组比较,观察其在诊断急性心肌梗死中的应用价值。[结果]AMI组CK、CK—MB、LDH以及HCY检测结果明显高于正常对照组,具有统计学意义（P〈0．01）。CK—MB、CK、LDH以及HCY的检出敏感性分别为87．5％,82．5％,75％和57．5％。[结论]心肌酶谱测定在诊断急性心肌梗死中具有较好的临床应用价值。     

Acute myocardial infarction

Patients with acute myocardial infarction as well as high risk patients for coronary artery disease has been shown to receive benefits from angiotensin-converting enzymes. Since angiotensin receptor blocker(ARB) provides more complete blockade of the RAA system, treatment with ARB may bring more fruitful results. In this article, secondary prevention trials(OPTIMAAL and VALIANT) for patients with acute myocardial infarction and primary prevention trials(LIFE, SCOPE, and VALUE) were reviewed.     

Acute myocardial infarct and nitrogen balance

Nitrogen balance studies were performed over 6 days in 20 consecutive patients with acute myocardial infarction and results compared with the haemodynamic parameters. 10 patients with unstable angina, but without acute myocardial infarction, formed a control group. All patients had a nitrogen input of 11.6 g/d. Nitrogen excretion was 13.9 g/d in patients with acute myocardial infarction and 8.9 g/d in the control group (p less than 0.001). 12 patients with complicated acute myocardial infarction had a mean nitrogen excretion of 15.6 g/d. There was no difference in nitrogen excretion between patients with or without diabetes mellitus. Mean nitrogen excretion in patients with acute myocardial infarction correlated significantly with severity of haemodynamic changes and blood glucose level on day of admission. The importance of parenteral nutrition in patients with complicated acute myocardial infarction and increased catabolism is emphasized.