THE Q WAVE IN L III AND aVF OF THE ELECTROCARDIOGRAM—A Vectorcardiographic Analysis With the Use of the Frank System

Seventy-three consecutive patients with a Q wave in Lead III and aVF in the electrocardiogram were studied. Vectorcardiograms were recorded with the use of the Frank system.In 32 cases the ECG''s were compatible with the diagnosis of an inferior myocardial infarction based on a Q wave in Lead III and/or aVF greater than 0.04 second duration and greater than 25 per cent of the amplitude of the R wave. In this group, there were 16 patients with coronary disease and the VCG confirmed the electrocardiographic diagnosis of an infarction in 14 cases. In 13 of the other 16 cases without history of coronary disease the VCG did not suggest the presence of an infarction.In all 17 cases with questionable electrocardiographic diagnosis of an inferior infarction, and without history of coronary disease, the VCG denied the presence of an infarction. In 18 cases with small Q III or Q aVF the VCG''s were within normal limits. In two cases with normal Q III and Q aVF the VCG''s did not detect the presence of an infarction in both cases.The vectorcardiographic diagnosis of an inferior myocardial infarction was based on the superior orientation (at or above 360 degrees) of the 10, 20, 25 and 30-msec vectors in the frontal plane, superior displacement of the maximum QRS vector and clockwise rotation. In the left sagittal plane the 10, 20, 25 and 30-msec vectors were oriented at or above 180 degrees with the loop rotating counterclockwise.The data presented suggest that vectorcardiography is a useful adjunct to electrocardiography in the diagnosis of an inferior myocardial infarction.     

MYOCARDIAL INFARCTION FOLLOWING CAROTID ENDARTERECTOMY

Myocardial infarction has been the major cause of mortality following operation for cerebrovascular insufficiency. In our institution, a clinical diagnosis of coronary artery disease was made in 37 of 125 (29.6%) consecutive male patients having carotid endarterectomy. Six of these 37 patients developed postoperative myocardial infarction. In contrast, none of the 88 patients without coronary artery disease developed myocardial infarction. A more recently treated group of 20 patients who had undergone carotid artery surgery and had previously undergone coronary artery bypass for angina did not develop postoperative myocardial infarction. These data suggest that in patients with both coronary artery and carotid artery disease, prior or concomitant coronary artery bypass should be considered. Myocardial infarction has been the leading cause of early and late death following operation for cerebrovascular insufficiency.(1) DeBakey(2) found operative mortality in patients having surgery for cerebrovascular insufficiency directly related to the incidence of coronary artery disease. An increased operative mortality due to reinfarction has been found in patients recovering from recent myocardial infarction.(3) Cooley(4) found that in patients having aortocoronary bypass there was no increased operative mortality 30 days after myocardial infarction and this may apply to patients having carotid endarterectomy. Subendocardial postoperative infarction associated with minor T wave changes and slight enzyme elevation had a better prognosis than did transmural infarction causing significant Q waves, sequential ST and T wave changes and marked enzyme elevations.(5) The purpose of this study was to document our experience with myocardial infarction in patients undergoing carotid artery operation for clinical coronary artery disease. Consideration of the role of saphenous vein bypass in those patients with coronary artery disease was the background for this review even though the evidence that myocardial infarction can be prevented with saphenous vein bypass operation is only preliminary at the present time.(6)     

Post mortem detection of early myocardial infarction by determination of the tissue K+/Na+ ratio

The K+/Na+ ratio was determined in myocardial specimens obtained post mortem from a total of 90 patients. The ratio was 1.0 or higher 25 cases in which there was firm evidence against myocardial infarction, and 0.7, or less in 30 cases with grossly visible signs of myocardial narcosis. The remaining 35 cases were suspect of myocardial infarction on the grounds of either clinical observation or sudden death, without gross change. Out of these the K+/Na+ ratio was above 0.7 histological evidence of myocardial infarction was absent, but other changes accounting for death were present in 17 cases. In another 16 cases a K+/Na+ ratio of 0.7 or less was the sole indication of myocardial infarction, and any other change likely to be responsible for death was absent. In two further cases a false negative result was obtained for the K+/Na+ ratio, owing in all probability to some technical error. The findings suggest that determination of the myocardial K+/Na+ ratio is a great aid in detecting early myocardial infarction. The technique is not affected by post mortem autolysis, and is simple enough for routine use.     

负荷量阿托伐他汀对稳定型冠心病患者非心脏手术围手术期保护作用的研究

目的:探讨负荷量阿托伐他汀对稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件的保护作用。方法:将拟行非心脏外科手术的60名稳定型冠心病患者随机分为负荷量阿托伐他汀组(n=30)和对照组(n=30),其中负荷量阿托伐他汀治疗组在术前12小时给予阿托伐他汀80 mg顿服,术前2小时阿托伐他汀40 mg顿服,且每晚服用阿托伐他汀40 mg,对照组术前每晚服用阿托伐他汀20 mg,而后进行非心脏的外科手术(主要病种为慢性胆囊结石胆囊炎、慢性阑尾炎、消化性溃疡、疝气),术后负荷量组给予每晚服用阿托伐他汀40 mg,对照组每晚服用阿托伐他汀20 mg。比较两组围手术期主要不良心脏事件(包括心脏性猝死,急性心肌梗死,非计划性血运重建)的发生情况。结果:对照组出现1例急性前壁ST段抬高型心肌梗死并行急诊前降支介入再灌注治疗和7例无症状型心肌梗死,负荷量阿托伐他汀组出现1例无症状型心肌梗死,围手术期心肌梗死发生率较对照组明显降低(P0.05)。结论:负荷量阿托伐他汀可显著降低稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件如心肌梗死,特别是无症状型心肌梗死的发生率,但该结果尚需大样本多中心随机对照临床试验进一步证实。     

Myocardial infarction after taking zolmitriptan

We report the case of a patient with mild non-obstructive coronary artery disease who sustained an inferior wall myocardial infarction shortly after taking zolmitriptan as abortive therapy for migraine headaches. A Medline search was performed to review all reported cases of myocardial infarction related to migraine therapy with zolmitriptan and related medications. Zolmitriptan may cause myocardial infarction (MI) even in the absence of significant coronary artery disease.     

Lipoprotein (a) and coronary heart disease: a prospective case-control study in a general population sample of middle aged men.

OBJECTIVE--To examine the association between the serum lipoprotein (a) concentration and subsequent coronary heart disease. DESIGN--Prospective case-control study based on a six year follow up of a general population sample of men aged 50 at baseline in 1983-4. Serum samples were frozen at the time of the baseline examination and kept at -70 degrees C for six years, after which the lipoprotein (a) concentrations in the samples were measured in cases and controls. SETTING--City of Gothenburg, Sweden. SUBJECTS--26 Men, from a general population sample of 776 men, who had sustained a myocardial infarction or died of coronary heart disease during the six years and 109 randomly selected controls from the same sample who had remained free of myocardial infarction. In neither cases nor controls was there a history of myocardial infarction at baseline. MAIN OUTCOME MEASURES--Proportion of myocardial infarction or deaths from coronary heart disease, or both, in relation to the serum lipoprotein (a) concentration. RESULTS--Men who suffered coronary heart disease had significantly higher serum lipoprotein (a) concentrations than controls (mean difference 105 mg/l; 95% confidence interval 18 to 192 mg/l). Men with the highest fifth of serum lipoprotein (a) concentrations (cut off point 365 mg/l) suffered a coronary heart disease rate which was more than twice that of men with the lowest four fifths of concentrations. Logistic regression analysis showed the serum lipoprotein (a) concentration to be significantly associated with coronary heart disease independently of other risk factors. CONCLUSION--The serum lipoprotein (a) concentration in middle aged men is an independent risk factor for subsequent myocardial infarction or death from coronary heart disease.     

Acute Myocardial Infarction: Clinical Application of Technetium 99m Stannous Pyrophosphate Infarct Scintigraphy

Acute myocardial infarction is being recognized as a spectrum of clinical subsets. This appreciation has been brought about to a large degree by the development of several new tools that can be applied clinically to aid in evaluation of patients with acute infarction, and in some cases to provide short and long-term prognostic information. In the realm of noninvasive methods, several tests utilizing radiopharmaceuticals and scintillation cameras have emerged and are rapidly becoming reliable diagnostic parameters in patients with coronary disease and infarction. Technetium 99m (stannous) pyrophosphate (TcPYP) scintigraphy, one of the first of these techniques to find clinical use, has been shown to be an accurate indicator of acute transmural myocardial infarction and provides added sensitivity and specificity to the diagnosis. Increased diagnostic accuracy, the dimension of visible localization and the potential for infarct sizing promise physicians better understanding of a patient''s clinical presentation and a more rational approach to management.     

Tying with thread of the rat coronary arteries, a method for the production of experimental coronary stenosis]

A method is described for producing a localized coronary artery stenosis by tieing two threads around the Ramus descendens of the left coronary artery, which produces progressive cell proliferation of the vascular wall. Studies on 102 male Wistar rats (70 experimental and 32 sham-operated control animals) have shown coronary artery stenosis narrowing the lumen by more than 50% (up to and exceeding 90%) to develop after 7 days in 30% of the animals, after 14 days in 75%, and after 21 days (postoperatively) in 100%. In about one-third of the cases subtotal infarction in the supply area of the left coronary artery occured as a result of post-operative damage to the coronary artery with obturating thrombosis. The induction of effective coronary stenosis limiting the coronary reserve offers possibilities for further experimental studies on the role of relative coronary insufficiency in the pathogenesis of myocardial infarction.     

CC类趋化因子亚家族与心肌梗死的研究进展

CC类趋化因子亚家族是趋化因子家族中成员最多、研究最广泛的一大类细胞因子,其主要功能参与炎症细胞激活、迁移、粘附等病理生理过程。大量研究表明,CC类趋化因子亚家族成员参与了心肌梗死后病理过程的各个阶段。其中研究最为深入的为单核细胞趋化蛋白-1（monocyte chemoattractant protein-1,MCP-1）及其受体CC趋化因子受体2（CC chemokine receptor 2,CCR2）,在心肌梗死后炎症期、增殖期及疤痕愈合期都发挥了重要作用从而影响梗死后心室重构。近年来,CC类趋化因子亚家族其他成员亦被逐渐揭示参与了心肌梗死的发展。本文结合以往大量文献将对CC类趋化因子亚家族在心肌梗死各个阶段中尤其是梗死后各期对于心室重构的影响进行综述,以期为今后的实验研究提供方向及疾病的预防和治疗提供药物靶点。     

Comparing Cognitive and Somatic Symptoms of Depression in Myocardial Infarction Patients and Depressed Patients in Primary and Mental Health Care

Depression in myocardial infarction patients is often a first episode with a late age of onset. Two studies that compared depressed myocardial infarction patients to psychiatric patients found similar levels of somatic symptoms, and one study reported lower levels of cognitive/affective symptoms in myocardial infarction patients. We hypothesized that myocardial infarction patients with first depression onset at a late age would experience fewer cognitive/affective symptoms than depressed patients without cardiovascular disease. Combined data from two large multicenter depression studies resulted in a sample of 734 depressed individuals (194 myocardial infarction, 214 primary care, and 326 mental health care patients). A structured clinical interview provided information about depression diagnosis. Summed cognitive/affective and somatic symptom levels were compared between groups using analysis of covariance, with and without adjusting for the effects of recurrence and age of onset. Depressed myocardial infarction and primary care patients reported significantly lower cognitive/affective symptom levels than mental health care patients (F (2,682) = 6.043, p = 0.003). Additional analyses showed that the difference between myocardial infarction and mental health care patients disappeared after adjusting for age of onset but not recurrence of depression. These group differences were also supported by data-driven latent class analyses. There were no significant group differences in somatic symptom levels. Depression after myocardial infarction appears to have a different phenomenology than depression observed in mental health care. Future studies should investigate the etiological factors predictive of symptom dimensions in myocardial infarction and late-onset depression patients.     

Diagnosis of Coronary Heart Diseases Using Gene Expression Profiling; Stable Coronary Artery Disease,Cardiac Ischemia with and without Myocardial Necrosis

Cardiovascular disease (including coronary artery disease and myocardial infarction) is one of the leading causes of death in Europe, and is influenced by both environmental and genetic factors. With the recent advances in genomic tools and technologies there is potential to predict and diagnose heart disease using molecular data from analysis of blood cells. We analyzed gene expression data from blood samples taken from normal people (n = 21), non-significant coronary artery disease (n = 93), patients with unstable angina (n = 16), stable coronary artery disease (n = 14) and myocardial infarction (MI; n = 207). We used a feature selection approach to identify a set of gene expression variables which successfully differentiate different cardiovascular diseases. The initial features were discovered by fitting a linear model for each probe set across all arrays of normal individuals and patients with myocardial infarction. Three different feature optimisation algorithms were devised which identified two discriminating sets of genes, one using MI and normal controls (total genes = 6) and another one using MI and unstable angina patients (total genes = 7). In all our classification approaches we used a non-parametric k-nearest neighbour (KNN) classification method (k = 3). The results proved the diagnostic robustness of the final feature sets in discriminating patients with myocardial infarction from healthy controls. Interestingly it also showed efficacy in discriminating myocardial infarction patients from patients with clinical symptoms of cardiac ischemia but no myocardial necrosis or stable coronary artery disease, despite the influence of batch effects and different microarray gene chips and platforms.     

Haplotype analysis of the beta2 adrenergic receptor gene and risk of myocardial infarction in humans

Polymorphisms in the beta2 adrenergic receptor (ADRB2), in particular G16R, Q27E, and T164I, have been implicated in the pathogenesis of cardiovascular and metabolic phenotypes. However, no prospective, genetic-epidemiological data are available on the risk of cardiovascular disease associated with these variants. Using DNA samples collected at baseline in a prospective cohort of 14,916 initially healthy American men, we evaluated the G16R, Q27E, and T164I polymorphisms among 523 individuals who subsequently developed myocardial infarction and among 2092 individuals who remained free of reported cardiovascular events during follow-up. The haplotype frequency distribution was significantly different among cases and controls (chi(2)(7d.f.) = 20.92, P = 0.0039). Haplotype-based logistic regression, adjusting for age, smoking, and randomized treatment group, indicated that G16-Q27-I164 (odds ratio 0.178, 95% C.I. 0.043-0.737, P = 0.017) and (non-G16-Q27)-T164 (odds ratio 1.235, 95% C.I. 1.031-1.480, P = 0.022) haplotypes were significantly associated with altered risk of myocardial infarction. These findings remained after further adjustment for BMI, history of hypertension, and presence or absence of diabetes. In conclusion, variation in haplotype frequencies for the beta2 adrenergic receptor gene was found to be associated with risk of myocardial infarction.     

Acute myocardial infarction and sudden death in Sioux Indians.

While some Indian tribes have low rates of acute myocardial infarction, Northern Plains Indians, including the Sioux, have rates of morbidity and mortality from acute myocardial infarction higher than those reported for the United States population in general. In a review of diagnosed cases of acute myocardial infarction over a 3-year period in 2 hospitals serving predominantly Sioux Indians, 8% of cases were found misclassified, and 22% failed to meet rigorous diagnostic criteria, although the patients did indeed have ischemic heart disease. Patients had high frequencies of complications and risk factors and a fatality rate of 16% within a month of admission. Sudden deaths likely due to ischemic heart disease but in persons not diagnosed as having acute myocardial infarction by chart review occurred 3 times more frequently than deaths occurring within a month of clinical diagnosis.     

In vivo estimation of elastic heterogeneity in an infarcted human heart

In myocardial infarction, muscle tissue of the heart is damaged as a result of ceased or severely impaired blood flow. Survivors have an increased risk of further complications, possibly leading to heart failure. Material properties play an important role in determining post-infarction outcome. Due to spatial variation in scarring, material properties can be expected to vary throughout the tissue of a heart after an infarction. In this study we propose a data assimilation technique that can efficiently estimate heterogeneous elastic material properties in a personalized model of cardiac mechanics. The proposed data assimilation is tested on a clinical dataset consisting of regional left ventricular strains and in vivo pressures during atrial systole from a human with a myocardial infarction. Good matches to regional strains are obtained, and simulated equi-biaxial tests are carried out to demonstrate regional heterogeneities in stress–strain relationships. A synthetic data test shows a good match of estimated versus ground truth material parameter fields in the presence of no to low levels of noise. This study is the first to apply adjoint-based data assimilation to the important problem of estimating cardiac elastic heterogeneities in 3-D from medical images.     

Thallium 201 Scintigraphy

The radioactive isotope thallium 201 behaves physiologically as a potassium analog, and when injected intravenously accumulates rapidly within the cells of many organs. Uptake of the isotope reflects both regional perfusion and sodium-potassium pump activity. The radionuclide emits 80 keV x-rays which are suitable for scintillation camera imaging.The main clinical application of ²⁰¹TI scintigraphy has been in myocardial imaging. Abnormal uptake of the isotope results in a cold spot on the myocardial image. In patients with coronary artery disease, the differentiation of ischemic and infarcted myocardium is made by comparing images obtained after injecting the radionuclide at the peak of a maximal exercise test with those obtained after injection at rest. Abnormalities due to ischemia usually are seen only on the stress image whereas fixed defects in both rest and stress studies usually indicate areas of infarction or scarring. Some investigators believe that redistribution images obtained four to six hours after stress injection (without administering further ²⁰¹TI) give the same information as a separate rest study. The sensitivity of stress imaging for detecting significant coronary disease is of the order of 80 percent to 95 percent, though computer processing of the images may be necessary to achieve the higher figure. The prediction of the extent of coronary disease from ²⁰¹TI images is less reliable. An abnormal ²⁰¹TI image is not entirely specific for coronary artery disease and the likelihood of an abnormal image being due to this diagnosis varies according to the clinical circumstances.The main clinical value of ²⁰¹TI myocardial imaging is likely to be in the noninvasive screening of patients with atypical chest pain or with ambiguous findings on stress electrocardiographic tests. It has also proved useful in studying patients with variant angina or following a coronary bypass operation. It is doubtful whether the technique is clinically helpful in most patients with suspected or established acute myocardial infarction.Imaging of organs other than the heart with ²⁰¹TI has received much less attention but has been reported in patients with peripheral vascular disease and various primary and secondary neoplasms.     

New aspects of ICD therapy: from rhythm therapy to complex cardiac monitoring. Development of an implantable, ICD-assisted, intrathoracic 6-channel ECG for continuous monitoring of high infarct risk patients]

Implantable defibrillator systems (ICD) are therapy of choice for the treatment of life-threatening ventricular arrhythmias and in prevention of sudden cardiac death. In more than 80% of patients who receive an ICD, the underlying cardiac disease is a coronary heart disease. Since arrhythmogenic sudden cardiac death can be reliably prevented in these patients by the use of ICD technology, the cardiac prognosis for these patients is determined by the occurrence of myocardial ischemia and myocardial infarction, as well as from the heart failure which develops in consequence. An intrathoracic 6-channel ECG comparable to the standard surface ECG can be reconstructed by further technical development of the electrode configurations currently present in ICD systems. The importance of this development in early diagnosis of myocardial ischemias and myocardial infarction can hardly be adequately estimated at the moment. The chronic consequences of myocardial infarction can be completely prevented or at least greatly reduced by means of such diagnostics and inclusion of immediate initiation of effective, appropriate early therapeutic measures before more serious symptoms even occur. In the development and pilot studies thus far, it has been found that the intrathoracic 6-channel ECG which can be generated in the ICD is capable of reliably recognizing acute myocardial ischemia, irrespective of localization or extent earlier and better than the standard surface ECG. Continuous preventive ischemia monitoring using the implanted ICD thus appears possible in patients at risk of infarction.     

Early exercise testing after treatment with thrombolytic drugs for acute myocardial infarction: importance of reciprocal ST segment depression.

OBJECTIVE--To investigate the clinical importance of reciprocal ST depression induced by exercise testing early after acute myocardial infarction in patients treated with thrombolysis. DESIGN--Prospective observational study. SETTING--District general hospital in London. SUBJECTS--202 patients (170 men) aged 33-69 with acute myocardial infarction treated with thrombolysis. MAIN OUTCOME MEASURES--All patients underwent exercise testing and coronary arteriography. ST depression induced by exercise was classified as either reciprocal (associated with ST elevation) or isolated (occurring on its own). The relation between reciprocal ST depression and the following end points was studied: characteristics of the infarct, left ventricular ejection fraction, extent of coronary artery disease on arteriography, and presence of angina induced by exercise. RESULTS--Reciprocal ST depression occurred almost exclusively in Q wave infarctions and was associated with a lower overall ejection fraction than isolated ST depression. It tended to be associated with persistent occlusion of the coronary artery related to the infarct and did not indicate remote ischaemia due to multivessel coronary disease. Unlike isolated ST depression, reciprocal ST depression was not associated with angina induced by exercise. CONCLUSIONS--Reciprocal ST depression induced by exercise is usually associated with extensive Q wave infarctions and persistent occlusion of the artery related to the infarct. It does not seem to indicate reversible ischaemia and should not be used as a non-invasive marker of multivessel disease in the assessment of requirements for further investigation soon after acute myocardial infarction.     

Cardiac predictors of death after non-cardiac surgery evaluated by intention to treat.

Cardiac risk factors were studied among patients who were admitted to hospital with appendicitis or a fracture of the proximal femur less than one year after being admitted with myocardial infarction. Of 99 patients with myocardial infarction and appendicitis, 87 underwent appendicectomy; and of 221 with myocardial infarction and hip fracture, 179 were operated on. The patients were studied on an intention to treat basis. The mortality within one month was 9% and 16% respectively. A history of congestive heart failure was the dominating risk factor, while ischaemic heart disease (recent myocardial infarction or angina pectoris) had no independent association with mortality. If the ventricular function is known additional preoperative information about the heart is of negligible value when estimating the mortality of non-cardiac surgery.     

心内膜下心肌梗死的常见误诊病例浅析

目的：探讨心内膜下心肌梗死的常见误诊原因及对策。方法：回顾性分析9例心内膜下心肌梗死患者的病历资料。包括病史、系统体格检查,ECG、心肌酶谱、胸片、超声心动图检查等。结果：9例心内膜下心肌梗死患者均有临床症状、ECG及心肌酶学指标的动态变化,诊断明确,以冠状动脉病变为其主要病因,在此基础上由其他因素诱导发病。结论：临床医师对心内膜下心肌梗死认识不足、对ECG和心肌酶谱的特异性动态改变耒充分认识,是导致误诊的主要原因,建议详细询问病史、系统体格检查及辅助检查,综合判断明确诊断。