Magnetic resonance imaging (MRI) in different stages of myocardial infarction using the contrast agent gadolinium-DTPA

We investigated 26 patients admitted to our catheterization laboratory with a diagnosis of acute myocardial infarction. In each case acute revascularization was unsuccessful, but the diagnosis was confirmed by angiography. In 11 patients with an uncomplicated course of acute myocardial infarction magnetic resonance imaging was carried out within 7 days of the acute event. In three additional cases imaging was performed within 3 weeks, while a remaining 12 patients underwent studies more than 3 weeks after the onset of symptoms. We determined signal intensity at three points within the area of infarction and at three other points in adjacent myocardial tissue. Decreased signal intensity within the area of infarction was present in native scans in 60% of all cases. Application of 0.1 mmol/kg body weight gadolinium-DTPA was followed by an average 70% increase in signal intensity within zones of acute infarction, as compared to a 20% increase in surrounding myocardial tissue. In cases of subacute and chronic infarction there was no significant signal enhancement after administration of gadolinium-DTPA. Uptake of gadolinium-DTPA in the area of acute myocardial infarction may be a positive marker of acute myocardial necrosis, which may be of potential clinical benefit.     

The possibility of spontaneous lysis of a coronary thrombus in patients with acute myocardial infarct

The results of coronary angiography in 108 patients within the first 24 hours of myocardial infarction were compared to autopsy coronary arterial findings in 78 cases of myocardial infarction death within similar periods of time. The rate of occlusion of the coronary artery, responsible for infarction, dropped considerably within 12-24 hours of its onset, as compared to the data obtained within the first 6 hours: from 90.3% to 57.1% as evidenced by coronarography, or from 87.8% to 68.4% as evidenced by postmortem findings. Coronarography conducted within the first day of myocardial infarction demonstrated markedly activated fibrinolysis that coincided with the drop in the incidence of coronary-arterial thrombosis. Fibrinolysis activation is a prerequisite for spontaneous coronary thrombolysis.     

Imaging of acute myocardial infarction by magnetic resonance tomography (MRT) using the paramagnetic relaxation substance gadolinium-DTPA

Summary Twenty-six patients admitted to the Free University of Berlin University Hospital catheterization laboratory with acute myocardial infarction were studied. The diagnosis was confirmed by angiography, but acute revascularization was unsuccessful in every case. MR imaging was performed within 7 days of the acute event in 11 patients with uncomplicated clinical courses after acute infarction. Imaging was performed within 3 weeks in three additional cases, while the remaining 12 patients underwent studies more than 3 weeks after infarction.We determined signal intensity at three points within the area of infarction and at three other points in adjacent myocardial tissue. Decreased signal intensity within the area of infarction was found in native scans in 60% of all cases. Administration of gadolinium-DTPA 0.1 mmol/kg body weight was followed by a mean 70% increase in signal intensity within the zones of acute infarction, as compared to a 20% increase in surrounding myocardial tissue. In cases of subacute and chronic infarction, there was no significant signal enhancement after administration of gadolinium-DTPA. Uptake of the substance in the area of acute infarction may be a positive marker of acute myocardial necrosis and as such may prove useful in the clinical setting.This study was supported by the Ministry of Science of the Federal Republic of Germany, No. 01 VF 8521/6. Gadolinium-DTPA was made available by the Schering AG, Berlin.     

Intravenous streptokinase in acute myocardial infarction (I.S.A.M.) trial: serial evaluation of left ventricular function up to 3 years after infarction estimated by radionuclide ventriculography. I.S.A.M. Study Group

The Intravenous Streptokinase in Acute Myocardial Infarction (I.S.A.M.) trial was a prospective, placebo-controlled, double-blind multicenter trial of high-dose short-term intravenous streptokinase in acute myocardial infarction administered within 6 h after the onset of symptoms. Global and regional left ventricular ejection fractions were determined by radionuclide ventriculography in a subset of 120 patients 3 days, 4 weeks, 7 months, 18 months and 3 years after acute myocardial infarction. In patients with anterior myocardial infarction, left ventricular ejection fraction was higher in the streptokinase than in the placebo group 3 days after acute infarction (49 +/- 14% vs. 40 +/- 11%, p = 0.02). This difference of about 10% units in ejection fraction persisted during the 3 year follow-up period. Among streptokinase-treated patients, regional left ventricular ejection fraction was higher within the infarct zone as well as in remote myocardium throughout the follow-up period. Among patients with inferior infarction, no significant differences between the treatment and control groups were demonstrable with respect to global and regional left ventricular ejection fraction. Thus, intravenous administration of streptokinase within 6 h after the onset of symptoms of acute myocardial infarction preserves left ventricular function over a period of greater than or equal to 3 years in patients with acute anterior myocardial infarction. It improves regional myocardial function within the infarct zone as well as in remote areas. In patients with acute inferior myocardial infarction, benefit from intravenous streptokinase is of only minor degree.     

The prehospital phase in patients with acute myocardial infarct in Slovakia. A challenge

Better management of patients with acute myocardial infarction during the prehospital phase is at present a challenge not only for health workers but for society as a whole. The authors pay attention to knowledge of the complex problem of the prehospital phase in patients with acute myocardial infarction which is a prerequisite for finding possible solutions for a favourable effect on their management. The authors analyzed 3,040 patients who were admitted to hospital alive within 96 hours after the development of complaints with suspicion of a first or repeated acute myocardial infarction. They focused attention in particular on prehospital time delay. They found that within a satisfactory time interval (within 2 hours) 29.8% patients were delivered and within a yet acceptable interval of 4 hours 51.6% patients (with respect to effectiveness of thrombolytic treatment). Similarly undesirable are also data on the patient time delay. Within the optimal first hour after development of complaints following the decision of the patient (subjects present) to ask for or seek medical assistance was the decision of 34% patients, during the first two hours 47.5% and within 4 hours 61.2% patients with acute myocardial infarction. The ratio of time delay of the patient in the total prehospital delay is 45.5% even in patients who were admitted during the first hour after development of acute myocardial infarction. In patients who were admitted 4 hours after development of complaints it is 79.5%. The patient is admitted to hospital most quickly if he calls the medical emergency service and latest when he decides to see a doctor. Physicians and other health workers contributed only in 16.4-20.9% patients with acute myocardial infarction to their early decision to seek medical assistance. Patients with an early decision (within one hour) call most frequently the medical emergency service and are taken to hospital by this service. The time delay due to transport is shortest in these patients. The late hospital admission of patients with acute myocardial infarction in Slovakia calls for reduction of the time interval from the development of complaints to hospital admission (total prehospital delay), in particular the time taken by the patient to make up his mind (patient time delay). Early calling of the emergency medical service and transport of the maximum possible number of patients with acute myocardial infarction to hospital by the emergency medical service will greatly improve the management of patients with acute myocardial infarction. Comprehensive implementation of the survival chain (24), the most comprehensive implementation of recommendations of the European Society of Cardiology and the European Resuscitation Council for in the management of patients with acute heart attacks during the prehospital phase (21) and early effective treatment which begins already in the prehospital phase has a favourable impact on the condition of patients with acute myocardial infarction and on their prognosis. Along with early and effective treatment of patients with acute myocardial infarction in hospital and their stratification these are the most important approaches to the development and control of sudden cardiac death. Knowledge of the complex problem of the prehospital phase in patients with acute myocardial infarction is the prerequisite for the elaboration of high standard prehospital management of patients with acute myocardial infarction.     

Heart failure complicating acute myocardial infarction

Older people with congestive heart failure associated with acute myocardial infarction should be treated with loop diuretic therapy. Class I indications for the use of early intravenous beta blockade in patients with acute myocardial infarction are patients without a contraindication to beta blockers who can be treated within 12 hours of onset of myocardial infarction; patients with continuing or recurrent ischemic pain; and patients with tachyarrythmias, such as atrial fibrillation with a rapid ventricular rate. Class I indications for the use of angiotensin-converting enzyme inhibitors during acute myocardial infarction are (1) patients within the first 24 hours of onset of a suspected acute myocardial infarction with ST segment elevation in two or more anterior precordial leads or with clinical heart failure in the absence of significant hypotension or contraindications to the use of angiotensin-converting enzyme inhibitors, (2) patients with myocardial infarction and a left ventricular ejection fraction of less then 40%, (3) and patients with clinical heart failure on the basis of systolic pump dysfunction during and after convalescence from acute myocardial infarction. No class I indications exist for using calcium channel blockers or magnesium during acute myocardial infarction.     

Late left ventricular pseudoaneurysm formation following subacute myocardial infarction

We describe a patient with a subacute inferior myocardial infarction who developed a pseudo-aneurysm more than 18 days after the acute event. This is an unusual case with three different complications of a myocardial infarction: Firstly, ventricular rupture is usually the result following transmural myocardial infarction without reperfusion. However, coronary angiography confirmed reperfusion after late thrombolysis in this patient. The subacute rupture could potentially be caused or aggravated by the late thrombolysis. Secondly, this patient developed a mural apical thrombus in a non-infarcted region. It seems most likely that the new infarct caused a low flow state which enhanced thrombus formation. Against expectations, this developed at the apex rather than the site of the recent inferior wall myocardial infarction. Thirdly, we documented the development of a pseudo-aneurysm more than 18 days after the myocardial infarction. This complication is rarely seen at this stage after a myocardial infarction, as most pseudo-aneurysms are formed within 7 days after a myocardial infarction. We have beautifully visualised the apical thrombus and pseudo-aneurysm with echocardiography. This report shows that serial echocardiography is a very useful tool in evaluating the patient's clinical and cardiac status in the period after a myocardial infarction.     

Acute Myocardial Infarction Following Hospitalization for Gastrointestinal Bleeding: Incidence,Predictors, Management,and Outcomes

BackgroundClinical characteristics of patients with acute myocardial infarction after gastrointestinal bleeding are poorly characterized. We sought to evaluate the incidence, management and outcomes of myocardial infarction following hospitalization for gastrointestinal bleeding.MethodsPatients admitted with a diagnosis of gastrointestinal bleeding with and without subsequent hospital readmissions for acute myocardial infarction within 90 days were identified in the 2014 U.S. Nationwide Readmission Database. Patients with myocardial infarction with and without a recent prior gastrointestinal bleed were compared to determine differences in management and in-hospital outcomes. Logistic regression models were used to estimate odds of invasive management and all-cause in-hospital mortality after covariate adjustment.ResultsA total of 644,622 patients with gastrointestinal bleeding were identified, of which 7523 (1.2%) were readmitted for myocardial infarction within 90 days. Compared to patients with myocardial infarction without recent gastrointestinal bleeding, patients with myocardial infarction within 90 days after gastrointestinal bleeding were older, more likely to be women, have kidney disease, presented with non-ST segment elevation myocarsdial infarction, and were less likely to undergo invasive management of acute myocardial infarction (28% vs 63%, P < .01). Prior gastrointestinal bleeding was associated with higher all-cause in-hospital myocardial infarction mortality (22% vs 9%, P < .01).ConclusionIn the first 3 months after hospitalization for gastrointestinal bleeding, 1 of every 83 patients was readmitted with acute myocardial infarction. Patients with myocardial infarction after gastrointestinal bleeding were less likely to undergo invasive management and coronary revascularization and had higher mortality than those without recent bleeding.     

The effect of various types of stress-limiting therapy on the outcome of myocardial infarction

A method for computed determination of death probability was used to examine the effects of various modalities of stress-limiting therapy on mortality rates within a month after myocardial infarction. The examination was made in 591 patients with large myocardial infarction. A significant decrease in mortality rates was seen in patients on finoptin and phosphocreatine (by 9.6 and 11.2, respectively) as compared to the expected drop. Other agents given within the first hours of myocardial infarction such as beta-blockers, opioid peptides, sodium oxybutyrate, piracetam, antioxidants were demonstrated to cause no reduction in mortality rates.     

Myocardial infarction and pregnancy

Acute myocardial infarction is rare in women of childbearing age, especially in the absence of common risk factors. We describe the case of a 38-year-old multiparous woman with anterior myocardial infarction treated with thrombolysis, followed by percutaneous coronary angioplasty. The patient developed transient heart failure within the first week. The rest of the follow-up was uneventful with delivery by caesarian section of a healthy baby at 36 weeks. We reviewed the literature concerning the physiopathological background of myocardial infarction during pregnancy, its epidemiology and management.     

Sensitivity of routine clinical criteria for diagnosing myocardial infarction within 24 hours of hospitalization

Myocardial infarction was diagnosed in 431 (30%) of 1460 patients with acute chest pain who had serial enzyme testing after admission to intensive or intermediate care units at three teaching and three community hospitals. The diagnosis was made within 12 hours of admission in 331 (77%) patients and within 24 hours in 415 (96%). Of the 16 patients with myocardial infarction who did not have enzyme abnormalities within 24 hours, 9 (56%) had recurrent ischemic pain during this 24-hour period. Of 451 patients who had neither enzyme abnormalities nor recurrent ischemic pain in the first 24 hours, only 7 (2%) ultimately met diagnostic criteria for myocardial infarction. These findings were prospectively validated in an independent testing set of 275 patients with myocardial infarction, 271 (99%) of whom either met diagnostic criteria for myocardial infarction or had recurrent ischemic pain within 24 hours of admission. These data suggest that 24 hours is nearly always a sufficient period to exclude myocardial infarction in patients without recurrent chest pain.     

Surgical intervention in acute myocardial infarction

The goal of surgical reperfusion during the first hours of acute evolving myocardial infarction is to limit the extent of the infarction. This should be reflected by improved ventricular function and low mortality. Over the past 10 years, 440 patients with transmural myocardial infarction and 261 patients with nontransmural myocardial infarction underwent coronary artery bypass graft surgery within 24 hours of peak symptoms. The in-hospital mortality was 5.2% in the transmural group and 3% in the non-transmural group. In a 10-year study period, the mortality in the transmural group rose to 12.5%, while the mortality in the nontransmural group, followed for an 8-year period, rose to a total of 6.5%. The transmural myocardial infarctions in patients revascularized within 6 hours, showed a significantly improved in-hospital mortality of 3.8% compared to an in-hospital mortality of 12% for reperfusion after 6 hours. Anterior transmural areas of myocardial infarctions were reperfused within 6 hours of symptom onset, and demonstrated improved global ejection fraction and regional wall motion. Little improvement was seen if revascularization was instituted later than 6 hours from symptoms except in patients with adequate collateral perfusion of non-total left anterior descending coronary occlusion. Long-term follow-up of patients revascularized for acute myocardial infarction shows a low rate of subsequent reinfarction, incapacitating angina and sudden death. Left ventricular function at the time of cardiac catheterization correlates well with subsequent long-term mortality.     

Serum creatine kinase B subunit activity in diagnosis of acute myocardial infarction.

The value of serum creatine kinase B subunit activity (CK B) in the diagnosis of acute myocardial infarction was studied in 238 consecutive cases. All were admitted to a coronary care unit because of suspected acute myocardial infarction. Serum CK B activity was determined by an immunoinhibition procedure, using a CK M subunit inhibiting antibody (anti-M). For the evaluation of serum CK B, patients were classified into acute myocardial infarction and non-acute myocardial infarction groups. This classification was based on electrocardiographic findings, on quantitative determinations of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total serum creatine kinase (CK) activities, and on qualitative electrophoretic determinations of serum CK and serum lactate dehydrogenase (LD) isoenzymes. The prevalence of acute myocardial infarction in the patient material was 0.47. Serum CK B subunit activity was found to be a highly selective indicator of acute myocardial infarction with a predictive value of a positive test result of 0.97 and a predictive value of a negative test result of 0.99. The serum CK B activity increased above the acute myocardial infarction discrimination limit within 12 hours from onset of symptoms. Two non-acute myocardial infarction patients, who were resuscitated after cardiac arrest, had increased serum CK B values caused by the transient presence of CK isoenzyme BB in serum.     

Mean platelet volume is an independent risk factor for myocardial infarction but not for coronary artery disease

After rupture of an arteriosclerotic plaque in a coronary artery, platelets play a crucial role in the subsequent thrombus formation, leading to myocardial infarction. An increased mean platelet volume (MPV), as an indicator of larger, more reactive platelets, may represent a risk factor for myocardial infarction. However, this hypothesis is still controversial and most studies addressing the role of MPV were performed comparing patients suffering from myocardial infarction with healthy controls. We intended to identify patients at high risk of suffering myocardial infarction in a group of patients with known coronary artery disease. One hundred and eighty-five consecutive patients with stable coronary artery disease were compared with 188 individuals who had suffered myocardial infarction. Patients within the highest quintile of MPV (> or = 11.6 fl) had a significantly higher risk of experiencing a myocardial infarction compared with patients within the lowest quintile (OR = 2.6, 95% CI 1.3-5.1) in a multivariate analysis that included sex, age, body mass index, hyperlipidaemia, hypertension, smoking and diabetes mellitus. Our results indicate that patients with pre-existing coronary artery disease and an increased MPV (> or = 11.6 fl) are at higher risk of myocardial infarction. These patients can be easily identified during routine haematological analysis and could possibly benefit from preventive treatment.     

Regional dysfunction by equilibrium radionuclide angiocardiography: a clinicopathologic study evaluating the relation of degree of dysfunction to the presence and extent of myocardial infarction

The relation of degree of regional wall motion abnormality by equilibrium radionuclide angiocardiography to the presence and mural extent of regional necrosis or scar at autopsy was evaluated in 23 autopsy patients who had a history of myocardial infarction and had equilibrium radionuclide angiocardiography within 40 days of death. Of the 228 regions evaluated by equilibrium radionuclide angiocardiography, 135 had abnormal regional wall motion and 102 (76%) of these 135 regions had evidence of myocardial infarction at autopsy. The overall sensitivity, specificity and predictive values of regional wall motion abnormality for regional necrosis or scar were 69, 59 and 76%, respectively. Of the 33 false positive regions, 20 (61%) had severe narrowing of the coronary artery supplying that region, 13 (39%) were adjacent to a region with a myocardial infarction and almost half (16 [48%]) were in the lateral wall. Eighty-three (36%) of the 228 regions were akinetic or dyskinetic, 52 (23%) were hypokinetic and 93 (41%) were normal. Sixty-three (76%) of the 83 akinetic/dyskinetic segments had transmural myocardial infarction at autopsy, 14 (17%) had nontransmural myocardial infarction and only 6 (7%) contained no necrosis or scar. In contrast, 14 (27%) of 52 hypokinetic segments had transmural myocardial infarction, 11 (21%) had nontransmural myocardial infarction and 27 (52%) were normal. Thus, the most severe regional wall motion abnormality (akinesia/dyskinesia) almost always indicates regional myocardial infarction which is usually transmural whereas less severe dysfunction (hypokinesia) is not necessarily associated with regional necrosis or scar. The severity of regional dysfunction must be considered if equilibrium radionuclide angiocardiography is used to evaluate the presence and mural extent of myocardial infarction within a region.     

Beta-blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists in treatment of elderly patients with acute myocardial infarction

Administration of beta-blockers reduces mortality among old persons during and after acute myocardial infarction. The American College of Cardiology/American Heart Association guidelines recommend that persons without contraindications to use of beta-blockers should be administered beta-blockers within a few days of myocardial infarction (if administration is not initiated acutely) and that their administration should be continued indefinitely. These guidelines also recommend the use of angiotensin converting enzyme inhibitors in treating persons within the first 24 h of suspected onset of acute myocardial infarction with ST-segment elevation in two or more anterior precordial leads or with congestive heart failure in the absence of significant hypotension or other contraindications to use of ACE inhibitors; and persons during and after convalescence from acute myocardial infarction with congestive heart failure associated with an abnormal left ventricular ejection fraction (LVEF) or with asymptomatic left ventricular systolic dysfunction with a LVEF < 40%. These guidelines state that there are no class I indications for using calcium antagonists after myocardial infarction. If patients have persistent angina pectoris after myocardial infarction despite treatment with beta-blockers and nitrates or hypertension inadequately controlled by other drugs, administration of a nondihydropyridine calcium antagonist such as verapamil or diltiazem should be added to the therapeutic regimen if the LVEF is normal. If the LVEF is abnormal, administration of amlodipine or felodipine should be added to the therapeutic regimen.     

植入型心律转复除颤器在心肌梗死后心脏性猝死中的研究进展

心脏性猝死(SCD)是由各种心脏因素引起的意外死亡,通常发生在症状出现后1 h内。冠心病和急性心肌梗死是SCD的主要病因。植入型心律转复除颤器是预防SCD最有效的措施,有效提高了心肌梗死后SCD高危患者的生存率,成为SCD一级预防的标准治疗方法。近年来,在临床上的应用有了新进展。现综述SCD的流行病学、心肌梗死后SCD的发生机制和心律转复除颤器在心肌梗死后SCD中的应用进展。     

Acute myocardial infarction diagnosed by myoglobinuria.

Myoglobin can be found in excess in the urines of some patients with acute myocardial infarction. To test the specificity of this finding, urine specimens were analyzed from 39 patients with provisional diagnosis of myocardial infarction by means of a hemagglutination-inhibition technique with prepared antisera to monkey myoglobin. Of 24 patients with subsequently documented myocardial infarction, 15 had at least one positive determination. None of the 15 patients without infarction had positive tests. Ten of 13 patients with infarction studied within 24 hours of the initial event had positive reactions. The percentage of positive reactions in the infarct group decreased sharply after the first 24 hours. This technique may be of value in rapid screening of patients with possible acute myocardial infarction during early stage of symptoms.     

Myocarditis confirmed by biopsy presenting as acute myocardial infarction.

Two cases of acute myocardial infarction occurred in association with myocarditis, which was confirmed by biopsy. The first patient suffered an anteroseptal and the second patient an inferior wall myocardial infarction shortly after an acute viral illness. In both patients, coronary angiography showed normal coronary arteries, and right ventricular endomyocardial biopsy confirmed myocarditis. Histological abnormalities attributable to ischaemic heart disease were absent. The first patient's condition became stable after immunosuppressive treatment. Myocarditis resolved spontaneously within three months in the second patient. Coronary artery spasm and myocardial involvement with a systemic disease were unlikely. Endomyocardial biopsy in patients with acute myocardial infarction and normal coronary arteries may be useful in identifying myocarditis associated with myocardial necrosis. Myocarditis in acute myocardial infarction in the absence of coronary artery obstruction has not previously been documented during life.     

Micro-focal myocardial infarct with a relapsing course]

The observation was conducted in 96 patients with micro-focal myocardial infarction who developed recurrences within the acute or subacute period (up to 2 months). In 47 patients the secondary infarction was of a micro-focal nature, in 49 -- macro-focal. Recurrence of micro-focal infarctions was observed predominantly in aged patients with a long history of angina pectoris who have had repeated myocardial infarctions earlier. Recurrent macro-focal myocardial infarctions were more often noted in younger patients with a brief coronary history, their primary infarction having been of a micro-focal nature. In both groups of patients congestive cardiac insufficiency and pulmonary oedema were often noted. Cardiogenic shock was mainly seen in those with relapses of macro-focal myocardial infarction. Recurrent microfocal myocardial infarction was often characterized by the development of rhythm and conductivity disorders and high mortality rate, especially when the recurrence was of a macro-focal type.