Acute therapy and prevention of ischemic cerebral infarct

The acute therapy of the cerebral infarct necessitates the fast evaluation of the favorable risk factors and the assessment of its pathogenetical mechanisms to facilitate a specific treatment as early as possible. Acute treatment procedures like the rheologic therapy, anticoagulation, thrombolysis, application of calcium antagonists, and antiedematous therapy are discussed. Recommendations for the secondary prophylaxis with drugs like acetylsalicylic acid or triclopidine after transitory ischemic attacks or manifest brain infarctions are given. The indications for the surgical therapy of stenoses of the extracranial vessels supplying the brain are discussed and rules for the emergency management of the transitory ischemic attack are introduced.     

Adjuvant therapy in patients with acute myocardial infarct

Besides the thrombolytic therapy several adjuvant therapeutic measures were identified which significantly improve the prognosis of patients with acute myocardial infarction (AMI). These measures include the treatment by means of acetylsalicylic acid (ASA), beta-blockers and ACE inhibitors. Early administration of ASA and beta-blockers are indicated in all patients with AMI who have no contraindications for this therapy. They are especially the patients with manifest heart failure or asymptomatic left ventricular dysfunction who benefit from ACE inhibitors. The effectivity of routine administration of other medicaments such as anticoagulants, nitrates, calcium channel blockers and magnesium, have not been convincingly proved. However, some selected patients with AMI can benefit from these medicaments. Intravenous administration of heparin is unambiguously justified only in thrombolysis with t-PA. Thrombolyses with streptokinase, urokinase, and anistreplase are justified only at high risk of thromboembolic complications. Their prevention and therapy include also the necessity to restrict the administration of pelentan. The use of nitrates is indicated in patients with AMI in case of sustaining stenocardia, arterial hypertension and manifest heart left ventricular failure. Until the definitive standpoint is gained regarding the effect of magnesium in patients with AIM, its administration remains especially indicated in cases of arterial hypertension, tachycardiac disturbances of the heart rhythm and states of assumed or proved hypomagnesiemia. In AMI cases when magnesium is used in order to protect the patient from reperfusion lesion, it must be administered prior to the reperfusion therapy. An intensive research in the field of therapeutical measures in patients with AMI still continues. It is certain that it will soon bring further knowledge which will in turn improve the prognosis and quality of life of patients with AMI. (Tab. 4, Ref. 133.)     

Intracranial hemorrhage following thrombolytic therapy in acute myocardial infarct

The course of the psychopathology and social functioning in an experimental day-treatment group referred for inpatient psychiatric treatment is compared with that of a control group receiving standard inpatient care. During a follow-up period of 2 years subjects were interviewed three times. The interview comprised information about psychiatric symptoms, psychological functions, psychiatric diagnosis and social-role functioning. Apart from these discrete assessments an effort was made to map episodes of illness throughout the follow-up period. Upon entry the groups did not differ in terms of psychopathology or social functioning. At follow-up both groups had improved significantly with respect to symptomatology, psychological and social functioning. The extent to which the groups improved did not differ significantly regarding pathology, but self-care improved more in the experimental group. The average duration of episodes of illness was similar for the experimental and control group. During the 2-year follow-up patients suffered from a well-defined disorder during an average of 11 months. The fact that approximately 40% of them were still a psychiatric case after 2 years further underscores the severity of their pathology.     

Perfusion-MRI in cerebral infarct

PURPOSE: To investigate the hemodynamic changes in patients with acute cerebral stroke by perfusion MRI. MATERIAL AND METHODS: In 12 patients with acute stroke in the territory of the middle cerebral artery, perfusion MRI was performed. Peak time, mean transit time, regional cerebral blood volume and regional cerebral blood flow were calculated in the infarction, the peri-infarction area and the contralateral hemisphere. RESULTS: In the infarction the mean blood flow was 29 ml/100 g/min, compared to about 40 ml/100 g/min in the peri-infarction area and the contralateral hemisphere. In two patients increased cortical blood flow was found in the infarction due to luxury perfusion. The cerebral blood volume was reduced in the infarction, but significantly increased, to 7.3 ml/100 g, in the peri-infarction tissue. CONCLUSION: Perfusion MRI allows one to differentiate various patterns of perfusion disorders in patients with acute cerebral stroke. The resulting data may be helpful in describing the pathophysiologic mechanisms of compensation.     

Thrombolytic therapy in ischemic infarct

Thrombolytic therapy in acute ischemic stroke is safe and effective in a defined subgroup of stroke patients. Until now, different fibrinolytic substances including urokinase, streptokinase and recombinant tissue plasminogen activator (rt-PA) have been tested regarding safety, efficacy, dosage and economic parameters in patients suffering from both carotid and basilar artery territory strokes. Recently, two large multicenter placebo-controlled intravenous rt-PA studies were published. The results show that thrombolysis of acute carotid territory strokes (European Cooperative Acute Stroke Study) and of strokes with a deficit measurable on the NIH Stroke Scale (National Institute of Neurological Disorders and Stroke rt-PA Stroke Study) improves clinical and economic outcome parameters in patients who were treated within 6 hours of the onset of symptoms and had that no signs of extended early infarction on the initial CT-scan. The occurrence of intracranial hemorrhages is more frequent after thombolytic therapy, but the majority of bleeding complications referred to petechial or more confluent hemorrhage limited to the infarcted tissue, without clinical deterioration. However, the identification of the appropriate patients is difficult and depends on the level of clinical and diagnostic experience. In vertebrobasilar artery territory stroke, local intraarterial thrombolysis with urokinase or streptokinase is performed in most cases. Thrombolytic treatment within twelve hours of the onset of symptoms was associated with significantly better results concerning both survival and neurological recovery.     

Percutaneous transluminal coronary angioplasty (PTCA) as primary therapy in acute myocardial infarct

BASIC PROBLEM AND OBJECTIVE: Percutaneous transluminal coronary angioplasty (PTCA) is being increasingly considered as an alternative to thrombolytic treatment of acute myocardial infarction. Studies performed so far, some on selected groups of patients, have produced high initial results of success. This prospective study was undertaken to determined primary success, complications and recurrence after primary PTCA in acute myocardial infarction (AMI). PATIENTS AND METHODS: Primary treatment in the form of immediate PTCA of the infarct vessel was undertaken in 111 patients (84 men, 27 women; mean age 58.6 +/- 10.3 years) with AMI. PTCA was judged successful if the infarct vessel had been reopened to perfusion grade 3 and restenosis was < 50%. No thrombolytic treatment was given, but heparin infusions were given during and for 24-48 hours after the procedure. 13 patients (11.7%) were in cardiogenic shock or required cardiopulmonary resuscitation for infarct-related arrhythmias. RESULTS: The primary success rate of PTCA for the whole group was 91% (101 of 111 patients), but only 77% (ten of 13) among patients in cardiogenic shock and (or) after resuscitation. Acute re-occlusion (0-6 days after PTCA) occurred in seven patients. Eight patients (7.2%) died during the hospital phase (0-4 weeks), seven of whom had been in shock or required resuscitation (death rate 54%). The overall complication rate of the intervention was 6.3%. No emergency aortocoronary bypass was necessary. Repeat coronary angiography was performed in 71 of the 101 successfully treated patients 6 or 12 weeks after the PTCA. Re-occlusion was demonstrated in four (5.6%), a restenosis of more than 50% in 25% of patients. Mean left ventricular ejection fraction, obtained by planimetry from the levocardiogram was 58.6 +/- 9.3%. CONCLUSION: PTCA, performed immediately after acute myocardial infarction is an effective therapeutic measure with a high primary success rate.     

The apexcardiogram in acute myocardial infarct

The relation between intracardial haemodynamics and apicocardiogram (ACG) parameters is explained. A wave (amplitude and duration), A/H ratio, true and total TCI, total systole, total expulsion, RIV, RFW, TE/TCI (total) and TE/TCI (true) findings in 22 patients with acute myocardial infarct are presented. Attention is also given to clinical and radiological signs of cardiac insufficiency and the infarct site. Constant and significant increases in the A wave, A/H ratio and RIV, together with a decrease in total expulsion, were noted, particularly in cases with clinical evident insufficiency. In the pre-expulsive stage, ACG Data could not be taken as a reliable index of myocardial contractility in cases where insufficiency was not manifest. It is felt, therefore, that ACG may be of assistance in the evaluation of changes in myocardial performance, even where clinical and radiological signs of decompensation are absent.     

High-resolution electrocardiography in acute myocardial infarct

The author starts by highlighting the importance of risk stratification in patients who have survived a myocardial infarction. High resolution electrocardiography, also called signal-averaged electrocardiography (SAECG), appears in this setting as a diagnostic tool that, by providing important information about the way the intraventricular conduction of the electrical impulse is made, contributes to the characterization of the arrhythmogenic substrate, which is the basis of ventricular tachycardia and fibrillation. By resorting to the averaging of the electrocardiographic signal, SAECG enables us to detect ventricular late potentials whenever the analysis of that signal is made in time-domain. Further details, which will enrich the information on ventricular activation, can be obtained if the analysis is made in the frequency-domain (spectral analysis). The importance of detecting abnormalities in the SAECG recordings lies in the fact that those abnormalities are related to the occurrence of ventricular tachycardia and fibrillation, which are responsible for arrhythmic death. After referring to the criteria of positivity of SAECG and its reproducibility, the author approaches the most important part of the paper: the clinical applications of SAECG. After focusing on the interest of the method in noncoronary conditions, its usefulness in patients with acute myocardial infarction is pointed out. The author then mentions the prevalence of abnormalities in SAECG in patients with acute myocardial infarction and emphasizes the interest of the method in risk stratification. The author then presents the results of his Group in what concerns prevalence and prognosis. Finally, the author refers to the application of SAECG in other forms of coronary artery disease besides myocardial infarction.     

Nutritional problems in acute myocardial infarct

Hypocaloric nutrition in patients during the first days of myocardial infarction cannot be suggested any longer. Because of several reasons the minimum calory uptake should be about 2000 kcal/per day. Patients with enddiastolic pulmonary artery pressures above 20 mm Hg which is especially a high risk group should be treated parenterally with solutions of carbohydrates, insulin, and potassium. This regimen appears to be of a special importance at beginning shock or during cardiogenic shock.     

Biochemical markers in acute myocardial infarct

Exact and early diagnosis of acute myocardial infarction is essential for the subsequent routine management of this frequent cardiovascular disease. At present, the clinical biochemistry possesses a set of more or less cardiospecific protein markers for early detection of myocardial ischemic damage. After the admission of patient to the hospital, serial estimations of rather non-specific enzyme activities (creatine kinase, its MB-izoenzyme, lactate dehydrogenase, hydroxybutyrate dehydrogenase) are currently used for the detection of acute myocardial infarction and for the further monitoring of the patient and managing his therapy. In the past decade, many cardiospecific biochemical markers were discovered and gradually introduced into the routine clinical practice. The most perspective markers are some molecules of contractile proteins of heart myofibrils (troponins, myosin chains) as well as "rediscovered" myoglobin. The aim of this review article is to inform about the commonly used, as well as about the new biochemical markers, to discuss some problems of diagnostic strategy in the early and exact detection of ischemic myocardial damage and to attract attention to the difficulties. However its disadvantage resides in its presence in both myocardium and skeletal muscles which arise when the diagnosis of acute myocardial infarction is prematurely excluded from consideration and such patients are discharged too soon from hospital. (Fig. 1, Tab. 1, Ref. 72.)     

The pre-hospitalization period in acute myocardial infarct

The article reviews the possibilities of biochemical markers in coincidence with the assessment of prognosis in acute coronary syndromes and in the revealing of effectivity of their therapy. The current options of clinical biochemistry in many cases allow to supplement, confirm, or exclude the results of modern physical and other clinical examination methods and in this way to contribute to the accuracy of the diagnostic process, and enable to comment the prognosis and the risk measure of the patient. A significant progress has been achieved in the assessment of effectivity in thrombolytic therapy in acute myocardial infarction, where especially the series assessment of myoglobin levels or specific troponin cardiomarkers can facilitate the process of physician's decision as to the assessment of the subsequent procedure in the treatment of patients. The assessment of levels of both specific and partly less specific cardiomarkers becomes one of the criteria of the decision in coincidence with ischaemic episodes in the peri and postoperative periods (the diagnosis of peri-operative myocardial infarction). Specific troponin cardiomarkers acquire an extraordinary significance in the prediction of the measure of risk in patients with unstable angina pectoris where already one single assessment of the level of these markers is sufficient for hospitalization of the patient and thus enables to change the physician's strategy of further therapy. (Ref. 95.).     

Angina in the acute phase of myocardial infarct

Factor VIII (AHG) activity was assayed in the plasma specimens from 1016 regular and controlled blood donors. Age and ABO blood groups had highly significant effects on factor VIII concentrations, whereas the effect of sex was not significant. The median in the donors of blood group O rose from 87% at the age of 20 to 119% at the age of 60 years, and the median in blood groups A and B+AB of corresponding ages rose from 108 to 147%. An interaction effect of age and blood groups was present only at the 5% level of significance. The present data and the previous findings of others suggest the existence of an association between high factor VIII levels and thrombotic states.     

Acute prognosis and differentiation of various cerebral infarct groups in comparison with cerebral hemorrhage

For clinical trials classification of stroke should be possible at the bedside by simple methods that are available every where. In this study are 1105 patients with every first ischaemic strokes and 130 patients with intracerebral haemorrhages. The differences between severity of clinical symptoms, outcome and risk factors of intracerebral haemorrhages, ischaemic stroke caused by cerebral microangiopathy, ischaemic stroke combined with extracranial carotid stenosis, cardiogenic brain embolism and atherothrombotic stroke, were analysed. Intracerebral haemorrhages show the poorest outcome of all groups (mortality 23.8%), due to increased intracranial pressure. Cardiogenic brain embolism is more frequent in older women (mean age 77.8 y.). Main risk factor is atrial fibrillation with absolute arrhythmia. The outcome of this group is the worst of all subgroups of ischaemic stroke and survivors most often in need of institutionalization. Patients with ischaemic stroke combined with extracranial carotid stenosis are significantly younger (mean age 67.6 y.), predominantly male, and smokers. Their mortality is low (0.63%), but recovery of paresis is slower than in other subgroups. Ischaemic strokes caused by cerebral microangiopathy with hypertension as main risk factor recover most quickly but acute mortality is higher than in ischaemic stroke combined with extracranial carotid stenosis because of higher age (mean age 74.5 y.). Institutionalization is more frequent too because of higher incidence of dementia in this subgroup. The main prognostic factors of all groups are age and severity of clinical symptoms. A special subgroup are infratentorial ischaemic strokes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Renaissance of beta blocker therapy in myocardial infarct

Beta-adrenergic blocking drugs have been evaluated for the treatment of arrhythmias and for the prevention of sudden cardia death, particularly in post-myocardial infarction patients. Betablockers have been demonstrated to reduce mortality, reinfarction, ventricular fibrillation and cardiac rupture in acute infarction. Therefore, in patients with suspected myocardial infarction and without contraindications, treatment with betablockers should be initiated early and continued for at least 2 years. Side-effects are mild and occur in approximately 10% of patients. Patients who have contraindications for betablockers use early in myocardial infarction should be reevaluated before discharge from the hospital and considered for such therapy. Because betablockers prevent some of the adverse arrhythmogenic mechanisms seen in chronic heart failure, it may be reasonable to expect that these drugs could have a role in preventing sudden cardiac death in these patients. Analysis of some of the betablocker post-infarction trials indicate that betablockers reduced the risk of sudden death in patients with heart failure at baseline. Some studies demonstrated also the symptomatic improvement following therapy with betablockers in patients with heart failure. But the currently available data are too limited to provide conclusive information.     

Heart muscle after heart infarct. Function of surviving heart muscle following acute myocardial infarct

In the initial phase of the infarction, there is a decrease of ventricular function due to loss of contractile activity. In addition, a negative effect of the paradoxical movement of the infarcted area on the hemodynamics of the ventricle is noted. The stiffening of the infarcted area in the early stage has a favorable influence on ventricular function, leading to a change in the elastic properties of the ventricle. The loss of ventricular compliance persists after the infarction, and its severity depends on the extent of myocardial destruction. In the non-compliant ventricle, the end-diastolic pressure rises without a proportionate increase in volume. Consequently, the ventricular function curve shows a shift downward and to the right, making it difficult to distinguish between the loss of contractile function or compliance in the heart in situ. Evaluation of the contractile properties of the surviving cardiac muscle in situ is, however, hardly possible due to the changed geometry and the additonal elastic elements functioning in series with the surviving muscle. To exclude these factors, a study of the contractile properties of the surviving cardiac muscle in the isolated state was carried out following experimental myocardial infarction in cats. By ligating several coronary branches, infarctions in the area of the left ventricle were caused; to avoid the ischaemic border zone of the infarction, right ventricular papillary muscles were studied. Haemodynamic investigations showed an increase in right ventricular end-diastolic pressure which persisted 6 weeks after infarction. As early as 48 hours but, more significantly 1 week after infarction, there was a decrease of actively developed force in the surviving cardiac muscle due to a lower rate of force development. The resting length tension curve of the surviving cardiac muscle after infarction showed no alterations; and 6 weeks following infarction, almost normal contractility parameters were observed. As a result of the infarction, a decrease in contractility in the surviving cardiac muscle is observed during the early stage, which regresses after complete recuperation.