Thrombolysis after acute myocardial infarction.

Appropriate use of a thrombolytic agent may save 20 to 30 lives per 1000 treatments. Thrombolysis should be considered in all patients presenting with cardiac chest pain lasting more than 30 minutes for up to 12 hours after symptom onset. ECG criteria include ST elevation of at least 1 mm in limb leads and/or at least 2 mm in two or more adjacent chest leads or left bundle branch block. There is no upper age limit. All patients should also receive oral aspirin and subcutaneous (intravenous with rt-PA) heparin. Other adjuvant treatments have been reviewed previously in this journal. Streptokinase is the drug of choice except where there is persistent hypotension, previous streptokinase or APSAC at any time, known allergy to streptokinase, or a recent proven streptococcal infection. In these circumstances the patient should receive rt-PA. Additional indications for rt-PA, based on subset analysis by the GUSTO investigators, include patients with ALL of the following: age less than 75 years, presentation within four hours of symptom onset, and ECG evidence of anterior acute myocardial infarction. Treatment should be initiated as soon as possible. The greatest benefit is observed in patients treated early, pain to treat intervals of less than one hour make possible mortality reductions of nearly 50%. "When" matters more than "where": fast tracking to the CCU is one option but A&E initiated thrombolysis is feasible and timely. Prehospital thrombolysis is appropriate in certain geographical situations. The development of practical guidelines for thrombolysis represents the most comprehensive example of evidence based medicine. Streptokinase was first shown to influence outcome in acute myocardial infarction nearly 40 years ago. More recently alternative regimes have been evaluated in several prospective randomised controlled trials yielding pooled data on nearly 60,000 patients. However, systematic review of cumulative data reveals a statistically significant mortality gain for intravenous streptokinase over placebo which could have been identified as early as 1971-at least 15 years before it became generally used in clinical practice.     

The value of exercise tests after acute myocardial infarction.

The aim of the present study was to relate the clinical course in patients after a first acute myocardial infarction with the response to exercise-tests performed one month after discharge. 90 consecutive patients who suffered an acute myocardial infarction for the first time were followed-up after 12 months in general practice. Six patients had died, and nine patients had suffered another MI. 23 patients were being treated for heart failure, 51 for angina pectoris, and 8 for arrhythmias. 14 patients received treatment for both heart failure and angina pectoris. Of the patients at work, 17.6% did not return to work because of the heart disease. 80 patients were in function groups I-II and 10 in function groups III-IV (New York Heart Association's Classification). Occurrence of ST-segment displacements was without prognostic value. Left ventricular function index (dRPP) and working capacity (W) were predictive with respect to mortality, heart failure, and angina pectoris requiring drug treatment. Exercise tests following acute myocardial infarction could not predict the chances of returning to work.     

The significance of measuring plasma leptin in acute myocardial infarction

We measured leptin concentrations in patients with acute myocardial infarction (AMI, n = 21) and in 15 age-matched controls, and compared leptin concentrations with levels of other myocardial enzymes and indicators of AMI. Blood was sampled immediately after hospital admission and at 1 h, 2 h, 3 h, 6 h and 9 h, then every 12 h until 5 days post-admission. Patients were stratified into three groups according to peak leptin concentrations: hypoleptinaemia (< 3 ng/ml); normoleptinaemia (> or = 3 - < 15 ng/ml) and hyperleptinaemia (> or = 15 ng/ml). Hypoleptinaemic AMI patients had significantly increased concentrations of plasma lactate dehydrogenase compared with normoleptinaemic patients. No significant differences in other serum markers were noted between hyperleptinaemic and normoleptinaemic AMI patients. A significant negative correlation was found between the peak concentrations of leptin and interleukin 6. Leptin may play a role in the regulation of the development of cardiac damage in patients with AMI.     

急性心肌梗死患者血浆凝血因子的变化

目的:研究凝血因子V、Ⅶ、Ⅷ、X、Ⅺ的活性在急性心肌梗死(acute myocardial infarction,AMI)的变化,并探讨其临床意义.方法:采用一期法测定AMI组(80例)和对照组(80名)因子V促凝活性(factor V coagulant activity,FV:C)、因子Ⅶ促凝活性(factorⅦcoagulant activity,FⅦ:C)、因子Ⅷ促凝活性(factor Ⅷ coagulant activity,FⅧ:C)、因子X促凝活性(factor X coagulant activity,FX:C)、因子Ⅺ促凝活性(factorⅪcoagulant activity,FⅪ:C).结果:①AMI组血浆FV:C、FⅦ:C、FⅧ:C、FX:C、FⅪ:C分别为(134±25)%、(187±32)%、(212±64)%、(140±29)%和(193±64)%,均高于健康对照组(均为P＜0.01),而AMI组凝血因子超过其临界值的发生率分别为63%、77%、90%、64%、81%;②AMI组中再发病例各凝血因子水平明显高于初发组(均为P＜0.01);③不同年龄患者各凝血因子促凝活性有差异.结论:AMI患者存在多个凝血因子活性水平增高,其中以FV:C、FⅦ:C、FⅧ:C、FX:C、FⅪ:C增高明显,存在着高凝状态,可能与AMI的发病相关,因此定期检查凝血因子活性对于及早发现高凝倾向,并加以预防和治疗均具有一定的参考价值.     

急性心肌梗死患者无复流现象与降低血浆胆固醇的临床观察

目的 观察服用他汀类药物对患者血浆总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)及发生急性心肌梗死后急诊经皮冠状动脉成形术(PCI)后发生无复流现象的影响.方法 行急诊PCI的患者于冠状动脉抽血测TC定、LDL-C水平.将急诊开通梗死相关血管的161例患者依据PCI后有无复流分为,未使用他汀类药物复流(NSNN组,n=88)、未使用他汀类药物无复流(NSN组,n=19)、使用他汀类药物复流(SNN组,n=52)、使用他汀类药物无复流(SN组,n=2).对各组复流发生情况、血浆TC、LDL-C水平数据进行分析.结果 各组之间无复流现象发生率,NSNN组88例(54.7%); NSN组19例(11.8%); SNN组52例(32.3%); SN组2例(1.2%).使用他汀治疗后发生无复流现象比例显著低于未使用他汀治疗组(P<0.05).未发生复流现象组患者(NSNN、SNN)血浆TC及LDL-C水平显著低于发生无复流现象组患者(NSN、SN)(P<0.05或<0.01).结论 急性心肌梗死患者再灌注治疗后发生无复流现象可能和血脂水平有关.他汀类药物可以显著改善急性心肌梗死患者急诊再灌注治疗无复流现象的发生,其机制之一可能通过降低血浆胆固醇.同时血浆胆固醇及LDL-C低水平的患者发生无复流概率可能较小.     

Effect of lipoprotein concentration and lecithin: cholesterol acyltransferase activity on cholesterol esterification in human plasma after plasma exchange

The rate of cholesterol esterification in plasma, plasma lecithin cholesterol acyltransferase (LCAT) activity and plasma lipoprotein levels have been measured in five subjects who underwent therapeutic plasma exchange to reduce their plasma cholesterol concentration. In the week following the exchange the cholesterol esterification rate and the plasma triglyceride concentration returned rapidly in parallel to pre-exchange levels, while high density lipoprotein (HDL) cholesterol and LCAT activity returned to normal more slowly but also in parallel. The data suggest that the rate-limiting factor for cholesterol esterification in plasma is unlikely to be solely the enzyme levels, but is probably a combination of factors, including the enzyme level and either substrate availabiltiy or product removal. Plasma very low density lipoprotein (VLDL) may either provide substrates for the reaction or provide a means of removing one of the products from the site of reaction.     

The response of plasma fibronectin to acute myocardial infarction in humans

The purpose of this study was to investigate the plasma fibronectin response to complicated and uncomplicated acute myocardial infarction. All patients admitted to a Coronary Care Unit over a six-month period were prospectively assessed by measuring admission and daily plasma fibronectin levels using an electroimmunoassay. Of 166 patients admitted to the Unit, 66 were diagnosed as having an acute myocardial infarction. Plasma fibronectin levels were significantly lower 48 h after the onset of symptoms in 15 patients with a complicated acute myocardial infarction, compared to fibronectin levels in patients with an uncomplicated course; patients who had received intracoronary streptokinase had consistently higher plasma fibronectin levels than those seen in patients who did not receive this thrombolytic agent. This hepatocyte-derived plasma protein not only has diagnostic potential, but alterations in its levels may also provide insight into the systemic response to acute myocardial injury.     

The relationship between dietary fat composition and plasma cholesterol esterification in man.

1. Cholesterol esterification has been studied in the plasma of subjects on diets rich in saturated or polyunsaturated fat. 2. The diet rich in polyunsaturated fat was associated with lower rates of plasma cholesterol esterification in vitro. The data suggest that there was a reduction of plasma lecithin-cholesterol acyltransferase activity as well as decreased ability of the lipoprotein substrates of the enzyme to support esterification. 3. On this diet, there was no change in the proportion of the plasma cholesterol esterified but the plasma cholesterol and triglyceride concentrations were reduced.     

Propranolol disposition after acute myocardial infarction

Serum propranolol concentration, elimination t 1/2, and protein binding were studied after a combined intravenous/oral regimen in 20 subjects with myocardial infarction (MI) and 15 with chest pain (CP). There was 1000% interindividual variation in propranolol concentrations in each group. In the MI group, mean total serum propranolol concentrations were greater than 100 nmol/l, except at 7 hr, when there was a trough not present in subjects with CP. Mean elimination t 1/2 s in subjects with MI (7.2) and CP (7.4 hr) did not differ. There were significantly higher alpha 1-acid glycoprotein concentrations and reduced percent unbound propranolol 27 hr after infarction. Free propranolol concentrations were lower 7 and 11 hr after dosing in the MI group, but concentrations thereafter were of the same order as those in subjects with CP. The only significant difference in any of the hemodynamic measurements was at 7 hr, when blood pressure was higher in the MI group. We conclude that propranolol kinetics were altered in subjects with MI and suggest that the regimen could be improved by increased propranolol dosage at commencement of therapy.     

Antiplatelet drugs after acute myocardial infarction

Summary Some considerations on the rationale for the use of antiplatelet drugs after acute myocardial infarction are reviewed and attention is drawn to the importance of using the results of clinical trials in the choice of the available drugs. Particular attention is focused on the advisability of using the dosages and the drugs evaluated in such trials, without following the current fashion of selecting new drugs or arbitrary dosage regimens of the old drugs.     

Family-centered care after acute myocardial infarction

The experience of a cardiac event is a significant source of stress for both patients and their family members. The acute phase after myocardial infarction reflects a crisis for patients and family members as they attempt to reconcile the affect of the event and adapt to the uncertainties associated with hospitalization and the initial recovery process. This article reviews empirical research available to cardiovascular nurses that may guide family-centered care during the acute phase after myocardial infarction. Directions for practice and research focus on cardiovascular nursing interventions that address family needs after an acute myocardial infarction. The experience of an acute myocardial infarction is a source of stress for both patients and their family members and may be viewed as a crisis that significantly disrupts family functioning and dynamics. The trajectory of cardiovascular disease involves multiple adjustments by patients and family members as they attempt to reconcile the affect of the event and adapt to the uncertainties associated with the acute phase of illness. Efforts by patients and family members to manage the stressors associated with the acute phase of cardiovascular illness are often associated with alterations in physiologic and psychologic functioning.     

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.     

The contemporary management of acute myocardial infarction.

The contemporary management of acute myocardial infarction continues to evolve rapidly. The ultimate goal of therapy is timely, complete, and sustained myocardial reperfusion. There is a powerful time-dependent effect on mortality, and thus the balance between the time and likelihood of maximal reperfusion is crucial in deciding whether to use primary percutaneous balloon angioplasty or thrombolysis as the initial reperfusion strategy. Newer thrombolytic agents allow for equivalent coronary reperfusion compared with the standard accelerated alteplase (tPA) regimen with the advantage of easier dosing regimens. Low molecular weight heparin has been shown to be superior to unfractionated heparin and likely will be the standard of care in the near future. The use of glycoprotein IIb/IIIa inhibitors has been shown to decrease the short- and long-term complication rates in patients with acute coronary syndromes treated medically and with percutaneous coronary interventions; however, the choice of the optimal agent and dosing regimen in various clinical settings remains controversial. Combination therapy with low-dose fibrinolytics, glycoprotein IIb/IIIa inhibitors, and low molecular weight heparin, with or without subsequent early planned percutaneous coronary interventions, may provide the optimal strategy for maximal coronary reperfusion, but the results of large, randomized mortality trials currently underway need to be analyzed. Risk stratification will continue to play a major role in determining which patients should receive a specific therapy. The care of the patient with an acute myocardial infarction will continue to be a challenge requiring the proper selection from the vast pharmaceutic and interventional options available.     

Depression after acute myocardial infarction. The role of primary care physicians in rehabilitation

Depression is a common problem after myocardial infarction. Diagnosis is facilitated by use of the criteria for depression in the Diagnostic and Statistical Manual of Mental Disorders and self-rating questionnaires. Treatment may involve both psychological and pharmacologic interventions. The patient's medical status must be carefully assessed before administration of antidepressant medication. All antidepressants are contraindicated immediately after myocardial infarction. When signs and symptoms of depression are exhibited early in the recovery phase, alprazolam (Xanax) may offer advantages over more traditional antidepressants. Further research is necessary to determine the safety of newer antidepressants.     

The role of exercise testing soon after acute myocardial infarction

Summary

Exercise testing is a readily available form of evaluation following acute myocardial infarction, especially in the early stages of recovery. Care is necessary to exclude bad-risk patients, but 70% of patients can be included. Either a treadmill or bicycle ergometer can be used. The important prognostic variables are left ventricular function indexes, and ventricular arrhythmias.

Résumé

Chez les sujets récemment atteints d'un infarctus du myocarde, l'épreuve ergométrique rípétée permet une bonne estimation du degré de récupération fonctionnelle. Chez certains patients à haut risque, ce type d'investigation est contre-indiqué, mais 70% des sujets peu vent ětre inclus. On utilise de préférence une bicyclette ergomítrique (évent. un tapis roulant). Les paramètres importants, quant au prognostic au long cours, sont les indices fonctionnels du ventricule gauche et l'arythmie ventriculaire.

Zusammenfassung

Die Kontrolle der Übungs- oder Arbeitsbelastung ist eine leicht zugängliche Art der Evaluation des Patienten nach akutem Myokardinfarkt, besonders in den Frtihstadien nach dem Ereignis. Sorgfalt ist nötig zum Ausschluss von Risikopatienten, jedoch können 70% der Patienten auf diese Weise untersucht werden. Als Übungsgerät können sowohl Tretmiihle wie Fahrrad-Ergometer benutzt werden. Die prognostisch wichtigen Variabeln sind die Indizes der Funktion des linken Ventrikels und ventrikuläre Arrhythmien.

Resumen

Las pruebas del ejercicio son un tipo de evaluación fácilmente asequible tras un infarto agudo de miocardio, especialmente en los primeros estadios de la recuperación. Tiene que tenerse cuidado de excluir aquellos pacientes que corren mucho peligro, pero pueden incluirse el 70% de los demas. Puede emplearse un tapiz rodante o una bicicleta ergométrica. Las variables pronosticadoras importantes son los índices de la función ventricular izquierda y las arritmias ventriculares.     

The role of exercise testing soon after acute myocardial infarction

Exercise testing is a readily available form of evaluation following acute myocardial infarction, especially in the early stages of recovery. Care is necessary to exclude bad-risk patients, but 70% of patients can be included. Either a treadmill or bicycle ergometer can be used. The important prognostic variables are left ventricular function indexes, and ventricular arrhythmias.     

急性心肌梗死溶栓治疗时血浆凝血酶抗凝血酶复合物水平的变化

目的观察急性心肌梗死(AMI)患者溶栓治疗后凝血系统的变化.方法对临床确诊的34例AMI患者和33名正常对照者,采用ELISA法检测血浆凝血酶抗凝血酶复合物(TAT),对其中6名患者溶栓前、溶栓6 h及溶栓12 h血浆TAT进行动态观察并与正常对照组进行比较.结果 AMI患者的TAT[(13.10±6.70) μg/L]较正常对照组[(6.96±3.60) μg/L]显著升高(P<0.01).6例患者TAT在溶栓治疗前[(11.60±5.10) μg/L]较正常对照组显著升高.溶栓治疗6 h后,TAT[(15.10±7.60) μg/L]较治疗前均有显著升高.溶栓治疗12 h后,TAT[(13.75±5.80) μg/L]下降接近治疗前水平,但仍高于正常人.结论 AMI患者的凝血酶活力增加,溶栓治疗后,导致TAT短时间内进一步提高.     

结肠癌术后突发急性广泛前壁心肌梗死合并室颤致心搏呼吸骤停成功救治一例

急性心肌梗死(myocardial infarction)即急性心肌缺血性坏死,大多是在冠脉血供急剧减少或中断,相应心肌出现严重而持久的急性缺血导致心肌坏死,美国35～ 84岁人群发病率男性为71‰,女性为22‰,每年约有150万人发生急性心肌梗死[1-2].随着我国老龄化的加重,外科围手术期出现急性心肌梗死的情况越来越多见[3],但出现反复心室颤动致心搏呼吸骤停而获得抢救成功病案较少[4],结肠癌根治术后出现急性广泛前壁心肌梗死并发室颤抢救成功的案例更是罕见.