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Principles of treatment of unstable angina pectoris and MI without Q wave.The principles of treatment of these conditions are determined by their main similar pathogenetic mechanisms - rupture of atherosclerotic plaques, thrombosis and impaired functional state of the vascular endothelium, and include:
... elimination (prevention) of the consequences of plaque rupture;
... symptomatic therapy.
The main objectives of ACS treatment at the prehospital stage are:
1) early diagnosis of heart attack and its complications;
2) relief of pain syndrome;
3) antiplatelet therapy;
3) prevention and treatment of shock and collapse;
4) Treatment of threatened rhythm disturbances and ventricular fibrillation.
Relief of a painful attack with any manifestations of ACS. Pain in ACS, affecting the sympathetic nervous system, can adversely affect heart rate, blood pressure and heart function. Therefore, it is necessary to stop the pain attack as soon as possible. You should give the patient nitroglycerin under the tongue, preferably in the form of a spray, this can ease the pain, you can repeat it after 5 minutes. It is not indicated for patients with systolic blood pressure below 90 mm Hg. Art.
At the same time, intravenous fractional morphine hydrochloride is injected at a dose of 4 to 8 mg, its re-introduction of 2 mg can be carried out every 5 minutes until the pain in the chest is completely relieved. The maximum dose is 2-3 mg per 1 kg of the patient's body weight. Morphine is especially indicated for persistent pain syndrome in young, physically strong men who drink alcohol, and in patients with acute heart failure.
Side effects of morphine (hypotension, bradycardia) are extremely rare and can be easily stopped by giving the legs an elevated position, injecting atropine, and sometimes plasma-replacing fluid. In elderly people, the inhibition of the respiratory center is often noted from the administration of morphine, therefore, the drug should be administered to them in a reduced (half) dose and carefully. In these cases, morphine can be replaced with a 1% solution of promedol.
When the respiratory center is inhibited, 1-2 ml of 0.5% morphine antagonist nalorphine should be administered. Antipsychotic drugs (fentanyl and droperidol) are significantly inferior to morphine in terms of the effectiveness of pain relief. Promedol at a dose of 10-20 mg (1 ml of 1-2% solution) can be used in patients over 60 years old, as well as in the presence of concomitant diseases with a bronchospastic component with bradycardia.
It should be noted that at the prehospital stage of drug administration in patients with ACS, intramuscular and subcutaneous injections, as well as oral administration of drugs, should be avoided. The intravenous route of administration of drugs is the preferred and most expedient from the standpoint of the time of the onset of the expected effect and safety.
Antithrombotic therapy
Aspirin inhibits platelet aggregation. It has been proven that aspirin in doses ranging from 75 to 325 mg / day significantly reduces the incidence of death and MI in patients with unstable angina pectoris. At the prehospital stage, regular aspirin (but not enteric) should be taken as early as possible, its dose, according to the recommendations of the ACC / AAS experts, should be 325 mg, the maintenance dose should be 75-100 mg / day. For a faster onset of the effect, it should be chewed. It is rapidly absorbed, and therefore its effect on platelets can be manifested as early as 20 minutes after ingestion.The use of ticlopidine at the stage of emergency care should be considered inappropriate due to the slow onset of the disaggregating effect.
When necessary, oxygen therapy is used through a nasal catheter.
Patients with ACS are subject to immediate and careful hospitalization in a specialized department.
Nesterov Yu.I.
The prevalence of cardiovascular diseases (CVD) in Ukraine has reached an extremely wide scale. The number of patients, according to statistics of recent years, is 47.8% of the country's population: 43.2% of them are patients with arterial hypertension (AH); 32.1% - with ischemic heart disease (CHD) and 12.7% - with cerebrovascular diseases (CVD). With such a prevalence, CVD causes 62.5% of all deaths (IHD - 40.9%, CVD - 13.6%), which is the worst indicator in Europe.
N.F. Sokolov, Ukrainian Scientific and Practical Center for Emergency Medicine and Disaster Medicine; T.I. Ganja, A.G. Loboda, National Medical Academy of Postgraduate Education named after P.L. Shupika, Kiev
In this situation, improving the quality of CVD treatment is one of the priority tasks. First of all, this concerns the prehospital stage, since the future fate of patients with acute coronary syndrome (ACS), hypertension, heart rhythm disturbances largely depends on the correct actions of the doctor during this period.
It has now been proven that atherosclerosis is a disease with phases of a stable course and exacerbations. The period of exacerbation of chronic ischemic heart disease is called acute coronary syndrome. This term encompasses clinical conditions such as myocardial infarction (MI), unstable angina pectoris (NS), and sudden cardiac death. The appearance of the term ACS is due to the fact that although MI and NA have different clinical manifestations, they have the same pathophysiological mechanism: rupture or erosion of atherosclerotic plaques with varying degrees of thrombosis, vasoconstriction, and distal embolization of coronary vessels. According to modern concepts, the main factors that lead to the destabilization of an atherosclerotic plaque are systemic and local inflammation. In turn, the agents that promote the development of inflammation are very diverse: infections, oxidative stress, hemodynamic disorders (hypertensive crisis), systemic immune responses, etc. The lipid-filled core of the plaque, which opens after its rupture, is highly thrombogenic. This leads to the launch of a cascade of reactions: adhesion of platelets to the damaged surface, activation of platelets and the blood coagulation system, secretion of serotonin and thromboxane A2, platelet aggregation. The development of acute thrombosis in the coronary vessel affected by the atherosclerotic process can be facilitated not only by plaque rupture, but also by increased blood clotting, which is more often observed in smokers, in women using oral contraceptives, in young patients who have had myocardial infarction.
Inhibition of the natural activation of plasminogen induces hypercoagulation and can lead to the development of extensive myocardial infarction even with angiographically little altered arteries. Plasminogen activation is subject to circadian rhythms that decline in the early morning hours, when the likelihood of MI, sudden death, and stroke is greatest.
If the thrombus does not completely block the lumen of the vessel, the clinical picture of NA develops. In the case when a thrombus in a coronary vessel causes its complete occlusion, myocardial infarction occurs, especially in the absence of developed collateral circulation, which is more common in young patients. This can also occur with hemodynamically insignificant coronary stenosis.
Based on the changes in the ECG, two main forms of ACS are distinguished: with elevation and without elevation of the ST segment.
In patients with ST segment elevation, as a rule, there is transmural myocardial ischemia due to complete occlusion of the coronary artery by a thrombus, and extensive necrosis develops. In patients with ST segment depression, ischemia occurs, which may or may not form necrosis, since coronary blood flow is partially preserved. The heart attack in these patients develops without the appearance of a Q wave on the ECG (MI without a Q wave). In the case of a rapid normalization of the ECG and the absence of an increase in the level of markers of myocardial necrosis, a diagnosis of NA is made.
The isolation of two forms of ACS is also associated with different prognosis and treatment tactics in these groups of patients.
ACS forms
Acute coronary syndrome with ST-segment elevation or acute-onset left bundle branch block
Persistent ST-segment elevations indicate acute complete occlusion of the coronary artery, possibly in the proximal region. Since a large area of the left ventricular myocardium is at risk of injury, the prognosis in these patients is the most difficult. The goal of treatment in this situation is to quickly restore the patency of the vessel. For this, thrombolytic drugs are used (in the absence of contraindications) or percutaneous angioplasty.
Acute coronary syndrome without ST-segment elevation
With this variant, changes on the ECG are characterized by persistent or transient depression of the ST segment, inversion, flattening or pseudo-normalization of the T wave.In some cases, the ECG in the first hours is normal, and the management of such patients is to eliminate pain and myocardial ischemia using aspirin, heparin , β-blockers, nitrates. Thrombolytic therapy is ineffective and may even worsen the prognosis in patients.
The diagnosis of ACS at the prehospital stage is based on clinical manifestations (anginal status) and ECG diagnostics.
Anginous status
ACS with ST segment elevation
Diagnosis is based on the presence of anginal pain in the chest for 20 minutes or more, which is not stopped by nitroglycerin and radiates to the neck, lower jaw, and left arm. In elderly people, the clinical picture may be dominated not by pain, but by weakness, shortness of breath, loss of consciousness, arterial hypotension, cardiac arrhythmias, and acute heart failure.
ACS without ST segment elevation
Clinical manifestations of an anginal attack in patients with this variant of ACS may be resting angina pectoris lasting more than 20 minutes, new-onset angina pectoris of the third functional class, progressive angina pectoris (increased frequency of attacks, an increase in their duration, a decrease in exercise tolerance).
Acute coronary syndrome can have an atypical clinical course. Atypical manifestations: epigastric pain with nausea and vomiting, stabbing pain in the chest, pain syndrome with signs characteristic of pleural lesions, increasing shortness of breath.
In these cases, the correct diagnosis is facilitated by indications of a history of ischemic heart disease and changes in the ECG.
ECG diagnostics
ECG is the main method for assessing patients with ACS, on the basis of which a prognosis is built and a therapeutic tactic is selected.
ACS with ST segment elevation
- ST segment elevation ≥ 0.2 mV in leads V1-V3 or ≥ 0.1 mV in other leads.
- The presence of any Q wave in leads V1-V3 or Q wave ≥ 0.03 s in leads I, avL, avF, V4-V6.
- Acute left bundle branch block.
ACS without ST segment elevation
ECG signs of this variant of ACS are ST segment depression and T wave changes. The likelihood of this syndrome is greatest when the clinical picture is combined with ST segment depression exceeding 1 mm in two adjacent leads with a predominant R wave or more. A normal ECG in patients with symptoms characteristic of ACS does not exclude its presence. In this case, it is necessary to exclude other possible causes of the patient's complaints.
Treatment of patients with ACS
The results of ACS treatment largely depend on the correct actions of the doctor at the prehospital stage. The main task of an ambulance doctor is effective relief of pain syndrome and possibly early reperfusion therapy.
Algorithm for the treatment of patients with ACS
- Sublingual nitroglycerin (0.4 mg) or nitroglycerin aerosol every five minutes. After taking three doses with persisting chest pain and systolic blood pressure of at least 90 mm Hg. Art. it is necessary to resolve the issue of prescribing nitroglycerin intravenously as an infusion.
- The drug of choice for relieving pain syndrome is morphine sulfate 10 mg intravenously in a stream in saline sodium chloride solution.
- Early appointment of acetylsalicylic acid at a dose of 160-325 mg (chewed). Patients who have previously taken aspirin can be prescribed clopidogrel 300 mg, followed by 75 mg / day.
- Immediate prescription of β-blockers is recommended for all patients if there are no contraindications to their use (atrioventricular blockade, history of bronchial asthma, acute left ventricular failure). Treatment should be started with short-acting drugs: propranolol at a dose of 20-40 mg or metroprolol (egilok) at 25-50 mg orally or sublingually.
- Elimination of factors that increase the load on the myocardium and contribute to increased ischemia: hypertension, heart rhythm disturbances.
Further tactics of providing care to patients with ACS, as already mentioned, is determined by the characteristics of the ECG picture.
Patients with clinical signs of ACS with persistent ST-segment elevation or acute left bundle branch block in the absence of contraindications need to restore patency of the coronary artery using thrombolytic therapy or primary percutaneous angioplasty.
If possible, thrombolytic therapy (TLT) is recommended at the prehospital stage. If TLT can be performed within the first 2 hours after the onset of symptoms (especially within the first hour), it can stop the development of MI and significantly reduce mortality. TLT is not performed if more than 12 hours have passed since the anginal attack, except when the ischemic attacks continue (pain, ST segment elevations).
Absolute contraindications for TLT
- Any history of intracranial bleeding.
- Ischemic stroke within the past three months.
- Structural damage to the vessels of the brain.
- Malignant neoplasm of the brain.
- Closed head injury or facial injury in the past three months.
- Aortic dissecting aneurysm.
- Gastrointestinal bleeding during the last month.
- Pathology of the blood coagulation system with a tendency to bleeding.
Relative contraindications for TLT
- Refractory arterial hypertension (systolic blood pressure more than 180 mm Hg).
- History of ischemic stroke (more than three months old).
- Traumatic or prolonged (more than 10 minutes) cardiopulmonary resuscitation.
- Major surgery (up to three weeks).
- Puncture of a vessel that cannot be pressed.
- Peptic ulcer in the acute stage.
- Anticoagulant therapy.
In the absence of conditions for TLT, as well as in patients with ACS without ST segment elevation, the ECG shows the appointment of anticoagulants: heparin 5000 U intravenously in a jet or low molecular weight heparin - enoxaparin 0.3 ml intravenously in a jet, followed by continuation of treatment in a hospital setting.
Literature
- The treatment of myocardial infarction in patients with ST segment deficiency in the debut of an illness: the leading position of the recommendations of the working group of the European Cardiological Association, 2003 // Heart and Judy. - 2003. - No. 2. - S. 16-27.
- Treatment of myocardial infarction from ST segment elevation: recommendations of the American College of Cardiology and American Association of Cardiologists // Heart and Judy. - 2005. - No. 2 (10). - S. 19-26.
- Dolzhenko M.N. European guidelines for the diagnosis and treatment of acute coronary syndrome // Therapy. - 2006. - No. 2. - S. 5-13.
- Raptov's cardial death: factors of risk and prevention / Recommendations of the Ukrainian Science Association of Cardiologists. - K., 2003 .-- 75 p.
- Sertsevo-sudinni ailment: classification, diag nostics and diagnostics schemes / Edited by professors V.M. Kovalenka, M.I. Lost. - K., 2003 .-- 77 p.
Stage 1. Assessment of the severity of the condition and the risk of death
At this stage, it is necessary to collect anamnesis and complaints of the patient. Anamnesis of the present disease, as well as concomitant and past diseases is collected. Then the patient is examined with an assessment of the frequency of respiratory movements, auscultation of the lungs,The presence of peripheral edema and other signs of decompensation (enlarged liver, hydrothorax) is also checked.
Stage 2. Analysis of the electrocardiogram
ECG in acute coronary syndrome. Variants of ST segment displacement in case of injury. On there is a change or displacement of the ST segment, a change in the T wave.
Stage 3. Treatment of acute coronary syndrome at the prehospital stage
Principles of prehospital treatment:
- Adequate pain relief
- Initial antithrombotic therapy
- Treatment of complications
- Fast and gentle transportation to the hospital
Anesthesia:
- nitroglycerin under blood pressure control
- IV analgin + diphenhydramine
- i / v morphine 1% - 1.0 per 20.0 saline.
Possible complications:
-
- acute heart failure
Initial antithrombotic therapy for acute coronary syndrome
- Aspirin 1 tab. chew (for intolerance to clopidogrel 300 mg.)- Heparin 5 thousand units. (as prescribed by a doctor).
Emergency hospitalization in the intensive care unit: for thrombolytic therapy (administration of streptokinase, streptodecase), as well as for resolving the issue of coronary angiography and balloon coronary angioplasty
For citation: Vertkin A.L., Moshina V.A. Treatment of acute coronary syndrome at the prehospital stage // BC. 2005. No. 2. P. 89
The clinical manifestations of coronary heart disease are stable angina pectoris, painless myocardial ischemia, unstable angina pectoris, myocardial infarction, heart failure, and sudden death. For many years, unstable angina pectoris was considered as an independent syndrome that occupies an intermediate position between chronic stable angina pectoris and acute myocardial infarction. However, in recent years, it has been shown that unstable angina pectoris and myocardial infarction, despite the differences in their clinical manifestations, are consequences of the same pathophysiological process, namely rupture or erosion of an atherosclerotic plaque in combination with associated thrombosis and embolization of more distally located areas of the vascular channel. In this regard, unstable angina pectoris and developing myocardial infarction are currently combined by the term acute coronary syndrome (ACS).
The introduction of this term into clinical practice is dictated primarily by considerations of a practical nature: firstly, the impossibility of a quick differentiation of these conditions and, secondly, the need for an early start of treatment before the final diagnosis is established. As a "working" diagnosis of ACS, it is best suited for the first contact between the patient and the doctor at the prehospital stage.
The relevance of creating balanced and carefully substantiated recommendations for EMS doctors on the treatment of ACS is largely due to the prevalence of this pathology. As you know, in total in the Russian Federation the number of calls to the SMP is 130,000 per day, including those related to ACS from 9,000 to 25,000.
The volume and adequacy of emergency care in the first minutes and hours of illness, i.e. at the prehospital stage, to a large extent determine the prognosis of the disease. Therapy is aimed at limiting the zone of necrosis by relieving pain, restoring coronary blood flow, reducing heart function and myocardial oxygen demand, as well as treating and preventing possible complications (Table 1).
One of the main factors determining the prognosis of patients with ACS is the adequacy of medical care in the first hours of the disease, since it is during this period that the highest mortality rate is noted. It is known that the earlier reperfusion therapy with the use of thrombolytic drugs is carried out, the higher the chances of a favorable outcome of the disease. The dynamics of pathomorphological changes in the myocardium in ACS is presented in Table 2.
According to Dracup K. et al. (2003), the delay from the onset of ACS symptoms to the initiation of therapy ranges from 2.5 hours in England to 6.4 hours in Australia. Naturally, this delay is largely determined by the population density, the nature of the area (urban, rural), living conditions, etc. Kentsch M. et al. (2002) believe that the delay with thrombolysis is also due to the time of day, year and weather conditions, which affect the speed of transportation of patients.
Within the framework of the program of the National Scientific and Practical Society of Emergency Medical Aid (NSPOSMP) to optimize the treatment of various pathological conditions at the prehospital stage, an open randomized study "NOCS" was conducted at 13 stations of the emergency medical service in Russia and Kazakhstan, one of the tasks of which was to assess the effectiveness of thrombolytic therapy on prehospital stage. It was shown that thrombolytic therapy for patients with ACS with ST segment elevation is carried out in less than 20% of cases, including in the megalopolis in 13%, in medium-sized cities - in 19%, in rural areas - in 9%. At the same time, the frequency of thrombolytic therapy (TLT) does not depend on the time of day and season, and the time for calling the emergency room is delayed by more than 1.5 hours, and in rural areas - by 2 hours or more. The time from the onset of pain to the "needle" is on average 2-4 hours and depends on the area, time of day and season. The gain in time is especially noticeable in large cities and rural areas, at night and in winter. The conclusions of the work indicate that prehospital thrombolysis can reduce mortality (13% with prehospital thrombolysis, 22.95% with inpatient thrombolysis), the incidence of postinfarction angina pectoris without significantly affecting the incidence of recurrent myocardial infarction and the appearance of signs of heart failure.
The benefits of postponing the initiation of thrombolytic therapy to the prehospital phase have been shown in the multicenter randomized clinical trials GREAT (1994) and EMIP (1993). According to the data obtained in the course of the CAPTIM study (2003), the results of early initiation of TLT at the prehospital stage are comparable in effectiveness with the results of direct angioplasty and are superior to the results of therapy started in the hospital.
This suggests that in Russia the damage caused by the impossibility of widespread dissemination of surgical methods of revascularization in ACS (the reasons for which are primarily economic) can be partially compensated for by the earliest possible onset of TLT.
The available evidence base concerns only the possibility of prehospital use of thrombolytics and does not contain arguments in favor of nitric oxide donors, which are traditionally used in patients with ACS, including their various forms.
According to the ACA / AHA recommendation (2002), the treatment of ACS involves the use of nitroglycerin to relieve pain, decrease heart function and myocardial oxygen demand, limit the size of myocardial infarction, and also for the treatment and prevention of complications of myocardial infarction (confidence level B). Pain relief in acute myocardial infarction is one of the most important tasks, and it begins with sublingual administration of nitroglycerin (0.4 mg aerosol or tablets). If there is no effect of sublingual nitroglycerin administration (three times with 5 min intervals), narcotic analgesic therapy should be started (Fig. 1).
The mechanism of action of nitroglycerin, which has been used in medicine for over 100 years, is well known and no one doubts that it is practically the only and most effective remedy for stopping an attack of angina pectoris.
However, the question of the most effective dosage form for relieving anginal pain, including at the prehospital stage, continues to be debated. Nitroglycerin comes in five main forms: sublingual tablets, oral tablets, aerosol, transdermal (buccal) and intravenous. For use in emergency treatment, aerosol forms (nitroglycerin-spray), tablets for sublingual use and solution for intravenous infusion are used.
The aerosol form of nitroglycerin has a number of undeniable advantages over other forms:
- the speed of relief of an attack of angina pectoris (the absence in the composition of essential oils that slow down absorption, provides a faster effect);
- dosage accuracy - when you press the valve of the cartridge, a precisely set dose of nitroglycerin is released;
- ease of use;
- safety and preservation of the drug due to special packaging (nitroglycerin is an extremely volatile substance);
- long shelf life (up to 3 years) compared to the tablet form (up to 3 months after opening the package);
- equal effectiveness with fewer side effects compared to parenteral forms;
- the possibility of using with difficult contact with the patient and in the absence of consciousness;
- use in elderly patients suffering from decreased salivation and delayed absorption of tablet forms of the drug;
- for reasons of pharmacoeconomics, the advantage of a spray, one package of which can be enough for 40-50 (!) Patients, is obvious compared to a more technically complex intravenous infusion, which requires an infusion system, a solvent, a venous catheter and the drug itself.
In the study of NOCS, a comparison was made of the antianginal effect, the effect on the main parameters of hemodynamics, the incidence of side effects of nitroglycerin with different forms of its administration - per os in aerosol or intravenous infusion.
The research methodology consisted in assessing the clinical state, assessing the presence of pain syndrome, measuring blood pressure, heart rate at baseline and 3, 15 and 30 minutes after parenteral or sublingual nitrate administration, ECG recording. The undesirable effects of drugs were also monitored. In addition, the 30-day prognosis in patients was assessed: mortality, the incidence of Q-myocardial infarction in patients with baseline ACS without ST segment elevation.
As follows from the data presented (Table 3), there were no differences in the 30-day mortality rate, as well as there were no significant differences in the incidence of ACS evolution without ST elevation in myocardial infarction (MI) with Q wave, as well as in the incidence combined endpoint (MI or death).
As a result of treatment in 54 patients of group 1, the use of 1 dose of aerosol contributed to the rapid relief of pain syndrome (less than 3 minutes), 78 patients required additional administration of the 2nd dose of the drug with a good effect in 21, after 15 minutes the pain persisted in 57 patients, which ( according to the protocol) required the introduction of drugs. After 30 minutes, the pain syndrome persisted in only 11 patients.
In group 2, the antianginal effect of intravenous infusion of nitroglycerin was noted significantly later. In particular, by the 3rd minute the pain disappeared only in 2 patients, by the 15th minute - the pain persisted in 71 patients, of which 64 received narcotic analgesia. By the 30th minute, the pain syndrome remained in 10 patients. It is very important that the frequency of recurrence of pain syndrome was equally small in both groups.
The use of nitroglycerin in both groups led to a significant decrease in the SBP level, and in patients receiving nitroglycerin per os - an insignificant decrease in the DBP level. In patients receiving nitroglycerin infusion, a statistically significant decrease in DBP was noted. There were no statistically significant changes in heart rate. As expected, the infusion of nitroglycerin was accompanied by a significantly higher incidence of side effects associated with a decrease in blood pressure (8 episodes of clinically significant hypotension), but all these episodes were transient and did not require the appointment of vasopressor agents. In all cases of hypotension, it was enough to suspend the infusion - and after 10-15 minutes the blood pressure returned to an acceptable level. In two cases, continuing the infusion at a slower rate again led to the development of hypotension, which required the final withdrawal of nitroglycerin. With sublingual use of nitroglycerin, persistent hypotension was obtained in only two cases.
Against the background of nitrate therapy, side effects in the form of hypotension were noted when using an aerosol in 1.3%, when using an intravenous form - in 12%; hyperemia of the face - in 10.7% and 12%, respectively; tachycardia in 2.8% and 11% of cases, respectively, headache with sublingual administration of the drug was noted in 29.9%, and with intravenous administration in 24% of cases (Table 4).
Thus, in patients with ACS without ST elevation, the sublingual forms of nitroglycerin are not inferior to the parenteral forms in terms of the analgesic effect; side effects in the form of hypotension and tachycardia with intravenous administration of nitroglycerin occur more often than with sublingual administration, and facial flushing and headache occur with intravenous administration with the same frequency as with sublingual administration.
The conclusions of the work indicate that nitroglycerin aerosol is the drug of choice as an antianginal agent at the prehospital stage.
Thus, in the provision of therapeutic benefits, the success of urgent therapy largely depends on the correct choice of the form of the drug, dosage, route of administration, and the possibility of adequate control over its effectiveness. Meanwhile, the quality of treatment at this stage often determines the outcome of the disease as a whole.
Literature
1. The effectiveness of nitroglycerin in acute coronary syndrome at the prehospital stage. // Cardiology. – 2003. – №2. - P.73–76. (Suleimenova B.A., Kovalev N.N., Totskiy A.D., Dmitrienko I.A., Malysheva V.V., Demyanenko V.P., Kovalev A.Z., Buklov T.B., Kork A.Yu., Dyakova T.G., Soltseva A.G., Kireeeva T.S., Tuberkulov K.K., Kumargalieva M.I., Talibov O.B., Polosyants O.B., Malsagova M.A. A., Vertkin M.A., Vertkin A.L.).
2. The use of various forms of nitrates in acute coronary syndrome at the prehospital stage. // Russian Journal of Cardiology. –2002. –P. 92–94. (Polosyants O.B., Malsagova M.A., Kovalev N.N., Kovalev A.Z., Suleimenova B.A., Dmitrienko I. A., Tuberkulov K.K., Prokhorovich E.A., Vertkin A.L.).
3. Clinical trials of drugs in urgent cardiological conditions at the prehospital stage. // Collection of materials of the second congress of cardiologists of the Southern Federal District "Modern problems of cardiovascular pathology." Rostov-on-Don.-2002- P. 58. (Vertkin A.L., Malsagova M.A., Polosyants O.B.).
4. New technologies of biochemical express diagnostics of acute coronary syndrome at the prehospital stage.
Emergency therapy.-2004.-№ 5-6.-P. 62-63. (M.A.Malsagova, M.A.Vertkin, M.I. Tishman).
Acute coronary syndrome (ACS)- any group of clinical signs or symptoms suggestive of myocardial infarction or unstable angina pectoris.
Elevation of the ST segment- as a rule, a consequence of transmural myocardial ischemia and occurs with the development of complete occlusion of the main coronary artery.
In the case when the ST elevation is of a short-term, transient nature, we can talk about vasospastic angina ( Prinzmetal's angina).
Such patients also require urgent hospitalization, but fall under the tactics of ACS management without persistent ST elevation. In particular, thrombolytic therapy is not performed.
Persistent ST-segment elevation lasting more than 20 minutes is associated with acute complete thrombotic occlusion of the coronary artery.
OKC with ST rise diagnosed in patients with an anginal attack or chest discomfort and changes in the form of a persistent elevation of the ST segment or "new", i.e. for the first time (or presumably for the first time) a complete left bundle branch block (LBBB) on.
ACS is a working diagnosis, used in the first hours and days of the disease, while the terms myocardial infarction (MI) and unstable angina pectoris (NS) are used to formulate the final diagnosis, depending on whether signs of myocardial necrosis are detected.
MI is diagnosed based on the following criteria:
- 1. A significant increase in biomarkers of cardiomyocyte necrosis in combination with at least one of the following:
- ischemic symptoms,
- episodes of ST segment elevation on or new-onset complete left bundle branch block,
- the appearance of a pathological Q wave on,
- the appearance of new zones of impaired local myocardial contractility,
- identification of intracoronary thrombosis at, or identification of thrombosis at autopsy.
The identification of ischemic changes on the electrocardiogram allows avoiding mistakes in the choice of medical tactics.
2.2. Asthmatic variant is a manifestation of acute left ventricular failure in the form of an attack of cardiac asthma or pulmonary edema and is usually observed in elderly patients, usually with a previous organic heart disease.
Chest discomfort does not correspond to classical characteristics or may be practically absent.
2.3. Arrhythmic variant differs in the predominant manifestations of rhythm and conduction disturbances, while the pain syndrome is absent or slightly expressed. Identification of ischemic electrocardiographic changes is of decisive importance.
2.4. Cerebrovascular variant occurs in elderly patients, with a history of strokes or severe chronic disorders of cerebral circulation.
The presence of intellectual-mnestic disorders or acute neurological pathology often does not allow assessing the nature of the pain syndrome in the chest.
Clinically, the disease manifests itself as neurological symptoms in the form of dizziness with nausea, vomiting, fainting, or impaired cerebral circulation.
Considering that severe strokes, even without the development of myocardial infarction, can be accompanied by infarct-like changes on, the decision on the introduction of thrombolytics or antithrombotic drugs should be postponed until the results of imaging studies are obtained.
In other cases, the patient management algorithm is determined by the nature of the electrocardiographic changes.
2.5. Painless form myocardial infarction is more often observed in patients with diabetes mellitus, in the elderly, after a previous violation of a heart attack and stroke.
The disease is detected as an accidental finding when filming, or performing an echocardiographic study, sometimes only at autopsy.
Some patients, when asked, do not describe chest discomfort as pain, or do not attach importance to an increase in short-term attacks of angina pectoris, while this may be a manifestation of a heart attack.
The perception of anginal pain can be impaired with depression of consciousness and the introduction of painkillers for strokes, injuries and surgical interventions.
In any case, even the suspicion of ACS in such patients should be the basis for immediate hospitalization.
It should be borne in mind that normal or slightly altered does not exclude the presence of ACS and therefore, in the presence of clinical signs of ischemia, the patient requires immediate hospitalization.
During dynamic observation (monitoring or re-registration), typical changes can be recorded later.
The combination of severe pain syndrome and persistently normal causes a differential diagnosis with other, sometimes life-threatening conditions.
The role of rapid determination of troponins increases when the clinic is unclear and initially changed.
At the same time, a negative result should not be a reason for refusing urgent hospitalization with suspected ACS.
Echocardiography can help in making a diagnosis in certain situations, but it should not delay the hospitalization. (IIb, C). This study is practically not performed by the ambulance team, therefore, it cannot be recommended for routine use.
DIFFERENTIAL DIAGNOSTICS
Differential diagnosis of STEMI should be performed with PE, aortic dissection, acute pericarditis, pleuropneumonia, pneumothorax, intercostal neuralgia, diseases of the esophagus, stomach and duodenum 12 (peptic ulcer), other organs of the upper abdominal cavity (diaphragmatic hernia, biliary stone disease, acute cholecystitis, acute pancreatitis).
TELA - in the clinic, sudden dyspnea prevails, which is not aggravated in a horizontal position, accompanied by pallor or diffuse cyanosis.
Pain syndrome may resemble anginal pain. In many cases, there are risk factors for venous thromboembolism.
At esophageal spasm retrosternal pain may resemble ischemic pain, often relieved by nitrates, but may also disappear after a sip of water. This does not change.
Diseases of the upper abdominal organs usually accompanied by various manifestations of dyspepsia (nausea, vomiting) and tenderness of the abdomen on palpation.
A heart attack can simulate a perforated ulcer, therefore, during examination, palpation of the abdomen should be performed, paying special attention to the presence of symptoms of peritoneal irritation.
It should be emphasized that in the differential diagnosis of these diseases is of paramount importance.
The choice of treatment tactics
Once the diagnosis of STEACS is established, it is necessary to urgently determine the tactics of reperfusion therapy, i.e. restoration of patency of the occluded coronary artery.
Reperfusion therapy (PCI or thrombolysis) is indicated for all patients with chest pain / discomfort lasting<12 ч и персистирующим подъемом сегмента ST или новой блокадой левой ножки пучка Гиса (I,A).
- If ischemia persists or pain and changes recur, reperfusion therapy (preferably PCI) is performed even if symptoms develop within> 12 hours (I, C).
- If more than 24 hours have passed since the onset of symptoms and the condition is stable, routine PCI is not planned (III, A).
- In the absence of contraindications and the impossibility of performing PCI within the recommended time frame, thrombolysis is performed (I, A), preferably at the prehospital stage.
- Thrombolytic therapy is performed if PCI cannot be performed within 120 minutes from the moment of the first contact with a healthcare professional (I, A).
- If less than 2 hours have passed since the onset of symptoms and PCI cannot be performed within 90 minutes, thrombolytic therapy should be given for large heart attacks and low risk of bleeding (I, A).
- After thrombolytic therapy, the patient is sent to the center with the possibility of performing PCI (I, A).
Absolute contraindications to thrombolytic therapy:
- Hemorrhagic stroke or stroke of unknown origin of any prescription
- Ischemic stroke in the previous 6 months
- Brain trauma or tumors, arteriovenous malformation
- Major trauma / surgery / trauma to the skull within the previous 3 weeks
- Gastrointestinal bleeding during the previous month
- Identified hemorrhagic disorders (excluding menses)
- Aortic dissection
- Puncture of an uncompressed area (including liver biopsy, lumbar puncture) in the previous 24 hours
Relative contraindications:
- Transient ischemic attack within the previous 6 months
- Oral anticoagulant therapy
- Pregnancy or postpartum condition within 1 week
- Resistant hypertension (systolic blood pressure> 180 mmHg and / or diastolic blood pressure> 110 mmHg)
- Severe liver disease
- Infective endocarditis
- Exacerbation of peptic ulcer
- Prolonged or traumatic resuscitation
Thrombolysis drugs:
- Alteplase (tissue plasminogen activator) 15 mg IV as a bolus of 0.75 mg / kg for 30 minutes, then 0.5 mg / kg for 60 minutes IV. The total dose should not exceed 100 mg
- Tenekteplaza- once in / in the form of a bolus, depending on body weight:
30 mg -<60 кг
35 mg - 60-<70 кг
40 mg - 70-<80 кг
45 mg - 80-<90 кг
50 mg - ≥90 kg
All patients with ACS in the absence of contraindications are shown double antiplatelet therapy ( I , A ):
If primary PCI is planned:
- Aspirin inside 150-300 mg or intravenous 80-150 mg, if oral administration is not possible
- Clopidogrel inside 600 mg (I, C). (If possible, Prasugrel is preferred in non-clopidogrel patients younger than 75 years of age 60 mg (I, B) or Ticagrelor 180 mg (I, B)).
If thrombolysis is planned:
- Aspirin by mouth 150-500 mg or IV 250 mg if oral administration is not possible
- Clopidogrel by mouth at a loading dose of 300 mg if age ≤75 years
If neither thrombolysis nor PCI is planned:
- Aspirin inside 150-500 mg
- Clopidogrel inside 75 mg
Other drug therapy
- Intravenous opioids (morphine 4-10 mg), in elderly patients, must be diluted in 10 ml of saline and administered in 2-3 ml fractions.
If necessary, additional doses of 2 mg are administered at intervals of 5-15 minutes until the pain is completely relieved). The development of side effects is possible: nausea and vomiting, arterial hypotension with bradycardia and respiratory depression.
Antiemetics (for example, metoclopramide 5-10 mg intravenously) can be administered concurrently with opioids.
Hypotension and bradycardia are usually controlled by atropine in a dose of 0.5-1 mg (total dose up to 2 mg) intravenously;
- Tranquilizer (Diazepam 2.5-10 mg IV) for severe anxiety
- Beta-blockers in the absence of contraindications (bradycardia, hypotension, heart failure, etc.):
Metoprolol - with severe tachycardia, preferably intravenously - 5 mg every 5 minutes 3 injections, then after 15 minutes 25-50 mg under the control of blood pressure and heart rate.
In the future, tablet preparations are usually prescribed.
- Nitrates for pain sublingually: Nitroglycerin 0.5-1 mg tablets or Nitrospray (0.4-0.8 mg). For recurrent angina pectoris and heart failure
Nitroglycerin is administered intravenously under the control of blood pressure: 10 ml of a 0.1% solution is diluted in 100 ml of saline.
Constant monitoring of heart rate and blood pressure is required, do not enter with a decrease in systolic blood pressure<90 мм рт. ст.
Oxygen inhalation (2-4 l / min) in the presence of shortness of breath and other signs of heart failure
RENDERING EMERGENCY CARE AT THE HOSPITAL STAGE IN THE INPATENT EMERGENCY DEPARTMENT (STOSMP)
ACS patients with pST should be referred to the ICU immediately.
In presenting the material, the classes of recommendations and levels of evidence proposed by the ACC / AHA and used in the Russian recommendations were used.
ClassIIa- The available evidence is more indicative of the usefulness and effectiveness of a diagnostic or treatment method
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