Unstable angina - Causes, symptoms and treatment. MF.

Causes of astable angina
Symptoms of
Diagnosis
Treatment of unstable stenocardia
Lifestyle with angina
Complications and prediction

To understand what unstable angina is, what it causes and what can lead to, it is necessary to briefly focus on the features of the blood supply to the heart.

For good performance of the heart muscle, it needs a sufficient amount of glucose and oxygen. These substances are delivered with arterial blood along the coronary( coronary) arteries originating from the aorta. Allocate the right and left arteries, the latter is divided into an anterior descending and enveloping branches. With physical or emotional stress, when the heart rate increases, myocardial oxygen demand increases, which should be accompanied by an adequate increase in coronary blood flow.

If the coronary arteries are spasmodic( compressed) or clogged from within with a thrombus and / or atherosclerotic plaque, the mismatch of myocardial blood supply to its oxygen demand is developing. There is myocardial ischemia - a chain of pathological processes in the heart muscle, characterized by hypoxia( lack of oxygen) of muscle cells, followed by their necrosis( death) and scar formation in this place. Ischemia is clinically manifested by symptoms of angina pectoris, and necrosis by myocardial infarction.

Angina is a clinical symptom complex that develops in ischemic heart disease, is characterized by the onset of myocardial ischemia during physical exertion or at rest and manifests as attacks of pressing, burning pain in the heart that disappear when nitroglycerin is taken.

The angina is classified on the as stable and unstable .Stability of angina pectoris is determined by the nature of the course of attacks( duration, intensity, frequency of pain), and the effectiveness of nitroglycerin for the removal of pain. This division is important in the prognostic plan, since the likelihood of myocardial infarction and its complications is several times higher with an unstable form of angina. Also, the patient management tactics depend on this, because doctors, when hospitalized with a patient with unstable angina, are already ready for the risk of developing a heart attack. Accordingly, intensive therapy will be aimed at preventing further full overlapping of the coronary arteries, while in a stable form it is sufficient to have outpatient monitoring and timely administration of prescribed medications.

Stable angina is divided into four functional classes, determined depending on the physical load that the patient can tolerate without pain in the heart.

Unstable angina is a kind of "exacerbation" of ischemic disease, when under the influence of certain causes there is an increase in the frequency, duration and intensity of attacks of cardiac pain with lower tolerance of loads than was previously. Unstable form includes the following types of angina:

- the first arising angina,
- angina of Prinzmetal,
- postinfarction angina,
- progressive angina.

Unstable angina can lead to either the development of myocardial infarction, or go into the category of stable angina pectoris, possibly with a higher functional class than the patient had before, that is, with a decrease in exercise tolerance. Often, when talking with a patient, doctors use the expression "pre-infarction state", characterizing the diagnosis of unstable angina, which is not entirely justified, since not in all cases, the end result will be the development of myocardial infarction.

Causes of unstable angina

The main cause of angina is the deposition of atherosclerotic plaques in the lumen of the coronary arteries, resulting in a decrease in the amount of blood that brings oxygen to the heart muscle. Clinically, this process begins to manifest itself when the artery lumen narrowing by more than 50%.Risk factors for atherosclerosis include obesity, lipid( fat) metabolism and cholesterol metabolism, arterial hypertension, diabetes mellitus, nicotine dependence, age over 45 years.

As the atherosclerotic plaque builds up, its destabilization occurs, that is, the rupture of the plaque capsule with the deposition of platelets on its surface and the formation of a thrombus further covering the lumen of the vessel. As a result of destabilization of the plaque, aggravated by the spasm of the affected vessel, the blood flow to the myocardium decreases, which is clinically manifested by the increase in heart attacks and may lead to the development of myocardial infarction. This is the reason for the progression of ischemic disease and the occurrence of unstable angina.

The figure shows that the formation of a thrombus on the surface of the plaque leads to complete occlusion( blockage) of the coronary artery.

Excessive physical exertion, severe emotional overstrain, deterioration in the course of arterial hypertension, alcohol abuse, cardiac decompensation( chronic heart failure, hypertrophic cardiomyopathy, heart defects) and some non-cardiac diseases( thyrotoxicosis, anemia, diabetes mellitus may be factors contributing to the development of unstable angina pectoris)).

Symptoms of unstable angina

With the development of unstable angina, the patient complains of pains in the region of the heart - pressing, burning, constrictive pains behind the breastbone or in the left half of the thorax, which can give to the left arm, scapula, jaw, left half of the neck. Sometimes pain can be more localized, without irradiation, for example, only between the shoulder blades or can take the character of shingles. In some cases, as a result of unstable angina, the abdominal form of myocardial infarction can develop, which manifests itself only in the abdomen. At attacks of pains of the patient the fear of death, feeling of shortage of air, dizziness, a sweating can disturb.

The main symptoms of unstable angina are the following symptoms:

- pains occur more often,
- attacks become stronger in intensity,
- seizures last longer, on the order of 10 -15 minutes or longer,
- seizures may occur both with less physical volumeactivity, than earlier, and in rest,
- reception of nitroglycerin under tongue remains without effect or brings short-term relief, the need for nitroglycerin intake increases.

With the development of newly emerging and progressive angina, these complaints are of concern to the patient during the last month, and in postinfarction angina - from two days to eight weeks after a heart attack.

Prinzmetalla ( variant, vasospastic angina) refers to unstable angina due to the fact that its occurrence is prognostically unfavorable and fraught with a high risk of developing a large-heart attack of the myocardium in the first two to three months from the onset of the first attack. It is characterized by the occurrence of complaints of pain in the heart more often in young men at rest, often in the early hours( probably due to a change in the influence of the autonomic nervous system on the heart at night, especially with the increase in the influence of the vagus nerve).Between bouts of pain patients are able to perform significant physical exertion. The depletion of blood supply to the cardiac muscle in this form of unstable angina is associated with spasm of the coronary vessels, and not necessarily the patient may have coronary atherosclerosis.

Diagnosis of unstable angina

In addition to questioning and examination of the patient, which assesses complaints, general condition, stability of hemodynamics( rhythm, frequency and pulse strength, blood pressure - low or high), a standard ECG record is mandatory. ECG - the criteria for unstable angina are depression( lifting) or elevation( lifting) of the ST segment, high coronary teeth T, negative teeth T, and a combination of these signs in different leads. These signs of ischemia can appear only at a load or at rest, and may be absent altogether.

Symptoms of myocardial ischemia on the ECG are depression of the ST segment( left) and negative T waves in the pectoral leads( right).

To make a decision on hospitalization of the patient in emergency, it is sufficient to conduct a single ECG at the level of the hospital admission department.

In the cardiological hospital, the examination will be supplemented by the following diagnostic methods:

- a general blood test - it is possible to increase the white blood cells( leukocytosis).
- biochemical blood test - increase in cholesterol and changes in the composition of its fractions, changes in the activity of LDH, ASAT, creatine phosphokinase( CK), troponin T( marker of damage to the heart muscle).The level of troponin increases with myocardial infarction.
- Daily monitoring of the ECG according to Holter reveals episodes of myocardial ischemia, including painless ones, establishes the association of pain attacks with physical activity through a diary that the patient conducts on the day of the study.
- echocardiography( ultrasound of the heart) - reveals zones of hypo - and akinesia( reduced or absent contractility of myocardium areas), there may be disturbances in left ventricular systolic function, decrease in stroke volume and ejection fraction.
- radionuclide diagnostic methods( perfusion scintigraphy of the myocardium) is informative in case of discrepancy between laboratory and clinical ECG data - criteria, allows to distinguish zones of necrosis from myocardial ischemia( myocardial infarction).
- coronary angiography( CAG) is performed in order to "see" from the inside and assess the patency of the coronary vessels, and also to decide the question of the appropriateness of stenting of the coronary arteries.

Although it sometimes happens that the patient presents the above symptoms, and the ECG does not show signs of ischemia or necrosis of the myocardium, the patient should still be hospitalized in a cardiac hospital( if the pains are treated by the doctor as anginal, cardiac, and not painfulwith intercostal neuralgia, gastritis, pancreatitis, for example).The need for hospitalization is explained by the fact that sometimes signs of myocardial damage by ECG may be delayed for a while, up to two days, even if the patient is already developing myocardial infarction.

Therefore, when deciding whether to hospitalize and prescribe intensive care for a patient with symptoms of unstable angina, one should rely not only on the combination of clinical and ECG criteria, but also on each of them separately.

Treatment of unstable angina

The patient should remember that if he has pain for the first time in his life in the field of the heart or there is an increase and pain in the existing angina, he should see a doctor, because only a doctor can conduct a full examination and decidethe question of the need for hospitalization in a hospital.

In case of sudden onset of intense pain that is not controlled by taking nitroglycerin in the heart, the patient should immediately call an ambulance team.

Therapy for unstable angina is performed necessarily in a cardiac or therapeutic hospital, and in case of a general severe condition of the patient - in the intensive care unit.

At the pre-hospital stage, alone or as directed by an emergency doctor, the patient should take 1 to 2 nitroglycerin tablets or 1 to 2 doses of nitrosprey under the tongue, then 300 mg of aspirin( three tablets) to be dissolved in the oral cavity to prevent further thickening of the blood and formationthrombi in the coronary vessels.

General measures for the treatment of unstable stenocardia:

- the regimen is assigned to bed or half-bed with physical activity restriction,
- the diet should be gentle, the intake of food in frequent and small portions( 5 to 6 times a day).

Drug therapy reduces to the appointment of the following drug groups:

- nitrates intravenously slow - nitroglycerin or isosorbide dinitrate are dripped continuously for the first two days, then gradually eliminated,
- intravenous bolus intravenous bolus at a dose of 5000 units, then subcutaneously 5000 units four times a day under the control of the coagulation system indicators( ACTTV every two -three days),
- aspirin in usual dose( 100 - 200 mg per day).To exclude the effect on the gastric mucosa, preparations with an enteric coating or capsule are used - aspirin Cardio, Cardiomagnum, thromboass, aspicor, etc.
- beta blockers - carvedilol, propranolol, etc. Contraindicated in bronchial asthma, chronic obstructive pulmonary disease, andwith Prinzmetall angina with angiographically intact coronary vessels( without signs of lesion by their atherosclerosis).With this type of angina, calcium channel antagonists are prescribed: verapamil, nifedipine, corinfar, cordafen. The last three drugs in cases of "pure" vasospastic angina may have a greater effect on relieving pain attacks than nitroglycerin. In coronary atherosclerosis, nifedipine is not indicated, as it causes an increase in heart rate.
- ACE inhibitors - perindopril, captopril, prearrhythmia, noliprel,
- diuretics are prescribed in cases of congestive heart failure, with cardiac asthma and pulmonary edema - furosemide or intravenous lasix, with initialsigns of stagnation - indapamide daily,
- with the preservation of the pain syndrome, neuroleptanalgesia, used in the treatment of myocardial infarction - the use of neuroleptics( droperidol) andnarcotic analgesics( promedol or fentanyl).

In the development of complications( myocardial infarction, pulmonary edema, cardiac arrhythmias, thromboembolic complications), postindromatherapy is performed in the cardiac recovery unit.

The coronary angiography assigned for diagnostic purposes can be extended to a treatment operation with an emergency balloon angioplasty or stenting of the coronary arteries. Also, aorto-coronary bypass surgery may be indicated from surgical methods of treatment. Indications and contraindications for operations are determined strictly individually in each specific case.

Lifestyle in unstable angina

For patients who have had unstable angina after discharge from the hospital or from a sanatorium( where the patient can be referred by a doctor directly from the hospital), the lifestyle should be subjected to general recommendations prescribed in the hospital - restrictive regimen and a sparing diet with regulartaking prescribed medications. The concept of regime restriction includes the exclusion of significant physical and psychoemotional loads, adherence to the work and rest regime( if the working capacity is maintained and there is no disability), organizing its daily routine with sufficient time for sleep and rest, long exposure to fresh air.

Salted, sharp, fatty, fried, smoked dishes, alcohol are excluded in the diet, fatty types of fish and meat, animal fats are limited, consumption of vegetables, fruits, juices, kissels, compotes, fermented milk, cereals is welcomed. Cooking products can be in steam, boiled, baked. The diet should meet the principles of proper nutrition and be aimed at combating obesity.

To prevent repeated severe attacks of pain in the heart and the development of a heart attack and other complications, continuous lifelong administration of medications prescribed by a doctor is required, with correction of the treatment regimen if necessary.

Restoration of working capacity in case of uncomplicated course of unstable angina is possible within 10-14 days from hospitalization and beginning of treatment, after treatment in sanatorium temporary incapacity for work is prolonged for 24 days, with complicated flow, the issue of examination of permanent disability( disability) by the medical commission of a polyclinicITU - medical and social expertise).

Complications of the disease

Complications of unstable angina include myocardial infarction, acute heart failure, including pulmonary edema, rhythm disturbances, ventricular fibrillation and sudden cardiac death. Prevention of complications is an early referral to a doctor with a deterioration of health due to severe pain in the heart, as well as timely intensive treatment in the hospital and subsequent regular intake of prescribed medications. It is important for the patient to remember that if the doctor considers hospitalization necessary in a hospital, it is not necessary to refuse it, as self-medication in this situation is unacceptable.

Prognosis for astable angina

Prognosis for timely hospitalization and timely started treatment is relatively favorable. Relatively, because no doctor will give a guarantee that a particular patient will have a smooth disease and will not end fatal. However, despite treatment, in 20% of patients in the first two to three months and in 11% of patients during the first year after unstable angina develops a large-heart attack of the myocardium.

When the complications develop, the prognosis becomes heavier and is determined by the nature of the pathology, for example, with the development of pulmonary edema and successful treatment, the patient will survive, and with pulmonary embolism or ventricular fibrillation, a fatal outcome may occur immediately.

Doctor therapist Sazykina O.Yu.