CARDIAC ISCHEMIA

ISCHEMIC HEART DISEASE - the pathology of the heart caused by acute or chronic recurrent myocardial ischemia (i.e., a mismatch between the supply of oxygen to the myocardium and the need for it) due to narrowing or plugging of atherosclerotic plaques of the coronary arteries lumen or as a result of their thrombosis or spasm.

To coronary heart disease (CHD) include several independently considered forms of pathology, differing manifestations and severity of the consequences of myocardial ischemia: angina pectoris, myocardial infarction; Diffuse (atherosclerotic) and focal, or postinfarction, cardiosclerosis (including heart aneurysm), manifested clinically by rhythm disturbances and / or the development of heart failure.

The development of IHD is facilitated by many internal and external factors, called risk factors. The main risk factors include some disorders of lipid metabolism, usually characterized by high cholesterol in the blood (hypercholesterolemia), arterial hypertension , diabetes mellitus , smoking , low physical activity, prolonged psychoemotional stress.

The basis for the pathogenesis of myocardial ischemia in all forms of IHD is the discrepancy between the need for cardiac muscle in oxygen and nutrients and their entry into the narrowed coronary arteries. This discrepancy is greater than the lumen of the coronary arteries and the greater the work of the heart; It increases during exercise, with psychoemotional stress, against which usually there are symptoms of exacerbation of IHD. An important pathogenetic factor in the development of myocardial ischemia in IHD can be a spasm of the coronary arteries of the heart. This factor is leading in the onset of coronary insufficiency in patients with minimal coronary artery atherosclerosis. In cases where sclerosis and calcification of the walls of the arteries impede the change in their lumen, the aggravation of coronary insufficiency can be facilitated by the spasm of the round (collateral) vessels participating in the blood supply of the part of the myocardium susceptible to ischemia. Of great importance in the pathogenesis of coronary insufficiency in IHD are abnormalities of platelet function and increased coagulability of blood, which can worsen microcirculation in myocardial capillaries and lead to arterial thrombosis, which is promoted by atherosclerotic changes in their walls and slowing of blood flow in the sites of arterial lumen narrowing. Repeated and prolonged attacks of angina are often due to the development of thrombosis. At the same time, the gradually progressing narrowing of the lumen of the affected artery by a thrombus leads to an increase in the duration of pain attacks, increased myocardial ischemia, and the development of dystrophy up to necrosis. The rupture or splitting of an atherosclerotic plaque with the formation of a thrombus, increased platelet aggregation and segmental spasm near the plaque underlies the pathogenesis of myocardial infarction and unstable angina.

Myocardial ischemia negatively affects the functions of the heart - its contractility, automatism, excitability, conductivity. Short-term ischemia is usually manifested by an attack of angina pectoris or its equivalents: a transient rhythm disturbance, dyspnea, dizziness, etc. At the same time, pronounced morphological changes do not occur in the myocardium. Prolonged ischemia (20 - 30 minutes or more), especially when the coronary artery is closed by a thrombus, is completed by necrosis of the site of the heart muscle that underwent ischemia, a myocardial infarction.

Diagnosis is based on an assessment of the totality of clinical manifestations, the results of studies and the study of ECG dynamics; Sometimes it is necessary to use echocardiography, radionuclide methods of heart examination, daily ECG monitoring, various methods of functional diagnostics of cardiac activity and pharmacological tests. The most typical clinical manifestations of angina in the form of attacks of chest pain (pressing, compressing or burning with irradiation in the neck, the left arm). It is more difficult to recognize the equivalents of angina and its atypical manifestations, when patients are not able to accurately characterize the pain sensation. With a painless form of ischemic heart disease, the diagnosis of myocardial ischemia, focal dystrophy and even myocardial infarction is sometimes established only by ECG monitoring, echocardiography and myocardial scintigraphy under stress. To detect atherosclerotic plaques allows one of the methods of X-ray study - coronarography.

In the case of typical pain attacks, evaluation of their duration and effectiveness of nitroglycerin is of great importance. Stenocardia is characterized by a clear connection between the onset of pain and the load, which increases the need for myocardium in oxygen, a short duration of attacks (usually less than 5 minutes, rarely up to 30 minutes), high nitroglycerin intake under the tongue (pain stops in 1-3 min), lack of ECG dynamics Or short-term changes during an attack, the absence of leukocytosis, an increase in ESR, and the activity of so-called cardiospecific enzymes (individual fractions of creatine phosphokinase, lactate dehydrogenase, aspartate aminotransferase). With myocardial infarction, pain lasts from half an hour to several hours (and if pericarditis is attached , then several days); It is usually more intense than with angina pectoris, it is not stopped by the intake of nitroglycerin. The ECG reveals a typical picture of the acute phase of myocardial infarction, which in the following days and weeks undergoes a characteristic change. In the first 2 days there is an increase in body temperature, neutrophilic leukocytosis , often aneosinophilia. The activity of cardiospecific enzymes increases. In the following days, the leukocytosis decreases, the ESR increases.

With any form of IHD, violations of various heart functions, including contractile, are possible. Most often, they develop and are most pronounced in myocardial infarction (pulmonary edema, cardiogenic shock , various cardiac arrhythmias), both large- focal post- infarction and diffuse cardiosclerosis , formed in patients with prolonged course of ischemic heart disease, are manifested by chronic heart rhythm disorders (including Atrial fibrillation), atrial-ventricular and peritoneal ventricular conduction, often chronic heart failure.

Treatment . With IHD, complex individual treatment is used, which is determined by the form of the disease, the phase of its course, and the specific features of the clinical manifestations. He is appointed by a doctor. Methods of treatment and rehabilitation of patients with IHD include diet, exercise therapy, a selected mode of physical training, psychotherapy, sometimes physiotherapy, sanatorium treatment. From drugs use drugs that reduce the need for myocardium in oxygen (beta-adrenergic receptor blockers - anaprilin, atenolol , metoprolol , etc.), antianginal drugs from the group of nitrates of different duration of action (nitroglycerin, isosorbide dinitrate and mononitrate), drugs from the group of calcium antagonists (Verapamil, diltiazem , etc.), as well as agents that prevent platelet aggregation (acetylsalicylic acid, trental, etc.), or heparin (with progressive angina and myocardial infarction), and in the acute phase of myocardial infarction - thrombolytics (streptokinase, etc.) ). The Moscow Association of Cardiologists has proposed a scheme for the medical treatment of chronic forms of ischemic heart disease - the so-called alphabet of a cardiologist. It includes:

A - aspirin in a dose of at least 325 mg once a day for the purpose of preventing thrombosis;

B - beta blockers in order to prevent ruptures and splitting of atherosclerotic plaques;

B - substances that lower the level of cholesterol in the blood (statins, etc. - see Atherosclerosis). In heart rhythm disorders, antiarrhythmic agents are prescribed, with cardiac insufficiency, cardiac glycosides, diuretics, angiotensin-converting enzyme inhibitors (captopril, enalapril , etc.).

Every health worker should be able to provide emergency relief for the management of pain in all forms of IHD. With angina pectoris for this it is usually enough to give the patient under the tongue 1-2 tablets nitroglycerin (rarely there is a need for repeated intake of nitroglycerin after 5-7 minutes). With angina pectoris caused mainly by spasm of the coronary arteries, it is not less, and often more effective, immediate mastication of one tablet (0.01 g) of corinphore to patients. With prolonged pain (more than 10 minutes) and no effect of nitroglycerin, it is necessary subcutaneously, intramuscularly, and it is better to inject intravenously fractional narcotic analgesics, for example 1 ml of a 2% solution of promedol or 1-2 ml of 1% morphine solution (or 1 ml of 2% Omnopon solution); If necessary, after 20 to 30 minutes, the injection is repeated. In such cases, the patient should immediately call a doctor or ambulance.

Surgical treatment of IHD is becoming more common, especially in severe angina. The most effective are operations that restore normal blood flow in a stenotic or clogged coronary artery. These include coronary artery bypass grafting and the operation of creating a mammary-coronary anastomosis. An alternative to coronary artery bypass grafting may be angioplasty - the introduction into the coronary artery of a catheter with a balloon inflated; Due to the dosed expansion of the cylinder, it is possible to reduce the degree of narrowing of the vessel.

Surgical treatment is used, and in some cases, an aneurysm of the heart, developed in the outcome of myocardial infarction. The purpose of the operation is to prevent the development of heart failure due to the presence of an aneurysm. An aneurysm is resected; Often during the operation, thrombotic masses in the aneurysm cavity are removed. Surgical treatment of IHD is performed in conditions of artificial circulation in specialized centers of cardiac surgery.

The prognosis depends on the shape and severity of the course of IHD. It is most favorable for stenocardia with rare, occurring only with excessive physical exertion attacks. The prognosis is worse with extensive, especially repeated myocardial infarction, complicated by heart rhythm disturbances and heart failure.

Prophylaxis is mainly aimed at eliminating risk factors for the development of IHD. It is necessary to observe a diet with restriction of animal fats, table salt and sugar, systematic physical training, complete elimination of smoking, adherence to the work and rest regime, and in the presence of hypertension or diabetes their timely treatment. Patients with coronary heart disease are subject to follow-up, during which the average medical staff monitors the correctness of the patient's recommendations, monitors the effectiveness of the treatment (for example, the frequency of angina attacks, their severity), notes changes in the course of the disease (dyspnea, arrhythmia, etc.). ) And informs the attending physician about them.