Cardiomyopathy (ICD-10 code: I42) is one of the types of myocardial diseases. In the medical field, this disease is called dysmetabolic cardiomyopathy. The main provocateur of a group of diseases is a disturbed metabolism, localized precisely in the region of the heart.
Features of the disease
During the onset of the disease, not only the heart muscle, but also other vital organs are subjected to "stress". A negative process occurs in the area of \u200b\u200bparts of the heart, and especially in the place where a large number of vessels are located. Such disorders cause myocardial disease, resulting in endotoxicosis.
Most often, the disease affects young people whose activities are related to sports. The development of the disease occurs during prolonged physical stress, the functional ability of the body weakens with a lack of vitamins in the body or with hormonal failure.
Cardiomyopathy is present in the international classification of diseases. The list includes various types associated with disorders in important body systems. The 10th revision of the International Classification of Diseases (ICD-10) includes such groups as:
- alcoholic cardiomyopathy;
- restrictive form;
- unspecified cardiopathy.
Cardiomyopathy is a group of inflammatory processes that are localized in the area of muscle tissue. For a long time, doctors could not determine the exact causes of the onset of the disease. That is why experts decided to identify a number of reasons that, under the influence of certain conditions and circumstances, cause a violation of the myocardium.
Each of the types (dilated, hypertrophic or restrictive) cardiomyopathy has characteristic features. But the treatment is the same for the entire group of diseases and is aimed at eliminating symptoms and chronic heart failure.
The main causes of the appearance of pathology
The development of the disease occurs under the influence of various factors. Myocardial damage in cardiomyopathy can act as a primary or secondary process as a result of exposure to systemic ailments. All this is accompanied by the development of insufficiency in the heart and in rare cases leads to death.
There are primary and secondary causes of the disease.
The cause of primary cardiomyopathy is a congenital pathology of the heart, which can develop as a result of laying myocardial tissue while the child is still in the womb. There may be enough reasons for this: starting from the bad habits of a woman and ending with the appearance of depression and stress. Improper nutrition before and during pregnancy can have a negative impact.
The primary causes also include a mixed and acquired form.
As for the secondary causes, this includes accumulation cardiopathy, toxic, endocrine and alimentary forms of the disease.
Symptoms of the disease
Symptoms of the disorder can appear at any age. Basically, they are not pronounced, so some people do not experience ailments until a certain point.
The term “cardiomyopathy” (CMP) was proposed by W. Brigden in 1957 to refer to primary myocardial lesions of unknown etiology, causing dysfunction of the heart and not resulting from diseases of the coronary arteries, valvular apparatus, pericardium, systemic or pulmonary hypertension, damage to the conduction system of the heart. The main criterion for distinguishing CMP from other myocardial lesions was considered a sign of “unknown” origin of these diseases.
Thanks to the introduction of modern methods of invasive and non-invasive diagnostics, it was possible to establish the genesis of some variants of CMP. The causes of most cases of RCMP are endomyocardial fibrosis, Loeffler's disease, Fabry's disease, and cardiac amyloidosis. In the genesis of DCMP, the role of viral infection, autoimmune processes, heredity and other factors has been proven. Therefore, J. Goodwin's designation of cardiomyopathies as diseases of unknown etiology has largely lost its original meaning. In half of the cases, the cause of the CMP cannot be established (idiopathic forms of the CMP). In many diseases of the internal organs of an infectious, metabolic, toxic and other nature, a regular specific damage to the myocardium occurs with a violation of its functions, which sometimes acquires some of the features of the above-described cardiomyopathy.
Dilated cardiomyopathy (DCM) is a primary myocardial lesion characterized by severe dilatation of the cavities and impaired ventricular systolic function. The term DCM is applicable only to those cases of heart disease in which significant dilatation of the cavities is not a consequence of a violation of the coronary circulation (CHD), congenital anomalies, valvular heart disease, systemic and pulmonary arterial hypertension, and pericardial disease. The prevalence of DCM is unknown, since there are still no clear criteria for its diagnosis, which makes it difficult to conduct epidemiological studies. The incidence according to different authors ranges from 5 to 10 people per 100 thousand population per year. DCM is 2-3 times more common in men, especially those aged 30-50 years.
The annual incidence of DCMP is 5-8 cases per 100,000 population. However, since some patients do not have clinical manifestations, the prevalence of this disease is probably higher. In the United States, DCM has an incidence of 36 cases per 100,000 population and causes 10,000 deaths per year. The frequency of DCMP among blacks and men is 2.5 times higher than among Caucasians and women. The prognosis of the disease in people of the Negroid race is also less favorable: due to the later clinical manifestation of the disease, the survival rate is lower.
Patients with DCMP account for 26 to 60% of all patients with cardiomyopathies. Although DCM is considered a "diagnosis of exclusion", there are reports of DCM being associated with hypertension, β-adrenergic agonists, or moderate alcohol consumption. Since dilatation and dysfunction of the ventricles can occur due to a variety of acquired or hereditary disorders, differentiation of the idiopathic form of the disease from secondary and potentially reversible forms of myocardial damage is of great prognostic value.
What causes dilated cardiomyopathy:
In the last decade, in most cases, the etiology of DCM cannot be established (idiopathic form of DCM). In about 20% of patients, the disease is associated with a previous infectious myocarditis. It is believed that the impact on myofibrils of infectious agents persisting in the body (primarily enteroviruses), including the incorporation of viral RNA into the genetic apparatus of cardiomyocytes or the influence of the autoimmune process “launched” by viruses, leads to damage to mitochondria and disruption of energy metabolism of cells. When using the polymerase chain reaction (PCR), in some patients it is possible to detect the presence of Coxsackie B viruses, hepatitis C virus, herpes, cytomegalovirus. Some have high titers of cardiospecific autoantibodies to heavy chain myosin, actin, tropomyosin, mitochondrial membrane of cardiomyocytes, and an increase in blood cytokines. This highlights the role of autoimmune disorders. Patients with autoimmune deficiency are more susceptible to the damaging effects of viruses and the development of DCMP.
In the origin of DCM, genetic predisposition to the onset of the disease is also of great importance. Familial DCM occurs approximately in cases of the disease. They are characterized by autosomal dominant inheritance. In some patients with DCMP, haplotypes HLA B27 and HLA DR4 are also found. There is evidence of an adverse effect of alcohol on the myocardium: a violation of the synthesis of contractile proteins of cardiomyocytes, damage to mitochondria, a violation of the energy metabolism of cells, a critical decrease in myocardial contractility, expansion of the heart cavities and the formation of DCMP.
In the genesis of DCMP, the interaction of several factors is important: genetic predisposition to the onset of the disease; exposure to exogenous factors (viral infection, alcohol) and autoimmune disorders. If in the initial stages of the development of DCMP in some cases it is possible to confirm the secondary nature of heart damage (the presence of a viral infection), then in the later stages the clinical picture is little dependent on the possible triggers of the disease. In practice, in most cases, the specific causes remain unclear and DCM is treated as an idiopathic form of the disease that meets the traditional criteria for CMP according to J. Goodwin.
Pathogenesis (what happens?) during dilated cardiomyopathy:
As a result of the impact of the above and some others, a decrease in the energy metabolism of cells and a decrease in the number of normally functioning myofibrils. This leads to a progressive decrease in myocardial contractility and pumping function of the heart. As a result of a decrease in the inotropic function of the myocardium, dilatation of the cavities of the heart occurs, which, according to the Starling mechanism, maintains SV and EF at a sufficient level for some time. Simultaneously developing tachycardia (activation of the SAS) also contributes to the preservation of cardiac output (MO, SI). However, such compensation is very unfavorable from the energy point of view, since, according to Laplace's law, in order to create adequate pressure in the ventricular cavity, the dilated LV wall must develop a significantly greater intramyocardial stress.
The consequences of such a progressive increase in afterload are: the development of compensatory hypertrophy of the ventricular myocardium, which contributes to some decrease in intramyocardial stress; an increase in myocardial oxygen demand, which eventually leads to the development of relative coronary insufficiency and myocardial ischemia; further damage to cardiomyocytes and an even greater decrease in contractility; development of diffuse and focal cardiofibrosis.
As a result, there is a decrease in the pumping function of the heart, an increase in blood pressure in the ventricles, and a pronounced myogenic dilatation of the heart cavities develops. These phenomena are exacerbated by the development of relative insufficiency of the mitral and tricuspid valves, which contributes to even greater dilatation of the atria and ventricles. CHF is formed and rapidly progresses with a predominant violation of the systolic function of the ventricles, blood stagnation in the pulmonary and systemic circulation, a decrease in cardiac output and impaired perfusion of peripheral organs and tissues.
A significant increase in heart mass due to myocardial hypertrophy is usually not accompanied by a noticeable thickening of the ventricular wall, since in DCM, pronounced dilatation of the heart chambers always predominates, which, as it were, levels out the increase in muscle mass. An important role in the remodeling of the heart muscle and the development of cardiac decompensation is the excessive activation of the neurohormonal systems of the body, including the SAS, RAAS, ADH, tissue RAS and endothelial factors.
As a result of the activation of these systems, there is a retention of Na + and water in the body, which exacerbates congestion in the small and large circles of blood circulation. An increased content of catecholamines, angiotensin II, cytokines, tumor growth factor, thromboxane leads to even greater damage to the myocardium, peripheral vasoconstriction, as well as significant disorders of the blood coagulation and fibrinolytic systems.
Symptoms of dilated cardiomyopathy:
CLASSIFICATION
According to the classification of J. Goodwin (1989), there are 3 groups of CMP: 1. Dilated cardiomyopathy (DCM) is characterized by significant dilatation of the heart chambers, systolic-diastolic dysfunction of the myocardium and the absence of pronounced hypertrophy of the heart muscle. 2. Hypertrophic cardiomyopathy (HCM) is characterized by significant, often asymmetric, myocardial hypertrophy of the left and / or right ventricles, a clear predominance of diastolic myocardial dysfunction and the absence of dilatation of the heart cavities. 3. Restrictive cardiomyopathy (RCMP) is characterized by impaired diastolic filling of the left ventricle and / or right ventricle, a decrease in their volume, normal or almost normal systolic function.
In 1995, experts from WHO and the International Society of Cardiology recommended using the term "cardiomyopathy" for all cases of myocardial damage associated with impaired function. According to this WHO classification, 6 groups of CMP are distinguished: DCM; GKMP; RKMP; arrhythmogenic pancreatic dysplasia; specific ILCs; unclassified ILC (table 37).
Table 37 Classification of cardiomyopathies (WHO, 1995)
| Groups | ILC options | Note |
| 1 | Dilated CMP | In 80% of cases - idiopathic |
| 2 | Hypertrophic IMP | idiopathic |
| 3 | Restrictive | In most cases, the etiology is known |
| 4 | Arrhythmogenic pancreatic dysplasia | Etiology unknown |
| 5 | Specific cardiomyopathy **: 1. Ischemic * 2. Hypertensive * 3. Valvular * 4. Inflammatory * 5. Dysmetabolic (diabetes mellitus, hyperthyroidism, hypothyroidism, hemochromatosis, hypovitaminosis, amyloidosis, accumulation diseases) 6. Toxic and allergic (alcohol , radiation, drug) Neuromuscular disorders (muscular dystrophy, myotonic dystrophy, Friedreich's ataxia) 8. Generalized systemic (connective tissue diseases, infiltrations, granulomatous diseases) | Myocardial lesions of known etiology |
| 6 | Unclassified ILCs | There are features of various types of ILC. The etiology is unknown. |
Note: * - terms that should be replaced by traditional ones: ischemic heart disease, hypertension, heart defects, myocarditis; ** - “specific (secondary) myocardial lesions”.
The above classification is not perfect. First, the term “cardiomyopathy” is proposed to be used to refer to an unlimited number of heart diseases of known and unknown etiology, which are characterized by myocardial damage associated with a violation of its function. This leads to an unreasonably wide use of the concept of "cardiomyopathy" and the complete loss of its nosological independence. Secondly, the legitimacy of including the so-called “ischemic”, “hypertensive”, “valvular” cardiomyopathies in the group of “specific cardiomyopathy” raises serious doubts, which in fact represent only the consequences of known diseases of the cardiovascular system (CHD, hypertension, malformations heart) complicated by heart failure and/or ventricular dysfunction.
The WHO recommendations mention that these variants of specific cardiomyopathy include those cases of the disease in which the severity of cardiac dysfunction does not correspond to the degree of coronary blood flow disorders, valvular lesions, and blood pressure levels. In practice, it is quite difficult to resolve the issue of such compliance or non-compliance in most cases.
Delated cardiomyopathy manifests more often at the age of 20-50 years, but it occurs in children and the elderly. The most common clinical manifestation is HF (75-85%). At the same time, at the time of diagnosis in 90% of patients, CHF III-IV FC according to NYHA is already determined. The symptomatology of left ventricular HF dominates - a decrease in exercise tolerance, progressive dyspnea, up to orthopnea and cardiac asthma. The main complaints of patients are usually shortness of breath on exertion (86%), palpitations (30%), and peripheral edema (29%). Asymptomatic cardiomegaly is detected in 4-13% of patients. As the disease progresses, HF symptoms appear in 95% of patients.
The modern clinical picture of DCMP is manifested by three main syndromes: 1. Systolic CHF (left ventricular or biventricular) with signs of blood stasis in the small and large circulation. 2. Frequent occurrence of arrhythmias and conduction disorders (ventricular arrhythmias, atrial fibrillation, AV blockade and bundle branch block). 3. Thromboembolic complications (PE and embolism in the artery of the systemic circulation). Clinical manifestations of DCMP and the results of instrumental and laboratory studies are nonspecific, which complicates the differential diagnosis. Therefore, the diagnosis of DCM is made by excluding other heart diseases with systolic ventricular dysfunction (CHD, hypertension, myocarditis, cor pulmonale.
Complaints
The disease can be asymptomatic for a long time, despite the presence of objective (echocardiographic) signs of ventricular dilatation and impaired function. Usually, the first clinical manifestations of the disease are associated with cardiac decompensation, stagnation of blood in the small, and then in the systemic circulation, and a decrease in cardiac output. Patients complain of shortness of breath during exercise and at rest, aggravated in the horizontal position of the patient (orthopnea). In advanced cases, there are attacks of suffocation, often developing at night (cardiac asthma and pulmonary edema).
Characterized by fatigue, muscle weakness, heaviness in the legs when performing physical exertion. Signs of right ventricular failure (swelling of the legs, heaviness in the right hypochondrium, an increase in the abdomen in volume, dyspeptic phenomena) appear later. Approximately half of the patients develop a variety of rhythm and conduction disturbances, some of which cause discomfort in patients with DCMP (palpitations, interruptions in the work of the heart, attacks of paroxysmal tachycardia and atrial fibrillation). The most severe complications are thrombosis and thromboembolism, which develop in 20% of patients with DCM. Most often, these complications occur in patients with atrial fibrillation. Sometimes patients with DCMP note pains in the region of the heart, which in most cases differ from typical angina attacks. Pain often has atypical localization and is not associated with physical activity.
Physical examination
Physical data obtained during the examination of patients with DCMP are nonspecific. A general examination reveals signs of heart failure: acrocyanosis, swelling of the legs, orthopnea position, abdominal enlargement, swelling of the jugular veins, and sometimes a positive venous pulse. When examining the lungs in the lower sections, moist fine bubbling rales can be heard. There is an increase in the liver, there are signs of cardiac cachexia.
Inspection, palpation, percussion of the heart
The apical impulse is strengthened, spilled and shifted to the left and down. Most often, it is also possible to detect an increased and diffuse cardiac impulse and epigastric pulsation, which indicates the presence of hypertrophy and dilatation of the pancreas. Usually, a shift to the left of the left border of the relative dullness of the heart and to the right of the right border is detected. Dilatation of the LA is accompanied by an upward displacement of the upper border of the heart and a smoothing of the "waist" of the heart. Absolute dullness of the heart is usually expanded due to dilatation of the pancreas.
Auscultation of the heart
The first tone at the top is weakened. With the development of pulmonary hypertension, the accent and splitting of the II tone is determined. Often, a proto-diastolic gallop rhythm is heard at the apex (due to the appearance of a III pathological tone), which is associated with a pronounced volume overload of the ventricles. Systolic murmurs are characteristic at the apex and at the point of listening to the tricuspid valve, which indicate the formation of relative insufficiency of the mitral and tricuspid valves. If atrial fibrillation or extrasystole occurs, the heart sounds are arrhythmic. There are no specific changes in arterial pulse.
With a significant decrease in cardiac output, there is a decrease in systolic and pulse blood pressure, and in severe cases, a decrease in filling and pulse tension. When atrial fibrillation occurs, the pulse is arrhythmic. The tachysystolic form of atrial fibrillation is accompanied by a pulse deficit. Sudden death in DCM may occur as a result of fibrillation, asystole, or thromboembolism in the pulmonary trunk or cerebral vessels. Frequent complications also include thromboembolism in the pulmonary artery and the arteries of the systemic circulation (cerebral, renal, mesenteric, arteries of the upper and lower extremities).
Using clinical, hemodynamic, ventriculographic data, it is possible to assess the risk in a large population, however, assessing the prognosis of a particular patient with DCM remains very difficult. It is known that DCMP is characterized by an unfavorable course and prognosis. Within five years, up to 50% of patients die, most of them suddenly due to ventricular fibrillation. Other causes of death include progressive chronic heart failure, thromboembolic complications. An unfavorable prognosis is associated with the degree of LV dysfunction, to a lesser extent with the development of ventricular arrhythmias and embolic complications. Although LV dilatation is usually an accurate prognostic sign, a mildly dilated form of DCM has been described in which contractility is severely affected and patients' prognosis is similar to that of normal DCM. Unfavorable prognosis factors are presented in Table 38.
Table 38. Predictors of mortality in patients with DCM
Increase in cardiothoracic index
Increase in end-diastolic volume and left ventricular ejection fraction, decrease in cardiac index less than 2.5 l/min/m2
Global decrease in contractility, increased LV sphericity
Syncope in history
Systemic hypotension
S3 - haplotype, development of right ventricular heart failure
Atrioventricular block I - II degree, blockade of the left leg of the bundle of His
Decreased heart rate variability
Hyponatremia (Na2+ serum less than 137 mmol/l)
Maximum systemic oxygen consumption during spiroergometry
The wedge pressure in the pulmonary artery is more than 20 mm. rt. Art., pulmonary hypertension, increased central venous pressure
Decreased content of intracellular microfilaments in endomyocardial biopsy
The five-year survival rate for patients with DCMP is 60-76%. A more favorable prognosis in women with DCMP and FC I-III HF, as well as in patients of a relatively young age. In recent years, the life expectancy of these patients has increased significantly. With the help of complex therapy with ACE inhibitors, b-adrenergic receptor blockers, diuretics, it is possible to prolong the life of some patients with DCMP up to 8-10 years. Heart transplantation significantly improves the prognosis. After surgery, ten-year survival reaches 70-80%.
Diagnosis of dilated cardiomyopathy:
INSTRUMENTAL DIAGNOSIS
Electrocardiography
An electrocardiographic study does not reveal the specific features of the electric field of the heart, characteristic of DCM. On the ECG are usually determined: signs of LV and LP hypertrophy, sometimes in combination with RV hypertrophy. Especially characteristic is the depression of the RS-T segment in the left chest leads (V5 and V6) and leads I and aVL; signs of blockade of the left leg of the bundle of His (a common finding); atrial fibrillation and / or other cardiac arrhythmias; prolongation of the Q-T interval. In some cases, the ECG can reveal signs of a macrofocal or transmural myocardial scar in the form of pathological Q waves and the QS complex. These changes reflect the development of focal fibrosis of the LV myocardium, which is characteristic of DCM.
echocardiography
EchoCG is the most informative non-invasive method for examining patients with DCMP. In many cases, echocardiographic examination allows for the first time to put forward the diagnostic concept of DCM, to assess the degree of violations of systolic and diastolic functions of the ventricles, and also to prove the absence of valvular lesions, pericardial diseases. The most characteristic echocardiographic signs of DCM are significant dilatation of the left ventricle with normal or reduced thickness of its walls and a decrease in EF (below 30-20%). Often there is an expansion of other chambers of the heart (RV, LA).
Total hypokinesia of the LV walls develops, a significant decrease in blood flow velocity in the ascending aorta and LV outflow tract and in the pulmonary artery (Doppler mode). Intracardiac parietal thrombi are often visualized. In some cases, with DCM, regional violations of LV contractility, aneurysm of the LV apex can be detected. This complicates the differential diagnosis of this disease with coronary artery disease. A study in two-dimensional and Doppler modes reveals signs of relative insufficiency of the mitral and tricuspid valves without deformation of their leaflets.
Radiography
X-ray examination allows you to visualize the following changes: signs of cardiomegaly; smoothness of the contours of the left parts of the heart; spherical shape of the heart due to dilatation of all cavities (in severe cases); signs of venous and arterial pulmonary hypertension and expansion of the roots of the lungs.
Coronary angiography and ventriculography
These invasive research methods are used in cases where there is a need for differential diagnosis of DCM and IHD when deciding on surgical treatment. In patients with DCMP, there is no hemodynamically significant narrowing of the CA, an increase in EDV and a sharp decrease in EF are determined. Sometimes it is possible to detect violations of local contractility of the LV myocardium.
Endomyocardial biopsy
It is carried out in specialized medical centers. The method allows to assess the degree of destruction of muscle filaments in the biopsy, which has a prognostic value.
DIFFERENTIAL DIAGNOSIS
Diagnosis of DCM begins with the detection of LV dilatation with low systolic function in a patient who presents with complaints of dyspnea, edema, and weakness. Anamnesis data, auscultatory picture, x-ray examination and echocardiogram (EchoCG) most often immediately allow to exclude a certain range of causes of dilatation and heart failure (LV aneurysm, hypertension, alcohol abuse, acquired and congenital heart defects). The collection of a family history helps in the diagnosis of hereditary cardiomyopathies, however, in asymptomatic disorders, it is possible to identify sick relatives only with the help of echocardiography.
The electrocardiogram may remain normal or reflect only nonspecific repolarization disorders. Conduction disturbances occur in almost 80% of patients and include first-degree atrioventricular block, left bundle branch block, left anterior branch block, and nonspecific intraventricular conduction disturbances. Blockade of the right leg of the bundle of His is less common.
Conduction disturbances are more often observed in patients with a long-term disease and indicate an increase in interstitial fibrosis and hypertrophy of cardiomyocytes. Often there are also signs of LV hypertrophy, QS complexes in the leads, reflecting the potential of the anterior wall, and the absence of an increase in the amplitude of the R wave in the chest leads. Atrial fibrillation, poorly tolerated by patients, develops in almost 20% of patients, but this is not evidence of a poor prognosis. The most widely used non-invasive technique is echocardiography. It allows you to identify LV dilatation, assess the thickness of its walls and their contractility.
Violation of contractility is a mandatory symptom of DCM, usually the diagnosis is established with a decrease in FI below 45%. Although a global contractility disorder is common in DCM, up to 60% of patients present with LV segmental dysfunction. A more favorable prognosis is available in patients with more pronounced segmental than total lesions. Atrial dilatation is also common, but is of lesser importance than ventricular dilatation. Intracavitary thrombi are most often detected in the apex of the left ventricle. Although DCMP is mainly a diffuse process, some authors have observed 10-15% of patients with isolated LV dysfunction without involvement of the right. In such a situation, it is necessary first of all to exclude the coronary genesis of dilatation. Doppler examination reveals mild mitral or tricuspid regurgitation that is not audible on auscultation.
Myocardial scintigraphy with 99mTc allows quantification of LV systolic and diastolic function and is used in situations where echocardiography is not possible (poor ultrasound window). There is no need to perform cardiac catheterization in all patients, and there is no need to conduct several consecutive studies. Right-sided catheterization is used to select therapy in patients with severe disease, but baseline hemodynamic evaluation before treatment is rarely indicated.
The low diagnostic value of endomyocardial biopsy makes it necessary to rethink the significance of this procedure. Endomyocardial biopsy is necessary in the presence of myocardial dysfunction and systemic disease affecting the myocardium and amenable to specific treatment (sarcoidosis, eosinophilia). The value of this method may increase when new technologies for diagnosing DCM at the subcellular and molecular levels are introduced.
Most often, difficulties arise when IHD and myocarditis are excluded as the causes of LV dilatation. The history and clinical picture of dilated cardiomyopathy often resembles angina pectoris, ECG changes (the presence of pathological Q waves) do not allow to exclude postinfarction changes. Therefore, in doubtful cases, patients with heart failure and LV dilatation are indicated for coronary angiography, since revascularization in the presence of coronary artery stenoses can lead to the restoration of systolic function.
A recent viral illness, especially accompanied by myalgia or pericarditis, suggests a dominant role for myocarditis. However, the differential diagnosis of dilated cardiomyopathy and chronic recurrent myocarditis (inflammatory cardiomyopathy) is not always straightforward. A more rare cause of LV dilatation and reduced systolic function is a long-term arrhythmia with a frequent ventricular contraction rhythm (tachycardia-induced cardiomyopathy). The differential diagnostic criterion is the restoration of LV systolic function and the complete reversibility of its dilatation after the restoration of sinus rhythm or heart rate control.
Treatment of dilated cardiomyopathy:
Treatment of patients with DCMP is currently a difficult task. Since the cause of the disease cannot be established, pathogenetic therapy of patients should be aimed at correcting CHF; treatment and prevention of arrhythmias; treatment and prevention of thromboembolic complications. Patients with DCMP are refractory to treatment with inotropic agents, which do not lead to a decrease in the clinical manifestations of CHF, and contribute to the occurrence of cardiac arrhythmias.
Conservative treatment
Treatment of CHF in patients with DCMP is based on certain principles. Limiting physical activity, salt intake, especially in the presence of edematous syndrome. ACE inhibitors are the first choice in the treatment of patients with DCM. The appointment of these drugs (in the absence of contraindications) is advisable at all stages of the development of the disease, even in the absence of severe clinical manifestations of CHF. ACE inhibitors are able to prevent necrosis of cardiomyocytes, the development of cardiofibrosis; contribute to the reverse development of hypertrophy, reduce the magnitude of the afterload (intramyocardial tension), reduce the degree of mitral regurgitation, pressure in the LA and secretion of PNUF.
Under the influence of long-term regular intake of ACE inhibitors, the quality of life of patients with DCMP improves. The use of ACE inhibitors significantly increases the life expectancy of patients with DCMP. The effect of ACE inhibitors in this disease is explained by the inhibition of excessive activation of the RAAS, SAS, tissue and neurohormonal systems responsible for the progression of the disease. Use of ACE inhibitors in patients with DCM should be cautious due to the possibility of a hypotensive reaction and orthostatic hypotension. Initial dose of the drug: enalapril 2.5 mg 2 times a day; ramipril 1.25 mg once a day; perindopril 2 mg once a day. With good tolerance, the dose should be increased (20-40 mg / day for enalapril, 10 mg for ramipril, 4 mg for perindopril).
B-blockers should be combined with ACE inhibitors. β-blockers are especially indicated in patients with persistent sinus tachycardia, as well as in patients with atrial fibrillation. In patients with DCMP, b-blockers are used not only as a means of preventing and treating heart rhythm disorders and heart rate control, but also as drugs that affect hyperactivated SAS and RAAS. Their action on these systems is accompanied by an improvement in hemodynamics, a decrease in myocardial ischemia and damage to cardiomyocytes. B-blockers improve the quality of life, prognosis and survival of patients with DCM. Use any b-blockers (metoprolol, bisoprolol, atenolol, carvedilol).
Treatment begins with small doses of drugs, gradually increasing them to the maximum tolerated. Some patients in the first 2-3 weeks of treatment with b-blockers may experience a decrease in EF, SV and some deterioration, which is associated mainly with the negative inotropic effect of these drugs. However, in most of these patients, over time, the positive effects of b-blockers begin to prevail due to stabilization of the neurohormonal regulation of blood circulation, restoration of the density of b-adrenoreceptors on the cell membranes of cardiomyocytes, and a decrease in the cardiotoxic effect of catecholamines. The EF gradually increases and the clinical manifestations of CHF decrease. The use of b-blockers in DCM requires caution, especially in patients with CHF III-IV FC according to NYHA, although they are not fundamentally contraindicated in severe decompensation.
Diuretics are used in the presence of stagnation of blood in the lungs and / and in the systemic circulation. Apply thiazide, thiazide-like and loop diuretics according to the usual scheme. In the presence of a pronounced edematous syndrome, it is advisable to combine the listed diuretics with the appointment of aldosterone antagonists (aldactone, veroshpiron). For the treatment of patients with chronic left ventricular heart failure, nitrates - isosorbide-dinatates or isosorbide-5-mononitrates can be used as an additional drug. The latter are distinguished by high bioavailability and predictability of action (olicard, imdur). These drugs contribute to the deposition of blood in the venous bed, reduce the amount of preload and stagnation of blood in the lungs.
Cardiac glycosides are indicated for patients with a permanent form of atrial fibrillation. In these cases, the positive effects of cardiac glycosides (decrease in heart rate) are explained not by the positive inotropic effect of these drugs, but by their vagotropic effect, manifested by an increase in the refractory periods of the AV node and a slowdown in the conduction of an electrical impulse along the AV junction. As a result, the tachysystolic form of atrial fibrillation can be converted into a normosystolic one, which improves the processes of LV diastolic filling, reduces pressure in the LA and veins of the pulmonary circulation, and helps to reduce shortness of breath and other manifestations of blood stasis in the lungs.
The issue of the advisability of using cardiac glycosides in patients with DCMP with sinus rhythm and severe LV systolic dysfunction (EF = 25-30%) remains debatable. Monotherapy with cardiac glycosides is ineffective, since in most cases there is no morphological substrate for the action of these inotropic drugs, namely: there is significant and widespread damage to cardiomyocytes, a decrease in the number of myofibrils, cellular metabolism disorders and pronounced cardiofibrosis.
The use of cardiac glycosides in severe patients with severe LV systolic dysfunction and sinus rhythm is possible only in combination with ACE inhibitors, diuretics under the control of electrolytes and ECG monitoring. Long-term use of non-glycoside inotropic agents in patients with DCM and CHF is not recommended, as it significantly increases the mortality of these patients. Short-term use of non-glycoside inotropic drugs (levodopa, dobutamine, milrinone, amrinone) is justified in preparing patients for heart transplantation.
The appointment of antiplatelet agents is indicated for all patients with DCM, since in 30% of cases the course of the disease is complicated by intracardiac thrombosis and the development of thromboembolism. For this purpose, a constant intake of acetylsalicylic acid at a dose of 0.25-0.3 g per day is used, the use of other antiplatelet agents according to the schemes (trental, dipyridamole, vasobral, tonacan). In patients with atrial fibrillation, the appointment of indirect anticoagulants (warfarin) under the control of coagulogram parameters is indicated. Doses of the drug are selected so that the value of the INR is 2-3 units. Many experts consider the detection of intracardiac thrombi in patients with DCM as an indication for the appointment of indirect anticoagulants.
Surgery
Heart transplantation is a highly effective method of treating DCM patients refractory to drug therapy. Indications for transplantation are: rapid progression of HF in patients with DCM, lack of effect from conservative therapy; the occurrence of life-threatening cardiac arrhythmias; high risk of thromboembolic complications. The latest world data show an improvement in the quality of life after a heart transplant and an increase in the survival of patients up to 79% in 1 year, 74% in 5 years, 72% in 10 years.
A serious problem that limits the widespread use of this method of treatment is the high cost of surgery and organizational problems. In recent years, in economically developed countries, the length of the waiting list for heart transplantation has increased significantly. Careful selection of patients is based on the identification of preoperative characteristics that are the best predictors of a good outcome.
Dual-chamber electrical stimulation of the heart using an implantable DDD-type pacemaker in some cases can improve intracardiac hemodynamics by increasing ventricular systolic function and preventing the development of severe complications.
Dynamic cardiomyoplasty plays an important role in the treatment of patients with DCM. Muscle gloss is used
RCHD (Republican Center for Health Development of the Ministry of Health of the Republic of Kazakhstan)
Version: Archive - Clinical Protocols of the Ministry of Health of the Republic of Kazakhstan - 2007 (Order No. 764)
Cardiomyopathy, unspecified (I42.9)
general information
Short description
Cardiomyopathy- primary myocardial lesions of unknown etiology, causing dysfunction of the heart and not resulting from diseases of the coronary arteries, valvular apparatus, pericardium, systemic or pulmonary hypertension, as well as some rare variants of damage to the conduction system of the heart (W. Brigden, 1957).
Previously, cardiomyopathies were defined as diseases of the heart muscle with an unknown cause and differentiated from specific myocardial diseases with a known cause. Without clarification of the etiology and pathogenesis, the differences between cardiomyopathies and specific myocardial diseases become indistinguishable. The original classification described three types with specific clinical manifestations, and this terminology has been retained.
Currently, cardiomyopathies are classified mainly by pathophysiology or, if possible, by etiological and pathogenetic factors.
Cardiomyopathy are defined as myocardial diseases associated with myocardial dysfunction. They are subdivided into hypertrophic, dilated and restrictive cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy (WHO, 1995).
Protocol code: P-T-026 "Cardiomyopathy" (Part II. Heart rhythm disturbances*)
Profile: therapeutic
Stage: PHC
Code (codes) according to ICD-10:
I42.0 Dilated cardiomyopathy
I42.1 Obstructive hypertrophic cardiomyopathy
I42.2. Other hypertrophic cardiomyopathy
I42.3 Endomyocardial (eosinophilic) disease
I42.4 Endocardial fibroelastosis
I42.5. Other restrictive cardiomyopathy
I42.6 Alcoholic cardiomyopathy
I42.8 Other cardiomyopathies
I42.9 Cardiomyopathy, unspecified
II. Heart rhythm disorders(Atrial fibrillation. Ventricular arrhythmias. Sudden cardiac death)
Atrial fibrillation
Atrial fibrillation(atrial fibrillation) - a type of supraventricular tachyarrhythmia, characterized by uncoordinated electrical activity of the atria with a subsequent deterioration in their contractile function.
(Methodological guidelines of the American College of Cardiology, American Heart Association, European Society of Cardiology - 2001)
Sudden cardiac death(VSS) - natural death due to cardiac causes with a previous loss of consciousness, occurring within an hour from the onset of acute symptoms; the underlying heart disease may be known, but the timing and nature of death are unexpected.
(European Society of Cardiology, WHO)
(ZHNRS) - ventricular extrasystole, ventricular tachycardia, fibrillation and ventricular flutter.
Classification
Classification of cardiomyopathies(World Heart Federation, 1995)
1. Dilation:
- idiopathic;
Family genetic;
Associated with recognized cardiovascular disease.
2. Restrictive.
3. Hypertrophic.
4. Inflammatory form (autoreactive and viral forms of DCMP).
5. Arrhythmogenic dysplasia of the right ventricle.
6. Unclassified cardiomyopathies.
7. Specific cardiomyopathies:
7.1 Ischemic.
7.2 Valve.
7.3 Hypertensive.
7.4 Dysmetabolic:
7.4.1 Endocrine: thyrotoxicosis, hypothyroidism, adrenal insufficiency, pheochromocytoma, acromegaly, diabetes mellitus.
7.4.2 Hereditary storage and infiltration diseases: hemochromatosis, glycogen storage diseases, Hurler syndrome, Refsum syndrome, Niemann-Pick disease, Hand-Schuller-Christian, Fabry-Anderson and Ulrich disease.
7.4.3 Electrolyte deficiencies and eating disorders: potassium metabolism disorder, magnesium deficiency, kwashiorkor, anemia, beriberi and selenium deficiency.
7.4.4 Amyloid: primary, secondary, familial and hereditary cardiac amyloidosis, familial Mediterranean fever and senile amyloidosis.
7.5 Generalized systemic.
7.6 Muscular dystrophies.
7.7 Neuromuscular disorders.
7.8 Peripartum.
7.9 Allergic and toxic (alcohol, radiation, drugs).
1. Dilated cardiomyopathy.
Definition: characterized by dilatation and impaired contraction of the left ventricle or both ventricles:
- idiopathic;
Family genetic;
Viral and / and autoimmune;
Associated with recognized cardiovascular disease, in which the degree of myocardial dysfunction is not explained by the state of abnormal load or the extent of ischemic damage.
Histology is not specific.
Clinic: usually manifested by heart failure, which often progresses. Arrhythmias, thromboembolism, and sudden death are very common and can occur at any stage.
Definition: characterized by left- or/right ventricular hypertrophy, which is usually asymmetric and involves the IVS with normal or reduced LV volume; a common feature is a systolic gradient, dominated by familial forms with autosomal dominant inheritance.
The disease is caused by mutations in the genes of sarcomeric proteins. Morphological changes include myocyte hypertrophy and disorder, surrounding areas of increased loose connective tissue.
Clinic: asymptomatic or shortness of breath, retrosternal pain (coronary syndrome), syncope or presyncope, and palpitations. Arrhythmias and VS are typical.
3. Restrictive cardiomyopathy.
Definition: characterized by impaired filling and reduced diastolic volume of one or both ventricles with normal or near-normal systolic function and wall thickness, massive interstitial fibrosis may be present:
- idiopathic;
With amyloidosis, endomyocardial fibrosis with or without hypereosinophilia (may accompany another disease).
Clinic: asymptomatic or heart failure, arrhythmias and sudden cardiac death.
4. Arrhythmogenic right ventricular cardiomyopathy.
Definition: progressive fibrofatty replacement of the myocardium of the right ventricle, initially with typical regional, and then with global involvement of the right and left ventricles with a relatively intact IVS. It is most often a familial disorder with autosomal dominant inheritance and incomplete penetrance; a recessive form has also been described.
Clinic: arrhythmias and sudden cardiac death, especially in adolescence.
5. Unclassified cardiomyopathies.
They include a small number of cases that do not fit into any of the previous groups (fibroelastosis, non-compacted myocardium, minimally dilated systolic dysfunction, mitochondrial involvement).
Specific cardiomyopathies
Definition: heart muscle diseases that are associated with specific cardiac or systemic diseases, previously defined as specific heart muscle diseases.
Ischemic cardiomyopathy presents with dilated cardiomyopathy with impaired contractility that is not explained by extensive coronary artery disease or ischemic injury.
Valvular cardiomyopathy represented by dysfunction of the ventricles is not proportional to changes in load.
Hypertensive often present with left ventricular hypertrophy and accompanied by manifestations of dilated or restrictive cardiomyopathy and heart failure.
Inflammatory defined as myocarditis associated with myocardial dysfunction. Myocarditis is an inflammatory myocardial disease diagnosed by standard histological, immunological, and immunohistochemical criteria.
There are: idiopathic, autoimmune and infectious forms of inflammatory cardiomyopathy. Myocardial inflammation is implicated in the pathogenesis of dilated and other cardiomyopathies, such as Chagas disease, HIV, enterovirus, cytomegalovirus, and adenovirus infections.
metabolic includes the following categories: endocrine (thyrotoxicosis, hypothyroidism, adrenal insufficiency, pheochromocytoma, acromegaly and diabetes mellitus), hereditary storage and infiltration diseases (hemochromatosis, glycogen storage diseases, Hurler syndrome, Refsum, Neman-Pick disease, Hand-Schuller-Christian disease, Fabry-Anderson and Ulrich); deficiencies (potassium metabolism disorder, magnesium deficiency and eating disorders (kwashiorkor, anemia, beriberi and selenium deficiency); amyloid (primary, secondary, familial and hereditary cardiac amyloidosis, familial Mediterranean fever and senile amyloidosis).
General systemic diseases include connective tissue disorders (SLE, polyarteritis nodosum, RA, scleroderma, and dermatomyositis). Infiltrations and granulomas include sarcoidosis and leukemia.
Muscular dystrophies include Duchenne and Becker myopathies and myotonic dystrophy.
Neuromuscular disorders include Friedrick's ataxia, Noonan's syndrome, and lentigines.
Hypersensitivity and toxic reactions include reactions to alcohol, catecholamines, anthracyclines, radiation, and mixed reactions.
Alcoholic cardiomyopathy may be associated with the intake of large amounts of alcohol. At present, we are unable to determine the causal and pathogenetic role of alcohol or determine precise diagnostic criteria.
Peripartum cardiomyopathy may first manifest in the perinatal period. Probably, it is represented by a heterogeneous group of diseases.
II. Heart rhythm disorders
Atrial fibrillation
1. By duration:
Paroxysmal - less than 7 days;
Protracted (persistent) paroxysm -> 2 and< 7 суток;
Permanent form - more than 7 days.
2. According to the frequency of ventricular contraction:
Normosystolic - the frequency of contraction of the ventricles 60-90 beats//min/;
Tachysystolic - the frequency of contraction of the ventricles over 90 beats//min/;
Bradysystolic - the frequency of contraction of the ventricles is less than 60 beats / min.
3. Primary vegetative control:
Vagus-dependent;
Sympathicus-dependent.
4. By causal factor:
Against the background of organic pathology of the heart (arterial hypertension, coronary artery disease, cardiomyopathy, heart defects);
Against the background of bronchopulmonary pathology (development of the pulmonary heart);
Against the background of an endocrinological disease (thyrotoxicosis, pheochromocytoma, diabetes mellitus);
Idiopathic - occurs in 30% of cases, the absence of cardiovascular, bronchopulmonary, endocrine pathology.
Ventricular arrhythmias.Sudden cardiac death
Classification of ventricular extrasystole (VE) according to Lown:
0 class - no PVC;
1 class - less than 30 per hour;
Grade 2 - 30 or more per hour;
Grade 3 - multiform;
4A class - two in a row (paired);
4B class - 3 or more in a row;
5 class - type R to T.
PVCs of 3-5 classes are called PVCs of high grades, prognostically unfavorable.
VT classification
1. Unsustained ventricular tachycardia(VT) - three or more ventricular complexes following one after another, lasting less than 30 seconds. with a frequency of ventricular contraction of more than 100 beats / min. (cycle time less than 600 ms).
2. Sustained VT- VT lasting more than 30 seconds. or requiring resuscitation.
3. Monomorphic VT- VT with a regular frequency and constant morphology of QRS complexes.
4. Polymorphic VT- VT with a regular frequency, but frequent changes in the shape of the QRS complexes.
5. VT reentry according to the type of bundle branch block. VT from the His-Purkinje system, more often by the type of left bundle branch block, complicates cardiomyopathy.
6. VT fusiform bidirectional(torsades de pointes) - polymorphic VT, which has the form of slow polymorphic ventricular flutter without distinguishable QRS complexes or T waves. Ventricular activity is characterized by a constantly changing amplitude, as if rotating around an isoelectric line. Associated with long QT syndrome.
7.ventricular flutter- fast organized ventricular activity without distinguishable QRS complexes or T waves on the ECG.
8. ventricular fibrillation- rapid and completely disorganized ventricular activity without distinguishable QRS complexes or T waves on the ECG.
Classification of ventricular disorders according to J.T. Bigger
It takes into account the nature of cardiac arrhythmias (sustained or unstable) and the presence of organic pathology of the heart.
1.benign- unstable heart rhythm disturbances, absence of organic pathology.
2. Potentially malignant- unstable heart rhythm disturbances, the presence of organic pathology.
3. Malignant- persistent paroxysms of VT, fibrillation, ventricular flutter against the background of organic pathology of the myocardium. High risk of SCD.
In addition, idiopathic VT is distinguished, in which no signs of organic pathology of the cardiovascular system are found (in 15-30%).
Factors and risk groups
cardiomyopathy
Risk factors: in cardiomyopathies of unknown etiology, there are no specific risk factors; with secondary cardiomyopathies - risk factors for the development of the underlying disease, for example, with ischemic cardiomyopathy - a risk factor for coronary artery disease; in alcoholic cardiomyopathy - alcohol abuse.
Primary prevention cardiomyopathies with unknown etiology are not carried out, specific cardiomyopathies - effective control of underlying diseases.
Diagnostics
Cardiomyopathy
Diagnostic criteria
The main diagnostic criterion for cardiomyopathy is the presence of myocardial dysfunction (systolic and / or diastolic), detected by ultrasound examination of the heart.
Clinical picture cardiomyopathy is defined:
1. Symptom complex of heart failure.
2. The presence of arrhythmias and conduction of the heart.
3. Thromboembolic complications.
4. The presence of the underlying disease in specific cardiomyopathy.
The list of basic and additional measures for diagnosing cardiomyopathy and evaluating treatment:
General blood analysis;
Biochemical blood test, electrolytes;
General urine analysis;
echocardiography and doppler echocardiography;
X-ray examination of the chest organs;
Immunogram of blood;
Blood for viruses - hepatitis, Epstein-Barr, cytomegalovirus, herpes 5 types by PCR;
Blood on BNP;
Blood - INR;
Walk test for 6 minutes;
Spirometry;
Daily monitoring of blood pressure;
Transesophageal echocardiography;
Stress test (VEM or treadmill).
II. Heart rhythm disorders
Atrial fibrillation
Risk factors:
1. Cardiovascular diseases leading to dilatation and / or increase in atrial mass, death of sympathetic and / or parasympathetic fibers.
2. Alcohol intoxication.
3. Electrical injury.
4. Acute bronchopulmonary diseases.
5. Endocrine diseases: thyrotoxicosis, pheochromocytoma, diabetes mellitus.
Primary Prevention: effective treatment of the underlying disease. With idiopathic MA - absent.
Diagnostic criteria
Clinical manifestations of atrial fibrillation:
"Patients with atrial fibrillation have symptoms such as palpitations and shortness of breath that limit their physical capacity and are at high risk of thromboembolic complications" (DP Zipes, 1997).
1. Heartbeat.
2. Heart failure, acute and chronic (see Part I "Chronic heart failure" of this protocol);
3. Thromboembolic complications - ischemic stroke, PE.
Complaints and anamnesis
Irregular heartbeat:
1. Paroxysms- occur during the day or at night, are provoked by physical exertion, food intake, alcohol, increased blood pressure, psycho-emotional stress.
Duration, whether they are accompanied by hemodynamic disorders (hypotension, presyncope, syncope), how they are stopped - spontaneously or with drugs (what doses), through asystole (dizziness at the time of cessation of the heartbeat, up to complete syncope), the frequency of occurrence of paroxysms, the experience of previous treatment with antiarrhythmic drugs.
2. Permanent- duration, presence of signs of NK, the presence of periods of sudden weakness or dizziness, whether it is aggravated by physical activity. Search for etiological, predisposing and provoking factors that may be subject to correction: hyperthyroidism, alcohol abuse, increased blood pressure, diabetes, etc.
Physical examination: auscultation of the heart - an irregular rhythm with a constant form of MA, signs of an organic pathology of the heart and CHF.
Laboratory research:
INR when selecting a dose of indirect anticoagulants (control, daily to an INR level of 2-2.5 for 3 days, then 1 time per month);
Thyroid function test - thyroid hormones.
ECG. Signs of ventricular myocardial hypertrophy, morphology and duration of the P wave in sinus rhythm in patients with paroxysmal AF, signs of conduction disturbances (blockade, asystole, sinus bradycardia), signs of organic changes in the myocardium (cicatricial lesions, etc.).
With a constant form, the replacement of normal P waves with rapid oscillations or fibrillation waves of various sizes and shapes associated with irregular frequent contractions of the ventricles with unimpaired AV conduction. The frequency of ventricular contraction in AF depends on the electrophysiological properties of the AV node, the level of activity of the sympathetic and parasympathetic nervous system, and the action of drugs.
Transthoracic echocardiography with color Doppler:
The presence of myocardial and valvular pathology;
Dimensions of the left atrium;
Size and function of the left ventricle.
Transesophageal echocardiography: intracardiac thrombi, left and right atrial appendages, spontaneous echo contrast.
(diagnostic and for monitoring therapy):
With a constant form - the minimum, maximum, average frequency of ventricular contraction, the presence of pauses (asystole), concomitant ventricular arrhythmias are assessed;
In the paroxysmal form - the presence of runs of atrial fibrillation, supraventricular extrasystoles, bradycardia (tachy-brady syndrome), episodes of restoration of sinus rhythm (through asystole).
Transesophageal electrical stimulation of the heart (TSES) - in the paroxysmal form for the induction of MA paroxysm and relief.
Indications for expert advice:
Arrhythmologist - to resolve the issue of the need for an invasive electrophysiological study (EPS) of the heart, followed by radiofrequency destruction of arrhythmogenic zones;
Endocrinologist - the presence of diseases of the thyroid gland, adrenal glands, diabetes mellitus;
Pulmonologist - the presence of a bronchopulmonary disease;
Narcologist - the presence of alcohol dependence.
Differential Diagnosis
Not carried out. A possible cause of MA is being investigated (see above).
The main diagnostic measures:
INR when selecting a dose of indirect anticoagulants;
Blood for thyroid hormones;
Transthoracic echocardiography and doppler echocardiography;
Transesophageal echocardiography;
Daily (Holter) ECG monitoring;
ChPES (with paroxysmal forms).
Additional diagnostic measures:
Daily monitoring of blood pressure (in sinus rhythm);
Stress test (treadmill test or VEM).
Ventricular arrhythmias. Sudden cardiac death
Risk factors for developing VT:
1. Any organic pathology of the cardiovascular system, leading to electrical instability of the ventricular myocardium, including rhythmogenic right ventricular dysplasia; Wolff-Parkinson-White syndrome; mitral valve prolapse.
2. Brugada syndrome.
3. Long QT syndrome (acquired, congenital).
4. Endocrine pathology - thyrotoxicosis, hypothyroidism, diabetes mellitus.
5. Changes in the neurovegetative control of the heart (hyperssympathicotonia).
6. Electrolyte disorders (hypokalemia, hypomagnesemia).
7. Sinus bradycardia. Bradyarrhythmias account for 17% of the causes of all cases of SCD - SSSU, AV block II stage. Mobitz II, stage III AV block, slowing of intraventricular conduction (QRS expansion greater than 160 ms).
8. Drug use (cocaine).
Risk factors for the development of SCD:
History of SCD;
Family history of SCD;
Paroxysms of ventricular tachycardia;
history of ACS;
Decreased pumping function of the heart of any etiology (LV EF less than 35%);
LV myocardial hypertrophy of any etiology.
SCC predictors:
1. Electrophysiological:
Late ventricular potentials (according to daily ECG monitoring);
QT dispersion (according to 24-hour ECG monitoring) 60 ms and above.
2. Functional according to echocardiography:
LV EF below 35%;
The degree of LV myocardial hypertrophy is more than 20 mm.
3. Vegetative imbalance:
Heart rate variability - SDNN less than 70 ms - according to 24-hour ECG monitoring;
Baroreflex sensitivity (below 3 ms/mm Hg).
4. QRS expansion more than 160 ms according to ECG.
Primary prevention of SCD
It is necessary to identify or not miss patients with a high risk of SCD:
Young patients with a history of syncope, ECG changes (Brugada syndrome, WPW, long QT interval);
Give a correct prognostic assessment for patients with organic heart disease: CAD, DCM, HCM, amyloidosis, sarcoidosis, valvular disease.
Diagnostic criteria
Complaints and anamnesis
The course is asymptomatic or complaints of palpitations, shortness of breath, pain behind the sternum or in the region of the heart, syncope or presyncope.
Paroxysms of palpitations- occur day or night, provoked by physical or psycho-emotional stress, alcohol intake. Duration, whether it is accompanied by hemodynamic disturbances (hypotension, presyncope, syncope), how they are stopped - spontaneously or with drugs (what doses), the frequency of occurrence of paroxysms, the experience of previous treatment with antiarrhythmic drugs.
Family history of SCD.
Physical examination
May not reveal signs of pathology or signs of the underlying disease that caused VNRS.
Laboratory research:
Blood for thyroid hormones.
Instrumental Research
1. ECG standard: the duration of the QT interval is estimated, the presence of an epsilon wave (a sign of arrhythmogenic right ventricular dysplasia), ST segment elevation with a rise at the J point ≥ 2 mm (0.2mV) followed by negative T in the right precordial leads (signs of Brugada syndrome), signs of the underlying disease (cicatricial changes, signs of LV myocardial hypertrophy), QRS expansion more than 160 ms.
2. Daily (Holter) ECG monitoring(disturbances in rhythm and conduction of the heart, heart rate variability, QT dispersion, ventricular late potentials).
3.echocardiography and doppler echocardiography: signs of organic pathology of the myocardium, valves, LV EF, signs and degree of myocardial hypertrophy.
Indications for expert advice
Arrhythmologist's consultation:
SCD, syncope, pre-syncope in history;
ZhE of high gradations;
VT of any origin;
- "Wide" tachycardia - tachycardia with QRS complexes lasting more than 120 ms.
Differential Diagnosis
VT with supraventricular tachyarrhythmia with aberration; carried out in a specialized institution by a specialist - arrhythmologist.
List of main diagnostic measures:
Blood for electrolytes (K+, Mg+);
Blood for thyroid hormones;
echocardiography and doppler echocardiography;
Daily (Holter) ECG monitoring.
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Treatment
cardiomyopathy
List of basic and additional medicines:
Treatment of CHF (see part 1 - "Chronic heart failure" of this protocol);
Treatment of cardiac arrhythmias (see below);
Prevention of thromboembolic complications;
Antiviral therapy, in the presence of a proven active viral infection;
Immunomodulatory therapy.
II. Heart rhythm disorders
Atrial fibrillation
Treatment goals:
- preservation of sinus rhythm in paroxysmal form of MA;
Control of heart rate in permanent form of MA, prevention of decompensation of heart failure;
Prevention of thromboembolic complications.
Non-drug treatment
There are no proven non-drug treatments for MA.
Medical treatment
1. Antiarrhythmic drugs- to control the rhythm of the heart.
Rhythm control in patients with PMA:
Improvement or complete elimination of symptoms;
Improvement of hemodynamics;
Reducing the risk of thromboembolism;
Cancellation of anticoagulants.
Most commonly used antiarrhythmic drugs with PMA
In the presence of organic heart disease:
Amiodarone - 600-800 mg / day. - 1 week, 400 mg/day. - 2 weeks, 200 mg/day. - maintenance dose daily;
Sotalol - 160-320 mg / day. daily.
In the absence of organic pathology of the heart:
Propafenone - 900-1200 mg / day. daily;
Allapinin - 75-150 mg / day. daily;
Etatsizin - 150-200 mg / day. daily.
Cardiomyopathy is a pathology of the heart muscle, which is based on various causes.
The disease can develop due to genetic disorders, hormonal changes, toxic effects of drugs, alcohol, and other pathological conditions.
Cardiomyopathy as a separate nosology has a common code according to ICD 10, indicated by column I42.
Types and manifestations
The classification of myocardial changes is based on the identification of pathogenetic mechanisms for the formation of cardiac disorders.
There are family cardiomyopathies, the cause of which lies in hereditary factors. Hypertrophy with subsequent wear of the heart muscle in athletes is not uncommon.
Contrary to the frequent asymptomatic course of the disease, cardiopathy can cause sudden death among the full "health" of a person.
Usually, pathology is diagnosed when patients present with characteristic cardiac complaints of palpitations, retrosternal pain, general deterioration, weakness, dizziness, and fainting.
What changes are taking place
There are several response processes from the myocardium when exposed to a damaging etiological factor:
- the heart muscle can hypertrophy;
- the cavities of the ventricles and atria are overstretched and expanded;
- directly due to inflammation, myocardial restructuring occurs.
Morphologically altered heart tissues are not able to adequately provide blood circulation. Heart failure and/or arrhythmia comes to the fore.
Diagnosis and treatment
Cardiomyopathy is diagnosed on the basis of the patient's history with additional studies. One of the screening methods are ECG (if necessary with daily monitoring) and echocardiography (using ultrasound). To determine the cause of the disease, study laboratory parameters of blood and urine.
Therapy of cardiopathy consists in the symptomatic treatment of the main manifestations. For this purpose, tablet forms of antiarrhythmics, diuretics, and cardiac glycosides are prescribed. To improve the nutrition of the myocardium, vitamins, antioxidants, and metabolic agents are prescribed.
To facilitate the work of the heart, drugs that reduce vascular resistance (calcium antagonists and beta-blockers) are used.
If necessary, surgical intervention is performed to install the pacemaker.
Code in the list of diseases
Among diseases of the circulatory system (Article IX, I00-I99), the diagnosis "Cardiomyopathy" of the ICD is singled out as a separate subsection of other heart diseases along with large nosological groups.
The division into cardiopathy, depending on the manifestations and etiology, is reflected in the international list of diseases through a dot after the main code.
So cardiomyopathy, which developed on the basis of long-term use of drugs, is coded according to ICD 10 as I42.7.
Myocardial pathology is often detected as part of the symptom complex of various diseases.
If cardiac disorders become part of a separate nosology, then in ICD 10 cardiomyopathy can be encrypted under the heading I43.
Currently, there are several theories explaining the development of dilated cardiomyopathy: hereditary, toxic, metabolic, autoimmune, viral. In 20–30% of cases, dilated cardiomyopathy is a familial disease, more often with an autosomal dominant, less often with an autosomal recessive or X-linked (Bart's syndrome) type of inheritance. Barth's syndrome, in addition to dilated cardiomyopathy, is characterized by multiple myopathies, heart failure, endocardial fibroelastosis, neutropenia, growth retardation, and pyoderma. Familial forms of dilated cardiomyopathy and have the most unfavorable course.
30% of patients with dilated cardiomyopathy have a history of alcohol abuse. The toxic effect of ethanol and its metabolites on the myocardium is expressed in damage to mitochondria, a decrease in the synthesis of contractile proteins, the formation of free radicals, and a metabolic disorder in cardiomyocytes. Among other toxic factors, professional contact with lubricants, aerosols, industrial dust, metals, etc. is distinguished.
In the etiology of dilated cardiomyopathy, the influence of alimentary factors is traced: malnutrition, protein deficiency, B1 hypovitaminosis, selenium deficiency, carnitine deficiency. Based on these observations, the metabolic theory of the development of dilated cardiomyopathy is based. Autoimmune disorders in dilated cardiomyopathy are manifested by the presence of organ-specific cardiac autoantibodies: antiactin, antilaminin, heavy chain antimyosin, antibodies to the mitochondrial membrane of cardiomyocytes, etc. However, autoimmune mechanisms are only a consequence of a factor that has not yet been established.
With the help of molecular biological technologies (including PCR), the role of viruses (enterovirus, adenovirus, herpes virus, cytomegalovirus) in the etiopathogenesis of dilated cardiomyopathy has been proven. Often, dilated cardiomyopathy is the outcome of viral myocarditis.
Risk factors for postpartum dilated cardiomyopathy, which develops in previously healthy women in the last trimester of pregnancy or shortly after childbirth, are age over 30 years, black race, multiple pregnancy, a history of more than 3 births, late pregnancy toxicosis.
In some cases, the etiology of dilated cardiomyopathy remains unknown (idiopathic dilated cardiomyopathy). Probably, myocardial dilatation occurs under the influence of a number of endogenous and exogenous factors, mainly in individuals with a genetic predisposition.
