Author Ольга Кияница
Restrictive cardiomyopathy (RKM) is a rare myocardial disease and is least common in comparison with two other clinically recognized and described cardiomyopathies. Characterized by diastolic dysfunction with disabilities. An enlargement of the atrium occurs due to a violation of the ventricular filling process during diastole, but the volume and thickness of the walls of the ventricular chambers usually remain within the normal range.
Restrictive cardiomyopathy accounts for approximately 5% of all cases of diagnosed cardiomyopathy. [1 - Huby AC; Mendsaikhan U; Takagi K; Martherus R; Wansapura J; Gong N; Osinskaya H; James JF; Kramer K; Saito K; Robbins J; Khuchua Z; Towbin JA; Purevjav E. Disturbance in Z-disk mechanosensitive proteins induced by a persistent mutant myopalladin causes familial restrictive cardiomyopathy. J Am Coll Cardiol. 2014; 64 (25): 2765-76]
RCM may be idiopathic or secondary to other diseases, in particular amyloidosis and endomyocardial disease with or without hyperheiosynophilia. The outlook for RCM depends on the clinic and the treatment. It has been found that the disease is a serious cause of the development of heart failure with a preserved fraction of ejection. Due to the difficulties associated with diagnosis of RCM, several methods should be used during the examination of patients.
Video: Restrictive Cardiomyopathy: Causes, Symptoms, Diagnosis, Treatment and Pathology
Restrictive cardiomyopathy can be both hereditary and acquired. In both cases, it is equally widespread among males and females. The increased stiffness of the myocardium causes the ventricular pressure to increase sharply even with a slight increase in blood volume. Thus, the highest filling measure is observed in the early phase of diastole and ends sharply at the end of rapid filling.
Reduced volume of left ventricular filling results in a decrease in cardiac output. At the beginning of the disease, the systolic function usually remains normal. The thickness of the wall may be increased in cases of infiltrative processes, such as amyloidosis, but the change is usually less pronounced than with hypertrophic cardiomyopathy.
As the disease progresses, there is a variable decrease in systolic function and the development of symptoms of cardiac output reduction. Increased filling pressure can be manifested as pulmonary and systemic overload. RCM affects both ventricles and can therefore cause symptoms and symptoms of both left-sided and right-sided heart failure.
In some cases, a complete blockage of the heart occurs as a result of developing fibrosis, covering the sinatricular or atrioventricular nodes.
Classification of restrictive cardiomyopathy by type (Kushwaha P. et al., 1997)
- Restrictive myocardial cardiomyopathy:
1.1 Idiopathic cardiomyopathy;
1.2 Family cardiomyopathy;
1.3 Hypertrophic cardiomyopathy;
1.5 Pseudoksanthoma elastic;
1.6 Diabetic cardiomyopathy
2.3 Gaucher disease;
2.4 Gurler's disease;
2.5 Fat infiltration
3. Diseases of accumulation:
3.2 Fabry's disease;
3.3 Disease of glycogen accumulation
- Restrictive cardiomyopathy endomyocardial:
- Endomyocardial fibrosis
- Carcinoid heart disease
- Metastatic Cancer Defeat
- Radiation defeat of the heart
- Toxic effect of anthracyclines
- Medicinally determined fibroids endocarditis
Endocardial fibrosis can spread to atrioventricular valves and cause regurgitation. There are two forms of endomyocardial fibrosis (EMF): active eosinophilic EMF and chronic EMF.
Prevalence of restrictive cardiomyopathy:
- Idiopathic RCM is observed primarily in the United States.
- Leffler's endocarditis is common in temperate countries.
- Chronic endomyocardial fibrosis is observed exclusively in tropical and subtropical countries of Africa, Asia and South America.
- EMF is most commonly encountered in children and young people living in Uganda and Nigeria, often accounting for one quarter of deaths in these areas due to heart failure.
Restrictive cardiomyopathy may be caused by various local and systemic disorders; many of them are found quite rarely.
According to the guidelines of the World Health Organization (WHO), the term "cardiomyopathy" refers to myocardial diseases, which are idiopathic (i.e., primary cardiomyopathies). However, secondary infiltrative myocardial diseases, which are in fact cardiac manifestations of systemic diseases, are often grouped together with cardiomyopathies.
The reasons for RCM can be divided into two large groups as follows:
- Primary / idiopathic RCM. This includes endomyocardial fibrosis (ECF), eosinophilic endomyocardial Leffler disease.
- Secondary RCM. The group includes causes such as amyloidosis, sarcoidosis, hemochromatosis, progressive systemic sclerosis (scleroderma), carcinoid heart disease, hemogenic heart disease, induced radiation / treatment, metastatic malignancy, anthracycline toxicity.
Primary (idiopathic) RCM
Both the genetic and sporadic cases of the primary (idiopathic) RCM were described. This is a rare disease that can manifest itself in children and adults, while men and women suffer the same. The outlook for children is worse than for adults. Genetic cases are most often based on an autosomal dominant inheritance with incomplete penetrance. The mutation appears to occur in the genes encoding sarcomodal proteins, including troponin I, troponin T, alpha-cardiac actin, and the heavy chain of beta myosin. The presence of a positive family history of RKM is determined in about 30% of cases. [2 - Huby AC; Mendsaikhan U; Takagi K; Martherus R; Wansapura J; Gong N; Osinskaya H; James JF; Kramer K; Saito K; Robbins J; Khuchua Z; Towbin JA; Purevjav E. Disturbance in Z-disk mechanosensitive proteins induced by a persistent mutant myopalladine causes familial restrictive cardiomyopathy. J Am Coll Cardiol. 2014; 64 (25): 2765-76]
In many cases, heart muscle disease has no known cause, but it manifests itself in heart failure and restrictive hemodynamics, but without significant ventricular hypertrophy. Endocardial thickening or fibrosis associated with eosinophilia or other histopathological changes may be noted
In addition to the symptoms of heart failure in the right or left heart department, one third of patients with idiopathic RCT may have thromboembolic complications. Pathologically, these patients have greatly enlarged the atrium, which is clearly noticeable on the chest X-ray. Echocardiography in such cases shows a bilateral extension of the atrium with normal size of the ventricle, as well as significant diffuse hypertrophy of the left ventricle, especially in the presence of amyloidosis. Histological features of idiopathic RCM are interstitial fibrosis, which is minimal in some patients and quite extensive in others.
Eosinophilic cardiomyopathy (Leffler's Endocarditis) and ECF are the most common global causes of RKM, affecting about 12 million people worldwide. This state is observed in equatorial Africa and, less commonly, in tropical and subtropical Asia and South America.
Severe long-term eosinophilia for any reason (eg allergic, autoimmune, parasitic, leukemic or idiopathic) can lead to eosinophilic infiltration of the myocardium.
Eosinophilic cardiomyopathy, also known as Leffler's endocarditis, begins with an acute inflammatory phase characterized by fever. Violation of the structure of the left and right ventricles occurs in the intermediate phase, and from a few months to several years, the final stage, including the development of endocardial fibrosis, lasts.
The prognosis is unfavorable for patients with diffuse heart disease. Localized lesions associated with valves can be surgically reconstructed or removed and replaced.
Infiltrative cardiomyopathies are characterized by deposition of abnormal substances (amyloid proteins, non-necrosis granules, iron) within the heart tissue. Infiltration leads to thickening of the walls of the ventricles, which contributes to the development of diastolic dysfunction. The disease occurs in a variety of age groups and, given the systemic nature of the underlying pathology, is characterized by extra-ordinary manifestations.
Restrictive disorders predominate in the early stages of the disease, causing conduction anomalies and diastolic cardiac insufficiency. Unfavorable remodeling can lead to systolic dysfunction and ventricular arrhythmia.
Amyloidosis is the most common cause of RKM in the United States. Studies have shown that a higher prevalence of amyloidosis in older patients with heart failure and preserved ejection fraction may be observed.
Amyloidosis is characterized by a multi-system deposition of proteins known as amyloid fibrils. It is usually a systemic disorder with infiltration of the liver, kidneys, intestines, nerves, skin and tongue. The involvement of the heart is also quite common, which is the main source of mortality associated with this disease.
When amyloidosis, the myocardium thickens and becomes solid, rubbery and incapable of contraction, since the amyloid accumulates in the tissues of the heart. These changes lead to anomalies of contractility, conduction, and coronary artery bypass grafts. Biventricular diastolic dysfunction causes an increase in intracardiac pressure and may progress to systolic dysfunction.
Amyloid can precipitate in any part of the heart, including myocardium, vessels, endocardium, valves, epicardium and parietal pericardium. The walls of the ventricles usually thicken, sometimes with a disproportionate increase in the septum and can mimic the appearance of hypertrophic cardiomyopathy. The dilatation of the atrium develops as a result of increased pressure and ventricular filling.
The results of classical two-dimensional echocardiography include increased wall thickness of the left ventricle and right ventricle, normal or small size of the left ventricular cavity with retained release fraction. One third of patients may have a normal size of the wall of the left ventricle. Typically, effusion and thickening of both the valves and papillary muscles are determined.
Other less common forms of infiltrative RCM include:
- Sarcoidosis: characterized by the presence of non-caesarean granules (cardiac involvement is 25-30%).
- Hemochromatosis and cardiomyopathy with excess iron.
- Danone Disease: Membrane Protein 2 (LAMP2) Deficiency.
- Friedreich Ataxia: Fractional Gene mutation (FXN).
Video: Amyloidosis Awareness (narrated by Michael York) - Available in 14 Languages
Post-Radial Fibrosis. Radiation-induced myocardial and endocardial fibrosis is the cause of non-infiltrative RCV. Fibrosis causes damage to the endothelial cells and subsequent microvascular dysfunction. An increase in the total collagen concentration results in a decrease in the stomach tissue of the ventricle. Radiation affects coronary vessels, valves and pericardium. This complication of radiotherapy, as in pericardial tamponade, is manifested several years after treatment. It is difficult to diagnose. Echocardiography can show normal wall thickness of the left ventricle with abnormal filling of the left, calcification of the valves and pericarditis.
Medicinal-Induced RCM is a rare disease that has been described after long-term use of antimalarials (chloroquinone and hydroxychloroquinone). General heart abnormalities are the conduction anomaly and valve expansion.
Symptoms of restrictive cardiomyopathy may include the following:
- Gradual appearance of shortness of breath
- Weight loss (heart cachexia)
- Paroxysmal night breath
- Intolerance to increased physical activity
- Abdominal discomfort or increased sensitivity in the liver region
- Chest pain, especially in patients with amyloidosis or angina pectoris
Extracardiac manifestations of systemic disorder can be expressed in the following:
- Increase jugular venous pressure
- Reducing pulse volume
- Appearance of ascites and acute edema of the lower extremities
- Hepatomegaly due to fluid infiltration or amyloid
- Light bruises, periorbital purpura, macroglossia (strongly enlarged tongue), and others.
The examination of the cardiovascular system can yield the following results:
- Normal sounds of the heart
- Loud sound of early diastolic filling
- Heart noise due to the smoothing of the mitral and tricuspid valve (usually not hemodynamically significant)
Results of respiratory examination:
- Auscultation breath can be heard less because of pleural effusion, often bilateral and extensive with amyloidosis
- Cremation or wheezing is rarely heard
Establishing the diagnosis of RCM and the elimination of constrictive pericarditis, as a rule, is mandatory.
In case of suspicion of restrictive cardiomyopathy, the following tests may be performed:
- Deep blood test
- Analysis of gas composition of blood
- Electrolytes of serum of blood, nitrogen, urea, creatinine
- Hepatobiliary markers
- Concentration of iron in the serum and other possible indicators of hemochromatosis
- Serum cerebral sodiumuretic peptide level
The instrumental diagnostic methods are as follows:
- Catheterization of the heart
- Radionuclide diagnostics
- Cardiovascular magnetic resonance imaging
- Computer tomography
- Ventricular biopsy
- Liver biopsy for diagnostics of hemochromatosis
Specialist treatment for restrictive cardiomyopathy has not been developed. Nevertheless, the therapy directed at the individual causes of RCM, in some cases, is effective.
Pharmacological therapy may include:
- Cardioselective blockers of calcium channels
- Anticoagulants for patients with atrial fibrillation
- Digoxin (should be used with caution)
- Melphalan (for the treatment of antiplasmic disorders with systemic amyloidosis)
- Chemotherapy (with amyloidosis)
- Corticosteroids, cytotoxic agents (for example, hydroxyurea) and interferon (with endocardium of Luoffler)
- Therapeutic phlebotomy (with hemochromatosis)
- Implantation of the pacemaker
- Heart transplantation
- New treatments (for example, RNA interference or freezing of genes that are involved in the development of an abnormal protein in family amyloidosis)
Video: Modern aspects of diagnosis and treatment of cardiomyopathies in childhood
Restrictive cardiomyopathy has the worst prognosis among all types of cardiovascular disease. In particular, the mortality rate from 2 to 5 years is 50% and 70%, respectively, and the highest rate of sudden cardiac death is recorded in RCM. Due to the severe development of the disease, patients with RKM eventually suffer from heart failure and pulmonary hypertension.
The prognostic conclusion depends mainly on the pathology clinic, while the treatment is often unsatisfactory. The outlook is generally unfavorable for adults, as the pathology is often associated with progressive deterioration.
Patients who are susceptible to maintenance therapy usually die from low-grade heart failure. A cardinal transplant can help solve the problem.
The following complications occur most frequently in RCMs:
- Pulmonary hypertension
- Cardiac, or cardiac cirrhosis of the liver
- Progressive deterioration of the function of the heart
Among all cardiovascular diseases, cardiomyopathy is distinguished in a special way. Pathology can develop not only in adults, but also in children. In the latter case, there are specific features of the course of the disease, its diagnosis and treatment, which should be known to loving parents.
Metabolic disorders can lead to metabolic cardiomyopathy. This disease can significantly disrupt the habitual lifestyle of a person, and in severe cases - lead to death. Therefore, at the slightest sign of a malfunction of the heart, an urgent need to consult a doctor.
Every year, the number of patients increases in alcoholic cardiomyopathy. This pathological condition is still known as an alcoholic heart, alcohol myocardial dystrophy, "beer heart" or "bull's heart". The more pronounced the signs of the disease, the more critical the state of health of the patient, therefore, it is extremely important to pay attention to the disturbance in time, which will allow for adequate treatment.