Restrictive cardiomyopathy in children: causes, symptoms, diagnosis, treatment

Restrictive cardiomyopathy in children is a rare disease of the myocardium, characterized by diastolic dysfunction and increased ventricular filling pressure with normal or little-changed systolic function of the myocardium, absence of its significant hypertrophy. Phenomena of circulatory failure in such patients are not accompanied by an increase in the volume of the left ventricle.

ICD Code 10

• 142.3. Endomiocardial (eosinophilic) disease.
• 142.5. Other restrictive cardiomyopathy.

Epidemiology

The disease is found in different age groups, both among adults and among children (from 4 to 63 years). However, children, adolescents and young men are more likely to get sick, they start the disease earlier and have a harder time. Restrictive cardiomyopathy accounts for 5% of all cases of cardiomyopathies. Possible family cases of the disease.

[1], [2], [3], [4],

Causes of restrictive cardiomyopathy

The disease can be idiopathic (primary) or secondary, caused by infiltrative systemic diseases (eg, amyloidosis, hemochromatosis, sarcoidosis, etc.). Assume genetic determinism of the disease, but the nature and localization of the genetic defect underlying the fibroplastic process has not yet been elucidated. Sporadic cases can be a consequence of autoimmune processes provoked by transferred bacterial (streptococcal) and viral (enteroviruses Coxsackie B or A) or parasitic (filariasis) diseases. One of the identified causes of restrictive cardiomyopathy is hypereosinophilic syndrome.

[5], [6], [7], [8]

Pathogenesis of restrictive cardiomyopathy

In endomyocardial form, the leading role in the development of restrictive cardiomyopathy belongs to disorders of immunity with hypereosinophilic syndrome, against the background of which, due to infiltration of degranulated forms of eosinophilic granulocytes into the endomyocardium, gross morphological disturbances of the heart structure are formed. In the pathogenesis, the deficit of T-suppressors, leading to hypereosinophilia, degranulation of eosinophilic granulocytes, is important. Which is accompanied by the release of cationic proteins that have a toxic effect on cell membranes and enzymes involved in the respiration of mitochondria, as well as thrombogenic action on the damaged myocardium. The damaging factors of granules of eosinophil granulocytes are partially identified, they include neurotoxins, an eosinophilic protein having a basic reaction, apparently damaging epithelial cells. Neutrophilic granulocytes can also have damaging effects on myocytes.

Due to endomyocardial fibrosis or infiltrative myocardial damage, the compliance of the ventricles decreases, their filling is impaired, which leads to an increase in the end-diastolic pressure, overload and dilatation of the atria and pulmonary hypertension. Systolic function of the myocardium is not disturbed for a long time, and ventricular dilation is not observed. The thickness of their walls is usually not increased (except for amyloidosis and lymphoma).

In the future, progressive endocardial fibrosis leads to a violation of the diastolic function of the heart and the development of chronic heart failure resistant to treatment.

Symptoms of restrictive cardiomyopathy in children

The disease for a long time is subclinical. The detection of pathology is due to the development of severe symptoms of heart failure. The clinical picture depends on the severity of chronic heart failure, usually with a predominance of stagnation in a large circle of blood circulation; heart failure is rapidly progressing. Venous stagnation of blood is detected on the way to the left and right ventricles. Typical complaints with restrictive cardiomyopathy are as follows:

• weakness, increased fatigue;
• with short physical exertion;
• cough;
• abdominal enlargement;
• edema of the upper half of the trunk.

Classification of restrictive cardiomyopathy

Of the two forms of restrictive cardiomyopathy identified in the new classification (1995): first, primary myocardial. Proceeds with isolated myocardial damage similar to that of dilated cardiomyopathy, the second, endomyocardial, characterized by endocardial thickening and infiltrative, necrotic and fibrotic changes in the heart muscle.

With endomyocardial form and detection of eosinophilic infiltration of the myocardium, the disease is regarded as a fibroplastic endocarditis of Loeffler. In the absence of eosinophilic infiltration of the myocardium, they speak of Davis's endomyocardial fibrosis. There is a view that eosinophilic endocarditis and endomyocardial fibrosis are stages of the same disease, found mainly in the tropical countries of South Africa and Latin America.

At the same time, primary myocardial restrictive cardiomyopathy, for which endocardial changes and eosinophilic infiltration of the heart muscle are not characteristic, is described in countries of other continents, including in our country. In these cases, with careful examination, including myocardial biopsy and coronarography, or at the autopsy, no specific changes could be detected, coronary artery atherosclerosis and constrictive pericarditis were absent. Histological examination of such patients revealed interstitial fibrosis of the myocardium, the mechanism of its development remains unclear. This form of restrictive cardiomyopathy is found in both adults and children.

[9], [10], [11], [12], [13], [14], [15]

Diagnosis of restrictive cardiomyopathy in children

The diagnosis of "restrictive cardiomyopathy" is based on a family history, clinical picture, physical examination results, ECG data, echocardiography, chest X-ray, CT or MRI, and cardiac catheterization and endomyocardial biopsy. The data of laboratory studies are not informative. Suspected restrictive myocardial damage follows in patients with chronic heart failure in the absence of dilatation and pronounced violations of the contractile function of the left ventricle.

For a long time the disease flows slowly, slowly and imperceptibly for others and parents. Children do not make complaints for a long time. The manifestation of the disease is due to cardiac decompensation. About the prescription of the disease shows a significant lag in physical development.

[16], [17], [18], [19]

Clinical examination

Clinical manifestations of the disease are caused by the development of circulatory insufficiency mainly in the right ventricular type, and violations along the venous inflow pathways to both ventricles are accompanied by increased pressure in the small circulatory system. On examination, note a cyanotic blush, a swelling of the cervical veins, more pronounced in a horizontal position. Pulse of weak filling, systolic blood pressure is reduced. The apical impulse is localized, the upper limit is shifted upwards due to atriomegaly. Often they listen to the "canter rhythm", in a large part of cases - the inefficient systolic murmur of mitral or tricuspid insufficiency. Hepatomegaly is markedly expressed, the liver is dense, the edge is sharp. Often noted peripheral edema, ascites. With severe circulatory failure during auscultation, small bubbling rales are heard over the lower parts of both lungs.

[20], [21], [22], [23], [24]

Electrocardiography

In ECG, signs of hypertrophy of the affected parts of the heart, especially pronounced atrial overload, are recorded. Often, the ST segment decreases and the T wave inversion is noted. Heart rhythm and conduction abnormalities are possible. Tachycardia is not typical.

[25], [26]

Radiography of chest organs

When radiographing the chest, the size of the heart is slightly enlarged or not changed, note the increase in the atria and venous congestion in the lungs.

Echocardiography

Echocardiographic signs are as follows:

• systolic function is not impaired;
• atrial dilation is expressed;
• reduction of the cavity of the affected ventricle;
• functional mitral and / or tricuspid regurgitation;
• restrictive thinn of diastolic dysfunction (shortening the time of isovolytic relaxation, increasing the peak of early filling, decreasing the peak of late atrial filling of the ventricles, increasing the ratio of early filling to late);
• signs of pulmonary hypertension;
• the thickness of the walls of the heart is usually not increased.

Echocardiography allows to exclude dilated and hypertrophic cardiomyopathies, but is not informative enough to exclude constrictive pericarditis.

[27], [28], [29], [30]

Computed tomography and magnetic resonance imaging

These methods are important for the differential diagnosis of restrictive cardiomyopathy with constrictive pericarditis, allow us to assess the condition of the pericardium leaflets and exclude their calcification.

[31], [32], [33],

Endomyovascular biopsy

This study is conducted to clarify the etiology of restrictive cardiomyopathy. It allows to reveal fibrosis of myocardium in idiopathic myocardial fibrosis, characteristic changes in amyloidosis, sarcoidosis and hemochromatosis.

The technique is rarely used due to the invasive nature, high cost and the need for specially trained personnel.

[34], [35]

Differential diagnosis of restrictive cardiomyopathy

RCMF is differentiated primarily with constrictive pericarditis. To do this, assess the condition of the pericardial sheets, exclude their calcification with CT. Differential diagnostics is also carried out between RCMP caused by different causes (in case of accumulation diseases - hemochromatosis, amyloidosis, sarcoidosis, glycogenoses, lipidosis).

[36], [37], [38], [39], [40], [41]

Treatment of restrictive cardiomyopathy for restrictive cardiomyopathy in children

Treatment of restrictive cardiomyopathy in children is ineffective, temporary improvement occurs during therapeutic measures in the early stages of the onset of the disease. Conduct symptomatic therapy in accordance with the general principles of treatment of heart failure, depending on the severity of clinical manifestations, if necessary - arresting cardiac arrhythmias.

With hemochromatosis, the improvement of heart function is achieved by influencing the underlying disease. Therapy of sarcoidosis with the use of glucocorticosteroids does not affect the pathological process in the myocardium. With endocardial fibrosis, resection of the endocardium with prosthetic mitral valve sometimes improves the condition of patients.

The only radical treatment for idiopathic restrictive cardiomyopathy is heart transplantation. In our country, the children do not spend it.

Prognosis for restrictive cardiomyopathy in children

The prognosis of restrictive cardiomyopathy in children is more often unfavorable, the patients die from refractory chronic heart failure, thromboembolism and other complications.