Treatment of patients with cardiac amyloidosis presents significant difficulties. In order to suppress amyloidogenesis, various polychemotherapy regimens and immunosuppressive drugs are used. In most cases, the treatment of amyloidosis of the heart comes down to slowing the progression of heart failure. Symptomatic drugs are prescribed – diuretics, cardiac glycosides, vitamins, anticoagulants.
When SSSU can be used implantation of an artificial pacemaker. Currently in cardiology, for the treatment of amyloidosis, transplantation of the affected organs, including the heart, is started. After diagnosis, patients with cardiac amyloidosis should be systematically monitored by a cardiologist, hematologist, neurologist, nephrologist, and other specialists.
Amyloidosis of the heart (amyloid cardiopathy) is a form of systemic impairment of protein metabolism with predominant deposition of b-fibrillar protein (amyloid) in the myocardium, endocardium, pericardium, aorta, and coronary vessel walls. Heart disease can be observed in the following types of amyloidosis: AL – light chain amyloidosis, SSA – senile systemic amyloidosis, FAP – familial amyloidosis, AA – secondary amyloidosis. In generalized amyloidosis, the heart is the dominant target organ, but in some cases, isolated atrial amyloidosis may occur. Among other clinical forms of the disease, along with amyloidosis of the heart, amyloidosis of the kidneys, lungs, spleen, intestines and other organs are most common.
Amyloidosis of the heart is a systemic dysproteinosis, leading to the deposition of amyloid, a specific protein-polysaccharide complex in heart tissues. Amyloidosis of the heart is accompanied by myocardial hypertrophy, a violation of its contractile ability, the development of chronic circulatory failure, arrhythmias, hypotension, valvular defects. The clinical diagnosis of amyloidosis of the heart is established using data from electrocardiography, echocardiography, X-ray, scintigraphy, laboratory studies of serum proteins, tissue biopsies. Treatment in cardiac amyloidosis is aimed at inhibiting amyloidogenesis (polychemotherapy) and slowing the progression of heart failure (diuretics, cardiac glycosides, vitamins).
Causes of heart amyloidosis
Talking about the trigger factors of amyloidogenesis in most cases is not possible. In familial amyloidosis, an autosomal dominant type of disease transmission occurs.
Hereditary heart amyloidosis is more common among representatives of the Mediterranean ethnic group.
To a greater extent, secondary systemic amyloidosis has been studied, the development of which can be associated with a prolonged course of rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, bronchiectasis, bronchitis, tuberculosis, Hodgkin’s disease, Crohn’s disease, syphilis, actinomycosis. Patients with chronic renal failure may develop amyloidosis associated with hemodialysis.
Pathogenesis of heart amyloidosis
In a familial, idiopathic and advanced senile form of amyloidosis, heart failure occurs in 80-100% of patients. Most often, the deposition of amyloid occurs in the muscular layer of the heart, less often – in the pericardium and endocardium. In the myocardium, amyloid accumulates between the myofibrils, leading to compression of the intramural arteries and arterioles.
With amyloidosis of the heart, the myocardium is compacted, it becomes less stretchable (“rubber” myocardium); the volume of the cavities of the heart usually varies slightly. Senile amyloidosis of the heart occurs as a diffuse lesion of muscle fibers, which is accompanied by their atrophy; amyloid deposition is often detected in the coronary arteries and the aorta. Structural changes in the myocardium result in impaired systolic and diastolic function, a decrease in cardiac output, and signs of heart failure.
In the case of amyloid deposition in the valve area, a valvular heart disease clinic develops; with the accumulation of fibrillar protein in the bundle of his, sinus and atrioventricular nodes, the symptoms of the blockade of the cardiac conduction system come to the fore.
In the classification developed by WHO, there are 4 stages of cardiac amyloidosis, taking into account the degree of organ involvement in the pathological process:
- І – the symptoms and signs of amyloidosis of the heart during non-invasive examination or biopsy are not detected;
- ІІ – heart damage is confirmed by non-invasive testing (ECG, EchoCG) or biopsy, however, the course of amyloidosis is asymptomatic;
- ІІІ – stage of compensated symptomatic cardiac amyloidosis;
- IV – stage of decompensated cardiomyopathy
Symptoms of amyloidosis of the heart
Amyloidosis of the heart is often masked by the clinic of ischemic heart disease, hypertrophic cardiomyopathy, which makes it difficult to timely recognize amyloid cardiopathy. In the initial stages of the development of amyloidosis of the heart occurs gradually, asymptomatic. There may be a decrease in weight, fatigue, irritability, dizziness, swelling.
Sharp deterioration of well-being is usually preceded by a postponed intercurrent disease, including respiratory infection, stress, emotional overstrain. In the advanced stage of amyloidosis of the heart, low blood pressure with symptoms of orthostatic hypotension draws attention; pain in the region of the heart, having a stenocardic character; syncopal conditions, arrhythmias. Signs of developing chronic heart failure are shortness of breath, hepatomegaly, edema. A distinctive feature of heart failure with heart amyloidosis is its rapid progression and resistance to treatment with cardiac glycosides.
Quite often, patients with cardiac amyloidosis have pericardial effusion and ascites. Due to amyloid infiltration, sick sinus syndrome develops, which is accompanied by bradycardia and can lead to sudden cardiac death.
In the event that cardiac amyloidosis is one of the manifestations of systemic amyloidosis, patients may experience renal failure, dysphagia, diarrhea, macroglossia, skin hemorrhages, periorbital purpura, and nervous system damage. For generalized amyloidosis, sequential addition of new and new symptoms is typical, creating a variegated clinical picture with multiorgan manifestations.
Diagnosis of amyloidosis of the heart
The absence of pathognomonic symptoms makes it difficult to diagnose cardiac amyloidosis in his lifetime. Often, reliable data for amyloid cardiopathy is detected only at autopsy.
During auscultation of the heart in patients with amyloidosis, the deafness of heart tones and the systolic murmur of regurgitation on the atrioventricular valves are heard. On the ECG, a decrease in the voltage of the QRS complexes, various disturbances of excitability and conductivity of the myocardium is recorded.
The echoCG signs of amyloidosis of the heart include thickening of the interventricular and interatrial septum, ventricular walls, heart valves, atrial dilatation, myocardial hypokinesia. Functional changes are characterized by a sharp decrease in the left ventricular ejection fraction, impaired diastolic filling, valvular regurgitation. Sometimes in the myocardium it is possible to identify echo-positive inclusions in the form of small granules, representing amyloid deposits.
On radiographs of the chest can be determined by the increase in the shadow of the heart, exudative pleurisy. Myocardium scintigraphy and MRI of the heart serve as more highly sensitive and specific methods in the lifetime diagnosis of cardiac amyloidosis.
Morphological confirmation of amyloidosis of the heart can be obtained by biopsy of the myocardium or other affected organs (tongue, gum, subcutaneous fat, lymph nodes, kidney, rectum, etc.).
In laboratory tests of urine and blood with amyloidosis of the heart, proteinuria, hypoproteinemia, hyperglobulinemia and hypoalbuminemia are found.
Differential diagnosis of amyloidosis of the heart is carried out with hereditary dystonic lipidosis (Fabry’s disease), myxedema, the cestiary heart syndrome, hypothyroidism, idiopathic cardiomyopathy, idiopathic restrictive cardiomyopathy, pulmonary heart, hemochromatosis, aortic stenosis, the cystosis;
Prognosis for amyloidosis of the heart
The timely intravital diagnosis of cardiac amyloidosis and its effective treatment are a difficult problem in cardiological practice. This is due to the rather rare prevalence of pathology, the nonsignificancy of specific symptoms in the clinic of the disease, the lack of specialized centers in Russia dealing with the problems of amyloidosis.
The prognosis of amyloidosis of the heart is unfavorable: heart failure is prone to steady progression. Death of patients occurs on average 1.5-2.5 years after the onset of signs of heart disease from heart failure or from non-cardiac complications.