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Heart accumulation of amyloid

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction A disease in which myocardial dysfunction caused by amyloid protein deposition in myocardial tissue.

Cause

Cause

(1) Causes of the disease

Clinically, it is generally divided into primary and secondary: it occurs in tuberculosis, rheumatoid arthritis, ulcerative colitis, chronic osteomyelitis, chronic suppurative and wasting disorders, or occurs in multiple myeloma. Secondary amyloidosis; if there is no above cause, it is a primary amyloidosis, which is mostly related to heredity.

Amyloidosis is a pathological noun, which refers to the accumulation of a large number of fibrous substances with glycoprotein properties in the tissue. The main protein components are immunological light chain protein (AC), non-immune amyloid (AA), calcitonin-like protein. (AEI) and four types of plasma pre-protein (SA) of senile amyloidosis.

1.AC-induced amyloidosis

For the most common clinical amyloidosis, it is more common in primary and systemic amyloidosis, which is caused by defects in immunoglobulin degradation or synthetic defects. Such amyloids are secreted by abnormally cloned beta cells; mainly involving the heart, tongue, gastrointestinal tract, muscles, tendons and skin. In addition, the liver, spleen, kidney, adrenal gland and thyroid gland can also be affected.

2.AA-induced amyloidosis

Clinically known as secondary amyloidosis, often caused by tuberculosis, rheumatoid arthritis, ulcerative colitis, chronic osteomyelitis, chronic suppurative diseases and other chronic infectious diseases, or multiple myeloma, is caused by a huge inflammatory response The phagocytic cells phagocytose the serum AA protein and cause it to decompose. Mainly involving the kidney, liver, spleen and adrenal gland and other tissues. In addition, it is still associated with atrial myxoma formation.

3. AEI-induced amyloidosis is more common in medullary thyroid carcinoma.

4.SA-induced amyloidosis of the heart, pancreas, prostate and brain is the main affected part, especially in the elderly, so it is often called senile systemic amyloidosis.

(two) pathogenesis

Pathogenesis

(1) Optical microscopy (light microscopy) of starch-like deposits: light-mirror-like starch deposits showed no qualitative, hematoxylin and eosin staining was eosinophilic, and stained with crystal violet, Congo Red has affinity. Specific green birefringence can be produced by observation with a polarizing microscope of Congo red stained specimens.

(2) Ultrastructure of starch-like deposits: Electron microscopic observation of amyloidosis has two different forms of components: one is a small fiber component; the other is a pentagonal substance (referred to as P component). The small fibers are about 10 nm (100 Å) wide, without branches, thin and hard, and are arranged in a lateral direction to form fibers. All amyloid-like proteins have a -folded configuration, which explains the green birefringence characteristics of amyloid deposition under Congo red staining.

The P component of the amyloid-like deposit is a dough-like structure formed by five globular subunits around a central cavity. It has a diameter of 8 nm (80 Å) and has a circumference of 4 nm (40 Å). The composition of the amyloid may be immunoglobulin, endocrine, senile, familial and unidentified. Can be divided into systemic, focal, or hereditary, acquired. Heritability can be systemic or focal; so is acquired.

2. Pathology

Ventricular hypertrophy, amyloplasts are diffusely deposited in cardiomyocytes, causing dystrophic, atrophic or myocardial cells completely replaced by amyloid-like substances. Electron microscopy showed that amyloid-like fibers were loosely distributed in the extracellular space, and the fibers were arranged irregularly away from the cells. The fibers and cell membranes close to the myocardial cells were oriented vertically or parallel. Small coronary artery involvement can cause angina pectoris, which can be thickened after heart valve involvement. Cardiac involvement is more common in primary amyloidosis, as well as secondary systemic amyloidosis and familial myocardial amyloidosis.

Histological infiltration of starches can cause stressful atrophy and organ dysfunction in substantial cells. Regardless of whether the cause of amyloidosis is primary, secondary or with myeloma or familial, the resulting amyloid accumulation has a consistent effect on the organ. Significant cardiomyopathy can be manifested by significant myosin infiltration caused by which type of amyloidosis syndrome.

Examine

an examination

Electrocardiogram

Almost all patients have abnormal electrocardiogram, including low voltage, ST-T changes, sinus tachycardia, arrhythmia with atrioventricular block, and bundle branch block, premature beat, atrial fibrillation, Occasionally Q wave or myocardial infarction pattern.

2. X-ray chest

It is often indicated that the heart size is normal, and the heart shape is slightly increased when there is pericardial effusion.

3. Echocardiography

Main manifestations: 1 except for the normal or small left ventricular internal diameter, the ventricular cavity is enlarged; the 2 ventricular septum and ventricular wall thickening, and symmetry; 3 atrioventricular or papillary muscles can also be thickened due to lesion involvement or Thickening; 4 about half of the pericardial effusion; 5 about 92% of patients with thickened myocardial visible scattered circular or irregular strong reflection small spots, which is a characteristic manifestation of the disease. In order to better recognize this kind of light spot, the long axis view and the short axis view of the sternum are generally taken, instead of taking the apical four-chamber view. It is believed that this strong reflection small spot is caused by nodules formed by colloidal and amyloid tissue.

Diagnosis

Differential diagnosis

Pericardial tamponade: The pericardial cavity is the space between the parietal pericardium and the visceral pericardium on the surface of the heart. A small amount of light yellow liquid in the normal pericardial cavity lubricates the surface of the heart. Traumatic heart rupture or pericardial vascular injury caused by blood accumulation in the pericardial cavity called blood pericardial or pericardial tamponade, which is the cause of rapid death of cardiac trauma. M-mode ultrasound showed the ventricle activity curve of the pericardium. When the pericardial tamponade, the direction of the anterior wall of the right ventricle changed, and the diastolic phase showed a centripetal movement, that is, the posterior displacement.

Endocardial fibroelastosis: also known as endocardial sclerosis, the cause is not yet clear. It is a common type of primary cardiomyopathy in children, also known as primary endocardial fibroelastosis. The characteristics of this disease are: most of the infants under 11 years old suddenly have heart failure from 2 to 6 months; 2X chest X-ray enlarges the left ventricle, the heart beats weakly; 3 the heart has no obvious murmur; 4 ECG shows left ventricle Hypertrophy, or V- and 6-lead T-wave inversion. 5 echocardiography showed left ventricular enlargement, endocardial echo thickening, and reduced systolic function. Histologically confirmed endocardial myocardial thrombosis. The age of onset of 2/3 sick children is within 1 year of age. Clinical manifestations are mainly congestive heart failure, often occurring after respiratory infections.

Infectious neoplasm: Infective endocarditis, which refers to the inflammation of the heart valve or ventricular wall by direct infection of bacteria, fungi and other microorganisms (such as viruses, rickettsia, chlamydia, spirochetes, etc.). Non-infective endocarditis due to rheumatic fever, rheumatoid, systemic lupus erythematosus, etc. The basic pathological change is the attachment of neoplasms composed of platelets, fibrin, red blood cells, white blood cells, and infectious pathogens on the surface of the heart valve. In the past, this disease was called bacterial endocarditis, which is not used because it is not comprehensive enough. Typical clinical manifestations of infective endocarditis include fever, murmur, anemia, embolism, skin lesions, splenomegaly, and blood culture positive.

Mixed blood is formed in the atria: a single atrium. Single atrial is a rare congenital heart disease caused by the absence of the first and second compartments of the interventricular septum during embryonic development. The traces of the room are also not present, and the compartment is complete, so it is also called the two-chamber three-chamber heart or the single-atrial three-chamber heart. Single atrium can exist alone, but often combined with the left superior vena cava and right heart, left heart or abdominal visceral transposition malformation, especially the anterior mitral lobes, and even the atrioventricular tube malformation.