Restrictive cardiomyopathy

Introduction to restrictive cardiomyopathy Restrictive cardiomyopathy (RCM) is characterized by unilateral or bilateral ventricular filling limitation and decreased diastolic volume, but the systolic function and wall thickness are normal or near normal. Cardiac interstitial fibrosis is the main pathological change, that is, there are several millimeters of fibrous thickening in the endocardium and subendocardium, intraventricular hardening, and expansion is constrained. Most restrictive cardiomyopathy is secondary to systemic diseases. Such as amyloidosis, sarcoidosis, scleroderma, hemochromatosis, endocardial cardiomyopathy with or without eosinophilia or due to radiation therapy. The disease is often complicated by heart failure, arrhythmia, arterial embolism and pericardial effusion. The main treatment is heart failure control. basic knowledge The proportion of illness: 0.0001%-0.0003% Susceptible people: no specific population Mode of infection: non-infectious Complications: heart failure, sudden death, arterial embolism

Causes of restricted cardiomyopathy

(1) Causes of the cause of the disease

Not yet clear, may be related to nutritional disorders, food serotonin poisoning, infection allergy and autoimmunity, a few cases are familial, may be associated with skeletal muscle disease and atrioventricular block, in recent years, eosinophils and This type of cardiomyopathy is closely related. In addition to invasive lesions, the pathogenesis of non-invasive cardiomyopathy is concentrated in eosinophils. Some of the patients with this type in the tropical and temperate regions are eosinophils. Increased, early necrosis, multiple eosinophils in the myocardium, usually within 5 weeks; up to 10 months, endocardial thickening and thrombosis, myocardial inflammation decreased, that is, thrombosis; 2 years After entering the fibrosis stage, the endocardium and myocardium can be fibrotic. In the restrictive cardiomyopathy caused by invasive lesions, there is amyloidosis (interstitial amyloid accumulation), sarcoma-like (intracardiac sarcoma-like) Material infiltration), hemochromatosis (myelin deposition in myocardium), glycogen accumulation (hyperglycemia in the myocardium), etc. In non-invasive restrictive cardiomyopathy, there are myocardial endocardial fibers and Lö Ffler endocarditis, the former is found in the tropics, the latter is seen in the temperate zone, the actual similarity, the appearance of the heart is mild or moderately increased, the endocardial fibrosis and thickening, with the ventricular inflow and apex as the main parts, Atrioventricular valve can also be affected, fibrosis can penetrate deep into the myocardium, the wall thrombus is easy to form, the ventricular cavity is reduced, and the myocardial endocardium can also have calcification.

(two) pathogenesis

The pathogenesis of restrictive cardiomyopathy is still unclear, and may be related to many factors, such as viral infection of endocardium, malnutrition, autoimmunity, etc. In recent years, eosinophils are closely related to such cardiomyopathy. Acidic granulocytosis may be the cause of part of the endocardial myocardium. Eosinophilia often precedes the onset of heart disease. This eosinophil has morphological abnormalities in vacuoles and degranulation, and eosinophil granules dissolve. Increased oxidative metabolism and release cytotoxic proteins, mainly cationic proteins, which can damage cardiomyocytes and act on enzyme components in the sarcoplasmic membrane and mitochondrial respiratory chain. The degree of endocardial myocardial damage depends on eosinophils. The severity and duration of myocardial infiltration into the endocardium, in addition, the cationic protein released from this degranulation can also affect the coagulation system, easily form a wall thrombus, can also damage endothelial cells, inhibit endothelial cell growth, eosinophilic Myeloid infiltration of myocardium causes myocarditis, and the distribution of inflammation is mainly limited to the inner layer, which can be the weight of microcirculation in the myocardium. Arrangement to explain, so they enter the stage of necrosis and thrombosis, and finally enter the healing and fibrosis stage. The reason for the infiltration of eosinophils into the myocardium and the degranulation of eosinophils is still unclear. Disease factors such as viruses, parasites, etc., which have the same antigenic clusters as myocardial tissue, induce an autoimmune response and cause restricted cardiomyopathy.

In addition, some patients with unexplained etiology are characterized by ventricular diastolic relaxation disorder and limited filling. The patient's endocardial thickening or fibrosis is also unknown, accompanied by eosinophilia, most of which have myocardial fibrosis. This is a primary (or idiopathic) restrictive cardiomyopathy. It has recently been reported that this disease is sometimes familial, with skeletal muscle disease and atrioventricular block.

(3) Pathophysiology

Endocardial and myocardial fibrosis can cause ventricular diastolic dysfunction, and can also be accompanied by varying degrees of systolic dysfunction, ventricular cavity reduction, ventricular filling is limited; ventricular apical degeneration is reduced, blood return is impediment, followed by The cardiac output is also reduced, causing pathophysiological changes similar to constrictive pericarditis, and mitral or tricuspid regurgitation may occur when the atrioventricular valve is involved.

Restrictive cardiomyopathy prevention

1. Prevention is limited to avoiding complications and should not be overworked to prevent infection.

2. If you have difficulty breathing, fatigue, dizziness, chest pain, edema, etc., you should go to the hospital as soon as possible. For patients diagnosed with restricted cardiomyopathy, it is advisable to avoid fatigue, prevent respiratory infection, quit smoking and alcohol, and maintain a good state of mind. Regularly go to the hospital for review, protect or improve heart function, improve the quality of life, such as severe breathing difficulties, increase in supine, sweating, may be severe cardiac insufficiency, should allow patients to take a sitting position or semi-sitting position, to medical The emergency center calls for help or sends it to a nearby hospital in the safest, smoother, and faster manner. After the onset, it should not go to a doctor who is not properly trained to avoid delay.

3. Strengthen publicity and education to improve the level of understanding of patients with this disease.

Restrictive cardiomyopathy Complications, heart failure, sudden arterial embolism

Ischemic complications often occur in this patient, so patients have a risk of concomitant heart failure and sudden death.

1, heart failure

Heart failure, also known as "myocardial failure", refers to the heart's inability to fight the same blood supply as the venous return and body tissue metabolism, often resulting in a decrease in myocardial contractility caused by various diseases, thereby reducing the blood output of the heart. Not enough to meet the needs of the body, and resulting in a series of symptoms and signs, heart valve disease, coronary atherosclerosis, hypertension, endocrine disorders, bacterial toxins, acute pulmonary infarction, emphysema or other chronic lung diseases can cause Cardiac and heart failure, pregnancy, fatigue, rapid intravenous rehydration, etc. can aggravate the burden of diseased heart, and induce heart failure, heart failure is divided into left heart failure and right heart failure, the main performance of left heart failure For fatigue and fatigue, difficulty breathing, initial labor fatigue, and eventually evolved into difficulty breathing at rest, can only sit breathing, paroxysmal dyspnea is a typical manifestation of left heart failure, more than asleep during sleep, Have chest tightness, shortness of breath, cough, wheezing, especially severe asthma that can develop into acute pulmonary edema Breathing, extreme anxiety and coughing foamy mucus sputum (typically pink foamy sputum), purpura and other symptoms of lung stagnation, right heart failure mainly manifests as lower extremity edema, jugular vein engorgement, loss of appetite, nausea and vomiting, Less urine, nocturia, separation of drinking water and urination.

2, dying

Sudden death refers to accidental death immediately after the onset of acute symptoms or within 24 hours. Most scholars tend to limit the time of sudden death to within 1 hour of onset. The clinical manifestations are mainly cardiac arrest and respiratory arrest, which can occur sequentially. The following symptoms and signs: 1 heart sound disappears; 2 pulse can not reach, blood pressure can not be measured; 3 sudden loss of consciousness, if accompanied by convulsions, called Aspen syndrome, the episode can be self-limiting, can be restored in seconds or 1-2 minutes Long duration can be fatal; 4 breathing intermittent, sigh-like, then stop; 5 coma; 6 pupil dilated, the most important feature of judging cardiac arrest is loss of consciousness and disappearance of aortic pulsation, electrocardiogram of patients with sudden cardiac death There are three types of watches: ventricular fibrillation, sinus rest and cardiac electromechanical separation.

3, arterial embolism

Intracardiac and endocardial myocardial fibrosis, leading to ventricular diastolic dysfunction, filling obstruction, pulmonary circulation and systemic congestion, easy to cause cardiac and peripheral venous thrombosis, once shedding can cause embolism.

4, pericardial effusion

Pericardial effusion of the disease and endocardial and subendocardial myocardial fibrosis, ventricular diastolic limitation, impaired filling, pulmonary circulation and systemic congestion, increased venous pressure, long-term malnutrition in patients with chronic disease may be associated with low protein blood disease.

5, arrhythmia

Restrictive cardiomyopathy complicated with arrhythmia is associated with progressive fibrosis and calcification of subendocardial myocardium. It is more common with sinus tachycardia, atrial flutter or tremor, right bundle branch block and pre-systolic contraction.

Restrictive cardiomyopathy symptoms Common symptoms Fatigue dyspnea jugular vein anger Qiqiqi unknown cause fever Qi ventricular hypertrophy Lower extremity edema dizziness right heart failure

1. General manifestations The onset of this disease is relatively slow, mostly occurs in tropical and temperate zones, tropical is slightly more than temperate, all age groups can be sick, male prevalence is higher than female, male to female ratio is about 3:1, early Only fever, general fatigue, dizziness, shortness of breath, more common in eosinophils, lesions in the left ventricle mainly left heart failure and pulmonary hypertension such as shortness of breath, cough, hemoptysis, lung basal rales, pulmonary artery The second sound of the valve area is hyperthyroidism; the lesions with right ventricle are mainly caused by left ventricular dysfunction, such as jugular vein engorgement, hepatomegaly, lower extremity edema, ascites, etc., pericardial effusion may also exist, visceral embolism is not uncommon.

2. Ventricular dysfunction, right ventricular or biventricular lesions are often dominated by right heart failure, clinical manifestations resemble constrictive pericarditis, left ventricular lesions, due to diastolic limitation, especially in the presence of concurrent mitral regurgitation, There may be significant manifestations of severe left heart failure such as dyspnea and angina pectoris.

3. Signs include abnormal signs of blood vessels and heart, heart beats are often weakened, voiced circles are slightly enlarged, heart sounds are light, heart rate is fast, there may be diastolic galloping and arrhythmia, common jugular vein engorgement, Kussmaul Sign, odd pulse, normal or slightly enlarged heart, the first heart sound is low and blunt, P2 is normal or hyperthyroidism, can smell the gallop and systolic murmur.

Examination of restrictive cardiomyopathy

Blood routine examination: increased blood eosinophils.

1. Electrocardiogram P wave is often high, QRS can be low voltage, ST segment and T wave change are common, arrhythmia such as pre-contraction and bundle branch block can occur, and atrial fibrillation can occur in about 50% of patients.

2. X-ray lesions are prone to invade the right ventricle, about 70% show an increase in the proportion of cardiothoracic, and the heart shadow of the right atrium enlargement may be spherical. When the left ventricle is involved, pulmonary congestion is often seen. In some patients, endocardial calcification is still visible. The angiography showed a reduction in the ventricular cavity.

3. Echocardiography is an important method for the diagnosis of RCM. About 82% of patients show ventricular stenosis, apical occlusion, endocardial echo, atrioventricular valve insufficiency, atrial enlargement and wall thrombus, and mitral leaflets Layer reflex, the posterior lobe often has no activity, the inner diameter of ventricular diastolic can be increased in the early stage, and the E-peak is high-pointed by the acceleration of the mitral blood flow, but the E-peak deceleration time is shortened ( often shortened deceleration time), often 150ms, Doppler blood In the flow chart, the rapid filling in the diastolic phase suddenly stops; in the middle of diastolic, the intraventricular diameter does not continue to expand, the A peak decreases, and the E/A ratio increases. The specific criteria are: E peak 1.0 m / s, A peak 0.5 m / s , E / A ratio 2.0, isovolumic relaxation time shortened 70ms.

4. Cardiac catheterization is an important method to identify RCM and constrictive pericarditis. In half of the cases, the ventricular pressure curve may have a typical "square root" shape change similar to constrictive pericarditis and an increase in right atrial pressure and Y-valley depression. The end-diastolic pressure of the ventricle gradually rises, causing the plateau pattern after subsidence. In the left ventricle, the pulmonary artery pressure can be increased, and in the right ventricle, the right atrial pressure is high, and the v-wave in the right atrial pressure curve is replaced by a. Wave, systolic time interval is not normal, but RCM patients with left and right ventricular diastolic pressure often exceed 5mmHg, right ventricular end-diastolic pressure <1/3 right ventricular systolic pressure, right ventricular systolic pressure often >50mmHg, left ventricular angiography It can be seen that the ventricular cavity is diminished, the apex is obtuse, and there are wall thrombus and mitral regurgitation. The left outdoor shape is smooth but stiff, and the ventricular systolic function is basically normal.

5. Endomyocardial biopsy is an important means of diagnosis of RCM. According to different stages of endocardial myocardium, there may be three pathological changes of necrosis, thrombosis and fibrosis. The endocardium may be attached with thrombus. Acidic granulocytes; endocardium can be inflammation, necrosis, granuloma, fibrosis and other changes; cardiomyocytes can undergo degeneration and necrosis and can be associated with interstitial fibrosis.

Some people have combined endocardial myocardial biopsy with hemodynamic examination results to analyze the characteristics and types of RCM. It is considered that the end-diastolic volume <100ml/m2 and left ventricular end-diastolic pressure>18mmHg are prominent features of primary RCM. A systematic study was performed on patients who met the above-mentioned hemodynamic criteria and underwent endocardial biopsy. The results suggest that:

1 simple restricted type ventricular weight / volume ratio of 1.2g / ml ± 0.5g / ml, ejection fraction of 58% ± 5%, left ventricular end-diastolic volume of 67.5ml / m2 ± 12.6ml / m2, left ventricular end-diastolic pressure 26.7mmHg±3.5mmHg;

2 hypertrophy combined with restricted type ventricular weight / volume ratio of 1.5g / ml ± 0.07g / ml, ejection fraction 62% ± 1%, left ventricular end-diastolic volume 69ml / m2 ± 10ml / m2, left ventricular end-diastolic pressure 30mmHg ± 7mmHg;

3 The ventricular weight/volume ratio of the mild dilatation restriction was 0.9g/ml, the left ventricular end-diastolic volume was 98ml/m2, and the left ventricular end-diastolic pressure was 40mmHg. Histological and electron microscopic observations showed that all types had myocardial and Disorder of myofibrils and endocardial myocardial interstitial fibrosis.

6. CT and magnetic resonance are the most accurate non-invasive methods for the identification of RCM and constrictive pericarditis. RCM patients do not thicken the pericardium, and constrictive pericarditis can be ruled out when pericardial thickness 4mm; Diagnosis of narrow pericarditis.

7. Radionuclide ventriculography The characteristics of right heart type RCM angiography are:

1 The right atrium is obviously enlarged with the retention of nuclide;

2 The right ventricle is displaced to the left, the apex of the right ventricle is unclear, the left ventricle is located at the left rear of the right ventricle, the right ventricular outflow tract is widened, the right ventricle phase is delayed, and the right heart function is decreased;

3 pulmonary imaging is poor, pulmonary nuclides pass time delay;

4 The left ventricle phase and function are generally in the normal range.

Diagnosis and diagnosis of restrictive cardiomyopathy

diagnosis

X-ray examination showed enlarged heart shadow, may see the shadow of endocardial myocardial calcification, ventricular angiography showed ventricular cavity shrinkage, electrocardiogram showed low voltage, atrial or ventricular hypertrophy, bundle branch block, ST-T change, atrial fibrillation There may also be abnormal Q waves in the V1 and V2 leads, endocardial thickening in the echocardiogram, ventricular occlusion in the apex, abnormal echogenicity of the myocardial endocardial structure, and weakened wall motion in the primary The patient's wall does not thicken, the wall of the invasive lesion can be thickened, the early filling of the diastolic is fast, the middle and the late is very slow, the pericardium is generally not thickened, and the cardiac catheterization shows that the end-diastolic pressure of the ventricle gradually rises, resulting in After the subsidence of the platform wave pattern, the pulmonary artery pressure in the left ventricle can be increased, and the right atrial pressure is higher in the right ventricle. The significant v wave in the right atrial pressure curve replaces the a wave, and the systolic time interval is not normal.

Under normal circumstances, the symptoms and signs of RCM are more obvious, there are few misdiagnosis opportunities, the diagnosis points:

1 ventricular cavity and contraction function is normal or close to normal;

2 diastolic dysfunction, ventricular pressure curve showed rapid dilation in early diastolic, and increased in the middle and late stages, plateau;

3 characteristic pathological changes, such as endocardial myocardial fibrosis, eosinophilic endocarditis, cardiac amyloidosis and scleroderma, can be diagnosed.

Differential diagnosis

1. Constrictive pericarditis should be differentiated from constrictive pericarditis in clinical practice, especially restrictive cardiomyopathy with predominantly right ventricular disease. The clinical manifestations are similar. The following points are helpful for the diagnosis of constrictive pericarditis:

1 has a history of active pericarditis;

2 odd pulse;

3 ECG has no atrioventricular conduction disorder;

4CT or MRI showed pericardial thickening;

5 chest X-ray has pericardial calcification;

6 echocardiography shows atrioventricular septal incision, and the coordination of ventricular motion is reduced;

7 ventricular pressure curve is characterized by the left and right ventricular filling pressure is almost equal, the difference <5mmHg;

8 endomyocardial biopsy showed no amyloidosis or other manifestations of myocardial invasive disease.

2. Hypertrophic cardiomyopathy Hypertrophic cardiomyopathy ventricular muscle may be symmetric or asymmetric thickening, ventricular diastolic compliance decreased, diastolic blood pressure increased, patients often have difficulty breathing, chest pain, syncope, obstructive hypertrophy Cardiomyopathy can be heard and contraction, late jet murmur, often accompanied by tremor, the intensity of murmur is related to drug and body position, echocardiographic lesions mainly involve ventricular septum, this disease has no RCM-specific early diastolic rapid filling and relaxation Medium and late filling characteristics are helpful for identification.

3. Ischemic cardiomyopathy and hypertensive cardiac hypertrophy can have different degrees of myocardial fibrosis in both cases, and have reduced ventricular compliance, increased end-diastolic pressure and decreased cardiac output and RCM Similar performance, but ischemic cardiomyopathy has clear evidence of coronary artery disease, coronary angiography can confirm the diagnosis; hypertensive cardiac hypertrophy has a long history of high blood pressure and left ventricular dysfunction; in addition, both clinically It is characterized by left heart involvement and left ventricular dysfunction, while RCM is often more prominent with chronic right heart failure.

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