What Is Nocardiosis?

Cardiomyopathy is a group of heterogeneous cardiomyopathy, caused by abnormal causes of mechanical and electrical activity of the heart, manifested as inappropriate hypertrophy or dilatation of the ventricle. Severe cardiomyopathy can cause cardiovascular death or progressive heart failure. Cardiomyopathy is usually divided into primary cardiomyopathy and secondary cardiomyopathy, of which primary cardiomyopathy includes dilated cardiomyopathy, hypertrophic cardiomyopathy, restricted cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and untyped cardiac disease. Secondary cardiomyopathy refers to cardiomyopathy as part of a systemic disease.

Basic Information

English name

Cardiomyopathies

Visiting department

Cardiology, Cardiac Surgery

Multiple groups

More common in people aged 20-50

Common locations

heart

Common causes

Unknown etiology, infection, metabolic cause, endocrine cause, tuberculosis disease, etc.

Common symptoms

Palpitations, fatigue, dyspnea, edema

Causes of Cardiomyopathy

The occurrence of cardiomyopathy is related to many factors. The cause of primary cardiomyopathy is unknown. Secondary cardiomyopathy is mainly related to infection, metabolic disease, endocrine disease, ischemia, allergy and other factors.

Primary cardiomyopathy

The cause of primary cardiomyopathy is not very clear.

2. Secondary cardiomyopathy

The common causes are as follows:

(1) Infectious causes: It is more common in severe bacterial, viral, rickettsia, and protozoan infections. Bacteria or viruses directly invade the heart muscle, or their toxins affect the heart muscle, causing cardiomyopathy, which is called post-myocarditis cardiomyopathy.

(2) Metabolic causes: The most common is cardiomyopathy caused by diabetes. Followed by familial glycogen accumulation, beriberi heart disease, alcoholic cardiomyopathy, cardiac amyloidosis and other myocardial changes.

(3) Endocrine causes: Commonly there are hyperthyroidism, hypothyroidism, acromegaly and other causes of myocardial disease.

(4) Connective tissue disease: It is more common in myocardial damage caused by lupus erythematosus, rheumatoid arthritis, and scleroderma.

(5) Ischemic causes: mainly refers to myocardial ischemic changes caused by coronary atherosclerosis and coronary spasm, leading to myocardial disease.

(6) Causes of allergies: Myocardial changes caused by allergies to sulfa drugs, penicillin and other drugs.

(7) Causes of toxicity: burns, diphtheria, typhoid and other bacterial toxins directly damage the myocardium and cause cardiomyopathy.

Cardiomyopathy classification

Divided into primary cardiomyopathy and secondary cardiomyopathy.

Primary cardiomyopathy

Primary cardiomyopathy refers to a kind of myocardial damage whose cause is not very clear, which causes the heart to enlarge and eventually develop into a heart disease with heart failure. Generally speaking, cardiomyopathy refers to primary cardiomyopathy.

Classified according to etiology and pathology, they are divided into three types:

(1) Dilated cardiomyopathy is characterized by ventricular dilatation. Congestive heart failure often occurs, so it is also called congestive cardiomyopathy. The most common, accounting for 70% to 80% of cardiomyopathy.

(2) Hypertrophic cardiomyopathy is characterized by ventricular hypertrophy. Because many patients have ventricular outflow tract obstruction due to asymmetric hypertrophy of the ventricular septum, it was previously referred to as obstructive cardiomyopathy. In fact, some patients have cardiac hypertrophy but do not cause obstruction. This type accounts for 10% to 20%.

(3) Restrictive cardiomyopathy is characterized by the formation of endocardial myocardial scars, and the ventricular cavity may be occluded. In the past, the formation of myocardial scars without hypertrophy was restricted cardiomyopathy; the ventricular cavity was closed due to fibrous hyperplasia and mural thrombus as occlusive cardiomyopathy. These two conditions are now combined into restricted cardiomyopathy.

For patients who cannot be classified into the above types, have mild abnormalities, and progress or do not progress to significant cardiomyopathy, they are included in "undefined cardiomyopathy" or "occult cardiomyopathy".

2. Secondary cardiomyopathy

Secondary cardiomyopathy, also known as "specific cardiomyopathy," refers to changes in the myocardium caused by a known cause or after other diseases.

Clinical manifestations of cardiomyopathy

The clinical manifestations of cardiomyopathy caused by different reasons are slightly different.

Dilated cardiomyopathy

Mostly middle-aged people. Onset is usually slow, sometimes reaching more than 10 years. Symptoms are congestive heart failure, of which shortness of breath and edema are the most common. Shortness of breath initially after work or exertion, shortness of breath during mild activities or rest, or paroxysmal dyspnea at night. Patients often feel weak.

Physical examination showed that the heart rate increased, the apex beat shifted to the left and left, there could be a lifting beat, the heart dullness circle expanded to the left, and the third or fourth sound was often audible. Due to the enlargement of the heart cavity, there may be systolic whistle-like murmurs caused by relative mitral or tricuspid valve insufficiency. Such murmurs are alleviated after cardiac function is improved. In advanced cases, the blood pressure is reduced, the pulse pressure is small, and the diastolic blood pressure may be slightly increased when heart failure occurs. The presence of alternating pulses suggests left heart failure. Pulse is often weak.

There can be snoring sounds in both lungs during heart failure. In right heart failure, the liver swells and the edema begins in the lower limbs. In the later stage, there may be pleural and abdominal effusions and various arrhythmias. High atrioventricular block, ventricular fibrillation, and sinoatrial block can lead to A-S syndrome. Sign, one of the causes of death. In addition, there may be embolism in the brain, kidney and lung.

2. Hypertrophic cardiomyopathy

It can be asymptomatic, palpitations, exertional dyspnea, anxiety in the precardiac area, fatigue, syncope, or even sudden death, and the symptoms of left heart failure in the later stages. Patients with obstructive hypertrophic myocardium may have rough contractions in the left margin of the sternum, with mid-to-late jetting murmurs, which may be associated with tremors. Digitalis, nitroglycerin, isoproterenol, and Valsalva may increase murmur after action, otherwise use beta receptors. Blockers, norepinephrine, and murmur are reduced when squatting. Some patients have heard S3 and S4 heart sounds and systolic murmurs of apical relative mitral regurgitation.

3. Restricted cardiomyopathy

Weakness, dyspnea and decreased exercise tolerance are common complaints of restrictive cardiomyopathy. In severe cases, symptoms of edema, sitting breathing, liver enlargement, oliguria, ascites, and digestive tract congestion may occur.

Physical examination revealed low blood pressure, small pulse pressure difference, jugular venous distension, and positive Kussmaul sign (increased venous pressure during inspiration). Heart dullness is enlarged, arrhythmia, third heart sound, fourth heart sound can be heard. When mitral and tricuspid regurgitation is combined, mitral and tricuspid regurgitation murmurs are often heard. Wet murmurs can be heard in both lungs. Enlarged liver and sometimes ascites. Edema of both lower limbs.

Cardiomyopathy examination

ECG, X-ray, echocardiography, cardiac catheterization, endocardial myocardial biopsy, CT and magnetic resonance, radionuclide ventriculography, etc.

Cardiomyopathy diagnosis

Diagnosable by understanding medical history, physical examination and electrocardiogram, X-ray, echocardiography, cardiac catheterization, endocardial myocardial biopsy, CT and magnetic resonance, radionuclide ventriculography

Cardiomyopathy

Mainly for the cause of the treatment and symptomatic treatment.

Dilated cardiomyopathy

(1) Principles of treatment

1) Maintain normal rest, use sedatives if necessary, and low-salt diets for heart failure.

2) Prevention and treatment of arrhythmia and cardiac insufficiency.

3) Those with a history of embolism were treated with anticoagulation.

4) If there is a large amount of pleural effusion, pleural puncture is performed.

5) Severe patients can consider artificial heart assist devices or heart transplantation, and can perform heart resynchronization therapy.

6) Symptomatic and supportive treatment.

(2) Heart failure treatment

1) It is necessary to pay great attention to rest and avoid fatigue. If the heart is enlarged and the heart function is reduced, more attention should be paid and long-term rest should be taken to prevent the condition from worsening.

2) Patients with heart failure use heart-strengthening drugs, diuretics and vasodilators. Due to the extensive myocardial damage, digitalis and diuretics are beneficial; hydrochlorothiazide may fail during low glomerular filtration. At this time, diuretics such as furosemide should be used. Vasodilators, such as angiotensin-converting enzyme inhibitors. Be sure to start with small doses, taking care to avoid hypotension. The use of beta-blockers when heart failure is stable is beneficial to improving the prognosis.

3) Arrhythmias, especially those with symptoms, should be treated with antiarrhythmic drugs or electrical methods. Those with rapid ventricular rhythm and high atrioventricular block and who are at risk of sudden death should be actively treated.

4) Oral anticoagulants or antiplatelet aggregation drugs can be used to prevent embolic complications.

5) For long-term heart failure, those who have failed medical treatment should consider heart transplantation, actively control infection after surgery, improve immunosuppression, and correct rejection. The survival rate can reach more than 85% after 1 year.

(3) Precautions for medication

1) Myocardial disease is sensitive to digitalis drugs, the application dose should be small, and pay attention to toxic reactions, or use non-cardioside positive inotropic drugs.

2) Electrolyte balance must be observed during diuretic application.

3) When using heart rate-inhibiting drugs or electrocardiac tachyarrhythmias, one should be alert to the possibility of sick sinus syndrome.

4) A permanent artificial pacemaker can be installed in patients with chronic complete atrioventricular block and sick sinus syndrome.

5) During the application of antiarrhythmic drugs, the ECG should be reviewed regularly.

6) During the use of anticoagulants, pay attention to bleeding performance, and regularly check the clotting time, prothrombin time and INR.

(4) Special treatment

Heart transplantation for dilated cardiomyopathy can prolong life. After heart transplantation, the prognosis is greatly improved.

2. Hypertrophic cardiomyopathy

(1) General treatment

1) Temporary observation of asymptomatic patients with indistinct ventricular hypertrophy and normal ECG.

2) Avoid strenuous exercise, especially competitive sports and emotional tension.

(2) Drug treatment

Avoid the use of digitalis preparations, nitroglycerin, isoprenaline and other drugs.

1) Beta-blockers: propranolol, aminoacid, metoprolol, bisoprolol.

2) Calcium antagonists: Isoptin, thiazezone.

3) Diuretics and vasodilators can be used for anti-heart failure treatment (end stage).

4) Antiarrhythmia: amiodarone and diisopropylamine have antiarrhythmic and negative muscle strength effects.

(3) Ventricular septal resection

Ineffective for drug treatment, severe obstruction of left ventricular outflow tract is applicable.

(4) Double-chamber pacing

The prognosis is uncertain.

(5) Percutaneous transluminal myocardial chemical ablation

It is a new method for treating hypertrophic cardiomyopathy in recent years by injecting absolute alcohol through the catheter into the septal branches of the supply compartment septal myocardial tissue, causing artificial septal myocardial infarction to relieve left ventricular outflow obstruction.

(6) Prevention of sudden death

For high-risk patients, in addition to avoiding strenuous exercise and medication, an implantable cardioverter defibrillator should be installed.

3. Restricted cardiomyopathy

(1) Cause treatment

For restricted cardiomyopathy with a clear cause, the primary disease should be treated first. For patients with eosinophilic syndrome, eosinophilia is the initiating factor of the disease, causing secondary, inflammation, necrosis, mural thrombosis, and embolism in endocardium and subendocardial myocytes. change. Therefore, the treatment of eosinophilia is very important to control the progress of the disease. Glucocorticoids (prednisone) and cytotoxic drugs can effectively reduce eosinophils and prevent the progression of intimal myocardial fibrosis. Restricted cardiomyopathy caused by deficiency of some genetic-related enzymes can also be performed with enzyme replacement therapy and gene therapy.

(2) symptomatic treatment

1) Reduce ventricular filling pressure Nitrate drugs and diuretics can effectively reduce preload, reduce pulmonary circulation and systemic circulation congestion, reduce ventricular filling pressure, reduce symptoms, improve patients' quality of life and activity tolerance, but can not improve the long-term prognosis of patients. However, it should be noted that the myocardial stiffness of patients with restricted cardiomyopathy increases, and changes in blood pressure are greatly affected by changes in ventricular filling pressure. Excessive reduction of preload will cause decreased cardiac output, decreased blood pressure, and worsened disease, so nitrate drugs And diuretics should be used as appropriate according to the patient's situation. Beta blockers can slow heart rate, prolong ventricular filling time, reduce myocardial oxygen consumption, and help improve ventricular diastolic function. They can be used as adjuvant drugs, but their role in the treatment of restricted cardiomyopathy is uncertain.

2) Digitalis drugs with limited diastolic function have no obvious effect, but they can be used to control ventricular rate during atrial fibrillation. For atrial fibrillation, amiodarone can also be used for oral prevention. However, antiarrhythmic drugs are not effective in preventing sudden death in patients with restricted cardiomyopathy and can also be treated with ICD.

3) Anticoagulation treatment The disease is prone to mural thrombosis and embolism. Anticoagulation or antiplatelet therapy can be given.

(3) Surgical treatment

For severe endocardial myocardial fibrosis, endocardial ablation can be performed to remove fibrous endocardium. With valve regurgitation, prosthetic valve replacement is feasible. Thrombectomy was performed for patients with mural thrombus. The operative mortality rate is 20%. For patients with idiopathic or familial restrictive cardiomyopathy with refractory heart failure, heart transplantation may be considered. Studies have shown that children with restricted cardiomyopathy still have a greater risk of sudden death, even if they do not have obvious symptoms of heart failure. Therefore, it is advocated that early transplantation of heart-diagnosed children can improve the prognosis.

4. Secondary cardiomyopathy

Mainly for etiological treatment.