Dilatative cardiomyopathy

Dilatative cardiomyopathy: description

Dilated Cardiomyopathy (DCM) is a serious condition in which left ventricular muscle changes its structure. It does not work properly anymore and thus the heart pumps less blood into the systemic circulation during the systole. In addition, the heart muscle usually can not relax properly, so that the phase in which the heart chambers fill with blood (diastole) and expand, is also disturbed.

This form of cardiomyopathy got its name because in the disease, the left ventricle dilated greatly, thus expanding. If the disease progresses, the right ventricle and the atria may also be affected. The heart walls may become thinner as they expand.

Who is a dilated cardiomyopathy?

Dilated cardiomyopathy is one of the most common forms of heart muscle disease. In Germany, it is detected annually in about 6 out of 100,000 people. But because there are also courses in which those affected do not notice any symptoms, one estimates the actual morbidity rate significantly higher. Most patients are diagnosed between the ages of 20 and 40 with men being two to three times more likely to be affected than women.

Dilatative cardiomyopathy: symptoms

Patients with DCM often have the typical symptoms of heart failure (heart failure). On the one hand, because of its limited performance, the heart does not manage to supply the body with sufficient blood and oxygen – doctors speak of a forward failure.

In addition, a heart failure is usually associated with a backward failure. That is, it accumulates the blood in those blood vessels that lead to the heart. As long as only the left heart is affected (left heart failure), such a congestion arises especially in the lungs. If the right ventricle is also weakened, the blood in the venous vessels, which come from the entire body, accumulates.

Dilated cardiomyopathy first becomes noticeable with the symptoms of progressive left ventricular failure. Patients suffer from:

• Fatigue and reduced performance. The sufferers often complain of a general feeling of weakness.
• Shortness of breath during exercise (exertional dyspnoea). If the cardiomyopathy is already very advanced, respiratory distress can also occur at rest (Ruhedyspnoe).
• Pulmonary congestion (pulmonary edema), which may increase the respiratory distress. You may notice a pulmonary edema due to rattle sounds when breathing.
• a tightness of the chest (angina pectoris). This feeling also appears above all during physical exertion.

During the course of the disease, dilated cardiomyopathy often also affects the right ventricle. In such cases, physicians speak of a global insufficiency. In addition to the symptoms of left ventricular failure, patients then complain of fluid retention (edema), especially in the legs. In addition, the jugular veins often stand out because it also backs up blood from the head and neck, which can not be sufficiently pumped from the heart into the circulation.

As the structure of the heart muscle changes in a DCM, the electrical stimulation and transmission of the heart is disturbed. Therefore, the disease is often associated with cardiac arrhythmia. Those affected sometimes feel this as heart stuttering (palpitations). As the disease progresses, arrhythmias can become more dangerous, causing circulatory collapse or, in the worst case, even sudden cardiac death.

Due to impaired blood flow in the atria and ventricles, blood clots are more likely to form in dilated cardiomyopathy than in healthy people. If such a clot dissolves, it can enter the arteries with the bloodstream and close them. This can lead to serious complications such as a pulmonary infarction or stroke.

Dilatative cardiomyopathy: causes and risk factors

Dilated cardiomyopathy may be primary or secondary. Primarily, it arises directly in the heart muscle and is limited to it. In secondary forms, other diseases or external influences are the trigger of the DCM. Heart or other organs are then damaged only as a result of these factors.

Primary dilated cardiomyopathy is genetically determined in some cases. In about a quarter of the diseases, other family members are affected. Often the triggers are a primary DCM but also unknown (idiopathic).

Dilated cardiomyopathy is a form of heart muscle disease that is relatively secondary. The triggers include, for example:

• long-term, excessive alcohol consumption and drug use (such as cocaine). Alcohol abuse is one of the main risk factors for dilated cardiomyopathy.
• a myocarditis caused by viruses or bacteria (examples: Chagas disease, Lyme disease).
• Valvular heart disease
• Autoimmune diseases, e.g. Systemic lupus erythematosus (SLE).
• Hormone disorders (especially the growth and thyroid hormones)
• Medicines: Certain anticancer drugs (cytostatics) can cause a rare side effect of a dilated heart muscle disease.
• malnutrition
• Radiotherapy in the thorax
• congenital disorders involving muscle protein synthesis, e.g. Muscular dystrophies.
• Environmental toxins: Above all, heavy metals such as lead or mercury accumulate in the heart muscle and interfere with cell metabolism.
• chronic but high pressure
• a coronary heart disease (CHD). In those affected, the heart muscle permanently gets too little oxygen and therefore changes its structure (ischemic cardiomyopathy). Guilt is a constriction of the coronary arteries.
• In very rare cases, dilated cardiomyopathy occurs during pregnancy. The connections are still unclear here.

According to recent definitions, only heart muscle diseases belong to the cardiomyopathies that are not a direct consequence of other cardiovascular diseases. Accordingly, ischemic cardiomyopathy should not be considered as dilated cardiomyopathy. However, in some textbooks they are still considered a secondary DCM.

Dilatative cardiomyopathy: examinations and diagnosis

First, the doctor interviews the patient about his medical history (anamnesis). Above all, he is interested in the symptoms of the patient, when these occur and how long they already exist. Of importance is also whether the patient drinks a lot of alcohol, other drugs, or already has other diseases.

The conversation is followed by a physical examination. Some signs of heart failure, the doctor can already see with the naked eye. For example, the skin of those affected often appears bluish (cyanosis) due to the chronic lack of oxygen. Pulmonary edema may be a rattle noise when listening to the lungs.

Many heart muscle diseases show similar symptoms. In order to be able to determine exactly what type of cardiomyopathy is present, it requires special diagnostics and the support of medical devices. The most important investigations are:

• Cardiac ultrasound (echocardiography). In the case of the DCM, the extended left ventricle is particularly noticeable. The heart walls may be thinner than normal.
• Electrocardiogram (ECG). Many DCM patients have a specific electrical cardiac activity disorder on the ECG called left bundle branch block.
• X-ray of the ribcage. Because of the enlarged left ventricle, the heart appears enlarged on x-rays (cardiomegaly). Even a pulmonary congestion can be seen so.
• Cardiac catheterization. Within the scope of this diagnostic method one can examine the coronary vessels (coronary angiography) and take tissue samples from the heart muscle (myocardial biopsy). The subsequent examination of the tissue under the microscope allows an accurate diagnosis.

There are also certain blood levels that may be elevated in connection with a DCM. These findings are not specific, but occur in many heart and other diseases. For example, high BNP levels generally indicate heart failure.

Dilatative cardiomyopathy: treatment

If possible, one tries to treat the cause of dilated cardiomyopathy. For example, viruses are fought if they are the cause of a heart attack, or possible hormone disorders are compensated. If alcohol or drugs are responsible for a DCM, the patient must avoid these harmful substances.

If the cause is not known and / or not treated, then only symptomatic treatment of DCM is possible. Priority is then to alleviate the symptoms of heart failure and delay their progress as possible. There are various drug groups such as beta-blockers, ACE inhibitors and diuretics available. Blood-thinning drugs are designed to prevent blood clots from forming.

Basically, patients with a dilated cardiomyopathy should take care of themselves, so as not to overwhelm the weak heart.

In an advanced DCM, it often makes sense to use the patient with a pacemaker (ICD implantation). This can prevent massive cardiac arrhythmias leading to sudden cardiac death. If the heart is severely damaged and there is no other way to help the patient, the last treatment option is a heart transplant.

Dilatative cardiomyopathy: disease course and prognosis

The disease prognosis is unfavorable for dilated cardiomyopathy. Life expectancy and disease progression depend on the degree of heart failure. With the appropriate medication, you can support the heart, but not stop the disease progress or even undo. A DCM restricts the everyday life of those affected more and more.

Within the first ten years after diagnosis, 85 to 90 percent of patients die from DCM. Often the consequences of heart failure or sudden cardiac death are the cause.

The patients themselves can hardly influence the disease history. But those who refrain from drugs and enjoy alcohol in moderation avoid at least two risk factors for one dilated cardiomyopathy.