Cardiomyopathies

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Cardiomyopathies are a group of different diseases in which the heart muscle is damaged. They can affect people of all ages, including children. Due to the different forms of the disease, it is not possible to say which age group is particularly affected or whether cardiomyopathies are more common in men or women. However, many of these diseases occur more frequently in individual families because they are caused by genetic alterations.

Clinical picture

In all forms of cardiomyopathy, the structure of the heart muscle tissue changes and the heart is not as efficient as a pump. In most cases there is an inappropriate thickening or dilatation of one or both chambers of the heart. Cardiomyopathies can lead to heart failure and arrhythmia. In the course of this often serious disease, heart muscle damage gets progressively worse, over time. In people under the age of 55, heart muscle diseases are the main cause of heart transplantation.

Since the heart can only pump to a limited extent, patients often have the typical symptoms of heart failure: they feel tired, weak and no longer able to perform as well. Fluid accumulation in the lungs and body tissues, for example in the arms and legs, can occur because the blood accumulates in veins and lungs. Symptoms can be distributed differently, depending on which heart muscle disease is present and may go unnoticed for years.

Causes

Cardiomyopathies are often genetic, although it is not always known which genes are altered. The American Heart Association (AHA) classifies cardiomyopathies into primary and secondary heart muscle diseases. Primary cardiomyopathies include genetic cardiomyopathies (for example, hypertrophic cardiomyopathies), mixed (genetic and acquired) cardiomyopathies (for example, dilated cardiomyopathies) and acquired primary cardiomyopathies (for example, as a result of myocarditis). Secondary cardiomyopathies arise from diseases that can affect the entire body. These include storage, metabolic or connective tissue disorders. Secondary cardiomyopathies can also be caused by the damaging effect of various substances (e.g. drugs, medicines, chemicals). A distinction is also made between ischemic and non-ischemic cardiomyopathies. Ischemic cardiomyopathies are caused by circulatory disorders in the heart, for example as a result of severely narrowed coronary vessels (coronary heart disease).

Two examples of cardiomyopathies:

Dilated cardiomyopathy

In dilated cardiomyopathy, the ventricles and atria are dilated. As a result, the heart can no longer pump properly and the patients suffer from the typical symptoms of heart failure: they are no longer able to perform their work, have difficulty breathing and water retention in the lungs and legs occurs. Heart rhythm disturbances and dizziness can also occur. Dilated cardiomyopathy is triggered by various events: For example, infectious myocarditis with bacteria, viruses or parasites or coronary heart disease. Genetic mutations are assumed to be present in about one third of cases, running in families. Drugs, especially chemotherapeutic agents, can also lead to the pathogenic remodelling processes in the heart. Despite comprehensive diagnostics, no clear cause can be found in some of the patients, who are then referred to as idiopathic dilated cardiomyopathy.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is also a common heart muscle disease and occurs in approximately one in 500 people - both men and women are affected. The causes are inherited faulty genes. The probability that a child will inherit the predisposition for HCM from their parent with HCM is 50 per cent. In hypertrophic cardiomyopathy, the heart muscle is thickened, usually affecting the left ventricle. HCM is divided into an obstructive and a non-obstructive form. In the obstructive form the thickened heart muscle causes an obstruction of the outflow of blood from the heart to the aorta. HCM often goes unnoticed, but can manifest itself as chest pain, shortness of breath or fatigue. In young people, especially athletes, it is the most common cause of sudden cardiac death.

Therapy

Since little is known about the development and course of the many forms of the disease, the treatment of cardiomyopathy is mainly concerned with alleviating the symptoms. Especially in the obstructive form, there are numerous drugs (e.g. beta blockers), interventional procedures (sclerotherapy of thickened heart muscle tissue by injection of alcohol, septal ablation) and surgical interventions (surgical removal of heart muscle tissue, septal myectomy) available. If there is a risk of sudden cardiac death, the implantation of a cardioverter defibrillator may become necessary. Patients should avoid intensive physical exercise, but in consultation with the treating physicians, moderate physical exercise is possible and even recommended.

The DZHK Register TORCH contains medical and socio-demographic data of patients suffering from a heart muscle disease which is hereditary or caused by inflammation. Too little is still known about the exact mechanisms by which these diseases develop. At the end of 2017, the 20 centres involved in TORCH were able to complete the first phase, in which data and samples from 2,300 patients were collected over a period of three years. The scientists are now evaluating the data and thus creating the prerequisites for new therapies and better diagnostic possibilities for these cardiomyopathies.


Information regarding further Cardiovascular Diseases

Find information on the most important cardiovascular diseases researched at the DZHK and tips for their prevention.

Please note: The articles contain only general information and must not be used for self-diagnosis or self-treatment. They cannot replace a visit to the doctor.


DZHK studies on cardiomyopathies

The DZHK wants to achieve that cardiovascular diseases can be better detected and treated. Clinical studies are indispensable to achieve progress in this area. This is why the DZHK supports this research.

TORCH-DZHK1 – Translational registry for cardiomyopathies