Heart muscle disease (cardiomyopathy and inflammation)
Diseases of the heart muscle, as opposed to problems with the heart’s blood supply » are called cardiomyopathies (CMP). These conditions are a frequent cause of heart failure. CMPs are, by definition, not caused by a narrowing of the arteries (coronary artery disease) which reduce the blood supply to the heart muscle (ischemia) and lead to reduced cardiac function as well as a heart attack (myocardial infarction). This is commonly referred to as ischemic cardiomyopathy in contrast to true CMPs which are caused either by genetic mutations or by acquired causes such as infections, chemotherapy, systemic/auto-immune diseases or alcohol/drug abuse. CMPs are usually of three types.
Dilated CMP includes patients who have reduced cardiac function accompanied by dilatation of the main pumping chamber or ventricle.
Hypertrophic CMP is associated with thickening and stiffening of the muscle of the main pumping chamber, the left ventricle. Arrhythmogenic CMP is associated with severe heart rhythm disturbances.
Genetic CMP is caused by an inborn genetic error affecting the structure or function of genes that control the heart’s development. Symptoms may be obvious from birth or may have a delayed onset in adolescence. As these genetic CMPs affect relatively young individuals (median age of 45 -50 years), the economic and emotional consequences of genetic CMP are especially important.
The diagnosis of a CMP must also consist of in-depth searches for uncovering acquired causes (e.g. previous chemotherapy), genetic counseling and testing, imaging, blood samples and, where indicated, cardiac sampling (biopsies) which are performed at specialized reference centers.
When to suspect a genetically acquired heart muscle disease:
- Presence in your family of unexplained heart failure, cardiac rhythm disturbances, sudden death, or any other general muscle disease at a young age < 55 years.
Unexplained fainting (syncope), shortness of breath (dyspnoea?), chest pain or abnormal electrocardiogram
Which diagnostic test to expect when going to a cardiologist for the diagnosis of your heart disease?
- Collecting information including familial history, recent infections (Lyme disease, viral infections), toxic causes (alcohol, chemotherapy, drug abuse), systemic diseases (inflammation, diseases, or complaints in other organs, including kidney, liver, joints, lungs)
- Blood sampling to test the function of other organs.
- Cardiac imaging: electrocardiogram (ECG), echocardiography, and magnetic resonance imaging (MRI) to look for structure, function, inflammation and scarring in the heart.
The treatment of CMP consists of removing or treating the underlying causes (e.g. chemotherapy, alcohol, or infections), and in addition the prescription of appropriate heart failure drugs. Promising novel treatment approaches are being researched based on an in-depth understanding of molecular changes in the heart. Overall, life expectancy is good, as most patients are young and usually do not have other diseases.