Cardiomyopathy

Doctors refer to a whole group of diseases as cardiomyopathies in which the heart muscle, the myocardium, is affected. The colloquial term is a heart muscle disease.

The word cardiomyopathy is derived from Greek. “Cardio” stands for heart, “myo” for muscle, and “pathie” for sick. Cardiomyopathy is a collective term for various heart diseases. A common feature of these diseases are changes in the heart muscle (myocardium), which are associated with a decline in cardiac output.

Cardiomyopathies are almost always very serious diseases which, without appropriate therapy, lead to heart failure.

Forms Of Cardiomyopathy

There are a number of cardiomyopathies. First of all, medical professionals differentiate between primary and secondary cardiomyopathies. Primary cardiomyopathies are caused by a disease or congenital malformation of the heart muscle. If other diseases affect the myocardium, doctors speak of secondary cardiomyopathies. In addition to the pure forms, there are also mixed forms.

Furthermore, medical professionals divide cardiomyopathies into four main types.

    • dilated cardiomyopathy
    • hypertrophic cardiomyopathy
    • restrictive cardiomyopathy
    • arrhythmogenic right ventricular cardiomyopathy (ARVC).

There are also other sub-forms such as

    • Non-compaction cardiomyopathy
    • Broken Heart Syndrome (Tako Tsubo Cardiomyopathy, Broken Heart Syndrome)
    • hypertensive cardiomyopathy (damage to the heart muscle caused by high blood pressure)

Frequency

By far the most common form is hypertrophic cardiomyopathy. There are around 200 cases for every 100,000 inhabitants (prevalence). The number of new cases per 100,000 inhabitants per year (annual incidence) is 19.

The second most common form is dilated cardiomyopathy, with a prevalence of 40 cases per 100,000 population and an annual incidence of 6 new cases.

Cardiomyopathies affect people of all ages. However, there are frequency peaks between 20 and 50 years on average for all forms. In men, the incidence is about twice as high as in women.

Symptoms

The common symptom of all cardiomyopathies is a more or less restricted beating and pumping power of the heart. Heart failure often occurs as the disease progresses. In the case of some heart muscle diseases, the symptoms resemble the symptoms of cardiac insufficiency at the onset of cardiomyopathy.

Complications

Cardiomyopathies are often very slow to develop and therefore often go unnoticed for many years. Without timely diagnosis and suitable therapy, the cardiac output – and with it the oxygen supply to the body – continues to decline.

The human heart is a very finely tuned system. When a component like the heart muscle itself changes, it has a variety of possible effects. An example: In the case of an emerging cardiac insufficiency, the heart compensates for the decreasing impact force by increasing the frequency and strength of the impact. This increases the mass of the heart muscle. If the heart muscle becomes too thick (heart muscle hypertrophy), mobility is restricted on the one hand. In addition, the blood flow in the heart changes. This can promote blood clots, which in turn can trigger a pulmonary embolism.

The extremely sensitive heart valves are also endangered by myocardial growth. Any heart valve defects increase the risk of heart failure.

Sometimes the heart expands as a result of the additional stress caused by cardiomyopathies, doctors speak of dilation. Then the heart chambers literally wear out. As a result, the heart’s pumping power and ejection performance drop drastically.

But cardiomyopathies also disrupt the heart’s excitation lines. This is a possible cause of cardiac arrhythmias, which can lead to ventricular fibrillation and sudden cardiac death.

Cardiomyopathy

Causes

Many primary cardiomyopathies are congenital. This does not necessarily mean that the heart muscle changes exist from birth. They can also only develop over the years. Most common, however, are primary cardiomyopathies with no apparent cause. In this case, medical professionals speak of idiopathic cardiomyopathies.

There are also acquired primary heart muscle diseases and secondary cardiomyopathies.

Acquired primary cardiomyopathies result from other diseases or are sometimes the result of pregnancy. Examples of such causes are:

    • Viral infections, such as a badly healed cold or flu, can lead to viral myocarditis. Infections with the mump pathogen during childbirth sometimes cause restrictive cardiomyopathy in children for years afterward.
    • Bacterial infections such as repeated inflammation of the inner lining of the heart also cause cardiomyopathies. Typical bacterial pathogens that cause myocardial disease are meningococci, streptococci, and diphtheria bacteria.
    • Fungi and parasites such as candida infections or toxoplasmosis
    • Tumor diseases
    • autoimmune connective tissue diseases such as scleroderma or sarcoid
    • Damage to the heart muscle due to deposits of foreign substances or metabolic products such as amyloidosis or hemochromatosis (iron storage disease)
    • Alcohol and drug abuse (toxic cardiomyopathy)
    • increased stress from pregnancy or competitive sport
    • Postmenopause or increased emotional stress (stress cardiomyopathy or, colloquially, broken heart syndrome).

Many other causes are conceivable, depending on the type of cardiomyopathy.

Secondary cardiomyopathies are mostly caused by other conditions. These can be congenital or acquired. Cause here are, for example, toxic substances, storage diseases, endocrine functional disorders, neurological and neuromuscular changes, autoimmune processes, drugs (especially chemotherapeutic agents), or malnutrition.

Examination

General practitioners, cardiologists, or internists usually suspect cardiomyopathy on the basis of declining physical performance. In pronounced cases, shortness of breath, blue discoloration of the skin (cyanosis), or water retention in the legs (edema) speak for themselves.

The diagnosis of cardiomyopathy is initially confirmed by an electrocardiogram (EKG, recording of heart activity), an X-ray of the chest, and an ultrasound examination of the heart (echocardiography). If the initial suspicion is confirmed, a cardiac catheter examination usually follows. During this procedure, a small piece of myocardial tissue is secured (biopsy) in order to better determine the exact type of cardiomyopathy.

Imaging methods such as computer and magnetic resonance tomography, stress tests, and rhythm diagnostics provide additional insights.

Treatment

Once the cause of the cardiomyopathy can be identified, the first step in therapy is to eliminate the causes. Often, however, therapy for heart muscle disease is limited to relieving symptoms and stopping the progression of cardiomyopathy.

Medical therapy

One of the most important goals of drug therapy for cardiomyopathies is to prevent the development or progression of cardiac insufficiency. For this purpose, drugs are used that relieve and strengthen the heart. It is not uncommon for several active ingredients to be combined.

Beta Blockers

The most commonly used active ingredients for the symptomatic therapy of heart failure come from the group of beta-blockers. Beta-blockers block activating hormones like adrenaline and northern adrenaline. Among other things, this causes the heart’s resting frequency to normalize and the blood vessels to expand. This lowers blood pressure, improves blood circulation and oxygen supply, and relieves the heart. They also reduce the excitability of the heart muscle.

Many used beta-blockers are bisoprolol and metoprolol.

Beta Blockers

ACE inhibitors block the action of the angiotensin-converting enzyme (ACE). This enzyme plays a key role in regulating blood pressure and water balance. ACE inhibitors such as benazepril, captopril, ramipril or zofenopril relieve the heart by widening blood vessels and thus lowering high blood pressure. At the same time, they help promote water excretion. This reduces the blood volume and the heart is relieved.

The excretion-promoting effect of ACE inhibitors is in many cases insufficient to relieve the heart of blood volume and to flush out edema caused by cardiac insufficiency. This task is carried out by the so-called water tablets (diuretics) such as hydrochlorothiazide, spironolactone and furosemide.

Antiarrhythmics

Antiarrhythmics are agents that normalize the heartbeat. As a rule, the aim is to slow down an accelerated heartbeat (tachycardia). Active ingredients such as ajmaline, flecainide, or phenytoin achieve this effect, among other things, by blocking the flow of sodium ions into the cells.

Other antiarrhythmics include potassium channel blockers such as amiodarone and sotalol and calcium channel blockers such as diltiazem and verapramil.

Anticoagulants

Anticoagulants such as Phenprocoumon or Eliquis, Pradaxa, and Xarelto are used in cardiomyopathies to prevent blood clots from forming in the heart. This is because these clots pose a significant risk. They can trigger pulmonary embolisms, for example.

Operative Therapy

If drug therapy for cardiomyopathies does not relieve the symptoms, surgery is another option. For example, damaged heart valves are replaced, parts of the heart muscle are removed or pacemakers are implanted.

The heart transplant remains the last possibility and the only causal therapy option.

Forecast

The prognosis for the course and life expectancy of cardiomyopathies depends on the type and extent of the heart muscle damage and the general state of health. In mild forms of blood pressure-related (hypertrophic) cardiomyopathy, for example, those affected have a normal life expectancy if the high blood pressure is consistently treated.

Dilated and restrictive cardiomyopathies, on the other hand, are often recognized very late and can then often hardly be treated effectively. Up to 80 percent of those affected die within 5 years of diagnosis.

Prevention

Cardiomyopathies are very often the result of cardiovascular disease. To reduce the risk of these diseases, you should lead a heart-healthy lifestyle. Above all, exercise keeps the circulation and the heart fit.

A fresh and varied diet provides the body with all the necessary nutrients and also helps to avoid obesity.

Lung and heart health are closely related. Quitting smoking is, therefore, a cornerstone in the prevention and accompanying treatment of heart muscle disorders. Regular consumption of alcohol is also harmful to the heart.

Finally, the prevention of cardiomyopathies also includes having favorable diseases (see causes) treated consistently.