Causes of myocarditis
General
Having an inflammation of the heart muscle (Myocarditis) one understands an inflammation of the heart muscle. The heart muscle cells, the cell spaces (Interstitium), as well as the heart muscle vessels.
The causes can be different. The most common causes include:
- Viral or bacterial infections
- Sport after an infection that has not healed
- Autoimmune disease
- stress
- alcohol
Infectious causes
Virus inflammation of the heart muscle
Infections, especially viruses, are by far the most common cause of myocarditis. The triggers are usually previous flu-like infections, which are carried over into the heart muscle.
Viruses that cause myocarditis are therefore primarily those that cause flu-like symptoms.
The most common viral pathogens that cause myocarditis include:
- Enteroviruses
- Coxackie Viruses
- ECHO viruses
- Adenoviruses
- Herpes viruses (especially the human herpes virus 6)
- Parvovirus B19 causes ringlet rubella.
The HI virus and cytomegalovirus (CMV) in question. The causative agent of three-day fever in infants and toddlers (i.e. children up to 6 years of age) can also cause myocarditis.
Possible sources of infection are objects contaminated through contact with faeces, such as Hands, toys and drinking water.
Inflammation of the heart muscle caused by bacteria
The bacterial causes of myocarditis include, among others the causative agents of:
- diphtheria
- tuberculosis
- Lyme disease
- Pneumococci.
However, people who are already immunocompromised are more likely to be affected by bacterial myocarditis.
Inflammation of the heart muscle caused by fungi or parasites
Various molds, yeasts and parasites, such as tapeworms and roundworms, can also trigger myocarditis, but they only make up a small number of them.
If the food is poorly processed, especially in the form of raw meat, the eggs of these parasites are ingested through them. In the hours that follow, they spread via the lymphatic system and bloodstream after they have matured into adult animals in the intestinal wall. They then settle in the host's muscle tissue. Fungi, on the other hand, can only be dangerous for patients with significantly impaired immunity.
Protozoa, animal unicellular organisms, some of which live parasitically, only play a role in the development of myocarditis in South America. An example of this is the causative agent of Chagas disease.
As a rule, the immune system eliminates the pathogen without any problems and spontaneous, effective healing occurs - the infection has no consequences. However, viral genetic information sometimes remains (RNA) or virus components that maintain the immune response and thus the inflammation. There is also the assumption that a genetically determined susceptibility orSusceptibility of the person affected clearly favors the transition to a chronic course.
Non-infectious causes
Myocarditis can also be triggered by a number of non-infectious factors, albeit much less frequently.
One of these is rheumatic fever. This is a secondary disease that occurs around 10-20 days after having a throat infection Streptococcus pyogenes, the causative agent of scarlet fever, can occur. In addition to an inflammatory reaction in the skin and joints, it can also lead to inflammation of all parts of the heart (Pancarditis) after the bacteria have previously provoked the body to produce antibodies against structures of the heart. This can be accompanied by damage to the heart valves.
Autoimmune diseases such as sarcoid, systemic lupus erythematosus, scleroderma, or vascular inflammation (Vasculitis), in which the human immune system is directed against the body's own structures, in some cases encroach on the heart muscle and cause the destruction of the muscle tissue as part of an inflammatory reaction. In so-called collagenoses, antibodies attack all possible types of connective tissue cells in the body. In addition to joint problems, this ultimately also leads to damage to the heart muscle.
A similar mechanism is present in vasculitis (inflammation of the blood vessels), with the difference that instead of connective tissue cells, the body's own antibodies attack vessels, including the vessels of the heart.
Read more on the subject at: What is an autoimmune disease?
Inflammation of the heart muscle due to stress
Stress is a risk factor for the development of heart muscle inflammation after a flu-like infection. Stress weakens the immune system, which makes it easier for an infection to spread to the heart muscles. At the same time, there is an additional strain on the heart muscles with an increased heart rate. If the muscles are already damaged, there is a risk of serious complications, as the heart muscle reaches its load limit earlier.
Read more on this topic at: Consequences of stress
Toxic causes
The most common causes of toxic myocarditis are:
- increased alcohol consumption
- Absorption of heavy metals
- Side effects of drugs such as Chemotherapy drugs, sleeping pills and anesthetics (barbiturates) or psychotropic drugs.
Inflammation of the heart muscle caused by alcohol
Another risk factor for developing myocarditis is regular alcohol consumption. The immune system is also inhibited by the increased blood alcohol level, which promotes the spread of a flu-like infection to the heart muscles.
At the same time, excessive alcohol consumption over a long period of time can also be the sole cause of heart muscle inflammation. One speaks here of a so-called toxic myocarditis. The permanently increased blood alcohol level promotes inflammation in the body. These can manifest themselves in the area of the heart muscles, among other things.
Read more on this topic at: Consequences of alcohol
Exercise for heart muscle inflammation
The most common cause of cardiac muscle inflammation in otherwise healthy young people is too early and too vigorous exercise after a flu-like infection. If the infection is not cured sufficiently before the stress is started again, the cold pathogens can attack the heart muscle and cause an inflammatory reaction there.
Exercise during a heart muscle inflammation is only possible to a very limited extent. In this context, many patients only notice that something is wrong, since heart muscle inflammation can present itself relatively asymptomatic under resting conditions.
The inflammation weakens and restricts the function of the heart muscle. The heart's pumping capacity gradually decreases. This manifests itself in particular through significant shortness of breath during physical exertion. The further the disease has progressed, the more pronounced the shortness of breath and the lower the body's upper limit.
Heart muscle inflammation is therefore quite a serious disease. Infections should always be carefully cured and sporting activities should be avoided during the illness phase. After the infection, physical activity should only be started slowly and gently in order to avoid the spread of pathogens into the organism and thus prevent myocarditis.
Read more on the topic: Myocarditis and exercise.
Symptoms of myocarditis
The symptoms during the illness are usually very unspecific.
Frequent symptoms in mild forms resemble a flu-like infection (headache and body aches) or manifest themselves in increased fatigue, a decrease in performance and heart palpitations. The disease often remains symptom-free and therefore goes undetected and heals without complications.
Also read: EKG for an inflammation of the heart muscle
More severe forms with symptoms such as pain when breathing in or general pain in the chest area, as well as signs of heart failure are rare. Heart failure is the inability of the heart to supply the body with enough oxygen even though the lungs are working properly.
Also read our main article Symptoms of myocarditis.
Forms of myocarditis
If an infection of the muscle layer of the heart is caused by microorganisms such as bacteria or viruses, it is known as infectious myocarditis. Furthermore, an already existing autoimmune disease (e.g. sarcoid, systemic lupus erythematosus, scleroderma, vascular inflammation) can be responsible for an inflammation of the heart muscle. However, if toxic substances are the cause, they are referred to as toxic myocarditis. Finally, the idiopathic form of myocarditis should be mentioned, in which there is no recognizable cause for the inflammatory process.
