What causes myocarditis?

Myocarditis refers to a localized and relatively diffuse inflammatory lesion in the myocardium, and viral myocarditis has occurred more frequently in recent years. So, in our daily lives, do we know what causes myocarditis? We must be aware of the great impact that timely cooperation has on the quality of myocarditis.

What is caused by myocarditis? In fact, myocarditis is an important component of a systemic disease. There are many causes of myocarditis. Common ones include infection factors, physical and chemical factors, drug-induced factors, etc. For example, the most common cause of myocarditis in our lives is viral myocarditis, which includes enterovirus, especially some Coxsackie B virus infection, which is also the most common cause of myocarditis.

In recent years, due to the widespread use of antibiotics, rheumatic fever caused by streptococcal infection has gradually decreased, the incidence of rheumatic myocarditis has significantly decreased, while the incidence of viral myocarditis has increased. Viral myocarditis can be caused by a variety of viral infections, among which Coxsackievirus B is the most common, and varicella and Epstein-Barr virus can also cause it. According to research, about 5% of people infected with the virus may develop myocarditis after the infection affects the heart. It can be caused by direct invasion of the myocardium after viral infection, or by an autoimmune response after viral infection. The former is more common in children, while the latter is more common in teenagers. Spring is the peak season for viral myocarditis, so people should be vigilant.

The disease initially presents with symptoms of upper respiratory tract infection or intestinal infection, and after 7-10 days, symptoms such as chest tightness, palpitations, extreme fatigue, and sweating appear. At this time, if an electrocardiogram is performed, arrhythmias such as premature beats and signs of myocardial damage may be found. Erythrocyte sedimentation rate and myocardial enzyme tests may show elevated levels. After 2-4 weeks, Coxsackie virus antibodies and anti-myocardial antibodies may be positive.

The severity of viral myocarditis varies, so the symptoms are also very different. Patients with mild, localized lesions may have no symptoms, no abnormal electrocardiogram, and no elevated erythrocyte sedimentation rate or myocardial enzymes. Some people are only discovered to have myocarditis during autopsy due to an accident. In severe cases, there are obvious symptoms, including diffuse enlargement of the heart, heart failure, resulting in significant shortness of breath and inability to lie flat; some have severe arrhythmia, resulting in repeated fainting and even sudden death.

Some relevant studies have shown that the cause of myocarditis is actually viral infection, which is the most important cause. Once a viral infection occurs, people will be constantly nervous and overtired, or people who engage in heavy physical labor or strenuous exercise are prone to viral myocarditis.