Myocarditis is an inflammation of the myocardium, the muscular tissue of the heart. This inflammation can be caused by viral, bacterial, or fungal infections, autoimmune diseases, allergic reactions, exposure to certain toxins or medications, among other factors.
When the myocardium becomes inflamed, it can weaken the heart's ability to pump blood efficiently, leading to severe symptoms and complications.
The symptoms of myocarditis can vary and, in some cases, may be mild or even asymptomatic. However, common symptoms include:
Chest pain or discomfort
Irregular heart palpitations
Swelling in the lower extremities
Flu-like symptoms, such as headache and muscle aches
There are several types of myocarditis, classified according to the underlying cause. Some of the most common types include:
Viral myocarditis, which is caused by viral infections such as Coxsackie B virus, herpes simplex virus, or influenza virus.
Autoimmune myocarditis, in which the immune system mistakenly attacks the cardiac tissue.
Toxic myocarditis, which occurs due to exposure to toxins or medications harmful to the heart.
For the diagnosis of myocarditis, the doctor may order blood tests to look for markers of inflammation and cardiac damage, as well as imaging tests such as echocardiograms or cardiac magnetic resonance imaging (MRI) to evaluate the structure and function of the heart.
In some cases, a biopsy of the cardiac tissue may be necessary to confirm the diagnosis.
Some risk factors for developing myocarditis include:
Viruses: Several viruses have been identified as associated with myocarditis, including those that cause the common cold (adenovirus), COVID-19, hepatitis B and C, parvovirus (causing fifth disease, a mild rash usually affecting children), and herpes simplex virus.
Gastrointestinal infections: Some viruses such as echo virus can cause myocarditis, as well as the Epstein-Barr virus that causes mononucleosis and the rubella virus (German measles).
Bacteria: Bacteria such as staphylococci, streptococci, and the bacterium responsible for diphtheria and Lyme disease can cause myocarditis.
Parasites: Among the parasites are Trypanosoma cruzi and Toxoplasma. Some parasites are transmitted through insects and can cause Chagas disease, which is more common in Central and South America than in the United States.
Fungi: Fungal infections can also cause myocarditis, especially in people with weakened immune systems. Some fungi associated with myocarditis include yeast infections such as vaginal candidiasis, mold infections such as Aspergillus, and Histoplasma, which is usually found in bird droppings.
There is no specific way to prevent myocarditis, but certain measures can be taken to help prevent it, such as:
Keeping vaccinations up to date.
Practicing good personal hygiene.
Avoiding direct contact with people who have viral infections.
Following the instructions and recommended doses of medications.
Avoiding excessive alcohol and drug consumption.
Adopting a healthy lifestyle.
Cardiac ablation is recommended when treatments are no longer effective or are not well tolerated to treat arrhythmias
Ventricular extrasystoles may not present symptoms; in other cases, they may cause unpleasant or alarming sensations.
A heart murmur is an unusual sound that is heard when blood flows through the heart.