Myocarditis: Causes, symptoms and treatment

Myocarditis is one of the most dangerous heart conditions. This is the phenomenon of cardiac muscle damage due to many different factors leading to inflammation, necrosis of cardiac muscle cells.

What is myocarditis?

Myocarditis is an acute or chronic inflammation of the heart muscle in which inflammatory cells are present simultaneously with the phenomenon of cardiac muscle death in the same cardiac muscle unit. Myocarditis can manifest under many symptoms and signs, ranging from moderate dyspnea, unresponsive chest pain with specific treatment to cardiogenic shock and death. This is the cause of dilated cardiomyopathy with chronic heart failure.

Myocarditis can manifest under many different symptoms and signs.

Causes of myocarditis

Myocarditis due to infectious agents:

• Virus: coxsackie B, adenovirus, hepatitis B, C, HSV, EBV viruses . Viral myocarditis is the most common cause but usually cannot be determined.
• Bacteria: staphylococci, streptococci, diphtheria, .
• Mushrooms: candida, aspergillus, .
• Parasites: toxoplasma, Trypanosoma cruzi, .

Myocarditis can occur due to non-infectious agents: anthracycline drugs (Daunorubicin, Adriamycin), cocaine, CO, lupus, giant cell vasculitis, Takayasu, .

Symptoms of myocarditis

Myocarditis symptoms can range from mild to very severe. Common symptoms of myocarditis:

• Signs of infection: fever, flu, body aches .
• Chest pain
• Difficulty breathing depends on the level of heart failure
• The arrhythmia: extrasystole, ventricular tachycardia .
• In severe cases, there are signs of cardiogenic shock: low blood pressure, cold limbs, little urination, persistent shortness of breath, and possible pulmonary edema.

Measures to diagnose myocarditis

• Endocardial biopsy is a useful tool for diagnosis, with definite evidence of myocarditis in histopathology, but has not been performed in Vietnam.
• Cardiac Doppler ultrasound: assesses cardiac function, regional musculoskeletal disorders, not related to coronary artery perfusion
• ECG: often shows signs of concave ST elevation in many leads showing pericarditis, to avoid confusion with ST elevation changes in myocardial infarction
  Cardiac magnetic resonance: is also a means of high diagnostic value, but it is rarely performed in the acute phase
• Blood tests: In addition to infection makers, special attention should be paid to Troponin T or Troponin I, which is a marker of myocardial necrosis. Based on that to diagnose myocardial damage. In addition to NT-proBNP, blood lactate is also needed to assess the level of heart failure, organ perfusion.
• Percutaneous coronary angiography : in patients with chest pain with risk factors for coronary artery disease, with elevated cardiac enzymes, coronary angiography is also needed to rule out myocardial infarction if conditions permit.

Measures to treat myocarditis

Treatment for myocarditis may be medically necessary but may also require extra circulatory support in cases of cardiogenic shock. In these cases, the death rate is very high, the cost of treatment is great.

• Medical treatment: in the acute phase, there is no specific treatment, mainly symptomatic treatment. Most acute myocarditis is reversible, with little effect on cardiac function. But there is also an incidence of myocarditis causing heart failure, dilated cardiomyopathy. Treatment at this stage is mainly for heart failure treatment, taking drugs according to the recommended treatment for heart failure.
• Severe cases : supportive vasopressors may be needed, but often requires external circulatory support (ECMO). Acute myocarditis can affect the pacemaker apparatus causing dangerous heart rhythm disorders such as ventricular tachycardia, or atrioventricular block. These cases require a combined temporary pacemaker.

Prevention of myocarditis

• Limit contact with people who are infected with the virus, the flu, or have protective equipment when exposed
• Special hygiene clean hand hygiene
• Inject some preventive vaccines: influenza, hepatitis B, etc.