miokardiit

Miokardiit is an inflammatory disease of the heart muscle (myocardium) that can impair the heart's pumping function and its electrical activity. The presentation varies from mild, self-limited illness to fulminant disease with severe heart failure or sudden death.

Causes include infectious agents (predominantly viruses), autoimmune or immune-mediated processes, toxins, and certain medications. Bacterial, fungal, and parasitic infections may be involved. Drugs such as some chemotherapeutic agents and alcohol or cocaine use are recognized contributors. In some individuals, myocarditis follows an autoimmune reaction after an infection.

Symptoms range from chest pain, shortness of breath, and fatigue to palpitations and fever. Some people have flu-like symptoms. In severe cases, signs of heart failure or life-threatening arrhythmias may occur, requiring urgent care.

Diagnosis relies on history and examination, plus tests such as ECG, measurements of cardiac troponin, echocardiography, and cardiac magnetic resonance imaging. Endomyocardial biopsy may be performed in selected patients to identify the cause and guide treatment.

Treatment is directed at the underlying cause and at supporting heart function. This may include rest, medications for heart failure and arrhythmias, and avoidance of strenuous activity for several months. Immunosuppressive therapy is reserved for specific autoimmune forms. In fulminant cases, intensive care and mechanical circulatory support may be necessary. Most patients recover, but some develop lasting dilated cardiomyopathy or chronic heart failure; rare cases lead to fatal outcomes.

Estimates of incidence vary; myocarditis can affect people of all ages, with higher apparent incidence in young adults. The condition is often underdiagnosed. Prevention focuses on reducing exposure to known infectious and toxic risk factors and treating infections promptly; vaccines can reduce certain infectious causes of myocarditis.