Myocarditis

Myocarditis, also known as inflammatory cardiomyopathy, is an acquired cardiomyopathy due to inflammation of the heart muscle. Symptoms can include shortness of breath, chest pain, decreased ability to exercise, and an irregular heartbeat.[1] The duration of problems can vary from hours to months. Complications may include heart failure due to dilated cardiomyopathy or cardiac arrest.[1]

Quick facts: Myocarditis, Other names, Specialty, Symptoms... ▼

Myocarditis
Other names	Inflammatory cardiomyopathy (infectious)
A microscope image of myocarditis at autopsy in a person with acute onset of heart failure
Specialty	Infectious disease, cardiology
Symptoms	Shortness of breath, chest pain, decreased ability to exercise, irregular heartbeat[1]
Complications	Heart failure due to dilated cardiomyopathy, cardiac arrest[1]
Duration	Hours to months[1]
Causes	Usually viral infection, also bacterial infections, certain medications, autoimmune disorders[1][2]
Diagnostic method	Electrocardiogram, blood troponin, heart MRI, heart biopsy[1][2]
Treatment	Medications, implantable cardiac defibrillator, heart transplant[1][2]
Medication	ACE inhibitors, beta blockers, diuretics, corticosteroids, intravenous immunoglobulin[1][2]
Prognosis	Variable[3]
Frequency	2.5 million with cardiomyopathy (2015)[4]
Deaths	354,000 with cardiomyopathy (2015)[5]

Myocarditis is most often due to a viral infection.[1] Other causes include bacterial infections, certain medications, toxins and autoimmune disorders.[1][2] A diagnosis may be supported by an electrocardiogram (ECG), increased troponin, heart MRI, and occasionally a heart biopsy.[1][2] An ultrasound of the heart is important to rule out other potential causes such as heart valve problems.[2]

Treatment depends on both the severity and the cause.[1][2] Medications such as ACE inhibitors, beta blockers, and diuretics are often used.[1][2] A period of no exercise is typically recommended during recovery.[1][2] Corticosteroids or intravenous immunoglobulin (IVIG) may be useful in certain cases.[1][2] In severe cases an implantable cardiac defibrillator or heart transplant may be recommended.[1][2]

In 2013, about 1.5 million cases of acute myocarditis occurred.[6] While people of all ages are affected, the young are most often affected.[7] It is slightly more common in males than females.[1] Most cases are mild.[2] In 2015 cardiomyopathy, including myocarditis, resulted in 354,000 deaths up from 294,000 in 1990.[8][5] The initial descriptions of the condition are from the mid-1800s.[9]