What is Myocarditis?

Myocarditis means inflammation of the heart muscle. In the United Kingdom, one young person dies suddenly each week due to undiagnosed myocarditis. It can affect anyone at any age and is usually related to recent viral infection. The virus may have gone but the immune system over-reacts causing inflammation that can persist in the heart.Other causes include bacterial infections, certain medications, toxins and autoimmune disorders. Symptoms are diverse and include chest pain, mimicking a heart attack, difficulty breathing due to weakened heart muscle, palpitation due to electrical rhythm disturbances, fever and abnormal fatigue.


Diagnosis is challenging with no specific blood test and taking a biopsy of the heart is definitive but high-risk. In practice, diagnosis is made on the basis of a raised troponin blood test, normal coronary angiogram and where available a cardiac MRI scan.

In some centres, a heart muscle biopsy may also be performed but carries additional risk.Most patients get better without any specific treatment apart from rest, anti-inflammatories and avoidance of exercise whilst the heart recovers.

There are no specific therapies to tackle the underlying viral infection. However, in a third of patients, the heart becomes weaker and enlarges (dilated cardiomyopathy) and this may require treatment with medications such as ACE inhibitors, beta blockers and diuretics.

Early Detection

Early detection and better treatment are key priorities supported by the Myocarditis UK fund. This includes new blood tests (‘biomarkers’) to accurately diagnose myocarditis, advances in cardiac MRI mapping technology to measure levels of inflammation and scar formation, and greater understanding of the role of genetic testing to predict why most patients recover whereas some experience complications such as sudden death and dilated cardiomyopathy.

Our hope is to find better treatments, enable much earlier diagnosis and better identification of patients that may be at risk.