What is myocarditis?
Myocarditis is an inflammation of the heart muscle that can affect all or part of the heart.
There are different types and severities of myocarditis. In some people, the condition develops suddenly and lasts a short time (acute myocarditis) and in others, it can be ongoing (chronic myocarditis).
Some cases of myocarditis can be mild, while others can be severe.
Myocarditis is a potentially life-threatening condition that needs immediate treatment, see your doctor or go to a hospital if you have, or think you may have, it.
What are the symptoms of myocarditis?
The symptoms of myocarditis vary greatly depending on the type, cause and severity of the condition. However, early symptoms can include:
- sore throat
- muscle or joint pains
- skin rash
- tummy pain, diarrhoea, nausea, vomiting, loss of appetite
These early symptoms may be followed by:
- shortness of breath when sitting, standing or lying down
- swelling of the arms or legs (oedema)
- chest pain
- fainting spells
- heart palpitations
- skin that looks pale and blue
- fits (seizures)
What causes myocarditis?
Many things can cause myocarditis, such as an infection, medical condition and certain medicines.
Infections that can lead to myocarditis include:
- viral infections - e.g. flu, mumps, rubella or HIV
- bacterial infections - e.g. gonorrhoea, syphilis, chlamydia, tetanus and tuberculosis
- single-celled organism (protozoal) infections - e.g. malaria
- fungal infections - e.g. thrush (candidiasis)
Medical conditions that can trigger myocarditis include:
- autoimmune conditions, such as rheumatoid arthritis and lupus
- inflammatory bowel disease
- diabetes mellitus
- overactive thyroid
Other causes of myocarditis include:
- toxins, - alcohol, carbon monoxide, cocaine, heavy metals (copper, iron, lead)
- certain medications - some antibiotics, heart medications and medicines to prevent fits (seizures)
- certain snake bites
How is myocarditis diagnosed?
Myocarditis can be a life-threatening condition. Go to a hospital immediately if you think you may have it.
Your doctor may diagnose myocarditis based on your symptoms, medical history and a physical examination.
You may be given tests, including:
- blood tests
- electrocardiogram (ECG)
- coronary angiography - often used to exclude other causes of your symptoms
- cardiac MRI scan
Less commonly, you may need a biopsy of the affected heart muscle to confirm the diagnosis.
What is the treatment for myocarditis?
The main aim of myocarditis treatment is to remove the cause of the inflammation and improve the heart’s function. If you have myocarditis, the exact treatment you will receive will usually depend on what caused the condition and how severe it is.
Treatment can include:
- steroids and other medications to make your immune system less active
- medications to prevent fluid from building up in your body
- drugs to help you breathe more easily
- medications to help your heart beat correctly
- drugs to prevent blood clots from forming in your body
If you have severe myocarditis, you may need additional treatment, such a heart transplant or a surgical procedure to implant a device to help your heart pump blood and beat correctly.
Things you can do yourself after diagnosis include:
- rest - you will usually need to limit how much physical exercise you do while your heart recovers. Speak to your doctor to find out when it is safe for you to start exercising again
- avoid drinking alcohol (or have no more than 1 alcoholic drink per day) as this can make myocarditis worse
- avoid non-steroidal inflammatory drugs (NSAIDs), as these may make heart inflammation worse
Will I be able to return to normal?
If you have had myocarditis, your recovery will usually depend on the cause of the inflammation and how severe your symptoms were.
It is likely that you will need to have regular check-ups, even after you feel better. These check-ups may include regular imaging scans to check how well your heart is working.
It is important to take time to rest and recover. Do not rush back into physical activity. Instead, speak with your doctor to find out when you can start exercising again and how much exercise is safe.
Date of last review: 1 July 2020
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