What is myocarditis?
What is myocarditis?
Myocarditis is inflammation of heart muscle.
What are the symptoms for myocarditis?
If you have a mild case of myocarditis or are in the early stages, you might have no symptoms or mild ones, such as chest pain or shortness of breath.
In serious cases, the signs and symptoms of myocarditis vary, depending on the cause of the disease. Common myocarditis signs and symptoms include:
- Chest pain
- Rapid or abnormal heart rhythms (arrhythmias)
- Shortness of breath, at rest or during physical activity
- Fluid retention with swelling of your legs, ankles and feet
- Other signs and symptoms of a viral infection, such as a headache, body aches, joint pain, fever, a sore throat or diarrhea
Myocarditis in children
When children develop myocarditis, they might have signs and symptoms including:
- Breathing difficulties
- Rapid breathing
- Rapid or abnormal heart rhythms (arrhythmias)
When to see a doctor
Contact your doctor if you have symptoms of myocarditis, particularly chest pain and shortness of breath. If you've had an infection, be alert for the symptoms of myocarditis and let your doctor know if they occur. If you have severe symptoms, go to the emergency room or call for emergency medical help.
What are the causes for myocarditis?
Often, the cause of myocarditis isn't identified. Potential causes are many, but the likelihood of developing myocarditis is rare. Potential causes include:
Viruses. Many viruses are commonly associated with myocarditis, including the viruses that cause the common cold (adenovirus); hepatitis B and C; parvovirus, which causes a mild rash, usually in children (fifth disease); and herpes simplex virus.
Gastrointestinal infections (echoviruses), mononucleosis (Epstein-Barr virus) and German measles (rubella) also can cause myocarditis. It's also common in people with HIV, the virus that causes AIDS.
- Bacteria. Numerous bacteria can cause myocarditis, including staphylococcus, streptococcus, the bacterium that causes diphtheria and the tick-borne bacterium responsible for Lyme disease.
- Parasites. Among these are such parasites as Trypanosoma cruzi and toxoplasma, including some that are transmitted by insects and can cause a condition called Chagas disease. This disease is much more prevalent in Central and South America than in the United States, but it can occur in travelers and in immigrants from that part of the world.
- Fungi. Yeast infections, such as candida; molds, such as aspergillus; and other fungi, such as histoplasma, often found in bird droppings, can sometimes cause myocarditis, particularly in people with weakened immune systems.
Myocarditis also sometimes occurs if you're exposed to:
- Medications or illegal drugs that might cause an allergic or toxic reaction. These include drugs used to treat cancer; antibiotics, such as penicillin and sulfonamide drugs; some anti-seizure medications; and some illegal substances, such as cocaine.
- Chemicals or radiation. Exposure to certain chemicals, such as carbon monoxide, and radiation can sometimes cause myocarditis.
- Other diseases. These include disorders such as lupus, Wegener's granulomatosis, giant cell arteritis and Takayasu's arteritis.
What are the treatments for myocarditis?
In many cases, myocarditis improves on its own or with treatment, leading to a complete recovery. Myocarditis treatment focuses on the cause and the symptoms, such as heart failure.
In mild cases, persons should avoid competitive sports for at least three to six months. Rest and medication to help your body fight off the infection causing myocarditis might be all you need. Although antiviral medications are available, they haven't proved effective in the treatment of most cases of myocarditis.
Certain rare types of viral myocarditis, such as giant cell and eosinophilic myocarditis, respond to corticosteroids or other medications to suppress your immune system. In some cases caused by chronic illnesses, such as lupus, treatment is directed at the underlying disease.
Drugs to help your heart
If myocarditis is causing heart failure or arrhythmias, your doctor might hospitalize you and prescribe drugs or other treatments. For certain abnormal heart rhythms or severe heart failure, you may be given medications to reduce the risk of blood clots forming in your heart.
If your heart is weak, your doctor might prescribe medications to reduce your heart's workload or help you eliminate excess fluid, including:
- Angiotensin-converting enzyme (ACE) inhibitors. These medications, such as enalapril (Vasotec), captopril (Capoten), lisinopril (Zestril, Prinivil) and ramipril (Altace), relax the blood vessels in your heart and help blood flow more easily.
- Angiotensin II receptor blockers (ARBs). These medications, such as losartan (Cozaar) and valsartan (Diovan), relax the blood vessels in your heart and help blood flow more easily.
- Beta blockers. Beta blockers, such as metoprolol (Lopressor, Toprol-XL), bisoprolol and carvedilol (Coreg), work in multiple ways to treat heart failure and help control arrhythmias.
- Diuretics. These medications, such as furosemide (Lasix), relieve sodium and fluid retention.
Treating severe cases
In some severe cases of myocarditis, aggressive treatment might include:
- Intravenous (IV) medications. These might improve the heart-pumping function more quickly.
- Ventricular assist devices. Ventricular assist devices (VADs) are mechanical pumps that help pump blood from the lower chambers of your heart (the ventricles) to the rest of your body. VADs are used in people who have weakened hearts or heart failure. This treatment may be used to allow the heart to recover or while waiting for other treatments, such as a heart transplant.
- Intra-aortic balloon pump. Doctors insert a thin tube (catheter) in a blood vessel in your leg and guide it to your heart using X-ray imaging. Doctors place a balloon attached to the end of the catheter in the main artery leading out to the body from the heart (aorta). As the balloon inflates and deflates, it helps to increase blood flow and decrease the workload on the heart.
- Extracorporeal membrane oxygenation (ECMO). With severe heart failure, this device can provide oxygen to the body. When blood is removed from the body, it passes through a special membrane in the ECMO machine that removes carbon dioxide and adds oxygen to the blood. The newly oxygenated blood is then returned to the body.
The ECMO machine takes over the work of the heart. This treatment may be used to allow the heart to recover or while waiting for other treatments, such as a heart transplant.
In the most severe cases, doctors might consider urgent heart transplantation.
Some people might have chronic and irreversible damage to the heart muscle requiring lifelong medications, while other people need medications for just a few months and then recover completely. Either way, your doctor is likely to recommend regular follow-up appointments, including tests to evaluate your condition.
What are the risk factors for myocarditis?
- Having close contact with people who are sick. Stay away from people with symptoms of the flu or other respiratory illness until they've recovered. If you're sick with symptoms of a viral infection, try to avoid exposing others.
- Not washing your hands regularly. Frequent hand-washing is one of the best ways to avoid getting sick and spreading illness.
- Do not avoid risky behaviors. To reduce the chances of getting an HIV-related myocardial infection, practice safe sex and don't use illegal drugs.
- Do not get recommended vaccines. Stay up to date on the recommended vaccines, including those that protect against COVID-19, influenza and rubella — diseases that can cause myocarditis. Rarely, the COVID-19 vaccine can cause inflammation of the heart muscle (myocarditis) and inflammation of the outer heart lining (pericarditis), particularly in males ages 12 to 29. Talk to your health care provider about the benefits and risks of vaccines
Is there a cure/medications for myocarditis?
The outlook for myocarditis diagnosis is generally positive. Many people with myocarditis will recover without any long-term negative effects on their heart.
It’s important to be patient with your recovery process. In some cases, it can take a long time to fully recover from a bout of myocarditis — up to 3 to 7 years.
During your recovery period, your doctor will continue to monitor you to determine if your treatment was effective and if there are any adverse effects on your heart.
In some cases, myocarditis can damage the heart and cause arrhythmia, heart failure, or cardiomyopathy. These conditions typically require some form of ongoing management.
It’s possible for acute myocarditis to recur. One 2014 study found that over a 4.5-year follow-up period, the recurrence rate of myocarditis was 10.3 percent.
Many people with myocarditis go on to recover completely. However, the condition can also cause permanent damage to the heart muscle. This can lead to complications like arrhythmia and heart failure.
It’s important to seek prompt medical attention if you experience unexplained symptoms like chest pain or shortness of breath. A doctor can evaluate your symptoms to determine if they’re due to myocarditis or another condition.