Charlotte, NC
Preeti Kharel
Myocarditis is the inflammation of the middle muscular layer of your heart. Inflammation means your heart muscle has swelling and irritation when fighting an infection, injury, or something harmful. This inflammation can affect your heart’s ability to pump blood and maintain normal rhythm. The condition affects people of all ages and can range from mild cases with few symptoms to life-threatening complications. [1]
It can happen suddenly when caused by infection, toxins, or drugs. But when the trigger is autoimmune diseases like lupus or rheumatoid arthritis, it affects the heart more slowly, causing a long-term effect like heart failure and cardiomyopathy. [1]
Commonly identified causes and risk factors of myocarditis include:
Myocarditis is more common in young adults, especially males, but it can affect people of any age. Children and infants are also vulnerable, particularly during viral outbreaks. [2]
Viral infection is the most common cause of myocarditis, directly infecting cardiac cells by releasing cytokines such as IL-1, IL-6, and TNF-α or inducing an immune-mediated response. Infections caused by various viruses, including influenza, herpes, adenovirus, coxsackievirus, parvovirus B19, and even SARS-CoV-2 (the virus responsible for COVID-19), can cause myocarditis. [1]
Exposure to toxins and radiation can lead to myocarditis by directly damaging the heart muscle or triggering inflammation. Substances like excessive alcohol, recreational drugs such as cocaine, heavy metals like lead or mercury, and industrial chemicals can harm heart tissues and cause inflammation. Similarly, radiation therapy, particularly when targeting the chest area for cancer treatment, can unintentionally damage the heart muscle and lead to myocarditis. [3]
Autoimmune diseases, such as lupus or rheumatoid arthritis, can cause your immune system to attack healthy tissues, including the heart muscle. Myocarditis may also occur due to autoimmune reactions triggered by infections or other conditions. [4]
Rheumatic fever is a condition that can develop if you’ve had an untreated or poorly treated strep throat infection. It happens when your immune system, mistakenly attacks healthy tissues, including your heart. If this affects your heart muscle, it can lead to myocarditis, causing swelling and irritation in your heart. [5]
Some medicines and vaccinations can, in rare cases, cause myocarditis as a side effect. Certain medications, such as chemotherapy drugs, antibiotics, or immune-suppressing treatments, may trigger an inflammatory response in your heart muscle. Vaccinations, including some for COVID-19, have been linked to very rare cases of myocarditis, typically occurring in younger males after their second dose. [6]
The symptoms of myocarditis can vary widely, and sometimes, there might be no noticeable symptoms at all. When symptoms do occur, they may include:
You may feel sharp, stabbing, or pressure-like pain in your chest, similar to what happens during a heart attack. This occurs due to inflammation of the heart muscle and can worsen with physical activity or deep breaths. [7]
You might struggle to catch your breath, especially when lying flat or after mild activity. This happens because the heart isn’t pumping blood effectively, causing fluid buildup in your lungs. [7]
Feeling unusually tired or weak, even after routine tasks, is common with myocarditis. This is due to the heart’s inability to supply oxygen-rich blood to your body efficiently. [8]
You might notice your heart racing, fluttering, or skipping beats. This indicates that the inflamed heart muscle interferes with your heart’s normal electrical signals. [9]
Swelling in your legs, ankles, or feet may occur due to fluid buildup caused by the heart’s reduced ability to pump blood. Swelling may also appear around your abdomen or even in the veins in your neck. [7]
If a virus triggers your myocarditis, you might first experience symptoms like fever, sore throat, headache, muscle aches, or general discomfort. These often precede heart-related symptoms.
You could feel dizzy or faint, especially during physical activity or when standing up suddenly. This happens because reduced blood flow to your brain can result from your heart’s inability to pump effectively. [7]
Knowing when to call for help is important if you have myocarditis. You should dial 911 immediately if your chest pain feels tight or heavy, lasts more than 15 minutes, or starts spreading to your arms, back, neck, or jaw. It’s also important to seek urgent help if you feel short of breath or nauseous along with the pain. These could be signs of a serious problem that needs immediate attention, so don’t wait to get the care you need. [10]
The inflammation caused by myocarditis can cause chest pain similar to that in a heart attack, making the diagnosis difficult. The following tests might be done to diagnose myocarditis:
A complete blood count may reveal an elevated white blood cell count, indicating an infection or inflammation. Tests like troponin and creatine kinase measure heart enzymes that are released when your heart muscle is damaged, helping to confirm myocarditis. C-reactive protein and erythrocyte sedimentation rate can show your body’s inflammation level. If a viral infection is suspected, blood tests can identify specific viruses or antibodies that may have triggered the condition. [7]
EKG is a test that checks your heart’s rhythm by recording its electrical activity. It can detect certain changes that might suggest myocarditis, although these changes aren’t specific to the condition. Importantly, even if your ECG looks normal, it doesn’t rule out myocarditis completely. [10]
A chest X-ray gives a clear image of your heart and lungs, helping to check for signs like an enlarged heart or fluid buildup in your lungs, which can happen when your heart isn’t pumping well. While it can’t confirm myocarditis independently, a chest X-ray helps your doctor rule out other conditions that can mimic myocarditis. [11]
An echocardiogram, or echo, is a test that uses sound waves to create detailed images of your heart. An echo can help see how well your heart is pumping and check for any areas of damage. It can also show if your heart is enlarged or if there’s fluid around it, which are signs of inflammation. This test is painless and non-invasive, and it gives information about how your heart is functioning. [12]
An MRI scan creates detailed images of the heart’s shape and structure. It’s especially useful for assessing heart function and detecting inflammation or scar tissue caused by myocarditis. [13]
A PET scan involves using radioactive dyes to produce body images, showing how the heart functions. Typically, it’s done alongside a CT or MRI scan for better assessment. [11]
If other tests are inconclusive, endomyocardial biopsy is done. During this procedure, tiny samples of heart muscle are taken. It helps identify the extent and type of inflammation linked to myocarditis. However, this procedure is uncommon. [14]
Myocarditis typically improves on its own or with treatment, often resulting in full recovery. If a viral infection causes myocarditis, the treatment typically focuses on managing symptoms and allowing your body to recover. This includes rest, avoiding strenuous activities to give your heart time to heal, and hydration to support overall health. Your doctor might also recommend pain relievers like acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce discomfort and inflammation. [7, 10]
Corticosteroids (such as prednisone) or immunosuppressants (like azathioprine or methotrexate) are used in the treatment of myocarditis. These medications help reduce the immune system’s activity and limit inflammation, improving heart function. However, their use depends on the underlying cause of myocarditis, and they are often reserved for more severe cases. [7]
When myocarditis causes the heart to weaken, making it less effective at pumping blood, you might be given medication to assist your heart. These include angiotensinogen converting enzyme (ACE) inhibitors (e.g., enalapril), which relax blood vessels, reduce blood pressure, and improve blood flow, and beta-blockers (like metoprolol), which slow down the heart rate and reduce the heart’s workload. Diuretics (such as furosemide) may also be used to remove excess fluid from your body, especially if you have swelling in your legs, abdomen, or around the lungs. [10]
Myocarditis can cause irregular heart rhythms, which can be life-threatening. Antiarrhythmic medications, like amiodarone or lidocaine, which help restore a normal heart rhythm, may be used to manage this. In some cases, if arrhythmias are severe or unresponsive to medication, your doctor may recommend implanting a pacemaker to regulate the heart’s rhythm and ensure it beats at a consistent pace. [9]
If a bacterial infection causes your myocarditis, your doctor will prescribe antibiotics to treat the infection. The type of antibiotic depends on the specific bacteria causing the condition. For example, penicillin may be used for infections caused by certain bacteria, while more broad-spectrum antibiotics may be needed for others. Early antibiotic treatment is important to prevent further heart damage. [15]
VADs are special devices that help weakened hearts pump blood throughout the body. It is usually performed as a bridge to a heart transplant. [9]
In extremely severe cases of myocarditis, where the heart is no longer able to function effectively despite other treatments, a heart transplant may be necessary. This is typically considered only when the heart failure is life-threatening, and all other options have been exhausted. A heart transplant is a complex procedure with risks, but it can offer a chance at life for patients with advanced heart failure due to myocarditis. [16]
ECMO, a specialized heart-lung support device, can significantly improve survival rates for patients with severe myocarditis, especially when conventional treatments aren’t effective. [17]
If left untreated, myocarditis can cause can lead to serious consequences over time. The inflammation in your heart can weaken its ability to pump blood, leading to heart failure, where your heart struggles to meet your body’s needs.
You might also develop life-threatening arrhythmias. In severe cases, myocarditis can cause cardiogenic shock, where your heart can’t pump enough blood to keep your organs working. Scarring from the inflammation may also lead to chronic heart damage, permanently weakening your heart. That’s why it is important to seek medical care early and follow your treatment plan to avoid these long-term complications. [18]
Myocarditis can sometimes come back, even after you’ve recovered from the initial episode. This is called recurrence and can happen if the underlying cause, like a viral infection or autoimmune condition, isn’t fully resolved or flares up again. Recurrence may bring similar symptoms, such as chest pain, fatigue, or shortness of breath, and can further stress your heart. If you experience any new or returning symptoms, it’s important to inform your doctor immediately. Early treatment of recurrent myocarditis can help protect your heart and prevent long-term damage. [18]
Preventing myocarditis starts with taking steps to protect your heart from infections and other triggers. Keeping up with your vaccinations, such as the flu shot and COVID-19 vaccine, can reduce the risk of viral infections that might lead to myocarditis. Practicing good hygiene, like washing your hands regularly and avoiding close contact with sick individuals, helps prevent the spread of germs. If you’re taking medications, use them only as prescribed to avoid harmful side effects, and stay away from substances like alcohol and recreational drugs that can damage your heart. Following your doctor’s treatment plan for autoimmune conditions can lower the chances of inflammation affecting your heart. [19]
