Myocarditis vs. Pericarditis: What You Should Know

If you or a loved one has been diagnosed with myocarditis or pericarditis, you’re probably spending a lot of time learning about the condition and what it means for your health. But it’s not always easy to untangle the differences between conditions that look oh-so-similar at first glance.

To start, it helps to know that myocarditis and pericarditis are two types of heart inflammation. “Carditis” is the medical word for inflammation of the heart, or your immune system’s response to an infection or injury.

But what exactly happens inside your heart when you have myocarditis versus pericarditis? And what do these conditions feel like?

Cardiologist and Director of the Cleveland Clinic Pericardial Disease Center Allan Klein, MD, explains key differences and why they matter for your treatment plan.

Key differences

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You can think of myocarditis and pericarditis as siblings or cousins. They may share a last name (carditis), but they’re unique in their own ways. Let’s take a closer look.

Affected area of your heart

Myocarditis and pericarditis both involve inflammation, but in different areas of your heart:

• Myocarditis: Your heart muscle (called the myocardium) is inflamed. “Myo” means muscle.
• Pericarditis: The sac that surrounds and protects your heart (called the pericardium) is inflamed. “Peri” means enclosing or surrounding.

But Dr. Klein emphasizes that there’s not always a hard and fast distinction between these two conditions. Rather, it’s possible to have inflammation in your myocardium and your pericardium. That’s why healthcare providers have started using the term “inflammatory myopericardial syndrome,” or “IMPS” for short.

“IMPS describes the whole spectrum of inflammatory conditions affecting your heart muscle and pericardium,” Dr. Klein explains. “It recognizes that there can be overlap, with more than one area of your heart inflamed at once.”

Under the IMPS umbrella, you might be diagnosed with:

• Myopericarditis: This means pericarditis is the main issue, but you also have some heart muscle (“myo”) inflammation.
• Perimyocarditis: This means myocarditis is the main issue, but you also have some pericardial (“peri”) inflammation.

Symptoms

Myocarditis and pericarditis share many symptoms, like fatigue, flu-like symptoms and shortness of breath.

It’s also possible for either condition to lead to swelling in your legs or belly. That’s because severe cases of myocarditis can lead to fluid buildup. A serious form of pericarditis, called constrictive pericarditis, may cause these symptoms when the pericardial sac gets stiffened or inflamed and compresses the heart.

But myocarditis and pericarditis also have some distinctive features that can help clue you in to what’s going on.

Chest pain difference

“Chest pain is a symptom that’s common both to myocarditis and pericarditis,” Dr. Klein notes. “But the exact nature of the chest pain varies according to the condition. Your doctor will ask you to describe your pain because that helps them narrow down the diagnosis.”

Myocarditis causes chest pain or discomfort that can easily be confused for a heart attack. You might feel like there’s heavy pressure on your chest. But you typically won’t have the sharp pain that’s associated with pericarditis (more on that in a moment). And the pain won’t change if you adjust your body position.

Pericarditis causes very sharp, stabbing pain in your chest that may spread to your left shoulder. “This is the classic symptom of pericarditis,” Dr. Klein says.

The pain typically gets worse when you breathe deeply or lie down. It gets better when you sit forward. This “positional” nature of the chest pain sets pericarditis apart from myocarditis.

Other distinctive symptoms

Certain symptoms are more likely to stem from myocarditis than pericarditis. These include:

• Heart palpitations: Myocarditis can cause irregular heart rhythms, which you may notice as your heart racing, pounding or beating out of sync. This is because heart muscle inflammation can disrupt the electrical signals that control your heartbeat.
• Fainting or dizziness: An irregular heart rhythm from myocarditis can cause you to feel woozy or pass out.

Signs and symptoms more likely to stem from pericarditis include:

• “Friction rub”: This is a sound your healthcare provider can hear through a stethoscope when listening to your heart. It’s a harsh, scratchy sound that’s due to the layers of your heart rubbing together with each beat.
• Dry cough: The irritated pericardial tissues around your heart can cause a dry cough. It may occur along with shortness of breath.

Treatments

Both myocarditis and pericarditis require medications to help your heart heal. But the specific meds you need — and any additional treatments your doctor may recommend — depend on your exact diagnosis and where along the IMPS spectrum you fall.

Dr. Klein walks us through the differences.

Differences in medications

“Myocarditis, which affects your heart muscle, typically requires medications to help your heart pump better and send enough blood to your body,” Dr. Klein says. “On the other hand, pericarditis calls for medications that directly reduce inflammation in your pericardium to ease symptoms and prevent recurrences.”

Medications for myocarditis include:

• ACE inhibitors or ARBs to lower the strain on your heart
• Beta-blockers to slow your heart rate and improve heart function
• Diuretics to manage and prevent fluid buildup
• Immunosuppressants for certain types, like lymphocytic or giant cell myocarditis

Medications for pericarditis include:

• NSAIDs, like ibuprofen, naproxen or aspirin (ASA), to calm inflammation
• Colchicine to further reduce inflammation and keep pericarditis from coming back.
• Interleukin-1 blockers (IL-1 blockers) to block an inflammatory pathway in your body that’s activated in pericarditis
• Corticosteroids to reduce inflammation if NSAIDs and colchicine aren’t enough (in select cases, including those linked to autoimmune disease)

Often, NSAIDs and colchicine are given together for pericarditis.

Differences in procedures and surgeries

Most people don’t need a procedure or surgery for either condition. But if you do need one, the options differ based on your diagnosis:

• Myocarditis: Heart muscle inflammation can lead to dangerous heart rhythms that require an implanted device, like an implantable cardioverter defibrillator (ICD). Or you may need a ventricular assist device if your heart is very weak.
• Pericarditis: “Your doctor may suggest a procedure called pericardiocentesis to treat severe fluid buildup around your heart,” Dr. Klein says. “You may need a surgery called pericardiectomy to remove your pericardium if it grows very stiff and is unable to function normally.”

Areas of overlap

Despite their differences, myocarditis and pericarditis share some common ground, including their:

• Causes: Across the IMPS spectrum, viral infections are the most common cause. These include illnesses like colds, flu and COVID-19. Autoimmune diseases, like rheumatoid arthritis and lupus, are also common causes, Dr. Klein notes.
• Physical activity restrictions: Whether you have myocarditis or pericarditis, or a mix, you need to take it easy so your heart can heal. This means sticking to the guidelines your doctor gives you for limited exercise and gradual return to sports.
• Potential to need emergency care: Myocarditis and pericarditis both can worsen quickly or unexpectedly. Plus, it’s not always easy to tell if the pain you’re feeling is from inflammation or from a heart attack. “When in doubt, seek help for chest pain or other symptoms right away,” Dr. Klein urges.
• Need for follow-up care: It’s vital to attend all your follow-up visits, even once you’re feeling better. Heart inflammation can return. Your doctor will run tests to catch signs of recurrence early so you can get the treatment you need.

Final thoughts

If you’re living with myocarditis or pericarditis, Dr. Klein wants you to know there’s hope.

“We’ve made significant strides in diagnosing and treating these conditions,” he shares. “Among many tools in our belt, we have advanced tests that can visualize the inflammation and track improvement. New medications are available, and more are under investigation. We’ve helped a lot of people heal their hearts and get back to doing what they love.”