Myocarditis and pericarditis are types of heart inflammation. Myocarditis affects the middle layer of heart muscle, and pericarditis only affects the heart’s outer lining.

Myocarditis and pericarditis symptoms have some overlap, but there are differences. Pericarditis tends to cause more severe chest pain, while myocarditis causes fatigue and shortness of breath.

This article compares myocarditis and pericarditis symptoms as well as the similarities and differences in their causes, diagnosis, and treatment.

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Myocarditis and pericarditis are both types of inflammation that affect the heart or its surrounding structures.

Myocarditis is inflammation of the heart muscle, or the myocardium, which is in the middle of the heart wall. Pericarditis is inflammation of the pericardium. This is the thin sac surrounding the heart.

In around 35% of cases, people with myocarditis also have pericarditis. Together, this is known as myopericarditis. The inflammation of either condition can disrupt the usual functioning of the heart.

The symptoms of myocarditis and pericarditis can vary significantly depending on the inflammation’s severity. Some people may only have mild symptoms. For others, these conditions become life threatening.

The symptoms of myocarditis can include:

If the cause of myocarditis is an infection, other symptoms may include flu-like symptoms, such as fever or general malaise. These symptoms may precede the onset of myocarditis or occur at the same time.

In severe cases, people can develop fulminant myocarditis. It causes a rapid decline in heart function.

In contrast, the main symptom of pericarditis is chest pain. This pain tends to be more severe than in myocarditis. It occurs in the center of the chest, behind the breastbone. The chest pain may:

  • worsen when a person inhales
  • improve when a person sits up and leans forward
  • radiate across the chest

People with both myocarditis and pericarditis may have a mixture of both types of pain as well as shortness of breath and other myocarditis symptoms.

Anyone experiencing chest pain and shortness of breath should seek immediate medical help. The symptoms of heart inflammation can be similar to those of a heart attack.

Various factors can trigger myocarditis, such as:

  • infections
  • autoimmune conditions
  • certain medications
  • venom from animal or insect bites
  • exposure to certain chemicals, such as hydrocarbons
  • injury

However, in around 50% of myocarditis cases, the cause is unknown.

Pericarditis has many of the same potential causes, including infections and injury. Other potential causes include:

However, unlike myocarditis, the cause of acute pericarditis is very often unclear. Up to 90% of cases have an unknown cause.

While many types of infection can cause either myocarditis or pericarditis, some are especially prevalent. They include:

COVID-19 can also cause either myocarditis or pericarditis. A 2023 review of previous research notes that the rates for both conditions in the United States became 15 times higher than before the pandemic.

Before the COVID-19 pandemic, the incidence of myocarditis was 1–10 cases in 100,000 people. After the pandemic, the incidence increased to 150–4,000 cases per 100,000 people.

People can also develop myocarditis or pericarditis following the COVID-19 vaccine. However, these cases are extremely rare.

Diagnosing myocarditis or pericarditis involves a comprehensive assessment by a doctor. Typically, the process begins with a doctor taking a detailed medical history. They will ask about symptoms and potential risk factors.

Next, they may conduct physical examinations, such as listening to the heart and lungs. Blood tests may help assess inflammation levels and detect any underlying infections.

A specific blood test for troponin can also indicate if the heart lacks blood flow or could have tissue damage, which may help doctors diagnose myocarditis.

Advanced diagnostic tools play a crucial role in confirming these conditions. Electrocardiograms can assess heart rhythm. Imaging tests such as echocardiograms provide detailed images of the heart’s structure and function.

Doctors may use MRI or CT scans too. An MRI may show soft tissue swelling around the heart, which can confirm a diagnosis.

The treatment for myocarditis and pericarditis may help alleviate symptoms, reduce inflammation, and address any underlying causes.

In cases where infections are the trigger, doctors may prescribe antiviral or antimicrobial medications. Anti-inflammatory drugs, such as nonsteroidal anti-inflammatory drugs or corticosteroids, can help reduce inflammation. Colchicine may also help with pericarditis.

A person may need to stay in the hospital in more severe cases of myocarditis or pericarditis, or if complications arise. Doctors may use interventions such as draining excess fluid from the pericardial sac to relieve pressure on the heart. If myocarditis results in heart failure, there are also medications to help treat it.

Recovery from either myocarditis or pericarditis can take time. Rest and gradual rehabilitation are important at this stage.

In some cases, mild forms of myocarditis or pericarditis may resolve on their own with adequate rest and supportive care. However, people should not try to manage these conditions without medical help.

Depending on the underlying cause, myocarditis or pericarditis could worsen or become chronic without treatment.

Below are answers to some frequently asked questions about myocarditis versus pericarditis.

Which is worse?

Comparing the severity of myocarditis and pericarditis is challenging. Both conditions can range from mild to life threatening depending on the cause.

That said, the overall outlook of acute pericarditis is excellent. Most people have a complete recovery. With myocarditis, there is a higher chance of complications.

At least 50% of people with myocarditis experience stiffening, enlargement, or thickening of the heart muscle on long-term follow-up.

However, because myocarditis can vary so much in severity and the underlying cause, the prognosis also varies case by case.

Does myocarditis or pericarditis affect life expectancy?

With treatment, myocarditis and pericarditis usually do not significantly affect life expectancy, but this can depend on whether the conditions cause any long-term complications.

Some people may need ongoing medications or other treatment if the inflammation harms heart function.

Can the heart fully recover?

In many cases, people can fully recover from myocarditis or pericarditis. It can take time, though.

The recovery process depends on various factors, including the underlying cause, the severity of inflammation, and how well the person and their condition respond to treatment.

Myocarditis and pericarditis are types of inflammation. While myocarditis only affects the heart muscle, pericarditis affects the lining around the heart. People can have just one or both conditions at the same time.

Myocarditis and pericarditis have similar causes and share some of the same symptoms. However, pericarditis tends to cause more severe chest pain. Myocarditis causes shortness of breath and fatigue.

Many people recover fully from both conditions, but it can take time and treatment. Anyone experiencing unexplained chest pain or shortness of breath should seek medical attention right away.