Lupus myocarditis is a rare condition where the immune system damages the heart tissue, possibly causing heart failure.

Lupus is a rare condition that can cause inflammation throughout your body. In some cases, lupus can cause myocarditis, which is the inflammation of the heart muscle (myocardium).

Because it can cause heart failure, lupus myocarditis can be fatal.

There are different types of lupus. The most common is systemic lupus erythematosus (SLE), which causes inflammation throughout the body.

SLE is the type of lupus that is most strongly associated with lupus myocarditis.

Lupus is an autoimmune disorder. This means your body attacks its own tissue, causing inflammation.

Although some forms of lupus affect only certain parts of the body, SLE can affect different tissue throughout the body. It can even affect your heart tissue (myocardium).

When SLE causes the inflammation of the myocardium, it’s called lupus myocarditis.

Lupus myocarditis can cause heart failure. This is when your heart fails to pump enough blood throughout your body.

How common is lupus myocarditis?

Lupus myocarditis is found in 3–9% of people with SLE. However, post-mortem analyses show that as many as 57% of SLE patients have lupus myocarditis. This suggests that the condition often goes undetected.

According to research from 2018, the symptoms of lupus myocarditis can include:

Because lupus myocarditis can cause heart failure, you may also experience the symptoms of heart failure.

The symptoms of heart failure include:

  • fatigue
  • exercise intolerance
  • getting short of breath while lying down
  • loss of appetite
  • protruding neck veins
  • shortness of breath, even when lying down
  • swollen legs, ankles, or abdomen
  • sudden weight gain

If you have lupus and recognize these symptoms in yourself, it’s a good idea to speak with a healthcare professional as soon as possible.

According to the current research, a number of factors may play a role in the formation of lupus.

Possible causes of lupus can be:

  • environmental toxins
  • genetics
  • hormones
  • illness
  • long-term use of certain medications
  • smoking
  • stress

But why do some SLE patients get lupus myocarditis while others don’t? It’s not entirely clear, but you may be more likely to develop the condition if you have certain health conditions, including heart valve disorders, high blood pressure (hypertension), and ischemia.

If you’ve already been diagnosed with lupus, the most accurate way to diagnose lupus myocarditis is an endomyocardial biopsy. This is a surgical procedure where a small piece of your heart tissue is removed and tested for lupus myocarditis.

But because a biopsy might be risky, your healthcare team might rather base their diagnosis on the following:

In general, the SLE diagnostic process involves:

  • blood tests
  • symptom assessments
  • urine tests
  • X-rays
  • physical examination

If you have early signs of lupus, it’s recommended that you make an appointment with a healthcare practitioner.

High dose corticosteroids, which are drugs used to treat inflammatory conditions, are typically used to treat lupus myocarditis. Corticosteroids resemble cortisol, a hormone that the body naturally produces. Different forms of corticosteroids are used to ease inflammation.

According to a 2017 study, other lupus myocarditis treatments include:

Sometimes a heart transplant is necessary. A 2022 case study reported on a 24-year-old woman with SLE and biventricular heart failure who had a successful heart transplant. However, it’s important to note that a heart transplant does not guarantee long-term survival as lupus might continue to damage the organ.

In a 2018 study based on evaluating 30 people with lupus myocarditis, the death rate was roughly 20%. Out of the 30 patients, 60% recovered completely, while 20% recovered in part. The research outcomes were based on a sample of people who received early treatment.

Since lupus myocarditis is underdiagnosed, it’s possible that it causes premature death in many people who do not receive a diagnosis.

Lupus myocarditis is a rare but potentially fatal condition. The immune system attacks heart tissue, possibly leading to heart failure.

If you have SLE and you’re experiencing symptoms of lupus myocarditis, it’s important that you talk with your healthcare team to schedule an appointment for a screening. Early diagnosis and treatment can help improve your outcome.