Heart inflammation is your body’s natural reaction to an infection or injury to the heart. To protect your body, your white blood cells send chemicals that increase blood flow to the affected area, which can lead to redness, swelling, or pain. Inflammation can affect the lining of your heart or valves, the heart muscle, or the tissue surrounding the heart. Inflammation in the heart can lead to serious health problems, including an irregular heartbeat (also called arrhythmia), heart failure, and coronary heart disease.
Many things cause heart inflammation. Common causes include viral or bacterial infections and medical conditions such as autoimmune diseases.
Heart inflammation can happen suddenly or progress slowly and may have severe symptoms or almost no symptoms. You may have different symptoms depending on the type and how serious the heart inflammation is. The treatment your doctor recommends may depend on whether you are diagnosed with inflammation of the lining of your heart or valves, the heart muscle itself, or the tissue surrounding the heart. You may be treated with medicine, procedures, or possibly surgery.
What causes heart inflammation?
Infections: Viral, bacterial, fungal, and parasitic infections can cause heart inflammation.
- Viral infections are the most common cause of myocarditis and pericarditis. These may include SARS-CoV-2 (the virus that causes COVID-19), adenovirus, coxsackievirus (including hand, foot, and mouth disease), herpes virus, and influenza (flu) virus and parvovirus B19 (which causes an infection common in children known as fifth disease). Viruses may infect the heart muscle tissue, causing the body’s immune system to react.
- Bacteria are the most common cause of endocarditis, which occurs when bacteria and blood cells form clumps, typically on the heart valves. In most developed countries Staphylococcus aureus (staph infection) is the most common type of bacteria that causes endocarditis. Bacteria can enter the blood in many ways, including during a medical or dental procedure or through intravenous drug use. Streptococcus (strep) bacteria can also cause endocarditis, but this is more common in less developed countries. Pericarditis caused by bacteria is not common in the United States.
- Fungi are rare causes of myocarditis and pericarditis. Most commonly, fungal endocarditis is caused by either Candida (yeast) or Aspergillus (mold). These infections are more common in people who have weakened immune systems from conditions such as HIV, cancer, or diabetes.
- Parasites are another infectious cause of myocarditis, such as the parasite that causes Chagas disease, a serious health problem in Latin America. The parasite can specifically affect the heart at the time of infection and may lead to the need for a pacemaker.
Autoimmune diseases: Autoimmune diseases such as rheumatoid arthritis and lupus may cause pericarditis or myocarditis. They can also damage the heart valves, which can lead to endocarditis.
Medicines: Medicines can cause side effects that may lead to myocarditis, pericarditis, or both. These include:
- Antibiotics, such as penicillin
- Antidepressants, such as tricyclic antidepressants
- Benzodiazepines, known as tranquilizers, such as lorazepam and diazepam
- Diuretics, which are medicines, such as furosemide and hydrochlorothiazide, that help your body get rid of extra fluid
- Heart medicines, such as amiodarone, hydralazine, methyldopa, and procainamide
- Psychiatric medicines, such as clozapine and lithium
- Seizure medicines, such as phenytoin
- Vaccines, which may cause allergic reactions leading to myocarditis, although this is rare
- Weight-loss medicines, such as phentermine-fenfluramine (phen-fen)
Endocarditis: Endocarditis is inflammation of the endocardium — the inner lining of the heart chambers and valves. Endocarditis is a rare but life-threatening disease. In endocarditis, clumps of bacteria or fungi from another part of your body get into your bloodstream and collect on the endocardium. These clumps occur more often on the heart valves than on the heart chambers. Pieces of these clumps can break off and travel to different parts of the body, blocking blood flow or spreading infection.
Myocarditis: Myocarditis is inflammation of the myocardium — the heart muscle. This inflammation can also cause other changes to the heart muscle cells that may be acute (short term) or chronic (long term). Myocarditis can affect small or large sections of the heart muscle, making it harder for the heart to pump blood, which in turn can lead to heart failure, when the heart cannot deliver enough blood to the rest of the body.
Pericarditis: Pericarditis is inflammation of the pericardium — the sac surrounding the heart. This sac is made of two thin layers of tissue with a small amount of fluid in between. The fluid keeps the layers from rubbing against each other and causing friction. The pericardium holds the heart in its position in the chest and protects it from infection.
Depending on how long you have had it, your doctor may label your pericarditis as acute (it occurs right after the infection or event that caused it but will last only a short time), subacute (it occurs within weeks or a few months after the initial event that caused it), chronic (long term), or recurrent (goes away and comes back).
The symptoms of heart inflammation can happen suddenly or progress slowly. You may have severe symptoms or almost no symptoms.
Some of the symptoms may feel like the flu, and most often, myocarditis and pericarditis go away on their own after a few weeks. However, for some symptoms, such as chest pain or shortness of breath, it can be hard to tell whether they will go away on their own, or if they are caused by a heart attack or other serious health problem.
If a virus causes your heart inflammation, you may have a cough, runny nose, or gastrointestinal (stomach or intestinal) symptoms a few weeks before you notice any symptoms of heart inflammation.
- Fever and chills
- New or worsening heart murmur
- Blood in urine
- Spleen that is larger than normal
- Stomach pain
- Chest pain
- Cough, with or without the presence of blood
- Loss of appetite and weight loss
- Muscle, joint, and back pain
- Night sweats
- Pain at the spot of a cardiac device, such as a pacemaker, which may mean it is infected
- Shortness of breath
- Skin changes, which may be tiny reddish-purple spots from broken blood vessels, red or purple bumps, or flat red spots on your palms or the soles of your feet
- Chest pain and discomfort
- Heart palpitations, or the feeling of a racing or pounding heart
- Shortness of breath
- Extreme tiredness
- Stomach pain
- Exercise intolerance, or no longer being able to exercise
- Loss of appetite
- Swelling of feet or legs
- Chest pain that feels sharp, gets worse with breathing, and feels better with sitting up and leaning forward
- Fast heartbeat
- Shortness of breath
To help diagnose heart inflammation, your healthcare provider may ask some basic questions.
- Have you had endocarditis, myocarditis, or pericarditis in the past?
- Have you had a recent illness or injury to the chest?
- Have you had any symptoms such as fever, chest pain, or shortness of breath?
- Do you have any other medical conditions or any other risk factors for heart inflammation, including exposure to certain medicines or toxins or a travel history that may be significant?
They may also do one or more of the following steps:
- Check your legs for swelling, a sign of heart failure.
- Check your skin for any changes, as may be seen in cases of endocarditis
- Check your temperature to determine if you have a fever
- Feel your stomach, particularly for a spleen that is larger than normal, or to determine if you have abdominal pain, which may occur with endocarditis
- Listen to your heart for a new murmur that may be heard with endocarditis, a pericardial rub that may be heard with pericarditis, or an abnormal heart rhythm
- Listen to your lungs
Imaging tests and procedures: Your doctor may need to do images tests or procedures to look at your heart.
- Heart imaging tests take pictures of your heart or its arteries or blood vessels to help your doctor see whether there are any problems.
- Endomyocardial Biopsies (EMB) tests very small pieces of the heart to look for myocarditis.
- Heart valve tissue testing identifies tiny germs or microbes from the heart valve or other growths found there that may be causing your endocarditis.
- Pericardiocentesis removes excess fluid in the pericardium, called pericardial effusion. Your doctor will insert a needle or tube, called a catheter, into the chest wall to remove this excess fluid. Your doctor will look at the fluid for bacteria, signs of cancer, or other causes of pericarditis.
Blood tests: Blood tests may help your healthcare provider find the cause of your heart inflammation.
- Blood cultures may identify and treat the exact bacterium, virus, or fungus that is causing the infection in endocarditis or pericarditis.
- Cardiac troponins or creatine kinase-MB are blood markers that increase when there is damage to your heart. Since there are no specific blood tests for myocarditis, these markers are useful to show injury to the heart muscle. However, they also increase with heart attack or heart failure and do not necessarily mean you have myocarditis. They are often normal in cases of subacute or chronic myocarditis.
- C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) may indicate inflammation in the body if higher than normal.
- Complete blood count looks for higher levels of white blood cells, which might indicate infection.
- Serum cardiac autoantibodies (AAbs) are substances that your body can make if you have an autoimmune disease. These antibodies attack your own heart muscle.
Your doctor may also test for specific organisms such as Borrelia burgdorferi, which causes Lyme disease; Mycobacterium tuberculosis, which causes tuberculosis; HIV; or hepatitis C.
- Antibiotics treat bacterial infections. Side effects of antibiotics depend on which antibiotic is used but may include diarrhea, problems with hearing, balance, kidneys, or decreased white blood cell counts. Some of these side effects may not happen until treatment is finished.
- Antifungal medicines treat fungal infections. Sometimes your doctor may recommend lifelong oral antifungal treatment to prevent the infection from returning. Possible side effects of antifungal medicines include allergic reactions, diarrhea, dizziness, itching, blisters or hives, difficulty breathing, weight loss, and skin and eye yellowing called jaundice.
- Corticosteroids lower the activity of the body’s immune system. Corticosteroids may be used to treat myocarditis caused by autoimmune diseases such as lupus.
- Intravenous immunoglobulin (IVIG) helps control the body’s immune and inflammatory response.
- Medicines to relieve pain and reduce inflammation include colchicine, aspirin, and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. Side effects are mainly gastrointestinal and include abdominal pain, nausea, vomiting, and diarrhea.
- Corticosteroids lower the activity of the body’s immune system. With pericarditis, corticosteroids are used only in people who are not responding to or cannot take NSAIDs.
- Intravenous immunoglobulin (IVIG) helps control the body’s immune and inflammatory response if you have an autoimmune disorder such as lupus.
Your doctor may consider procedures and surgeries to treat your heart inflammation.
- Heart surgery can manage damage to valves or nearby heart tissue from endocarditis. It may involve removal of infected tissues or reconstruction of the heart, including repairing or replacing the affected valve.
- Pericardiocentesis removes extra fluid in the pericardium (called pericardial effusion).
- An implantable cardioverter defibrillator or pacemaker can control irregular heartbeats that don’t go away after a short time.
- Pericardiectomy is surgery to remove the pericardium. This treatment is only recommended when medicine or other treatments have not worked. It can be a successful option for people who have pericarditis that goes away and comes back or who have end-stage constrictive pericarditis, where the pericardium becomes thickened and scarred.